KB-2288 Application Server Heap Memory FAQ

Maggie Deppe-Walker — Wed, 31 Jan 2024 06:17:42 GMT

Current Revision posted to Appian Knowledge Base by Maggie Deppe-Walker on 1/31/2024 6:17:42 AM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

Heap, also known as heap memory, is the portion of hardware memory that is allocated to the Java Virtual Machine that is running the application server. The heap memory is consumed only by the application server and enables it to perform all the actions required to run your Appian environment and interact with all the other Appian components on your environment.

What is the difference between heap memory and total memory of the application server?

The default amount of heap allocated to an application server in Appian Cloud is 3 GB. The total physical memory used by the application server is always more than the allocated heap memory given to the application server. This is because the application server runs as a Java process which also includes a Java Virtual Machine (JVM). The heap memory exists inside the JVM, and the Java process and JVM also require their own portion of the physical memory to run.

To see more information on the physical memory used by the application server, please see the following Knowledge Base article: KB-1248 How to address high memory usage in self-managed Appian environments.

What is garbage collection?

As the application server runs, it loads runtime objects into the heap memory. Heap memory will become exhausted unless the objects that are no longer needed from the heap memory are removed by a process called Garbage collection.

When is heap usage a concern?

High heap alone is nothing to be concerned about. If all the required objects to complete an item of work are in the heap memory, the work item will perform identically regardless of how much of the heap memory is utilized.

High heap utilization, and consequently garbage collection events, are expected behavior and not indicative of any environment performance or configuration issues. Garbage collection can lead to performance issues when it occurs at a high frequency, which often indicates a problematic activity that is either processing too many objects in memory, processing objects that are too large, or both.

Customers can investigate heap utilization and garbage collection performance by inspecting the system metrics log, which for Appian Cloud customers can be accessed via the system logs page. Appian Cloud customers can conveniently leverage the inbuilt monitoring provided within MyAppian to more easily view their heap utilization and garbage collection performance.

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

1. Slowness across the entire environment

Slowness across the entire environment can be caused by the garbage collection process running too often. This occurs when the rate of new objects being introduced into the heap memory is higher than garbage collection can keep up with, or when there are long-lived objects in the heap memory that cannot be removed because they are being referenced by a long-running activity.

Common causes of this issue include:

Large looping, text manipulation or array-based operations
Inefficient application design and/or excessive volume of work
Undersized heap memory allocation relative to the workload required

2. An application server 'crash' and restart

An application server restart occurs when the application server is unable to load necessary objects into heap memory without exceeding the heap space limit. In this situation an 'OutOfMemoryError' Java Exception may be thrown in the application server log, after which the application server is then forcibly ‘crashed’ and restarted. An application server restart may or may not proceed a period of environment slowness due to garbage collection.

Common causes of an application server restart include:

Queries with large result sets
Document generation using plugins
Very large process variables or inputs
Any of the above causes of slowness

How to fix common heap issues?

The behavior of the application server heap memory is directly affected by user and process activity. Therefore, identifying and modifying the problematic activity is the primary solution for remediating performance issues involving heap memory.

1. Slowness across the entire environment

Slowness can be representative of a high and/or excessively complex volume of work. The main troubleshooting steps are to identify the implicated activity using logs and heap dumps, determine whether the load is expected/required, and action any opportunities for optimization.

Some solutions for remediating slowness related to garbage collection include:

Avoid running bulk processes simultaneously
Re-designing intensive processes to run gradually over a longer time frame
Avoiding logic that operates on and/or iterates large arrays of texts or objects
Running intensive process(es) during business off hours where there are fewer concurrent users
Re-designing the application causing the excessive volume, starting with the most expensive operations

Slowness can also be representative of a long running process that continuously holds references to an increasing number of objects in the heap memory. The process monitoring view can be used to identify and kill long running processes that are actively causing slowness across the entire environment. The identified processes should then be redesigned to not require continuous object references over an extended time period.

2. An application server 'crash' and restart

Processes that cause application server restarts will usually require a re-design to break the large size or amount of objects manipulated into smaller volumes that the application server heap memory can accommodate.

Some solutions include:

Adding additional filters and/or batching to problematic queries
Limiting the size of uploaded documents before they are manipulated
Any of the above recommendations to remediate slowness

Will increasing the heap memory allocation help improve performance?

