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UCP and WLS Spawn Hundreds Of "oracle.ucp.util.UCPTimerManagerImpl.scheduleHelper" Timer Threads (Doc ID 2467453.1)

Last updated on AUGUST 02, 2019

Applies to:

Universal Connection Pool - Version 12.1.0.2.0 and later
Information in this document applies to any platform.

Symptoms

The method createStatement() creates new threads. Hundreds of these threads remain live in WebLogic Server 12.2.1.2.0.

A thread dump looks like this:

java.lang.Exception: new java.util.Timer name: Timer-625 daemon: true
     at java.util.Timer.<init>(Timer.java:94)
     at java.util.Timer.<init>(Timer.java:62)
     at oracle.ucp.util.UCPTimerManagerImpl.scheduleHelper(UCPTimerManagerImpl.java:46)
     at oracle.ucp.util.UCPTimerManagerImpl.scheduleAtFixedRate(UCPTimerManagerImpl.java:98)
     at oracle.ucp.common.Clock.compute(Clock.java:124)
     at oracle.ucp.common.Clock.clock(Clock.java:83)
     at oracle.ucp.common.UniversalPooledConnectionImpl.heartbeat(UniversalPooledConnectionImpl.java:208)
     at oracle.ucp.common.FailoverableUniversalPooledConnectionBase.heartbeat(FailoverableUniversalPooledConnectionBase.java:14)
     at oracle.ucp.jdbc.proxy.JDBCConnectionProxyFactory.invoke(JDBCConnectionProxyFactory.java:221)
     at oracle.ucp.jdbc.proxy.ConnectionProxyFactory.invoke(ConnectionProxyFactory.java:50)
    ...

Changes

 

Cause

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In this Document
Symptoms
Changes
Cause
Solution
References


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