[ https://issues.apache.org/jira/browse/ACCUMULO-3508?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Eric Newton resolved ACCUMULO-3508. ----------------------------------- Resolution: Fixed Patch applied on [~phrocker]'s behalf. > Zoocache utilizes course grained locking causing unnecessary synchronization > in many tserver ops > ------------------------------------------------------------------------------------------------ > > Key: ACCUMULO-3508 > URL: https://issues.apache.org/jira/browse/ACCUMULO-3508 > Project: Accumulo > Issue Type: Sub-task > Components: fate > Affects Versions: 1.6.0 > Reporter: marco polo > Assignee: marco polo > Priority: Minor > Fix For: 1.8.0 > > Time Spent: 10m > Remaining Estimate: 0h > > Through jstacking I have observed busy tablet server threads waiting for the > Zoocache to be updated or even read. Profiling via yourkit indicates > potential deadlocks when threads wait for a long period of time ( in my case > my waits were 10+s ) when many scans were running against my instance. > My patch, which is forthcoming, removes synchronization and utilizes a > reentrant read/write lock (RERWL) to synchronize the maps. My initial design > utilized concurrent hash maps, but the design of existence becomes simpler > and changes fewer by using the RERWL. -- This message was sent by Atlassian JIRA (v6.3.4#6332)