FATAL: sorry, too many clients already - Workload Automation DE (dSeries)

Products

• ESP dSeries Workload Automation

Issue/Introduction

After upgrading to dSeries 25.1, the server repeatedly encounters connection errors to the PostgreSQL database and restarts the server process. The following error is observed in the desktop client or logs:

• "There are temporary network problems causing interruptions in the database connection. The server is attempting to reconnect."
• FATAL: sorry, too many clients already (SQL state 53300)

Environment

Product: Workload Automation DE (dSeries)
Version: ALL
Database: PostgreSQL

Cause

The issue is caused by the database connection pool reaching its limit. In dSeries 25.1, the database.maxconnections.in.pool parameter defaults to 100 if not explicitly defined in the db.properties file. If the PostgreSQL max_connections setting is also set to 100, the server quickly exhausts available connections, leaving no room for administrative tools, reporting, or desktop client connections.

Resolution

To resolve this issue, increase the maximum number of connections allowed in the dSeries connection pool and ensure the database itself is configured to support the higher limit.

• Step 1: Update dSeries Configuration
  Use the setdbparm utility from the command line of your dSeries server to increase the pool size.
  
  
  1. Navigate to the dSeries installation directory.
     
     
  2. Run the following command:
     setdbparm database.maxconnections.in.pool


  3. Enter the new value when prompted (e.g., 250):
     Example:
     Enter new max connections in pool: 250


  4. Verify and confirm the new value.
     
     
  5. Restart the dSeries Server for the changes to take effect.
     
     
• Step 2: Update Database Configuration
  Coordinate with your Database Administrator (DBA) to ensure the PostgreSQL max_connections parameter is set higher than the dSeries pool size to accommodate additional overhead (e.g., administrative tools, HA nodes).
  
  
• Step 3: Verification
  Review the db.properties file. You should see the following entry:
  # Added by Manager
database.maxconnections.in.pool=250

Additional Information

For more details on the setdbparm utility, refer to the documentation: Configuring the Database Connection