Increasing the allocated heap memory to the application server has the consequence of reducing the remaining available memory for all the other Appian components to run on your environment. This can include, but is not limited to:

Appian Engines
Search Server
Data Server
Database
RPA

Therefore, increasing the heap memory allocated to the application server should only be considered if there is more than enough memory available on the environment during peak usage. Additionally, increasing the heap memory allocation is not a universal solution to all heap memory performance issues. Some causes of heap memory performance issues will still impact performance regardless of the size of the heap memory.

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

Recommendations to increase heap memory allocated are discussed on a case by case basis. Appian Support carefully evaluates this option when handling performance-related Support Cases and will recommend an increase if it will improve the performance of your environment.

What is a heap dump?

A heap dump is a snapshot of the entire contents of heap memory, written to disk as a single file. Heap dumps are analyzed by Appian Support in order to investigate what was being processed by the application server during the time that the heap dump was taken.

The size of the heap dump on disk directly correlates to the magnitude of the heap utilization at the time that the heap dump was taken. Additionally, Appian Support creates more files to aid in analyzing the generated heap dump. As a result, when heap dumps are generated and investigated, there will be an increase in the disk consumption on the environment.

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

For Self Managed customers, Appian Support may request for a heap dump from your application server. Please use the following Knowledge Base article for instructions on how to do so: KB-1176 How to generate a Java heap dump.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

The process to analyze heap dumps requires an amount of memory that is proportional to the size of the heap dump that is being analyzed. In cases where Appian Support identifies that the available resources on the site are not enough to safely run the heap analysis, a maintenance window is required to complete the analysis. During the maintenance window, some Appian components are gracefully brought down in order to free memory to run the heap analysis.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Maggie Deppe-Walker — Wed, 31 Jan 2024 06:16:22 GMT

Revision 73 posted to Appian Knowledge Base by Maggie Deppe-Walker on 1/31/2024 6:16:22 AM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

1. Slowness across the entire environment

Common causes of this issue include:

Large looping, text manipulation or array-based operations
Inefficient application design and/or excessive volume of work
Undersized heap memory allocation relative to the workload required

2. An application server 'crash' and restart

Common causes of an application server restart include:

Queries with large result sets
Document generation using plugins
Very large process variables or inputs
Any of the above causes of slowness

How to fix common heap issues?

1. Slowness across the entire environment

Some solutions for remediating slowness related to garbage collection include:

Avoid running bulk processes simultaneously
Re-designing intensive processes to run gradually over a longer time frame
Avoiding logic that operates on and/or iterates large arrays of texts or objects
Running intensive process(es) during business off hours where there are fewer concurrent users
Re-designing the application causing the excessive volume, starting with the most expensive operations

2. An application server 'crash' and restart

Some solutions include:

Adding additional filters and/or batching to problematic queries
Limiting the size of uploaded documents before they are manipulated
Any of the above recommendations to remediate slowness

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Maggie Deppe-Walker — Wed, 31 Jan 2024 06:15:22 GMT

Revision 72 posted to Appian Knowledge Base by Maggie Deppe-Walker on 1/31/2024 6:15:22 AM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

1. Slowness across the entire environment

Common causes of this issue include:

Large looping, text manipulation or array-based operations
Inefficient application design and/or excessive volume of work
Undersized heap memory allocation relative to the workload required

2. An application server 'crash' and restart

Common causes of an application server restart include:

Queries with large result sets
Document generation using plugins
Very large process variables or inputs
Any of the above causes of slowness

How to fix common heap issues?

1. Slowness across the entire environment

Some solutions for remediating slowness related to garbage collection include:

Avoid running bulk processes simultaneously
Re-designing intensive processes to run gradually over a longer time frame
Avoiding logic that operates on and/or iterates large arrays of texts or objects
Running intensive process(es) during business off hours where there are fewer concurrent users
Re-designing the application causing the excessive volume, starting with the most expensive operations

2. An application server 'crash' and restart

Some solutions include:

Adding additional filters and/or batching to problematic queries
Limiting the size of uploaded documents before they are manipulated
Any of the above recommendations to remediate slowness

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Maggie Deppe-Walker — Wed, 31 Jan 2024 06:11:30 GMT

Revision 71 posted to Appian Knowledge Base by Maggie Deppe-Walker on 1/31/2024 6:11:30 AM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

1. Slowness across the entire environment

Common causes of this issue include:

Large looping, text manipulation or array-based operations
Inefficient application design and/or excessive volume of work
Undersized heap memory allocation relative to the workload required

2. An application server 'crash' and restart

Common causes of an application server restart include:

Queries with large result sets
Document generation using plugins
Very large process variables or inputs
Any of the above causes of slowness

How to fix common heap issues?

