Yeah our content is on NFS mounts backed by regular non-SSD disks, so IO is pretty crappy. But its cheap and perfect for serving yum content.
My recommendation would be having pulp-manage-db spit out a message before each big migration that says “this next migration is a big deal!” that would be a nice fyi. And perhaps a URL to see migration details. This doesn’t prep people ahead of time to schedule downtime, but at least keeps them from thinking something is wrong. From: pulp-list-boun...@redhat.com [mailto:pulp-list-boun...@redhat.com] On Behalf Of Michael Hrivnak Sent: Friday, July 01, 2016 4:19 PM To: Eric Helms <ehe...@redhat.com> Cc: pulp-list <pulp-list@redhat.com> Subject: Re: [Pulp-list] Long upgrade times from 2.6 -> 2.8 I expect the performance will be highly dependent on disk access speed. Latency is far more important than throughput for those two migrations. Deployments using NFS for example may benefit from finding ways to reduce latency during the migration; there may be mount options that can be adjusted only while the migration runs, or perhaps the code itself can be run on a machine closer to the data than where pulp usually runs. Michael On Fri, Jul 1, 2016 at 11:53 AM, Eric Helms <ehe...@redhat.com<mailto:ehe...@redhat.com>> wrote: My main worry or first check I wanted to put to rest was that it was an actual issue. Given that everything is sane, I think warning users that upgrades will scale with the amount of content and giving them some rough estimates based on other users data is the best option. That way they can at least prepare themselves with knowledge for planning their upgrade outages. Thanks for looking into this so quickly, Eric On Fri, Jul 1, 2016 at 11:50 AM, Brian Bouterse <bbout...@redhat.com<mailto:bbout...@redhat.com>> wrote: With 2.8 specifically there is a *lot* of work done by the migrations and the runtime should scale with the content size. In other words I don't think it's doing useless work, there is just a lot of it. I just did a quick audit of the two major offending migrations and they are implemented sanely so I don't think there is a quick fix to improve the runtime. I believe to get a shorter runtime we would have to parallelize the migrations. Regarding things going wrong, we do assume that migrations should be re-entrant meaning that if for some reason something strange occurs it should always be safe to run pulp-manage-db and it will pick up where it left off. Just a behavioral FYI. These migration with 2.8 should not be norm, so I don't expect this to be very common in the future until maybe a major release (3.0). Given all ^, what do you think we should do? -Brian On 07/01/2016 11:23 AM, Eric Helms wrote: I think there are a couple of considerations. 1) The first issue is that a 6-18 hour upgrade window is not something users expect and we've not been warning them of such so they can plan an outage accordingly. Lengthy upgrades also have that tendency to make users feel something is wrong or increase the risk that something can go wrong in between. 2) The fundamental question of - is this a bug or does this make perfect sense and how it has to work? 3) Applying the upgrade on an existing 2.6 if it changed nothing of the environment could work, the tough part is having to distribute that backwards. Pulp would have to distribute it back to 2.6, and Katello would have to push out patches to our 2.4 release channel. Eric On Fri, Jul 1, 2016 at 11:14 AM, Brian Bouterse <bbout...@redhat.com<mailto:bbout...@redhat.com> <mailto:bbout...@redhat.com<mailto:bbout...@redhat.com>>> wrote: I'm trying to understand if the pain point is related to downtime or total runtime. For instance, what if these migration could be run as a pre-migration step, ahead of time while Pulp was still online? The upgrade would still take just as long but you could use your (in this case) 2.6 install normally while the migrations are applying. Once they are done then the actual upgrade of the codebase could be very short. -Brian On 07/01/2016 09:20 AM, Eric Helms wrote: On Fri, Jul 1, 2016 at 8:52 AM, Ashby, Jason (IMS) <ash...