KB-1926 How to remove servers from a distributed installation for self-managed

Maggie Deppe-Walker — Fri, 28 Apr 2023 05:46:32 GMT

Current Revision posted to Appian Knowledge Base by Maggie Deppe-Walker on 4/28/2023 5:46:32 AM

Purpose

This article describes how to remove servers from an self-managed distributed installation of Appian. The documentation here applies only for self-managed customers running on Linux servers - a distributed installation of Appian on Windows servers is not supported. Customers who are on Appian Cloud should not follow these instructions and instead create a case with Appian Technical Support detailing their request.

The below steps will cause Appian to be unavailable until all steps are completed. Please schedule a maintenance window and inform your users.

Note: When moving from High Availability to Standalone, it is recommended to adjust autocheckpoint configuration so that checkpoints do not run during business hours. More information is provided in the Configuring Checkpointing Frequency documentation.

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper.
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to the 'Change Topology' section and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all engine nodes by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s).
1. A list of Kafka host and ports can be found in under the <kafka-cluster> element in the below file path. Please see the below path depending on the version of Appian installed:
  1. 19.1 and later: <APPIAN_HOME>/conf/appian-topology.xml
  2. Pre-19.1: <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml
2. The first Kafka broker listed in the topology is recognized as the primary broker and cannot be excluded from the cluster. If the node you would like to keep is not the first Kafka broker listed in the topology, update the topology file to make it the first broker in the cluster and restart IMS components in the environment.
3. Kafka brokers should be removed in the reverse order in which they are listed in the topology file.
Remove partitions from the brokers that will be removed by running the following on one of the Kafka nodes:
<APPIAN_HOME>/services/lib/scripts/decreaseBrokerCount.sh --exclude-brokers host:port
1. Run the script to exclude unneeded brokers one at a time. Replace host:port with <kafka-hostname> and Kafka port (the default port is 9092)
Make sure that the brokers in step 2 are no longer replicating any partitions by running the following using any Kafka host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --bootstrap-server <kafka-hostname>:9092
1. <kafka-hostname>:9092 is the hostname or IP address where any of the Kafka servers is running. If Kafka is not running with the default client port (9092), include the port as well: hostname:1234
2. Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed = (your target Kafka cluster size) - 1.

Stop Remaining Appian Services

Stop Kafka cluster on all engine nodes.
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all engine nodes by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

Edit <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) on every server that will remain. The topology file must be the same on all servers.

The topology file should reflect the end state of where each Appian Service will be running.

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
  <server host="<hostname>">
    <engine name="forums"/>
    <engine name="notify"/>
    <engine name="notify-email"/>
    <engine name="channels"/>
    <engine name="content"/>
    <engine name="collaboration-statistics"/>
    <engine name="personalization"/>
    <engine name="portal"/>
    <engine name="process-design"/>
    <engine name="process-analytics0"/>
    <engine name="process-analytics1"/>
    <engine name="process-analytics2"/>
    <engine name="process-execution0"/>
    <engine name="process-execution1"/>
    <engine name="process-execution2"/>
  </server>
  <search-cluster>
    <search-server host="<hostname>" port="9300"/>
  </search-cluster>
  <kafkaCluster>
    <broker host="<hostname>" port="9092"/>
  </kafkaCluster>
  <zookeeperCluster>
    <zookeeper host="<hostname>" port="2181"/>
  </zookeeperCluster>
  <data-server-cluster>
    <data-server host="<hostname>" port="5400" rts-count="2"/>
  </data-server-cluster>
</topology>

Deactivate the unnecessary server(s).
This step is handled by the customer’s System Administrator.

Restart Appian

Make sure you are looking at the version of the documentation that matches the version of Appian you are running.
Follow all steps in Starting the Application Suite on Linux.

Affected Versions

This article applies to Appian 18.2 and later.