1. Slowness across the entire environment

Some solutions for remediating slowness related to garbage collection include:

Avoid running bulk processes simultaneously
Re-designing intensive processes to run gradually over a longer time frame
Avoiding logic that operates on and/or iterates large arrays of texts or objects
Running intensive process(es) during business off hours where there are fewer concurrent users
Re-designing the application causing the excessive volume, starting with the most expensive operations

2. An application server 'crash' and restart

Some solutions include:

Adding additional filters and/or batching to problematic queries
Limiting the size of uploaded documents before they are manipulated
Any of the above recommendations to remediate slowness

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Maggie Deppe-Walker — Wed, 31 Jan 2024 06:09:29 GMT

Revision 70 posted to Appian Knowledge Base by Maggie Deppe-Walker on 1/31/2024 6:09:29 AM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

1. Slowness across the entire environment

Common causes of this issue include:

Large looping, text manipulation or array-based operations
Inefficient application design and/or excessive volume of work
Undersized heap memory allocation relative to the workload required

2. An application server 'crash' and restart

Common causes of an application server restart include:

Queries with large result sets
Document generation using plugins
Very large process variables or inputs
Any of the above causes of slowness

How to fix common heap issues?

1. Slowness across the entire environment

Some solutions for remediating slowness related to garbage collection include:

Avoid running bulk processes simultaneously
Re-designing intensive processes to run gradually over a longer time frame
Avoiding logic that operates on and/or iterates large arrays of texts or objects
Running intensive process(es) during business off hours where there are fewer concurrent users
Re-designing the application causing the excessive volume, starting with the most expensive operations

2. An application server 'crash' and restart

Some solutions include:

Adding additional filters and/or batching to problematic queries
Limiting the size of uploaded documents before they are manipulated
Any of the above recommendations to remediate slowness

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Daniel DeVeau — Wed, 24 Jan 2024 21:24:36 GMT

Revision 69 posted to Appian Knowledge Base by Daniel DeVeau on 1/24/2024 9:24:36 PM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

Common causes of this issue include:

Large looping, text manipulation or array-based operations
Inefficient application design and/or excessive volume of work
Undersized heap memory allocation relative to the workload required

An application server 'crash' and restart

Common causes of an application server restart include:

Queries with large result sets
Document generation using plugins
Very large process variables or inputs
Any of the above causes of slowness

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating slowness related to garbage collection include:

Avoid running bulk processes simultaneously
Re-designing intensive processes to run gradually over a longer time frame
Avoiding logic that operates on and/or iterates large arrays of texts or objects
Running intensive process(es) during business off hours where there are fewer concurrent users
Re-designing the application causing the excessive volume, starting with the most expensive operations

An application server 'crash' and restart

Some solutions include:

Adding additional filters and/or batching to problematic queries
Limiting the size of uploaded documents before they are manipulated
Any of the above recommendations to remediate slowness

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Kevin Kleinegger — Wed, 24 Jan 2024 21:11:51 GMT

Revision 68 posted to Appian Knowledge Base by Kevin Kleinegger on 1/24/2024 9:11:51 PM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

Common causes of this issue include:

Large looping, text manipulation or array-based operations
Inefficient application design and/or excessive volume of work
Undersized heap memory allocation relative to the workload required

An application server 'crash' and restart

Common causes of an application server restart include:

Queries with large result sets
Document generation using plugins
Very large process variables or inputs
Any of the above causes of slowness

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating high volumes of work include:

Avoid running bulk processes simultaneously
Re-designing intensive processes to run gradually over a longer time frame
Running intensive process(es) during business off hours where there are fewer concurrent users
Re-designing the application causing the excessive volume, starting with the most expensive operations

An application server 'crash' and restart

Some solutions include:

Avoid designing processes with large looping iterations
Adding additional filters and/or batching to problematic queries
Limiting the size of uploaded documents before they are manipulated
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are fewer concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Daniel DeVeau — Wed, 24 Jan 2024 16:11:16 GMT

Revision 67 posted to Appian Knowledge Base by Daniel DeVeau on 1/24/2024 4:11:16 PM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

Common causes of this issue include:

