KB-1354 How to manage high disk usage in Appian Cloud environments

Purpose

This article details root causes as well as corrective actions to be taken in situations where an Appian Cloud environment is experiencing higher than normal disk usage. In addition, some strategies to optimize and control disk usage in Appian environments are listed. In Appian Cloud environments specifically, the top disk consumers are usually those that are listed below.

Instructions

Depending on which component of Appian is experiencing high disk usage, the steps to remediate the issue will vary.

Archived Processes

Appian Support may reach out to you regarding high disk usage on your cloud environment. If archived processes are the top consumers of disk space in your environment, there are a few options to remediate the issue going forward: 

  1. Auto-compress archived processes - The site can be configured to automatically compress archived processes after a certain number of days (e.g. automatically compress archives older than 7 days).
  2. Auto-delete archived processes (recommended for non-production environments only) - The site can be configured to automatically delete process archives after a number of days (e.g. automatically delete archives older than 7 days).

Appian Support requires that you provide a number of days to set as the value for the properties above. Please be aware that Appian Support will need to schedule a maintenance window to deploy the change. 

Note: Starting in Appian 17.2 and later, archived processes are automatically compressed after 90 days. Refer to the 17.2 Release Notes for more information.

Process Execution Engines

A cleanup of processes in the environment is the best way to reduce disk usage for these engines. Please archive and delete any unnecessary processes in the environment as soon as possible. We also recommend reviewing your Data Management setting and configuring your process models appropriately. You may use the sizing section of the health check report to identify Appian processes that have the highest resource consumption. Ensure you have the most current version of the Appian Health Check plugin installed.

Note: Archiving large processes will not immediately reduce disk usage, as it just moves the data to a separate archive on disk that is the same size of the process in the engine. In order to reduce disk space, these archived processes must be compressed. See the above section for steps to proactively compress process archives.

Knowledge Center/Documents

If one or more knowledge centers are the top consumers of disk space in your environment, Appian Technical Support may open a case to notify you of this and will provide a list of IDs corresponding to the offending knowledge centers upon request. You are responsible for deleting any unneeded documents in the appropriate knowledge centers. Appian Support is unable to delete documents for you on Cloud sites. 

Appian 18.1 and Later

In order to access and delete the documents in the specified knowledge centers, perform the following:

  1. Navigate to <APPIAN_URL>/suite/design/.
  2. Click on the Objects tab. 
  3. Filter by the Folder object type.
  4. Type <id> in the search bar, where <id> is one of the IDs in the list provided.
  5. Click Search.
  6. Toggle the "Search UUID and ID" radio button (in the upper right).

Appian 17.4 and Earlier

In order to access and delete the documents in the specified knowledge centers, navigate to <APPIAN_URL>/suite/kc/<id> where <id> is one of the IDs in the list provided.

Note: Documents that are expired are not fully deleted from the system and may contribute to the high disk usage. In order to save on disk usage, a document must be fully deleted from the system.

MySQL

The amount of disk space MySQL consumes is directly related to the amount of data being stored in the database. If adding more disk space to the Appian Cloud server is not feasible, consider moving the data from the Appian Cloud server to an external database server.

Logs

If logs are consuming a large amount of disk space, this can be indicative of a recurring issue in your Appian environment that is repeatedly printing errors in the logs. These errors should be addressed as soon as possible to avoid further increases in disk space. 

Once the error is resolved, Appian Technical Support can compress log files so that they consume less space. These logs will still be available to download via <APPIAN_URL>/suite/logs as a .gz file.

If you have requested additional loggers to be enabled or existing loggers to be modified, it is important that you let Appian Technical Support know as soon as these loggers can be disabled. Leaving them on can increase the size and disk utilization of the logs and is not recommended for long periods of time. Note that all loggers will be reset to default values upon a site restart.

Purchasing additional disk usage

If you have followed all the steps in this article and disk usage remains high, please work with your Account Executive to purchase additional storage space. Additional storage is hot-deployable, meaning a site restart is not required to add additional disk space.

Note: Once additional disk space has been added to the server, it cannot be removed.

Affected Versions

This article applies to all versions of Appian. 

Last Reviewed: August 2021

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