Last Reviewed: Feb 2023

Tags: high availability, kafka, zookeeper, installation, how-to, infrastructure

KB-1926 How to remove servers from a distributed installation for self-managed

Maggie Deppe-Walker — Fri, 28 Apr 2023 05:45:47 GMT

Revision 33 posted to Appian Knowledge Base by Maggie Deppe-Walker on 4/28/2023 5:45:47 AM

Purpose

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper.
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to the 'Change Topology' section and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all engine nodes by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s).
1. A list of Kafka host and ports can be found in under the <kafka-cluster> element in the below file path. Please see the below path depending on the version of Appian installed:
  1. 19.1 and later: <APPIAN_HOME>/conf/appian-topology.xml
  2. Pre-19.1: <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml
2. The first Kafka broker listed in the topology is recognized as the primary broker and cannot be excluded from the cluster. If the node you would like to keep is not the first Kafka broker listed in the topology, update the topology file to make it the first broker in the cluster and restart IMS components in the environment.
3. Kafka brokers should be removed in the reverse order in which they are listed in the topology file.
Remove partitions from the brokers that will be removed by running the following on one of the Kafka nodes:
<APPIAN_HOME>/services/lib/scripts/decreaseBrokerCount.sh --exclude-brokers host:port
1. Run the script to exclude unneeded brokers one at a time. Replace host:port with <kafka-hostname> and Kafka port (the default port is 9092)
Make sure that the brokers in step 2 are no longer replicating any partitions by running the following using any Kafka host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --bootstrap-server <kafka-hostname>:9092
1. <kafka-hostname>:9092 is the hostname or IP address where any of the Kafka servers is running. If Kafka is not running with the default client port (9092), include the port as well: hostname:1234
2. Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed = (your target Kafka cluster size) - 1.

Stop Remaining Appian Services

Stop Kafka cluster on all engine nodes.
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all engine nodes by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
  <server host="<hostname>">
    <engine name="forums"/>
    <engine name="notify"/>
    <engine name="notify-email"/>
    <engine name="channels"/>
    <engine name="content"/>
    <engine name="collaboration-statistics"/>
    <engine name="personalization"/>
    <engine name="portal"/>
    <engine name="process-design"/>
    <engine name="process-analytics0"/>
    <engine name="process-analytics1"/>
    <engine name="process-analytics2"/>
    <engine name="process-execution0"/>
    <engine name="process-execution1"/>
    <engine name="process-execution2"/>
  </server>
  <search-cluster>
    <search-server host="<hostname>" port="9300"/>
  </search-cluster>
  <kafkaCluster>
    <broker host="<hostname>" port="9092"/>
  </kafkaCluster>
  <zookeeperCluster>
    <zookeeper host="<hostname>" port="2181"/>
  </zookeeperCluster>
  <data-server-cluster>
    <data-server host="<hostname>" port="5400" rts-count="2"/>
  </data-server-cluster>
</topology>

Deactivate the unnecessary server(s).
This step is handled by the customer’s System Administrator.

Restart Appian

Make sure you are looking at the version of the documentation that matches the version of Appian you are running.
Follow all steps in Starting the Application Suite on Linux.

Affected Versions

This article applies to Appian 18.2 and later.

Last Reviewed: Feb 2023

Tags: high availability, kafka, zookeeper, installation, how-to, infrastructure

KB-1926 How to remove servers from a distributed installation for self-managed

Parmida Borhani — Wed, 07 Oct 2020 01:07:51 GMT

Revision 32 posted to Appian Knowledge Base by Parmida Borhani on 10/7/2020 1:07:51 AM

Purpose

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper.
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to the 'Change Topology' section and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s).
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) under the <kafka-cluster> element. Kafka servers have to be removed in the reverse order in which they are listed in the topology file.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 are no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 1.

Stop Remaining Appian Services

Stop Kafka on all servers.
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster> <data-server-cluster> <data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s).
This step is handled by the customer’s Appian System Administrator.

Restart Appian

Make sure you are looking at the version of the documentation that matches the version of Appian you are running.
Follow all steps in Starting the Application Suite on Linux.

