WebLogic Server (WLS) Support Pattern: Investigating JDBC Issues (Doc ID 1280894.1)

Last updated on JANUARY 06, 2023

Applies to:

Purpose

Problem Description

We conventionally refer to as JDBC issues all problems involving database-related application code, Weblogic Datasource/Pooling, drivers, DBMS and network.

Problem Troubleshooting

This pattern provides troubleshooting tips and is aimed at educating on how to narrow down where JDBC problems lie. Understanding the issue is key to understand how to debug and resolve it. The following topics will be covered in this document.

• JDBC Datasource/Pooling Issues
  Weblogic Server obtains JDBC connections from a Datasource. Each configured datasource contains a pool of database connections. Configuring it correctly ensures performance and stability of applications and the server itself. Some misconfiguration could lead to many problems such as, but not limited to:
  
  • weblogic.jdbc.extensions.PoolLimitSQLException
  • weblogic.common.resourcepool.ResourceLimitException: No resources currently available in pool
  • Leaks caused by incorrect management of connections in application code
  • Poor performance of the DBMS or the network, so that connection requests to the underlying database lead to very long startup or communication times for the WebLogic Server
  • Errors or java exceptions during JDBC connectivity setup
  • Connection refresh/reconnect problems after the database was down
• Database Issues
  JDBC connections represent database sessions in the database. Therefore WebLogic Server JDBC configuration can lead to problems in the database itself too. In addition, the network connection between WebLogic Server and the database system can lead to issues such as, but not limited to:
  
  • ORA-01000: Too Many Open Cursorsin the Oracle database
  • Poor performance if getVendorConnection()is used to receive the underlying physical connection and the property RemoveInfectedConnectionsis not set to true as it should to essentially disable the pooling of connections.
• WebLogic Server Issues
  JDBC connectivity issues could even lead to severe problems with WebLogic Server itself:
  
  • The server could crash due to the use of native JDBC driver libraries.
  • The server or an application could hang in JDBC driver methods or functions.
  • A memory leak of JDBC objects could lead to an OutOfMemoryErroror a concerning growing size of the java process under which the server is running.
• General Topics
  This section provides tuning, debugging and troubleshooting information for generic JDBC connection pool topics:
  
  • Troubleshooting JDBC problems, debugging or tracing JDBC
  • How to tune JDBC datasource/pooling targeted to for production environments
  • WebLogic Server and Oracle RAC/TAF

Troubleshooting Steps

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