Large looping, text manipulation or array-based operations
Inefficient application design and/or excessive volume of work
Undersized heap memory allocation relative to the workload required

An application server 'crash' and restart

Common causes of an application server restart include:

Queries with large result sets
Document generation using plugins
Very large process variables or inputs
Any of the above causes of slowness

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating high volumes of work include:

Avoid running bulk processes simultaneously
Re-designing intensive processes to run gradually over a longer time frame
Running intensive process(es) during business off hours where there are fewer concurrent users
Re-designing the application causing the excessive volume, starting with the most expensive operations

An application server 'crash' and restart

Some solutions include:

Avoid designing processes with large looping iterations
Adding additional filters and/or batching to problamatic queries
Limiting the size of uploaded documents before they are manipulated
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are fewer concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

saketh.darbhamulla — Tue, 16 Jan 2024 05:53:47 GMT

Revision 66 posted to Appian Knowledge Base by saketh.darbhamulla on 1/16/2024 5:53:47 AM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

Slowness across the entire environment can be caused by the garbage collection process running too often. This occurs when the rate of new objects being introduced into the heap memory is significantly high, or when there are long-lived objects in the heap memory that cannot be removed because they are being referenced by a long-running active process.

The most common causes of this issue are:

High process volume
Undersized heap memory allocation
Inefficient application design
Long running I/O requests such as queries and API calls

An application server 'crash' and restart

The most common causes of an application server restart are:

The generation of documents from data or objects using plugins
Very large process variables or inputs
Bulky text manipulation
Large query result sets
Large looping or array based operations

How to fix common heap issues?

The behavior of the application server heap memory is directly affected by the process activity in the application server. Therefore, modifying the process activity in the application server is the primary solution for remediating performance issues with the heap memory.

Slowness across the entire environment

Slowness can be representative of high process volume. The main troubleshooting steps are to identify whether this process load is expected and whether the cause of this increased process volume is resultant from an application design issue.

Some solutions for remediating high process volume include:

Re-designing the application causing the increased process volume
Avoid running bulk processes simultaneously
Re-design intensive processes to run gradually over a longer time frame
Running the intensive process(es) during business off hours where there are fewer concurrent users

An application server 'crash' and restart

Some solutions include:

Adding additional filters to queries used to pull data into the identified process
Breaking larger documents into smaller documents when being processed
Avoid designing processes with large looping iterations
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are less concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

saketh.darbhamulla — Tue, 16 Jan 2024 05:41:22 GMT

Revision 65 posted to Appian Knowledge Base by saketh.darbhamulla on 1/16/2024 5:41:22 AM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

Slowness across the entire environment can be caused by the garbage collection process running too often. This occurs when the rate of new objects being introduced into the heap memory is significantly high, or when there are long-lived objects in the heap memory that cannot be removed because they are being referenced by a long-running active process.

The most common causes of this issue are:

High process volume
Undersized heap memory allocation
Inefficient application design
Long running I/O requests such as queries and API calls

An application server 'crash' and restart

The most common causes of an application server restart are:

The generation of documents from data or objects using plugins
Very large process variables or inputs
Bulky text manipulation
Large query result sets
Large looping or array based operations

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating high process volume include:

Re-designing the application causing the increased process volume
Avoid running bulk processes simultaneously
Re-design intensive processes to run gradually over a longer time frame
Running the intensive process(es) during business off hours where there are fewer concurrent users

An application server 'crash' and restart

Some solutions include:

Adding additional filters to queries used to pull data into the identified process
Breaking larger documents into smaller documents when being processed
Avoid designing processes with large looping iterations
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are less concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Daniel DeVeau — Fri, 05 Jan 2024 17:23:48 GMT

Revision 64 posted to Appian Knowledge Base by Daniel DeVeau on 1/5/2024 5:23:48 PM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

Garbage collection is a form of automatic heap memory management which frees currently unreferenced objects stored in heap. Garbage collection is accomplished with a set of algorithms which organize, scan, and free unneeded objects from heap memory. Appian uses the G1 Java garbage collector algorithm as of Appian version 20.1. See the following Knowledge Base article for more details on how the G1 Java garbage collector algorithm is used in Appian: KB-2109 G1 garbage collector FAQ.

When is heap usage a concern?

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

Slowness across the entire environment can be caused by the garbage collection process running too often. This occurs when the rate of new objects being introduced into the heap memory is significantly high, or when there are long-lived objects in the heap memory that cannot be removed because they are being referenced by a long-running active process.

