The ipc numActiveHandler is documented here <https://hbase.apache.org/1.2/book.html> as:
The number of RPC handlers actively servicing requests I am looking for a more detailed explanation about the significance of that metric. I am trying to debug a scenario, where numActiveHandler is stuck at 32. I think 32 is a pre-configured max.[image: numActiveHandler stuck at max timing] <https://i.stack.imgur.com/Lnqo7.png> During that time, the same regionserver is stuck at 100% cpu consumption. For one of the regions on that reqionserver, the rate of processed read requests look like they are reduced by some pressure, a bottleneck somewhere. The read request latencies also increase about 5X. What could lead to this behavior ? My intuition is that there has been too many connections to that region server during that time and the bottleneck is before a read request could be processed. Any suggestions where to look next ? Update The numActiveHandler metric was added here <https://jira.apache.org/jira/plugins/servlet/mobile#issue/HBASE-10212>. The description in that ticket says: We found [numActiveHandler] is a good metric to measure how busy of a server. If this number is too high (compared to the total number of handlers), the server has risks in getting call queue full. Update2 During the same period, another metric hbase.regionserver.ipc.numCallsInGeneralQueuebehaves abnormally too. Attaching a plot showing them together. [image: enter image description here] <https://i.stack.imgur.com/dDuBd.png> Thanks Hakan
