On Thu, Feb 07, 2013 at 04:41:31PM +0100, Erik Brakkee wrote: > Hi, > > > We have been benchmarking a java server application (java 6 update 29) > that requires a mysql database. The scenario is quite simple. We open a > web page which displays a lot of search results. To get the content of the > page one big query is done with many smaller queries to retrieve the data. > The test from the java side is single threaded. > > We have used the following deployment scenarios: > 1. JBoss in VM, MySql in separate VM > 2. JBoss in VM, MySQL native > 3. JBoss native, MySQL in vm. > 4. JBoss native and MySQL native on the same physical machine > 5. JBoss and MySQL virtualized on the same VM. > > What we see is that the performance (time to execute) is practically the > same for all scenarios (approx. 30 seconds), except for scenario 4 that > takes approx. 21 seconds. This difference is quite large and contrasts > many other test on the internet and other benchmarks we did previously. > > We have tried pinning the VMs, turning hyperthreading off, varying the CPU > model (including host-passthrough), but this did not have any significant > impact. > > The hardware on which we are running is a dual socket E5-2650 machine with > 64 GB memory. The server is a Dell poweredge R720 server with SAS disks, > RAID controller with battery backup (writeback cache). Transparent huge > pages is turned on. > > We are at a loss to explain the differences in the test. In particular, we > would have expected the least performance when both were running > virtualized and we would have expected a better performance when JBoss and > MySQL were running virtualized in the same VM as compared to JBoss and > MySQL both running in different virtual machines. It looks like we are > dealing with multiple issues here and not just one. > > Right now we have a 30% penalty for running virtualized which is too much > for us; 10% would be allright. What would you suggest to do to > troubleshoot this further? > What is you kernel/qemu versions and command line you are using to start a VM? -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