The most common causes of this issue are:

High process volume
Undersized heap memory allocation
Inefficient application design
Long running I/O requests such as queries and API calls

An application server 'crash' and restart

The most common causes of an application server restart are:

The generation of documents from data or objects using plugins
Very large process variables or inputs
Bulky text manipulation
Large query result sets
Large looping or array based operations

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating high process volume include:

Re-designing the application causing the increased process volume
Avoid running bulk processes simultaneously
Re-design intensive processes to run gradually over a longer time frame
Running the intensive process(es) during business off hours where there are fewer concurrent users

An application server 'crash' and restart

Some solutions include:

Adding additional filters to queries used to pull data into the identified process
Breaking larger documents into smaller documents when being processed
Avoid designing processes with large looping iterations
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are less concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Daniel DeVeau — Fri, 05 Jan 2024 17:21:49 GMT

Revision 63 posted to Appian Knowledge Base by Daniel DeVeau on 1/5/2024 5:21:49 PM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

Slowness across the entire environment can be caused by the garbage collection process running too often. This occurs when the rate of new objects being introduced into the heap memory is significantly high, or when there are long-lived objects in the heap memory that cannot be removed because they are being referenced by a long-running active process.

The most common causes of this issue are:

High process volume
Undersized heap memory allocation
Inefficient application design
Long running I/O requests such as queries and API calls

An application server 'crash' and restart

The most common causes of an application server restart are:

The generation of documents from data or objects using plugins
Very large process variables or inputs
Bulky text manipulation
Large query result sets
Large looping or array based operations

In all of the causes listed above, the root cause of the issue is the same. A large object or amount of objects is being loaded in the heap memory to be acted on that either exceeds the capacity of the heap memory, or prevents new objects from being introduced into the heap memory.

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating high process volume include:

Re-designing the application causing the increased process volume
Avoid running bulk processes simultaneously
Re-design intensive processes to run gradually over a longer time frame
Running the intensive process(es) during business off hours where there are fewer concurrent users

An application server 'crash' and restart

Some solutions include:

Adding additional filters to queries used to pull data into the identified process
Breaking larger documents into smaller documents when being processed
Avoid designing processes with large looping iterations
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are less concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Daniel DeVeau — Fri, 05 Jan 2024 17:21:27 GMT

Revision 62 posted to Appian Knowledge Base by Daniel DeVeau on 1/5/2024 5:21:27 PM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

Slowness across the entire environment can be caused by the garbage collection process running too often. This occurs when the rate of new objects being introduced into the heap memory is significantly high, or when there are long-lived objects in the heap memory that cannot be removed because they are being referenced by a long-running active process.

The most common causes of slowness observed across the entire environment are:

High process volume
Undersized heap memory allocation
Inefficient application design
Long running I/O requests such as queries and API calls

An application server 'crash' and restart

The most common causes of an application server restart are:

The generation of documents from data or objects using plugins
Very large process variables or inputs
Bulky text manipulation
Large query result sets
Large looping or array based operations

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating high process volume include:

Re-designing the application causing the increased process volume
Avoid running bulk processes simultaneously
Re-design intensive processes to run gradually over a longer time frame
Running the intensive process(es) during business off hours where there are fewer concurrent users

An application server 'crash' and restart

Some solutions include:

Adding additional filters to queries used to pull data into the identified process
Breaking larger documents into smaller documents when being processed
Avoid designing processes with large looping iterations
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are less concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Daniel DeVeau — Fri, 05 Jan 2024 17:19:23 GMT

Revision 61 posted to Appian Knowledge Base by Daniel DeVeau on 1/5/2024 5:19:23 PM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

Slowness across the entire environment is caused by the garbage collection process running intensely and continuously as described in the previous section. This can occur when the rate of new objects being introduced into the heap memory is significantly high, or when there are long-lived objects in the heap memory that cannot be removed because they are being referenced by a long running active process.

