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Robert Stupp commented on CASSANDRA-8341: ----------------------------------------- Yea - that {{TheadMXBean.getCurrentThread...()}} hopefully directly accesses the CPU registers for that. Not sure about that since the implementations are very OS specific (in {{hotspot/os/*/vm/os_*.cpp}} in OpenJDK source) and as such also specific to the CPU model. If all the implementations access the CPU registers for that, it definitely better than {{System.nanoTime()}, which is consistent over CPU codes (-> NUMA - expensive). Note: I don't want to make this ticket more complicated as necessary - just want to mention that metrics have their own overhead and should be used with care in sensitive areas like thread scheduling. > Expose time spent in each thread pool > ------------------------------------- > > Key: CASSANDRA-8341 > URL: https://issues.apache.org/jira/browse/CASSANDRA-8341 > Project: Cassandra > Issue Type: New Feature > Components: Core > Reporter: Chris Lohfink > Priority: Minor > Labels: metrics > Attachments: 8341.patch, 8341v2.txt > > > Can increment a counter with time spent in each queue. This can provide > context on how much time is spent percentage wise in each stage. > Additionally can be used with littles law in future if ever want to try to > tune the size of the pools. -- This message was sent by Atlassian JIRA (v6.3.4#6332)