What is the recommended Heap Size value for JVM when Thruput is increased?

[ahmedn_splunk]

Thruput has increased to around 385 kbps due to the increase in number of inputs to be more than 150. Need to know what is the recommended Heap Size to set? and How to set it?

[ahmedn_splunk · Accepted solution]

Hi
As per Splunk Engineering, the recommended Heap Size for such Thruput is 2048.

To set the heap size Go to:

1)$SPLUNK_HOME$/etc/apps/Splunk_TA_jmx/bin/java_const.py

2) On line number 43 change the code
from :

JAVA_COMMON_ARGS = [JAVA_EXECUTABLE ,"-classpath", CLASSPATH, "-Dconfighome=" + CONFIG_HOME,
"-Dsplunkhome="+ SPLUNK_HOME]

to

JAVA_COMMON_ARGS = [JAVA_EXECUTABLE, "-Xmx2048m" ,"-classpath", CLASSPATH, "-Dconfighome=" + CONFIG_HOME,
"-Dsplunkhome="+ SPLUNK_HOME]

3) Navigate to $SPLUNK_HOME$/bin and fire command : ./splunk restart

You can also use the below SPL query to get the current Average Thruput:

index=_internal source="*/splunk/var/log/splunk/metrics.log" group=per_sourcetype_thruput series=jmx | stats avg(kbps)

Proper time range needs to be specified while executing the query