The most common causes of slowness observed across the entire environment are:

High process volume
Undersized heap memory allocation
Inefficient application design
Long running I/O requests such as queries and API calls

An application server 'crash' and restart

The most common causes of an application server restart are:

The generation of documents from data or objects using plugins
Very large process variables or inputs
Bulky text manipulation
Large query result sets
Large looping or array based operations

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating high process volume include:

Re-designing the application causing the increased process volume
Avoid running bulk processes simultaneously
Re-design intensive processes to run gradually over a longer time frame
Running the intensive process(es) during business off hours where there are fewer concurrent users

An application server 'crash' and restart

Some solutions include:

Adding additional filters to queries used to pull data into the identified process
Breaking larger documents into smaller documents when being processed
Avoid designing processes with large looping iterations
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are less concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Daniel DeVeau — Fri, 05 Jan 2024 17:13:23 GMT

Revision 60 posted to Appian Knowledge Base by Daniel DeVeau on 1/5/2024 5:13:23 PM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are many Appian components that allocate their own heap memory space. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

High heap utilization, and consequently garbage collection events, are expected behavior and not indicative of any environment performance or configuration issues. Garbage collection can lead to issues when there is a need for a high frequency of garbage collections. This is where the garbage collection process runs intensely and continuously, causing general slowness across the environment since all work in the application server utilizes the heap memory.

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

The most common causes of slowness observed across the entire environment are:

High process volume
Undersized heap memory allocation
Inefficient application design
Long running I/O requests such as queries and API calls

An application server 'crash' and restart

The most common causes of an application server restart are:

The generation of documents from data or objects using plugins
Very large process variables or inputs
Bulky text manipulation
Large query result sets
Large looping or array based operations

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating high process volume include:

Re-designing the application causing the increased process volume
Avoid running bulk processes simultaneously
Re-design intensive processes to run gradually over a longer time frame
Running the intensive process(es) during business off hours where there are fewer concurrent users

An application server 'crash' and restart

Some solutions include:

Adding additional filters to queries used to pull data into the identified process
Breaking larger documents into smaller documents when being processed
Avoid designing processes with large looping iterations
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are less concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

saketh.darbhamulla — Fri, 05 Jan 2024 04:12:52 GMT

Revision 59 posted to Appian Knowledge Base by saketh.darbhamulla on 1/5/2024 4:12:52 AM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are other Appian components that use their own heap memory. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

High heap utilization, and consequently garbage collection events, are expected behavior and not indicative of any environment performance or configuration issues. Garbage collection can lead to issues when there is a need for a high frequency of garbage collections. This is where the garbage collection process runs intensely and continuously, causing general slowness across the environment since all work in the application server utilizes the heap memory.

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

The most common causes of slowness observed across the entire environment are:

High process volume
Undersized heap memory allocation
Inefficient application design
Long running I/O requests such as queries and API calls

An application server 'crash' and restart

The most common causes of an application server restart are:

The generation of documents from data or objects using plugins
Very large process variables or inputs
Bulky text manipulation
Large query result sets
Large looping or array based operations

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating high process volume include:

Re-designing the application causing the increased process volume
Avoid running bulk processes simultaneously
Re-design intensive processes to run gradually over a longer time frame
Running the intensive process(es) during business off hours where there are fewer concurrent users

An application server 'crash' and restart

Some solutions include:

Adding additional filters to queries used to pull data into the identified process
Breaking larger documents into smaller documents when being processed
Avoid designing processes with large looping iterations
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are less concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2024

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

saketh.darbhamulla — Fri, 05 Jan 2024 04:08:39 GMT

Revision 58 posted to Appian Knowledge Base by saketh.darbhamulla on 1/5/2024 4:08:39 AM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are other Appian components that use their own heap memory. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

High heap utilization, and consequently garbage collection events, are expected behavior and not indicative of any environment performance or configuration issues. Garbage collection can lead to issues when there is a need for a high frequency of garbage collections. This is where the garbage collection process runs intensely and continuously, causing general slowness across the environment since all work in the application server utilizes the heap memory.

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

The most common causes of slowness observed across the entire environment are:

High process volume
Undersized heap memory allocation
Inefficient application design
Long running I/O requests such as queries and API calls

An application server 'crash' and restart

The most common causes of an application server restart are:

The generation of documents from data or objects using plugins
Very large process variables or inputs
Bulky text manipulation
Large query result sets
Large looping or array based operations

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating high process volume include:

Re-designing the application causing the increased process volume
Avoid running bulk processes simultaneously
Re-design intensive processes to run gradually over a longer time frame
Running the intensive process(es) during business off hours where there are fewer concurrent users

An application server 'crash' and restart

Some solutions include:

Adding additional filters to queries used to pull data into the identified process
Breaking larger documents into smaller documents when being processed
Avoid designing processes with large looping iterations
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are less concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process Load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on their Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: December 2023

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Daniel DeVeau — Wed, 03 Jan 2024 22:12:53 GMT

Revision 57 posted to Appian Knowledge Base by Daniel DeVeau on 1/3/2024 10:12:53 PM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?le
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are other Appian components that use their own heap memory. This article only applies to the heap memory allocated to the application server.