@imsweb.com<mailto:ash...@imsweb.com> <mailto:ash...@imsweb.com<mailto:ash...@imsweb.com>> <mailto:ash...@imsweb.com<mailto:ash...@imsweb.com> <mailto:ash...@imsweb.com<mailto:ash...@imsweb.com>>>> wrote: FWIW I just upgraded from 2.7 -> 2.8 and it was approx. 1-2 hr upgrade to get through the migrations in pulp-manage-db.____ __ __ 290 GB /var/lib/pulp____ 16 GB MongoDB____ __ __ *From:*pulp-list-boun...@redhat.com<mailto:pulp-list-boun...@redhat.com> <mailto:pulp-list-boun...@redhat.com<mailto:pulp-list-boun...@redhat.com>> <mailto:pulp-list-boun...@redhat.com<mailto:pulp-list-boun...@redhat.com> <mailto:pulp-list-boun...@redhat.com<mailto:pulp-list-boun...@redhat.com>>> [mailto:pulp-list-boun...@redhat.com<mailto:pulp-list-boun...@redhat.com> <mailto:pulp-list-boun...@redhat.com<mailto:pulp-list-boun...@redhat.com>> <mailto:pulp-list-boun...@redhat.com<mailto:pulp-list-boun...@redhat.com> <mailto:pulp-list-boun...@redhat.com<mailto:pulp-list-boun...@redhat.com>>>] *On Behalf Of *Michael Hrivnak *Sent:* Friday, July 01, 2016 8:31 AM *To:* Eric Helms <ehe...@redhat.com<mailto:ehe...@redhat.com> <mailto:ehe...@redhat.com<mailto:ehe...@redhat.com>> <mailto:ehe...@redhat.com<mailto:ehe...@redhat.com> <mailto:ehe...@redhat.com<mailto:ehe...@redhat.com>>>> *Cc:* pulp-list <pulp-list@redhat.com<mailto:pulp-list@redhat.com> <mailto:pulp-list@redhat.com<mailto:pulp-list@redhat.com>> <mailto:pulp-list@redhat.com<mailto:pulp-list@redhat.com> <mailto:pulp-list@redhat.com<mailto:pulp-list@redhat.com>>>> *Subject:* Re: [Pulp-list] Long upgrade times from 2.6 -> 2.8____ __ __ Did you get any feedback on whether one particular migration seemed to be running for a lot of that time? For the 1.5TB/100GB MongoDB scenario here is what I am able to glean from user logs (which I can share privately with anyone debugging): ~5 hours: Applying pulp_puppet.plugins.migrations version 4 ~10 hours: Applying pulp_rpm.plugins.migrations version 28 Use reports "lots of stating, unlinking, and linking of all the symlinks in /var/lib/pulb" if that helps. Another user reports ~6 hours on 176G of data. Eric ____ __ __ Michael____ __ __ On Fri, Jul 1, 2016 at 7:23 AM, Eric Helms <ehe...@redhat.com<mailto:ehe...@redhat.com> <mailto:ehe...@redhat.com<mailto:ehe...@redhat.com>> <mailto:ehe...@redhat.com<mailto:ehe...@redhat.com> <mailto:ehe...@redhat.com<mailto:ehe...@redhat.com>>>> wrote:____ Howdy,____ __ __ We (Katello) have had users reporting incredibly long upgrade times when upgrading from 2.6 to 2.8. This occurs during the pulp-manage-db step that is run as the beginning of our installers upgrade process. Based on the numbers below, does this make sense at all?____ __ __ Some numbers:____ __ __ 18 hour upgrade____ 1.5 TB /var/lib/pulp____ 100GB MongoDB____ __ __ __ __ Thanks,____ Eric____ _______________________________________________ Pulp-list mailing list Pulp-list@redhat.com<mailto:Pulp-list@redhat.com> <mailto:Pulp-list@redhat.com<mailto:Pulp-list@redhat.com>> <mailto:Pulp-list@redhat.com<mailto:Pulp-list@redhat.com> <mailto:Pulp-list@redhat.com<mailto:Pulp-list@redhat.com>>> https://www.redhat.com/mailman/listinfo/pulp-list____ __ __ ------------------------------------------------------------------------ Information in this e-mail may be confidential. It is intended only for the addressee(s) identified above. If you are not the addressee(s), or an employee or agent of the addressee(s), please note that any dissemination, distribution, or copying of this communication is strictly prohibited. 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