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Posted: June 9, 2017
Last activity: June 11, 2017
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What determines the heap size for the cassandra process in Pega 7.2.2?
I have noticed that since updating to Pega 7.2.2 from 7.2, that cassandra, which now has it's own java process, has a varying heap size on different servers.
For example...on one server with 32GB memory, it is 8027M, on another server with 64GB memory, it is 8192M; and one another server with 16GB memory, it is 3978M.
What determines the heap size for the cassandra java process?
***Updated by moderator: Lochan to add Categories***
Hi this is from an internal post which should answer your question:
Cassandra heap can be configured via the following prconfig.xml settings. Note that you need to set both properties if you want to override the Cassandra defaults.
<env name="dnode/cassandra_heap_new_size" value="400M" />
<env name="dnode/cassandra_max_heap_size" value="2G" />
By default Cassandra uses the following rules to calculate what the heap should be
# set max heap size based on the following
# max(min(1/2 ram, 1024MB), min(1/4 ram, 8GB))
# calculate 1/2 ram and cap to 1024MB
# calculate 1/4 ram and cap to 8192MB
# pick the max
Heap new size should be 100MB*number of cores.