Hi Frank, "With our mimic cluster I have absolutely no problems migrating pools in one go to a completely new set of disks. I have no problems doubling the number of disks and at the same time doubling the number of PGs in a pooI and let the rebalancing loose in one single go. No need for slowly increasing weights. No need for slow changes of PG counts. In such cases,..." This is also my experience. I have 2 clusters running on Nautilus 14.2.8, one upgraded 2 weeks ago from mimic. I do NOT see any performance drop from the client side. But recovering is extremely slow, after replacing a defect OSD. When I need to replace an OSD, I destroy them, turn on the noout flag, turn off the server, replace the disk, and turn the server on. All within 30min. In Mimic I had only some misplaced objects and it recovered within an hour. In Nautilis, when I do exactly the same, I get beside misplaced objects, also degraded PGs and undersized PGs, and the recovery takes almost a day. I still need to investigate this (tips are welcome ;) ) But what is standing out, is the load on the manager. Grtz, Jiri On Thu, 25 Jun 2020 at 17:18, Frank Schilder <frans@xxxxxx> wrote: > I actually don't think this is the problem. I removed a 120TB file system > EC-data pool in mimic without any special flags and magic. The OSDs of the > data pool are HDD with everything collocated. I had absolutely no problem, > the data was removed after 2-3 days and nobody even noticed. This is a > standard operation and should just work without OPS queues running full, > heartbeat losses and manual compaction or the like. > > Looking at all the different reports that came in on this list over the > past 1-2 years about performance issues starting with nautilus, it really > sounds to me that a serious regression happened. Maybe the messenger > introduction? Maybe the prioritizing problem that Robert LeBlanc reported > in > https://lists.ceph.io/hyperkitty/list/ceph-users@xxxxxxx/thread/W4M5XQRDBLXFGJGDYZALG6TQ4QBVGGAJ/#W4M5XQRDBLXFGJGDYZALG6TQ4QBVGGAJ > ? > > I guess anyone who started with nautilus doesn't know the good old times > of being able to do admin work without a completely normal cluster > collapsing for no reason. Others do. I find it a bit strange that there is > such a long silence on this topic. There are numerous reports of people > having issues with PG changes or rebalancing. Benign operations that should > just work. > > With our mimic cluster I have absolutely no problems migrating pools in > one go to a completely new set of disks. I have no problems doubling the > number of disks and at the same time doubling the number of PGs in a pooI > and let the rebalancing loose in one single go. No need for slowly > increasing weights. No need for slow changes of PG counts. In such cases, I > casually push the recovery options up close to max available bandwidth and > nobody even notices a performance drop. And all this with WAL/DB and data > collocated on the same disk and with rather low RAM available, I can only > afford 2GB per HDD OSD. > > Anyone on nautilus or higher who has the same experience? > > Best regards, > ================= > Frank Schilder > AIT Risø Campus > Bygning 109, rum S14 > > ________________________________________ > From: Eugen Block <eblock@xxxxxx> > Sent: 25 June 2020 16:42:57 > To: ceph-users@xxxxxxx > Subject: Re: Removing pool in nautilus is incredibly slow > > I'm not sure if your OSDs have their rocksDB on faster devices, if not > it sounds a lot like rocksdb fragmentation [1] leading to a very high > load on the OSDs and occasionally crashing OSDs. If you don't plan to > delete so much data at once on a regular basis you could sit this one > out, but one solution is to re-create the OSDs with rocksDB/WAL on > faster devices. > > > [1] https://www.mail-archive.com/ceph-users@xxxxxxx/msg03160.html > > > Zitat von Francois Legrand <fleg@xxxxxxxxxxxxxx>: > > > Thanks for the hint. > > I tryed but it doesn't seems to change anything... > > Moreover, as the osds seems quite loaded I had regularly some osd > > marked down which triggered some new peering and thus more load !!! > > I set the osd no down flag, but I still have some osd reported > > (wrongly) as down (and back up in the minute) which generate peering > > and remapping. I don't really understand the action of no down > > parameter ! > > Is there a way to tell ceph not to peer immediately after an osd is > > reported down (let say wait for 60s) ? > > I am thinking about restarting all osd (or maybe the whole cluster) > > to get osd_op_queue_cut_off changed to high and > > osd_op_thread_timeout to something higher than 15 (but I don't think > > it will really improve the situation). > > F. > > > > > > Le 25/06/2020 à 14:26, Wout van Heeswijk a écrit : > >> Hi Francois, > >> > >> Have you already looked at the option "osd_delete_sleep"? It will > >> not speed up the process but I will give you some control over your > >> cluster performance. > >> > >> Something like: > >> > >> ceph tell osd.\* injectargs '--osd_delete_sleep1' > >> kind regards, > >> > >> Wout > >> 42on > >> On 25-06-2020 09:57, Francois Legrand wrote: > >>> Does someone have an idea ? > >>> F. > >>> _______________________________________________ > >>> ceph-users mailing list --ceph-users@xxxxxxx > >>> To unsubscribe send an email toceph-users-leave@xxxxxxx > >> > > > > _______________________________________________ > > ceph-users mailing list -- ceph-users@xxxxxxx > > To unsubscribe send an email to ceph-users-leave@xxxxxxx > > > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx > _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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