Affected Versions

This article applies to Appian 18.2 and later.

Last Reviewed: May 2019

Tags: high availability, kafka, zookeeper, installation, how-to, infrastructure

KB-1926 How to remove servers from a distributed installation for self-managed

Jordan Horwat — Fri, 03 May 2019 20:02:48 GMT

Revision 31 posted to Appian Knowledge Base by Jordan Horwat on 5/3/2019 8:02:48 PM

Purpose

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper.
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to the 'Change Topology' section and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s).
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) under the <kafka-cluster> element. Kafka servers have to be removed in the reverse order in which they are listed in the topology file.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 are no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 1.

Stop Remaining Appian Services

Stop Kafka on all servers.
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster> <data-server-cluster> <data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s).
This step is handled by the customer’s Appian System Administrator.

Restart Appian

Make sure you are looking at the version of the documentation that matches the version of Appian you are running.
Follow all steps in Starting the Application Suite on Linux.

Affected Versions

This article applies to Appian 18.2 and later.

Last Reviewed: May 2019

Tags: high availability, kafka, zookeeper, installation, how-to, infrastructure

KB-1926 How to remove servers from a distributed installation for on premise

Jordan Horwat — Fri, 03 May 2019 20:02:06 GMT

Revision 30 posted to Appian Knowledge Base by Jordan Horwat on 5/3/2019 8:02:06 PM

Purpose

This article describes how to remove servers from an on-premise distributed installation of Appian. The documentation here applies only for on-premise customers running on Linux servers - a distributed installation of Appian on Windows servers is not supported. Customers who are on Appian Cloud should not follow these instructions and instead create a case with Appian Support detailing their request.

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper.
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to the 'Change Topology' section and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s).
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) under the <kafka-cluster> element. Kafka servers have to be removed in the reverse order in which they are listed in the topology file.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 are no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 1.

Stop Remaining Appian Services

Stop Kafka on all servers.
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s).
This step is handled by the customer’s Appian System Administrator.

Restart Appian

Make sure you are looking at the version of the documentation that matches the version of Appian you are running.
Follow all steps in Starting the Application Suite on Linux.

Affected Versions

This article applies to Appian 18.2 and later

Last Reviewed: May 2019

Tags: kafka, high availibility, zookeeper, installation, how-to, infrastructure

KB-1926 How to remove servers from a distributed installation for on premise

Parmida Borhani — Wed, 01 May 2019 02:12:28 GMT

Revision 29 posted to Appian Knowledge Base by Parmida Borhani on 5/1/2019 2:12:28 AM

Purpose

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper.
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to the 'Change Topology' section and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s).
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) under the <kafka-cluster> element. Kafka servers have to be removed in the reverse order in which they are listed in the topology file.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 are no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 1.

Stop Remaining Appian Services

Stop Kafka on all servers.
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s).
This step is handled by the customer’s Appian System Administrator.

Restart Appian

Make sure you are looking at the version of the documentation that matches the version of Appian you are running.
Follow all steps in Starting the Application Suite on Linux.

Affected Versions

This article applies to Appian 17.4 and later

Last Reviewed: April 2019

Tags: kafka, high availibility, zookeeper, installation, how-to, infrastructure

KB-XXXXX [DRAFT] How to remove servers from a distributed installation for on premise

Parmida Borhani — Wed, 01 May 2019 02:11:25 GMT

Revision 28 posted to Appian Knowledge Base by Parmida Borhani on 5/1/2019 2:11:25 AM

Purpose

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper.
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to the 'Change Topology' section and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s).
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) under the <kafka-cluster> element. Kafka servers have to be removed in the reverse order in which they are listed in the topology file.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 are no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 1.

Stop Remaining Appian Services

Stop Kafka on all servers.
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s).
This step is handled by the customer’s Appian System Administrator.

Restart Appian

Make sure you are looking at the version of the documentation that matches the version of Appian you are running.
Follow all steps in Starting the Application Suite on Linux.

