Thank you for your reply. I will reconsider my architecture and make the same tests with dedicated resources for each database. My goal is to get an average response time during the execution of particular repetitious requests scenarios. Then I will compare obtained results with my two others architectures which are MySQL cluster (NDB engine) and a Circular replication again with MySQL 5.1.
I noticed significative difference with the two other architectures, that's why I thought I made a mistake in the configuration, or I forgot something important. I'am conscious it will be difficult to draw precise conclusions with such heterogeneous architectures, but I need to get an order of idea to be able to select the best suitable architecture for my application. Thank you for your advice. gaël On Thu, Jun 26, 2008 at 11:10 PM, Emmanuel Cecchet <[EMAIL PROTECTED]> wrote: > gaël charrière wrote: > >> Actually the 2 backends are collocated on the same machine with the >> controller precisely because I'm in testing mode. My final goal is to >> compare the performance of different cluster architecture without being >> impacted by some external noise. >> > My experience shows that such configuration has such a high variance in > performance measurements that it makes it impractical to draw any useful > conclusion. > >> With my sequoia architecture, as I explained, I still noticed very slow >> responses, even if all my nodes are located on the same machine. So I don't >> think it will be better through the network... That's why I would like to >> improve it now before involving myself into a much more complex >> architecture. >> > There is very little information going through the network and the main > cost is serialization of data, not the cost of sending on the wires. So > having dedicated resources for each database rather than sharing resources > (cpu, mem, and especially io) will make a difference. Note that each > database commit requires a flush to disk so if you don't use different disks > for each database, performance will be horrendous. > > What other architectures are you considering to compare Sequoia with? > > Don't hesitate to let me know if your results are different from my > experience. > Emmanuel > > > On Thu, Jun 26, 2008 at 5:41 PM, Emmanuel Cecchet <[EMAIL PROTECTED]<mailto: >> [EMAIL PROTECTED]>> wrote: >> >> Hi Gael, >> >> 1 controller, 2 backends (MySQL 5.1) and 1 recovery (MySQL 5.1) >> >> You don't need group communication with a single controller. The >> performance might be altered by the way the group communication >> handles loopback delivery. >> >> I can start the controller and enable the backends. I can also >> access the cluster and perform some queries. Items appeared on >> the backends. Everything seems to work fine. >> >> However, I noticed bad performances, especially for insertion >> queries. A simple insertion in a virtual database takes about >> 0.500 s. >> >> Does anybody already notice that kind of measures? I'm looking >> for a way to optimize these queries. I tried different appia >> configurations, but I wasn't able to find one which correspond >> to what I expected. >> >> >From your config file it looks like the 2 backends are collocated >> on the same machine with the controller. This probably defeats the >> purpose of both performance scalability and availability, so I >> don't know how relevant performance measurements on such >> configuration could be. We usually use such config for testing >> only (mostly functional) but not for performance. >> >> Don't hesitate to keep us posted with your findings, >> Emmanuel >> >> > -- > Emmanuel Cecchet > FTO @ Frog Thinker Open Source Development & Consulting > -- > Web: http://www.frogthinker.org > email: [EMAIL PROTECTED] > Skype: emmanuel_cecchet > > _______________________________________________ > Sequoia mailing list > [email protected] > https://forge.continuent.org/mailman/listinfo/sequoia >
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