keith-turner opened a new issue, #2700: URL: https://github.com/apache/accumulo/issues/2700
**Describe the bug** While testing the scan server feature #2665 I was running a query client I wrote that was doing 512 concurrent small random lookups. These lookups were going to scan servers which were not behaving as expected. I ran java flight recorder and saw contention on 3 locks. Two locks were scan servers specific and one was related to the sha512 computation. I also saw that outside of lock contention, the sha512 computation was the top method for profiling. Even though I saw these issues in the scan server, I suspect the tserver would have the same problem because it uses the same code. **To Reproduce** Steps to reproduce the behavior (or a link to an example repository that reproduces the problem): 1. Go to '...' 2. Click on '....' 3. Scroll down to '....' 4. See error **Expected behavior** Would be good to avoid the lock contention and research the performance of the sha512 computation relative to small scan. **Screenshots** The following is the JFR data that shows lock contention  The following is the JFR data that shows hot methods.  The JFR data came from profiling the scan server for 2 minutes while my test code was running doing 512 concurrent small lookups. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
