Lars Hofhansl created HBASE-15453: ------------------------------------- Summary: Considering reverting HBASE-10015 - reinstance synchronized in StoreScanner Key: HBASE-15453 URL: https://issues.apache.org/jira/browse/HBASE-15453 Project: HBase Issue Type: Bug Reporter: Lars Hofhansl
In HBASE-10015 back then I found that intrinsic locks (synchronized) in StoreScanner are slower that explicit locks. I was surprised by this. To make sure I added a simple perf test and many folks ran it on their machines. All found that explicit locks were faster. Now... I just ran that test again. On the latest JDK8 I find that now the intrinsic locks are significantly faster: Explicit locks: 10 runs mean:2223.6 sigma:72.29412147609237 Intrinsic locks: 10 runs mean:1865.3 sigma:32.63755505548784 I confirmed the same with timing some Phoenix scans. We can save a bunch of time by changing this back Arrghhh... So maybe it's time to revert this now...? (Note that in trunk due to [~ram_krish]'s work, we do not lock in StoreScanner anymore) I'll attach the perf test and a patch that changes lock to synchronized, if some folks could run this on 0.98, that'd be great. -- This message was sent by Atlassian JIRA (v6.3.4#6332)