Coherence Nodes Using the G1 Garbage Collector Prior to Oracle Java HotSpot JDK 7U4 Could Encounter Memory Problems (Doc ID 1489410.1)

Last updated on NOVEMBER 17, 2023

Applies to:

Symptoms

Coherence nodes using new G1 GC algorithm that is introduced in the Java 7 could see this problem.

For example:

• Created distributed cache running on 4 storage nodes.
• Loading data 300,000 records from a database using JPACacheStore.
• Using JConsole to monitor memory usage of each nodes. After the initial load is finished, all nodes use around 500MB
• Using a script to update data by modifying value in the cache with around 300 requests/sec over a 60 minute period.
• Memory of each node increases while the script is running.
• After 60 minutes, JConsole shows that each node is using memory around 1GB.
• Leaving the cluster for one day with no active workload, then checking with JConsole shows the memory of each nodes is still around 1 GB.

The question is why memory usage does not reduce to around 500 MB after script finish when cache size still 300,000 objects?

Changes

Cause

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