Test methodology: I'm running a single standalone HBase on local filesystem. I rm the dir from /tmp, then start the master, create a table with a single column family, then restart the master with "time bin/hbase master". I then insert 1M rows from YCSB, and hit ^C on the master. I ran the test with the preput hook left in, and with it commented out, and flipped between the two setups twice to make sure I could reproduce. I'm reporting the user and system CPU here, since the wall clock time is sensitive to how quickly I ran the commands.
with hook commented out:
with cp hook left in:
I also re-ran the original oprofile analysis and "doMiniBatchPut" basically dropped off the CPU profile results once I made this change.
I verified for sure that I have no coprocessors installed by adding a println in RegionCoprocessorHost - it didn't print out.