The Finalizer thread occasionally consumes 100% of a single core

[CokkkeZ]

Describe the bug

The ConnectionWrapper.finalize occasionally causes one CPU core to spike to 100% for a few minutes.

Expected Behavior

Expect ConnectionWrapper.finalize won't cause any cpu spikes

What plugins are used? What other connection properties were set?

failover2,efm2,auroraConnectionTracker

Current Behavior

Here is the stacktrace of the Finalizer thread：

"Finalizer" #3 daemon prio=8 os_prio=0 cpu=7887916.39ms elapsed=207053.18s tid=0x00007f92c9442800 nid=0xd7a runnable [0x00007f9274155000] java.lang.Thread.State: RUNNABLE at software.amazon.jdbc.plugin.OpenedConnectionTracker.lambda$null$10(OpenedConnectionTracker.java:207) at software.amazon.jdbc.plugin.OpenedConnectionTracker$$Lambda$1325/0x0000000800b50c40.test(Unknown Source) at java.util.concurrent.ConcurrentLinkedQueue.bulkRemove(java.base@11.0.16/ConcurrentLinkedQueue.java:1004) at java.util.concurrent.ConcurrentLinkedQueue.removeIf(java.base@11.0.16/ConcurrentLinkedQueue.java:964) at software.amazon.jdbc.plugin.OpenedConnectionTracker.lambda$pruneNullConnections$11(OpenedConnectionTracker.java:202) at software.amazon.jdbc.plugin.OpenedConnectionTracker$$Lambda$1324/0x0000000800b50840.accept(Unknown Source) at java.util.concurrent.ConcurrentHashMap.forEach(java.base@11.0.16/ConcurrentHashMap.java:1603) at software.amazon.jdbc.plugin.OpenedConnectionTracker.pruneNullConnections(OpenedConnectionTracker.java:201) at software.amazon.jdbc.plugin.AuroraConnectionTrackerPlugin.releaseResources(AuroraConnectionTrackerPlugin.java:176) at software.amazon.jdbc.ConnectionPluginManager.lambda$releaseResources$15(ConnectionPluginManager.java:588) at software.amazon.jdbc.ConnectionPluginManager$$Lambda$1323/0x0000000800b50440.accept(Unknown Source) at java.util.ArrayList.forEach(java.base@11.0.16/ArrayList.java:1541) at software.amazon.jdbc.ConnectionPluginManager.releaseResources(ConnectionPluginManager.java:585) at software.amazon.jdbc.wrapper.ConnectionWrapper.releaseResources(ConnectionWrapper.java:174) at software.amazon.jdbc.wrapper.ConnectionWrapper.finalize(ConnectionWrapper.java:957) at java.lang.System$2.invokeFinalize(java.base@11.0.16/System.java:2125) at java.lang.ref.Finalizer.runFinalizer(java.base@11.0.16/Finalizer.java:87) at java.lang.ref.Finalizer$FinalizerThread.run(java.base@11.0.16/Finalizer.java:171)

Reproduction Steps

Not clear

Possible Solution

No response

Additional Information/Context

No response

The AWS Advanced JDBC Driver version used

2.5.4

JDK version used

11

Operating System and version

linux 4.14.256

[sergiyvamz]

Hi @CokkkeZ

We made some improvements to tracked connection clean-up logic. It should help to unload an application thread. Could you please try the latest snapshot build to see if this resolves your issue?

[karenc-bq]

Hi @CokkkeZ , the fix is now available in version 2.6.0. We will be closing this ticket now, please let us know if you run into this or any other issues again. Thank you for raising this issue to us.