What is heap?

When any process is run in your Appian Environment, the application server pulls all the objects referenced by the process from their storage on disk into the heap memory so the process can then be executed.

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

High heap alone is nothing to be concerned about. The more objects the application server is able to keep in memory, the faster it can perform work with those objects.

Appian designs the application server to run normally with high heap utilization as well to limit the amount of time spent on garbage collection, therefore reducing the impact of garbage collection on performance. Garbage collection can lead to issues when there is a need for multiple garbage collections in a short amount of time. This is where the garbage collection process runs intensely and continuously. Ordinarily, the garbage collection process is able to complete quickly without impacting the performance of the heap memory. However, when the garbage collection process runs intensely and continuously, the heap memory essentially freezes, causing general slowness across the environment since all processes utilise the heap memory.

The determining factor for how the heap memory and garbage collection process behave in an application server is the process activity running in that application server. It can be related to process activity causing difficulties with removing objects from the heap memory or with pulling new objects into the heap memory. When processes are efficiently designed and the heap memory is behaving normally, there will be no difficulties with moving objects in and out of the heap memory.

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

The most common causes of slowness observed across the entire environment are:

High process volume
Undersized heap memory allocation
Inefficient application design
Long running I/O requests such as queries and API calls

An application server 'crash' and restart

The most common causes of an application server restart are:

The generation of documents from data or objects using plugins
Very large process variables or inputs
Bulky text manipulation
Large query result sets
Large looping or array based operations

In all of the causes listed above, the root cause of the issue is the same - a large object or amount of objects is being loaded in the heap memory to be acted on. In some cases these objects may need to be loaded into memory multiple times, creating further heap concerns. For instance, when manipulating bulky text which consumes a large portion of memory, any object that interacts with the text will also require the same amount of memory, exponentially increasing the used heap memory very rapidly if there are multiple objects involved in the same process.

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating high process volume include:

Re-designing the application causing the increased process volume
Avoid running bulk processes simultaneously
Re-design intensive processes to run gradually over a longer time frame
Running the intensive process(es) during business off hours where there are fewer concurrent users

An application server 'crash' and restart

Some solutions include:

Adding additional filters to queries used to pull data into the identified process
Breaking larger documents into smaller documents when being processed
Avoid designing processes with large looping iterations
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are less concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process Load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on the Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: December 2023

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Daniel DeVeau — Wed, 03 Jan 2024 22:11:42 GMT

Revision 56 posted to Appian Knowledge Base by Daniel DeVeau on 1/3/2024 10:11:42 PM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?le
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are other Appian components that use their own heap memory. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

High heap alone is nothing to be concerned about. The more objects the application server is able to keep in memory, the faster it can perform work with those objects.

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

The most common causes of slowness observed across the entire environment are:

High process volume
Undersized heap memory allocation
Inefficient application design
Long running I/O requests such as queries and API calls

An application server 'crash' and restart

The most common causes of an application server restart are:

The generation of documents from data or objects using plugins
Very large process variables or inputs
Bulky text manipulation
Large query result sets
Large looping or array based operations

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating high process volume include:

Re-designing the application causing the increased process volume
Avoid running bulk processes simultaneously
Re-design intensive processes to run gradually over a longer time frame
Running the intensive process(es) during business off hours where there are fewer concurrent users

An application server 'crash' and restart

Some solutions include:

Adding additional filters to queries used to pull data into the identified process
Breaking larger documents into smaller documents when being processed
Avoid designing processes with large looping iterations
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are less concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process Load

Due to the complex nature of heap allocation and performance issues in Appian, recommendations on increases to the allocated heap memory are discussed on a case by case basis. Appian Support carefully evaluates this option when handling performance-related Support Cases and will recommend an increase if it will help improve the performance of your environment.

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on the Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: December 2023

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Daniel DeVeau — Wed, 03 Jan 2024 22:11:23 GMT

Revision 55 posted to Appian Knowledge Base by Daniel DeVeau on 1/3/2024 10:11:23 PM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?le
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are other Appian components that use their own heap memory. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

High heap alone is nothing to be concerned about. The more objects the application server is able to keep in memory, the faster it can perform work with those objects.

