Hey Igor, sadly we do not have the data from the time where c1 was on nautilus. The RocksDB warning persisted the recreation. Here are the measurements. I've picked the same SSD models from the clusters to have some comparablity. For the 8TB disks it's even the same chassis configuration (CPU/Memory/Board/Network) The IOPS seem VERY low for me. Or are these normal values for SSDs? After recreation the IOPS are a lot better on the pacific cluster. I also blkdiscarded the SSDs before recreating them. Nautilus Cluster osd.22 = 8TB osd.343 = 2TB https://pastebin.com/EfSSLmYS Pacific Cluster before recreating OSDs osd.40 = 8TB osd.162 = 2TB https://pastebin.com/wKMmSW9T Pacific Cluster after recreation OSDs osd.40 = 8TB osd.162 = 2TB https://pastebin.com/80eMwwBW Am Mi., 22. März 2023 um 11:09 Uhr schrieb Igor Fedotov < igor.fedotov@xxxxxxxx>: > Hi Boris, > > first of all I'm not sure if it's valid to compare two different clusters > (pacific vs . nautilus, C1 vs. C2 respectively). The perf numbers > difference might be caused by a bunch of other factors: different H/W, user > load, network etc... I can see that you got ~2x latency increase after > Octopus to Pacific upgrade at C1 but Octopus numbers had been much above > Nautilus at C2 before the upgrade. Did you observe even lower numbers at C1 > when it was running Nautilus if any? > > > You might want to try "ceph tell osd.N bench" to compare OSDs performance > for both C1 and C2. Would it be that different? > > > Then redeploy a single OSD at C1, wait till rebalance completion and > benchmark it again. What would be the new numbers? Please also collect perf > counters from the to-be-redeployed OSD beforehand. > > W.r.t. rocksdb warning - I presume this might be caused by newer RocksDB > version running on top of DB with a legacy format.. Perhaps redeployment > would fix that... > > > Thanks, > > Igor > On 3/21/2023 5:31 PM, Boris Behrens wrote: > > Hi Igor, > i've offline compacted all the OSDs and reenabled the bluefs_buffered_io > > It didn't change anything and the commit and apply latencies are around > 5-10 times higher than on our nautlus cluster. The pacific cluster got a 5 > minute mean over all OSDs 2.2ms, while the nautilus cluster is around 0.2 - > 0.7 ms. > > I also see these kind of logs. Google didn't really help: > 2023-03-21T14:08:22.089+0000 7efe7b911700 3 rocksdb: > [le/block_based/filter_policy.cc:579] Using legacy Bloom filter with high > (20) bits/key. Dramatic filter space and/or accuracy improvement is > available with format_version>=5. > > > > > Am Di., 21. März 2023 um 10:46 Uhr schrieb Igor Fedotov <igor.fedotov@xxxxxxxx>: > > > Hi Boris, > > additionally you might want to manually compact RocksDB for every OSD. > > > Thanks, > > Igor > On 3/21/2023 12:22 PM, Boris Behrens wrote: > > Disabling the write cache and the bluefs_buffered_io did not change > anything. > What we see is that larger disks seem to be the leader in therms of > slowness (we have 70% 2TB, 20% 4TB and 10% 8TB SSDs in the cluster), but > removing some of the 8TB disks and replace them with 2TB (because it's by > far the majority and we have a lot of them) disks did also not change > anything. > > Are there any other ideas I could try. Customer start to complain about the > slower performance and our k8s team mentions problems with ETCD because the > latency is too high. > > Would it be an option to recreate every OSD? > > Cheers > Boris > > Am Di., 28. Feb. 2023 um 22:46 Uhr schrieb Boris Behrens <bb@xxxxxxxxx> <bb@xxxxxxxxx> <bb@xxxxxxxxx> <bb@xxxxxxxxx>: > > > Hi Josh, > thanks a lot for the breakdown and the links. > I disabled the write cache but it didn't change anything. Tomorrow I will > try to disable bluefs_buffered_io. > > It doesn't sound that I can mitigate the problem with more SSDs. > > > Am Di., 28. Feb. 2023 um 15:42 Uhr schrieb Josh Baergen <jbaergen@xxxxxxxxxxxxxxxx> <jbaergen@xxxxxxxxxxxxxxxx>: > > > Hi Boris, > > OK, what I'm wondering is whetherhttps://tracker.ceph.com/issues/58530 is involved. There are two > aspects to that ticket: > * A measurable increase in the number of bytes written to disk in > Pacific as compared to Nautilus > * The same, but for IOPS > > Per the current theory, both are due to the loss of rocksdb log > recycling when using default recovery options in rocksdb 6.8; Octopus > uses version 6.1.2, Pacific uses 6.8.1. > > 16.2.11 largely addressed the bytes-written amplification, but the > IOPS amplification remains. In practice, whether this results in a > write performance degradation depends on the speed of the underlying > media and the workload, and thus the things I mention in the next > paragraph may or may not be applicable to you. > > There's no known workaround or solution for this at this time. In some > cases I've seen that disabling bluefs_buffered_io (which itself can > cause IOPS amplification in some cases) can help; I think most folks > do this by setting it in local conf and then restarting OSDs in order > to gain the config change. Something else to consider ishttps://docs.ceph.com/en/quincy/start/hardware-recommendations/#write-caches > , > as sometimes disabling these write caches can improve the IOPS > performance of SSDs. > > Josh > > On Tue, Feb 28, 2023 at 7:19 AM Boris Behrens <bb@xxxxxxxxx> <bb@xxxxxxxxx> <bb@xxxxxxxxx> <bb@xxxxxxxxx> wrote: > > Hi Josh, > we upgraded 15.2.17 -> 16.2.11 and we only use rbd workload. > > > > Am Di., 28. Feb. 2023 um 15:00 Uhr schrieb Josh Baergen < > jbaergen@xxxxxxxxxxxxxxxx>: > > Hi Boris, > > Which version did you upgrade from and to, specifically? And what > workload are you running (RBD, etc.)? > > Josh > > On Tue, Feb 28, 2023 at 6:51 AM Boris Behrens <bb@xxxxxxxxx> <bb@xxxxxxxxx> <bb@xxxxxxxxx> <bb@xxxxxxxxx> wrote: > > Hi, > today I did the first update from octopus to pacific, and it looks > > like the > > avg apply latency went up from 1ms to 2ms. > > All 36 OSDs are 4TB SSDs and nothing else changed. > Someone knows if this is an issue, or am I just missing a config > > value? > > Cheers > Boris > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx > > -- > Die Selbsthilfegruppe "UTF-8-Probleme" trifft sich diesmal abweichend > > im groüen Saal. > > > -- > Die Selbsthilfegruppe "UTF-8-Probleme" trifft sich diesmal abweichend im > groüen Saal. > > > -- > Igor Fedotov > Ceph Lead Developer > -- > croit GmbH, Freseniusstr. 31h, 81247 Munich > CEO: Martin Verges - VAT-ID: DE310638492 > Com. register: Amtsgericht Munich HRB 231263 > Web <https://croit.io/> <https://croit.io/> | LinkedIn <http://linkedin.com/company/croit> <http://linkedin.com/company/croit> | > Youtube <https://www.youtube.com/channel/UCIJJSKVdcSLGLBtwSFx_epw> <https://www.youtube.com/channel/UCIJJSKVdcSLGLBtwSFx_epw> | > Twitter <https://twitter.com/croit_io> <https://twitter.com/croit_io> > > Meet us at the SC22 Conference! 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