Affected Versions

This article applies to Appian 17.4 and later

Last Reviewed: April 2019

Tags: kafka, high availibility, zookeeper, installation, how-to, infrastructure

KB-XXXXX [DRAFT] How to remove servers from a distributed installation for on premise

Parmida Borhani — Wed, 01 May 2019 02:10:15 GMT

Revision 27 posted to Appian Knowledge Base by Parmida Borhani on 5/1/2019 2:10:15 AM

Purpose

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper.
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to the 'Change Topology' section and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s).
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) under the <kafka-cluster> element. Kafka servers have to be removed in the reverse order in which they are listed in the topology file.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 are no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 1.

Stop Remaining Appian Services

Stop Kafka on all servers.
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s).
This step is handled by the customer’s Appian System Administrator.

Restart Appian

Make sure you are looking at the version of the documentation that matches the version of Appian you are running.
Follow all steps in Starting the Application Suite on Linux.

Affected Versions

This article applies to Appian 17.4 and later

Last Reviewed: April 2019

Tags: kafka, high availibility, zookeeper, installation, how-to, infrastructure

KB-XXXXX [DRAFT] How to remove servers from a distributed installation for on premise

Parmida Borhani — Wed, 01 May 2019 02:08:08 GMT

Revision 26 posted to Appian Knowledge Base by Parmida Borhani on 5/1/2019 2:08:08 AM

Purpose

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper.
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to 'Change Topology' and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s).
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) under the <kafka-cluster> element. Kafka servers have to be removed in the reverse order in which they are listed in the topology file.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 are no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 1.

Stop Remaining Appian Services

Stop Kafka on all servers.
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s).
This step is handled by the customer’s Appian System Administrator.

Restart Appian

Make sure you are looking at the version of the documentation that matches the version of Appian you are running.
Follow all steps in Starting the Application Suite on Linux.

Affected Versions

This article applies to Appian 17.4 and later

Last Reviewed: April 2019

Tags: kafka, high availibility, zookeeper, installation, how-to, infrastructure

KB-XXXXX [DRAFT] How to remove servers from a distributed installation for on premise

Jennifer Wu — Tue, 30 Apr 2019 20:43:26 GMT

Revision 25 posted to Appian Knowledge Base by Jennifer Wu on 4/30/2019 8:43:26 PM

Purpose

This article describes how to remove servers from an on-premise distributed installation of Appian. The documentation here applies only for On-Premise customers running on Linux servers - a distributed installation of Appian on Windows servers is not supported. Customers who are on Appian Cloud should not follow these instructions and instead create a case with Appian Support detailing their request.

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to 'Change Topology' and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s)
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) under the <kafka-cluster> element. Kafka servers have to be removed in the reverse order in which they are listed in the topology file.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 is no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 1.

Stop Remaining Appian Services

Stop Kafka on all servers
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

Edit <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) on every server that will remain. The topology file must be the same on all servers

The topology file should reflect the end state of where each Appian Service will be running.

Below is an example topology file where there is only a single instance of each Appian Service on Machine A.

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s)
This step is handled by the customer’s Appian System Administrator

Restart Appian

Make sure you are looking at the version of docs that matches the version of Appian you are running
Follow all steps in Starting the Application Suite on Linux

Affected Versions

This article applies to Appian 17.4 and later

Last Reviewed: April 2019

Tags: kafka, high availibility, zookeeper, how-to

KB-XXXXX [DRAFT] How to remove servers from a distributed installation for on premise

Jennifer Wu — Tue, 30 Apr 2019 20:42:44 GMT

Revision 24 posted to Appian Knowledge Base by Jennifer Wu on 4/30/2019 8:42:44 PM

Purpose

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to 'Change Topology' and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s)
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) under the <kafka-cluster> element. Kafka servers have to be removed in the reverse order in which they are listed in the topology file.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 is no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 1.

