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All Connections In The Universal Connection Pool Are In Use (Doc ID 1592840.1)

Last updated on OCTOBER 20, 2022

Applies to:

Oracle REST Data Services - Version 3.0 and later
Oracle Database Cloud Service - Version N/A and later
Information in this document applies to any platform.


Using Oracle REST Data Services - ORDS (aka Apex Listener) when attempting to connect to APEX applications the following error occurs:

HTTP-500 error

In ords.log the following message appears:

Feb 06, 2019 9:43:46 AM
SEVERE: *** Error: Could not obtain a database connection because all connections in the pool: |apex|| were in use. Borrowed Connections: nn Available Connections: 0 Maximum Connections: nn***
Feb 06, 2019 9:43:46 AM
SEVERE: java.sql.SQLException: Exception occurred while getting connection: oracle.ucp.UniversalConnectionPoolException: All connections in the Universal Connection Pool are in use
ServiceUnavailableException [statusCode=503, reasons=[]]

The ORDS configuration shows:

<entry key="jdbc.MaxConnectionReuseCount">1000</entry>
<entry key="jdbc.MaxLimit">10</entry>
<entry key="jdbc.MaxStatementsLimit">10</entry>

The issue can be reproduced at will with the following steps:
1. Configure ORDS  to access APEX
2. Call the the APEX URL in a browser


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