Re: [Engine-devel] Updates in VdsUpdateRuntimeInfo

----- 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