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

The most common causes of slowness observed across the entire environment are:

High process volume
Undersized heap memory allocation
Inefficient application design
Long running I/O requests such as queries and API calls

An application server 'crash' and restart

The most common causes of an application server restart are:

The generation of documents from data or objects using plugins
Very large process variables or inputs
Bulky text manipulation
Large query result sets
Large looping or array based operations

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating high process volume include:

Re-designing the application causing the increased process volume
Avoid running bulk processes simultaneously
Re-design intensive processes to run gradually over a longer time frame
Running the intensive process(es) during business off hours where there are fewer concurrent users

An application server 'crash' and restart

Some solutions include:

Adding additional filters to queries used to pull data into the identified process
Breaking larger documents into smaller documents when being processed
Avoid designing processes with large looping iterations
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are less concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Therefore, increasing the heap memory allocated to the application server should only be considered if there is more than enough memory available on the environment. Additionally, increasing the heap memory allocation is not a universal solution to all heap memory performance issues. Some causes of heap memory performance issues will still impact performance regardless of the size of the heap memory.

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process Load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on the Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: December 2023

Tags: heap, application server, Performance, FAQ

DRAFT-SP-9359 Application Server Heap Memory FAQ

Daniel DeVeau — Wed, 03 Jan 2024 22:10:28 GMT

Revision 54 posted to Appian Knowledge Base by Daniel DeVeau on 1/3/2024 10:10:28 PM

Table of Contents:

What is heap?
What is the difference between heap memory and total memory?
What is garbage collection?
When is heap usage a concern?
What are some common heap issues?
How to fix common heap issues?
Will increasing the heap memory allocation help improve performance?
What is a heap dump?le
Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Note : There are other Appian components that use their own heap memory. This article only applies to the heap memory allocated to the application server.

What is heap?

What is the difference between heap memory and total memory of the application server?

What is garbage collection?

When is heap usage a concern?

High heap alone is nothing to be concerned about. The more objects the application server is able to keep in memory, the faster it can perform work with those objects.

What are some common heap issues?

There are two effects of performance issues with heap memory in an Appian environment:

Slowness across the entire environment
An application server crash and restart

Note: An application server crash on an environment with only one application server node will always result in a complete site outage until the affected application server finishes restarting.

Slowness across the entire environment

The most common causes of slowness observed across the entire environment are:

High process volume
Undersized heap memory allocation
Inefficient application design
Long running I/O requests such as queries and API calls

An application server 'crash' and restart

The most common causes of an application server restart are:

The generation of documents from data or objects using plugins
Very large process variables or inputs
Bulky text manipulation
Large query result sets
Large looping or array based operations

How to fix common heap issues?

Slowness across the entire environment

Some solutions for remediating high process volume include:

Re-designing the application causing the increased process volume
Avoid running bulk processes simultaneously
Re-design intensive processes to run gradually over a longer time frame
Running the intensive process(es) during business off hours where there are fewer concurrent users

An application server 'crash' and restart

Some solutions include:

Adding additional filters to queries used to pull data into the identified process
Breaking larger documents into smaller documents when being processed
Avoid designing processes with large looping iterations
Avoid designing processes that operate over large arrays of texts or objects
Running the process(es) during business off hours where there are less concurrent users

Will increasing the heap memory allocation help improve performance?

Appian Engines
Search Server
Data Server
Database
RPA

Therefore, increasing the heap memory allocated to the application server should only be considered if there is more than enough resources available on the environment. Additionally, increasing the heap memory allocation is not a universal solution to all heap memory performance issues. Some causes of heap memory performance issues will still impact performance regardless of the size of the heap memory.

Some scenarios where increasing the heap memory would be considered can include, but is not limited to:

An overwhelming amount of resources being available in the environment
Process Load

What is a heap dump?

For Appian Cloud customers, Appian Support can generate heap dumps directly on the Appian Cloud server.

Note: Heap dumps contain sensitive information.

Why does Appian Support need a maintenance window to analyze a heap dump in Appian Cloud?

Heap dumps contain sensitive information that should not be shared or stored in insecure locations. For Appian Cloud customers, heap dumps are analyzed directly on the Appian Cloud site.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: December 2023

Tags: heap, application server, Performance, FAQ