The pool keeps idle connections ready. The system creates additional connections when all existing connections are busy until they reach the connection pool size value. When a requestor arrives and the maximum number of connections are busy, the requestor waits until reaching the connection timeout value. Connections that remain out of the pool for the duration of the leak detection value log a connection leak error. Database connections remain open until Pega Platform stops running.

• Connection pools:
  • Standard user – 20 connections
  • Administrator – 5 connections (if an administrator is configured on the external database)
  • Read-only user – 5 connections (if a read-only user is configured on the external database)
• Connection timeout: 300 seconds

  The timeout value applies to all connection pools on this node.

• Leak detection threshold: 0 milliseconds (off)

1. In the navigation pane of Dev Studio, click App.
2. In the header of Dev Studio, click CreateSysAdminDynamic System Settings.
3. In the dynamic system settings Short Description field, enter a summary of the new setting.
4. In the Owning Ruleset field, enter Pega-Engine.
5. In the Setting Purpose field, enter the key string for the database connection size and timeout value:
   1. Create dynamic system settings for each database user connection pool by entering the corresponding key strings.
      Use the following key strings:

      • Standard user: prconfig/database/databases/<database name>/connectionPoolSize/default
      • Administrator: prconfig/database/databases/<database name>/connectionPoolSize/admin/default
      • Read-only user: prconfig/database/databases/<database name>/connectionPoolSize/readonly/default
   2. Create a dynamic system setting for the connection timeout by entering the following key string:

      prconfig/database/databases/<database name>/MaxConnectionTime/default

   3. Create a dynamic system setting for the leak detection threshold by entering the following key string:

      prconfig/database/databases/<database name>/leakDetectionThreshold/default

6. Click Create.
7. On the Settings tab, in the Value field, enter the following values:
   • For the connection pool size dynamic system settings, enter the number of connection pools that can be active for a user type.
   • For the connection timeout value dynamic system setting, enter the number of seconds that an idle requestor remains open.
   • For the leak detection threshold dynamic system setting, enter the number of milliseconds a connection can remain out of the pool before logging a leak error message. The value must belong to the following set of integers:
     • 0 (no leak detection)
     • Greater than or equal to 2000 (2 seconds)
8. Click Save.
9. To modify other connection pools or the timeout threshold for other users, repeat step 1 through 8.
10. For on-premises clients, restart the node:
    1. For Pega Cloud Services clients, log in to your My Support Portal account.
    2. On the Support Request tab, file a cloud service request for applicable node restarts in your environment by clicking Create.
    Caution: Do not set connection limits too low to avoid deadlocks and poor response time. You can set a threshold for PEGA0026 alerts to detect long waits.