Stop Remaining Appian Services

Stop Kafka on all servers
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

Edit <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) on every server that will remain. The topology file must be the same on all servers

The topology file should reflect the end state of where each Appian Service will be running.

Below is an example topology file where there is only a single instance of each Appian Service on Machine A.

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s)
This step is handled by the customer’s Appian System Administrator

Restart Appian

Make sure you are looking at the version of docs that matches the version of Appian you are running
Follow all steps in Starting the Application Suite on Linux

Affected Versions

This article applies to Appian 17.4 and later

Last Reviewed: April 2019

Tags: kafka, high availibility, zookeeper, how-to

KB-XXXXX [DRAFT] How to remove servers from a distributed installation for on premise

Jennifer Wu — Tue, 30 Apr 2019 20:40:28 GMT

Revision 23 posted to Appian Knowledge Base by Jennifer Wu on 4/30/2019 8:40:28 PM

Purpose

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to 'Change Topology' and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s)
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) under the <kafka-cluster> element. Kafka servers have to be removed in the reverse order in which they are listed in the topology file.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 is no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 1.

Stop Remaining Appian Services

Stop Kafka on all servers
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

Edit <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) on every server that will remain. The topology file must be the same on all servers

The topology file should reflect the end state of where each Appian Service will be running.

Below is an example topology file where there is only a single instance of each Appian Service on Machine A.

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s)
This step is handled by the customer’s Appian System Administrator

Restart Appian

Make sure you are looking at the version of docs that matches the version of Appian you are running
Follow all steps in Starting the Application Suite on Linux

Affected Versions

This article applies to Appian 17.4 and later

Last Reviewed: April 2019

Tags: kafka, high availibility, zookeeper, how-to

KB-XXXXX [DRAFT] How to remove servers from a distributed installation for on premise

Jennifer Wu — Tue, 30 Apr 2019 14:48:02 GMT

Revision 22 posted to Appian Knowledge Base by Jennifer Wu on 4/30/2019 2:48:02 PM

Purpose

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to 'Change Topology' and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s)
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) under the <kafka-cluster> element. Kafka servers have to be removed in the reverse order in which they are listed in the topology file.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 is no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 1.

Stop Remaining Appian Services

Stop Kafka on all servers
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

Edit <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) on every server that will remain. The topology file must be the same on all servers

The topology file should reflect the end state of where each Appian Service will be running.

Below is an example topology file where there is only a single instance of each Appian Service on Machine A.

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s)
This step is handled by the customer’s Appian System Administrator

Restart Appian

Make sure you are looking at the version of docs that matches the version of Appian you are running
Follow all steps in Starting the Application Suite on Linux

Affected Versions

This article applies to Appian 17.4 and later

Last Reviewed: April 2019

Tags: kafka, high availibility, zookeeper, how-to

KB-XXXXX [DRAFT] How to remove servers from a distributed installation for on premise

Jennifer Wu — Tue, 30 Apr 2019 14:37:55 GMT

Revision 21 posted to Appian Knowledge Base by Jennifer Wu on 4/30/2019 2:37:55 PM

Purpose

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to 'Change Topology' and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s)
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) under the <kafka-cluster> element. Kafka servers have to be removed in the reverse chronological order in which they were added.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 is no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 1.

Stop Remaining Appian Services

Stop Kafka on all servers
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

Edit <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) on every server that will remain. The topology file must be the same on all servers

The topology file should reflect the end state of where each Appian Service will be running.

Below is an example topology file where there is only a single instance of each Appian Service on Machine A.

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s)
This step is handled by the customer’s Appian System Administrator

Restart Appian

Make sure you are looking at the version of docs that matches the version of Appian you are running
Follow all steps in Starting the Application Suite on Linux

Affected Versions

This article applies to Appian 17.4 and later

Last Reviewed: April 2019

Tags: kafka, high availibility, zookeeper, how-to

KB-XXXXX [DRAFT] How to remove servers from a distributed installation for on premise

Jennifer Wu — Tue, 30 Apr 2019 14:37:03 GMT

Revision 20 posted to Appian Knowledge Base by Jennifer Wu on 4/30/2019 2:37:03 PM

Purpose

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to 'Change Topology' and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s)
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) under the <kafka-cluster> element. Kafka servers have to be removed in the reverse chronological order in which they were added.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 is no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 2.

