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I'm using apache cassandra-3.0.6 ,4 node cluster, RF=3, CONSISTENCY is '1', Heap 16GB.

Im getting info message in system.log as

INFO  [SharedPool-Worker-1] 2017-03-14 20:47:14,929 NoSpamLogger.java:91 - Maximum memory usage reached (536870912 bytes), cannot allocate chunk of 1048576 bytes

don't know exactly which memory it mean and I have tried by increasing the file_cache_size_in_mb to 1024 from 512 in Cassandra.yaml file But again it immediatly filled the remaining 512MB increased and stoping the application recording by showing the same info message as

INFO  [SharedPool-Worker-5] 2017-03-16 06:01:27,034 NoSpamLogger.java:91 - Maximum memory usage reached (1073741824 bytes), cannot allocate chunk of 1048576 bytes

please suggest if anyone has faced the same issue..Thanks!!

Bhargav

Erick Ramirez
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Bhargav Naidu M
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2 Answers2

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As far as I can tell with Cassandra 3.11, no matter how large you set file_cache_size_in_mb, you will still get this message. The cache fills up, and writes this useless message. It happens in my case whether I set it to 2GB or 20GB. This may be a bug in the cache eviction strategy, but I can't tell.

Scott Carey
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The log message indicates that the node's off-heap cache is full because the node is busy servicing reads.

The 536870912 bytes in the log message is equivalent to 512 MB which is the default file_cache_size_in_mb.

It is fine to see the occasional occurrences of the message in the logs which is why it is logged at INFO level but if it gets logged repeatedly, it is an indicator that the node is getting overloaded and you should consider increasing the capacity of your cluster by adding more nodes.

For more info, see my post on DBA Stack Exchange -- What does "Maximum memory usage reached" mean in the Cassandra logs?. Cheers!

Erick Ramirez
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