Re: [Engine-devel] Updates in VdsUpdateRuntimeInfo

Hi all, Current status of VdsUpdateRuntimeInfo (please note - patch is not yet committed). Initial UpdateRuntimeInfo performance wasted roughly 57% of CPU time on DB activity. Of that, about 25% of CPU time wasted on update behavior. After modification (moving updates to batch update) UpdateRuntimeInfo performance wasted roughly 40% of CPU time on DB activity. And only 12% of that was wasted on update behavior.

My next task is to try and optimize the rest of overall database performance. ----- Original Message ----- From: "Liran Zelkha" <liran.zelkha(a)gmail.com&gt; To: "Barak Azulay" <bazulay(a)redhat.com&gt; Cc: "engine-devel" <engine-devel(a)ovirt.org&gt; Sent: Wednesday, June 12, 2013 12:35:03 PM Subject: Re: [Engine-devel] Updates in VdsUpdateRuntimeInfo Hi guys, I'm working hard on this. I'll send summary mail and findings later today. On Jun 12, 2013, at 10:45 AM, Barak Azulay wrote: > > > ----- Original Message ----- >> From: "Itamar Heim" <iheim(a)redhat.com&gt; >> To: "Barak Azulay" <bazulay(a)redhat.com&gt; >> Cc: "engine-devel" <engine-devel(a)ovirt.org&gt; >> Sent: Wednesday, June 12, 2013 10:09:09 AM >> Subject: Re: [Engine-devel] Updates in VdsUpdateRuntimeInfo >> >> On 06/12/2013 09:41 AM, Barak Azulay wrote: >>> >>> >>> ----- Original Message ----- >>>> From: "Itamar Heim" <iheim(a)redhat.com&gt; >>>> To: "Liran Zelkha" <lzelkha(a)redhat.com&gt; >>>> Cc: "engine-devel" <engine-devel(a)ovirt.org&gt; >>>> Sent: Tuesday, June 11, 2013 4:00:21 PM >>>> Subject: Re: [Engine-devel] Updates in VdsUpdateRuntimeInfo >>>> >>>> On 06/11/2013 03:26 PM, Liran Zelkha wrote: >>>>> Hi all, >>>>> >>>>> I'm checking performance for VdsUpdateRunTimeInfo. >>>>> Naturally, much of the performance surrounds database activity >>>>> (getVmsRunningOnVds queries, updateDeviceRuntimeInfo, updateVmDynamic) >>>>> >>>>> Few questions: >>>>> 1. I have implemented batch updates for procedure >>>>> UpdateVmDeviceRuntimeInfo >>>>> for improved performance. >>>>> 2. Seems like the only parameters UpdateVmDeviceRuntimeInfo is getting >>>>> are >>>>> vm_id,vm_device_id,address and alias. Are those rapidly changing, or will >>>>> it be beneficial to implement caching on those updates (to ensure >>>>> not-required updates do not travel to the database). >>>> >>>> slowly changing, but how will you cover all flows changing these devices >>>> to invalidate the cache (iiuc, this table is modified by engine when >>>> adding devices to a VM as well?) >>> >>> >>> I don't think that in the device run time info we need to invalidate once >>> we add a device. >>> This is a specific case where we actually get the information from the VDSM >>> (addresses are received from libvirt) >>> The commands IIRC are first send to VDSM and than update the runtime info >>> only on changed info (we can also hash it), >>> It may put the placeholder in the DB first but it still relies on the data >>> received from VDSM. >> >> if this table is only updated from vdsm to save it, i agree. >> but isn't the engine also manipulating it? >> wasn't there a request to be able to maybe edit the addresses some day? > > Even if there was such a request, we still update when we receive the info from libvirt. > > Anyway there are obviously a few improvements to be done before caching. > - update only when info received from VDSM change (need to verify it is the practice here) > - do batch update for the new updated data received. > - do the hashing (of vm device runtime info) on VDSM for the data , and update only when hash changes > - caching ... > > Barak > > > >> >> _______________________________________________ >> Engine-devel mailing list >> Engine-devel(a)ovirt.org >> http://lists.ovirt.org/mailman/listinfo/engine-devel >> >> >> > _______________________________________________ > Engine-devel mailing list > Engine-devel(a)ovirt.org > http://lists.ovirt.org/mailman/listinfo/engine-devel _______________________________________________ Engine-devel mailing list Engine-devel(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel _______________________________________________ Engine-devel mailing list Engine-devel(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel