On 2/14/19 11:26 AM, Dan van der Ster wrote: > On Thu, Feb 14, 2019 at 11:13 AM Wido den Hollander <wido@xxxxxxxx> wrote: >> >> On 2/14/19 10:20 AM, Dan van der Ster wrote: >>> On Thu., Feb. 14, 2019, 6:17 a.m. Wido den Hollander <wido@xxxxxxxx wrote: >>>> >>>> Hi, >>>> >>>> On a cluster running RGW only I'm running into BlueStore 12.2.11 OSDs >>>> being 100% busy sometimes. >>>> >>>> This cluster has 85k stale indexes (stale-instances list) and I've been >>>> slowly trying to remove them. >>>> >>> >>> Is your implication here that 'stale-instances rm' isn't going to work >>> for your case? >>> >> >> No, just saying that I've been running it to remove stale indexes. But >> suddenly the OSDs are spiking to 100% busy when reading from BlueFS. > > How do you "slowly" rm the stale-instances? If you called > stale-instances rm, doesn't that mean there's some rgw in your cluster > busily now trying to delete 85k indices? I imagine that could be > triggering this load spike. I ran it with: $ timeout 900 <command> Just to see what would happen. The problem is that even without this running I now see OSDs spiking too 100% busy. The bluefs debug logs tell me that when a particular object is queried it will cause the OSD to scan it's RocksDB database and render the OSD useless for a few minutes. > (I'm trying to grok the stale-instances rm implementation -- it seems > to do the work 1000 keys at a time, but will nevertheless queue up the > work to rm all indices from one call to the command <--- please > correct me if I'm wrong). > > -- dan > > >> >>> (We haven't updated to 12.2.11 yet but have a similar number of stale >>> instances to remove). >>> >> >> In this case the index pool already went from 222k objects to 186k and >> is still going down if we run the GC. >> >>> For the rest below, I didn't understand *when* are the osd's getting >>> 100% busy -- is that just during normal operations (after the 12.2.11 >>> upgrade) or is it while listing the indexes? >>> >> >> Not sure either. For certain Objects this can be triggered by just >> listing the OMAP keys. This OSD eats all I/O at that moment. >> >>> Also, have you already tried compacting the omap on the relevant osds? >>> >> >> I tried that, but on a offline OSD I cancelled it after 25 minutes as it >> was still running. >> >> Not sure yet why this happens on those OSDs. >> >> Wido >> >>> -- Dan >>> >>> >>>> >>>> >>>> I noticed that regularly OSDs read their HDD heavily and that device >>>> then becomes 100% busy. (iostat) >>>> >>>> $ radosgw-admin reshard stale-instances list > stale.json >>>> $ cat stale.json|jq -r '.[]'|wc -l >>>> >>>> I increased debug_bluefs and debug_bluestore to 10 and I found: >>>> >>>> 2019-02-14 05:11:18.417097 7f627732d700 10 >>>> bluestore(/var/lib/ceph/osd/ceph-266) omap_get_header 13.205_head oid >>>> #13:a05231a1:::.dir.ams02.36062237.821.79:head# = 0 >>>> 2019-02-14 05:11:18.417127 7f627732d700 10 >>>> bluestore(/var/lib/ceph/osd/ceph-266) get_omap_iterator 13.205_head >>>> #13:a05231a1:::.dir.ams02.36062237.821.79:head# >>>> 2019-02-14 05:11:18.417133 7f627732d700 10 >>>> bluestore(/var/lib/ceph/osd/ceph-266) get_omap_iterator has_omap = 1 >>>> >>>> 2019-02-14 05:11:18.417169 7f627732d700 10 bluefs _read_random h >>>> 0x560cb77c5080 0x17a8cd0~fba from file(ino 71562 size 0x2d96a43 mtime >>>> 2019-02-14 02:52:16.370746 bdev 1 allocated 2e00000 extents >>>> [1:0x3228f00000+2e00000]) >>>> 2019-02-14 05:11:23.129645 7f627732d700 10 bluefs _read_random h >>>> 0x560c14167780 0x17bb6b7~f52 from file(ino 68900 size 0x41919ef mtime >>>> 2019-02-01 01:19:59.216218 bdev 1 allocated 4200000 extents >>>> [1:0x8b31a00000+200000,1:0x8b31e00000+e00000,1:0x8b32d00000+1700000,1:0x8b3ce00000+1b00000]) >>>> 2019-02-14 05:11:23.144550 7f627732d700 10 bluefs _read_random h >>>> 0x560c14c86b80 0x96d020~ef3 from file(ino 67189 size 0x419b603 mtime >>>> 2019-02-01 00:45:12.743836 bdev 1 allocated 4200000 extents >>>> [1:0x53da9a00000+4200000]) >>>> >>>> 2019-02-14 05:11:23.149958 7f627732d700 10 >>>> bluestore(/var/lib/ceph/osd/ceph-266) omap_get_header 13.e8_head oid >>>> #13:171bcbd3:::.dir.ams02.39023047.682.114:head# = 0 >>>> 2019-02-14 05:11:23.149975 7f627732d700 10 >>>> bluestore(/var/lib/ceph/osd/ceph-266) get_omap_iterator 13.e8_head >>>> #13:171bcbd3:::.dir.ams02.39023047.682.114:head# >>>> 2019-02-14 05:11:23.149981 7f627732d700 10 >>>> bluestore(/var/lib/ceph/osd/ceph-266) get_omap_iterator has_omap = 1 >>>> >>>> 2019-02-14 05:11:23.150012 7f627732d700 10 bluefs _read_random h >>>> 0x560c14e42500 0x1a18670~ff0 from file(ino 71519 size 0x417a60f mtime >>>> 2019-02-14 02:51:35.125629 bdev 1 allocated 4200000 extents >>>> [1:0x1c30d00000+4200000]) >>>> 2019-02-14 05:11:23.155679 7f627732d700 10 bluefs _read_random h >>>> 0x560c1c1ab980 0xedad4c~fde from file(ino 71391 size 0x25d4a89 mtime >>>> 2019-02-13 22:25:22.801676 bdev 1 allocated 2600000 extents >>>> [1:0x38b00000+2600000]) >>>> 2019-02-14 05:11:23.158995 7f627732d700 10 bluefs _read_random h >>>> 0x560c1c1ab980 0xedbd2a~fba from file(ino 71391 size 0x25d4a89 mtime >>>> 2019-02-13 22:25:22.801676 bdev 1 allocated 2600000 extents >>>> [1:0x38b00000+2600000]) >>>> 2019-02-14 05:11:23.159233 7f627732d700 10 bluefs _read_random h >>>> 0x560c14c86b80 0x96df13~fca from file(ino 67189 size 0x419b603 mtime >>>> 2019-02-01 00:45:12.743836 bdev 1 allocated 4200000 extents >>>> [1:0x53da9a00000+4200000]) >>>> 2019-02-14 05:11:23.159456 7f627732d700 10 bluefs _read_random h >>>> 0x560c14c86b80 0x96eedd~f1b from file(ino 67189 size 0x419b603 mtime >>>> 2019-02-01 00:45:12.743836 bdev 1 allocated 4200000 extents >>>> [1:0x53da9a00000+4200000]) >>>> 2019-02-14 05:11:23.159639 7f627732d700 10 bluefs _read_random h >>>> 0x560c14c86b80 0x96fdf8~eba from file(ino 67189 size 0x419b603 mtime >>>> 2019-02-01 00:45:12.743836 bdev 1 allocated 4200000 extents >>>> [1:0x53da9a00000+4200000]) >>>> >>>> After this the _random_read just continues for thousands of lines and >>>> the OSD becomes very slow. Slow requests, heartbeat timeouts and even >>>> OSDs being marked as down. >>>> >>>> So I tried to list the omap keys: >>>> >>>> $ rados -p .rgw.buckets.index listomapkeys .dir.ams02.36062237.821.79 >>>> $ rados -p .rgw.buckets.index listomapkeys .dir.ams02.39023047.682.114 >>>> >>>> .dir.ams02.36062237.821.79: <1s >>>> .dir.ams02.39023047.682.114: ~30s >>>> >>>> Both objects are on the same OSD (266), but if I list the omapkeys for >>>> the last Object the disk jumps to 100% busy and stays there for ~1min. >>>> >>>> I've seen this before with RBD and SSD-backed OSDs where on a omap key >>>> list the disks would jump to 100% busy and cause slow requests. >>>> >>>> This case seems very similar to that one. >>>> >>>> I can keep triggering it in this case by listing the omap keys for >>>> object .dir.ams02.39023047.682.114, which doesn't have any keys though. >>>> >>>> Has anybody seen this before? >>>> >>>> Some information: >>>> >>>> - Ceph 12.2.11 >>>> - BlueStore (default memory target of 4G) >>>> - RGW-only use-case >>>> - WAL+DB+DATA on HDD >>>> >>>> Thanks, >>>> >>>> Wido >>>> >>>> _______________________________________________ >>>> ceph-users mailing list >>>> ceph-users@xxxxxxxxxxxxxx >>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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