Stop Remaining Appian Services

Stop Kafka on all servers
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

Edit <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) on every server that will remain. The topology file must be the same on all servers

The topology file should reflect the end state of where each Appian Service will be running.

Below is an example topology file where there is only a single instance of each Appian Service on Machine A.

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s)
This step is handled by the customer’s Appian System Administrator

Restart Appian

Make sure you are looking at the version of docs that matches the version of Appian you are running
Follow all steps in Starting the Application Suite on Linux

Affected Versions

This article applies to Appian 17.4 and later

Last Reviewed: April 2019

Tags: kafka, high availibility, zookeeper, how-to

KB-XXXXX [DRAFT] How to remove servers from a distributed installation for on premise

Jennifer Wu — Tue, 30 Apr 2019 14:36:22 GMT

Revision 19 posted to Appian Knowledge Base by Jennifer Wu on 4/30/2019 2:36:22 PM

Purpose

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to 'Change Topology' and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s)
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) under the <kafka-cluster> element. Kafka servers have to be removed in the reverse chronological order in which they were added.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 is no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 2.

Stop Remaining Appian Services

Stop Kafka on all servers
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

Edit <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) on every server that will remain. The topology file must be the same on all servers

The topology file should reflect the end state of where each Appian Service will be running.

Below is an example topology file where there is only a single instance of each Appian Service on Machine A.

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s)
This step is handled by the customer’s Appian System Administrator

Restart Appian

Make sure you are looking at the version of docs that matches the version of Appian you are running
Follow all steps in Starting the Application Suite on Linux

Affected Versions

This article applies to Appian 17.4 and later

Last Reviewed: April 2019

Tags: kafka, high availibility, zookeeper, how-to

KB-XXXXX [DRAFT] How to remove servers from a distributed installation for on premise

Jennifer Wu — Tue, 30 Apr 2019 14:33:52 GMT

Revision 18 posted to Appian Knowledge Base by Jennifer Wu on 4/30/2019 2:33:52 PM

Purpose

Instructions

The links redirect to documentation corresponding to the latest version of Appian. Be sure to select the documentation version that corresponds to the version of Appian you have installed.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to 'Change Topology' and skip all instructions in between.

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s)
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml under the <kafka-cluster> element. Kafka servers have to be removed in the reverse chronological order in which they were added.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1.
Make sure that the brokers in step 2 is no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 2.

Stop Remaining Appian Services

Stop Kafka on all servers
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

Edit <APPIAN_HOME>/conf/appian-topology.xml (after 19.1) or <APPIAN_HOME>/ear/suite.ear/conf/appian-topology.xml (before 19.1) on every server that will remain. The topology file must be the same on all servers

The topology file should reflect the end state of where each Appian Service will be running.

Below is an example topology file where there is only a single instance of each Appian Service on Machine A.

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s)
This step is handled by the customer’s Appian System Administrator

Restart Appian

Make sure you are looking at the version of docs that matches the version of Appian you are running
Follow all steps in Starting the Application Suite on Linux

Affected Versions

This article applies to Appian 17.4 and later

Last Reviewed: April 2019

Tags: kafka, high availibility, zookeeper, how-to

KB-XXXXX [DRAFT] How To Remove Servers from a Distributed Installation for On Premise

Jennifer Wu — Mon, 29 Apr 2019 16:07:02 GMT

Revision 17 posted to Appian Knowledge Base by Jennifer Wu on 4/29/2019 4:07:02 PM

The documentation here applies only for On-Premise customers with Linux servers - a distributed installation of Appian on Windows servers is not supported. Customers who are on Appian Cloud should not follow these instructions and instead contact Appian Support with their request.

The below steps will cause Appian to be unavailable until all steps are completed. Please schedule a maintenance window and inform your users.
Note: When moving from High Availability to Standalone, it is recommended to adjust autocheckpoint configuration so that checkpoints do not run during business hours. More information is provided in the Configuring Checkpointing Frequency documentation.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper
If not, complete all steps in Stopping the Application Suite on Linux, then proceed to 'Change Topology' and skip all instructions in between

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s)
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml under the <kafka-cluster> element. Kafka servers have to be removed in the reverse chronological order in which they were added.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1
Make sure that the brokers in step 2 is no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 2

Stop Remaining Appian Services

Stop Kafka on all servers
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

Edit appian-topology.xml on every server that will remain. The topology file must be the same on all servers
Location: <APPIAN_HOME>conf/appian-topology.xml
The topology file should reflect the end state of where each Appian Service will be running.

Below is an example topology file where there is only a single instance of each Appian Service on Machine A.

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s)
This step is handled by the customer’s Appian System Administrator

Restart Appian

Make sure you are looking at the version of docs that matches the version of Appian you are running
Follow all steps in Starting the Application Suite on Linux

Affected Versions

This article applies to Appian 17.4 and later

Tags: kafka, high availibility, zookeeper, how-to

KB-XXXXX [DRAFT] How To Remove Servers from a Distributed Installation for On Premise

Jennifer Wu — Mon, 29 Apr 2019 16:06:44 GMT

Revision 16 posted to Appian Knowledge Base by Jennifer Wu on 4/29/2019 4:06:44 PM

The below steps will cause Appian to be unavailable until all steps are completed. Please schedule a maintenance window and inform your users.
Note: When moving from High Availability to Standalone, it is recommended to adjust autocheckpoint configuration so that checkpoints do not run during business hours. More information is provided in the Configuring Checkpointing Frequency documentation.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper
If not, complete all steps in Stopping the Application Suite on Linux ,then proceed to 'Change Topology' and skip all instructions in between

Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s)
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml under the <kafka-cluster> element. Kafka servers have to be removed in the reverse chronological order in which they were added.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1
Make sure that the brokers in step 2 is no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 2

Stop Remaining Appian Services

Stop Kafka on all servers
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s)
This step is handled by the customer’s Appian System Administrator

Restart Appian

Make sure you are looking at the version of docs that matches the version of Appian you are running
Follow all steps in Starting the Application Suite on Linux

Affected Versions

This article applies to Appian 17.4 and later

Tags: kafka, high availibility, zookeeper, how-to

KB-XXXXX [DRAFT] How To Remove Servers from a Distributed Installation for On Premise

Jennifer Wu — Mon, 29 Apr 2019 16:06:08 GMT

Revision 15 posted to Appian Knowledge Base by Jennifer Wu on 4/29/2019 4:06:08 PM

The below steps will cause Appian to be unavailable until all steps are completed. Please schedule a maintenance window and inform your users.
Note: When moving from High Availability to Standalone, it is recommended to adjust autocheckpoint configuration so that checkpoints do not run during business hours. More information is provided in the Configuring Checkpointing Frequency documentation.

Stop a Subset of Appian Services

Determine if any of the servers you are removing are hosting Kafka & Zookeeper
If not, complete all steps in Stopping the Application Suite on Linux ,then proceed to 'Change Topology' and skip all instructions in between
Otherwise, complete all steps prior to the one that says to “Stop the Appian engines” in Stopping the Application Suite on Linux and follow all directions in the rest of this article
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Remaining Servers

If the server(s) you are removing are running Kafka, note their hostnames and Kafka ports of those server(s)
A list of Kafka host and ports can be found in <APPIAN_HOME>/conf/appian-topology.xml under the <kafka-cluster> element. Kafka servers have to be removed in the reverse chronological order in which they were added.
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed a list of the hostnames and Kafka ports determined in step 1
Make sure that the brokers in step 2 is no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the brokers that will be removed do NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 2

Stop Remaining Appian Services

Stop Kafka on all servers
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server(s)
This step is handled by the customer’s Appian System Administrator

Restart Appian

Make sure you are looking at the version of docs that matches the version of Appian you are running
Follow all steps in Starting the Application Suite on Linux

Affected Versions

This article applies to Appian 17.4 and later

Tags: kafka, high availibility, zookeeper, how-to

KB-XXXXX [DRAFT] How To Go From High Availability to Standalone for On Premise Installations

Jennifer Wu — Mon, 29 Apr 2019 15:37:53 GMT

Revision 14 posted to Appian Knowledge Base by Jennifer Wu on 4/29/2019 3:37:53 PM

The below steps will cause Appian to be unavailable until all steps are completed. Please schedule a maintenance window and inform your users.
Note: When moving from High Availability to Standalone, it is recommended to adjust autocheckpoint configuration so that checkpoints do not run during business hours. More information is provided in the Configuring Checkpointing Frequency documentation.

Stop a Subset of Appian Services

Stop all Services that are dependent on the Messaging Service (Kafka & Zookeeper) on all servers
Stopping the Application Suite on Linux Complete all steps prior to the one that says to “Stop the Appian engines”.
Stop Service Manager & Engines without stopping Zookeeper & Kafka on all servers by running:
<APPIAN_HOME>/services/bin/stop.sh -p <password> -no-kafka -cluster -s all

Move Kafka Data to Appropriate Servers

Note the host and port of the last two Kafka broker listed in <APPIAN_HOME>/conf/appian-topology.xml.
The servers being removed should correspond to the two most recently added Kafka brokers. Kafka brokers are listed under the <kafka-cluster> element
Remove partitions from the brokers that will be removed by running the following on any one server:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/decreaseBrokerCount.sh --exclude-brokers [<host:port, host:port>]
1. The script needs to be passed the hostnames and Kafka ports of the two servers that will be removed. This is determined in step 1
Make sure that the broker in step 2 is no longer replicating any partitions by running the following using any Zookeeper host and port:
<APPIAN_HOME>/services/kafka_<versionInfo>/bin/kafka-topics.sh --describe --zookeeper <Zookeeper host>:<Zookeeper port>
Make sure that the broker-id of the broker that will be removed does NOT appear in the values for any column. The highest broker-id displayed should be your target Kafka cluster size - 1

Stop Remaining Appian Services

Stop Kafka on all servers
<APPIAN_HOME>/services/stop.sh -p <password> -s kafka
Once all Kafka brokers have stopped, stop Zookeeper on all servers by running:
<APPIAN_HOME>/services/stop.sh -p <password> -s zookeeper

Change Topology

Edit appian-topology.xml on every server that will remain. The topology file must be the same on all servers
Location: <APPIAN_HOME>conf/appian-topology.xml
There should be only one instance of each Appian Service - Kafka, Zookeeper, Data Server, Search Server, and one instance of each engine and they should be hosted on the same server.

Below is an example topology file

<?xml version="1.0" encoding="UTF-8"?>
<topology port="5000">
<server host="<MACHINE_A_IP>">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster>
<search-server host="<MACHINE_A_IP>" port="9301"/>
</search-cluster>
<kafkaCluster>
<broker host="<MACHINE_A_IP>" port="9092"/>
</kafkaCluster>
<zookeeperCluster>
<zookeeper host="<MACHINE_A_IP>" port="2181"/>
</zookeeperCluster>
<data-server-cluster>
<data-server host="<MACHINE_A_IP>"port="5400" rts-count="1"/> 
</data-server-cluster>
</topology>

Deactivate server
This step is handled by the customer’s Appian System Administrator

Restart Appian

Make sure you are looking at the version of docs that matches the version of Appian you are running
Starting the Application Suite on Linux

Affected Versions

This article applies to Appian 17.4 and later

Tags: kafka, high availibility, zookeeper, how-to