Re: Potential OSD deadlock?

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On Mon, 5 Oct 2015, Robert LeBlanc wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA256
> 
> With some off-list help, we have adjusted
> osd_client_message_cap=10000. This seems to have helped a bit and we
> have seen some OSDs have a value up to 4,000 for client messages. But
> it does not solve the problem with the blocked I/O.
> 
> One thing that I have noticed is that almost exactly 30 seconds elapse
> between an OSD boots and the first blocked I/O message. I don't know
> if the OSD doesn't have time to get it's brain right about a PG before
> it starts servicing it or what exactly.

I'm downloading the logs from yesterday now; sorry it's taking so long.

> On another note, I tried upgrading our CentOS dev cluster from Hammer
> to master and things didn't go so well. The OSDs would not start
> because /var/lib/ceph was not owned by ceph. I chowned the directory
> and all OSDs and the OSD then started, but never became active in the
> cluster. It just sat there after reading all the PGs. There were
> sockets open to the monitor, but no OSD to OSD sockets. I tried
> downgrading to the Infernalis branch and still no luck getting the
> OSDs to come up. The OSD processes were idle after the initial boot.
> All packages were installed from gitbuilder.

Did you chown -R ?

	https://github.com/ceph/ceph/blob/infernalis/doc/release-notes.rst#upgrading-from-hammer

My guess is you only chowned the root dir, and the OSD didn't throw 
an error when it encountered the other files?  If you can generate a debug 
osd = 20 log, that would be helpful.. thanks!

sage


> 
> Thanks,
> -----BEGIN PGP SIGNATURE-----
> Version: Mailvelope v1.2.0
> Comment: https://www.mailvelope.com
> 
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> =Aigq
> -----END PGP SIGNATURE-----
> ----------------
> Robert LeBlanc
> PGP Fingerprint 79A2 9CA4 6CC4 45DD A904  C70E E654 3BB2 FA62 B9F1
> 
> 
> On Sun, Oct 4, 2015 at 3:04 PM, Robert LeBlanc <robert@xxxxxxxxxxxxx> wrote:
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA256
> >
> > I have eight nodes running the fio job rbd_test_real to different RBD
> > volumes. I've included the CRUSH map in the tarball.
> >
> > I stopped one OSD process and marked it out. I let it recover for a
> > few minutes and then I started the process again and marked it in. I
> > started getting block I/O messages during the recovery.
> >
> > The logs are located at http://162.144.87.113/files/ushou1.tar.xz
> >
> > Thanks,
> > -----BEGIN PGP SIGNATURE-----
> > Version: Mailvelope v1.2.0
> > Comment: https://www.mailvelope.com
> >
> > wsFcBAEBCAAQBQJWEZRcCRDmVDuy+mK58QAALbEQAK5pFiixJarUdLm50zp/
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> > =UDIV
> > -----END PGP SIGNATURE-----
> >
> > ----------------
> > Robert LeBlanc
> > PGP Fingerprint 79A2 9CA4 6CC4 45DD A904  C70E E654 3BB2 FA62 B9F1
> >
> >
> > On Sun, Oct 4, 2015 at 7:48 AM, Sage Weil <sweil@xxxxxxxxxx> wrote:
> >> On Sat, 3 Oct 2015, Robert LeBlanc wrote:
> >>> -----BEGIN PGP SIGNED MESSAGE-----
> >>> Hash: SHA256
> >>>
> >>> We are still struggling with this and have tried a lot of different
> >>> things. Unfortunately, Inktank (now Red Hat) no longer provides
> >>> consulting services for non-Red Hat systems. If there are some
> >>> certified Ceph consultants in the US that we can do both remote and
> >>> on-site engagements, please let us know.
> >>>
> >>> This certainly seems to be network related, but somewhere in the
> >>> kernel. We have tried increasing the network and TCP buffers, number
> >>> of TCP sockets, reduced the FIN_WAIT2 state. There is about 25% idle
> >>> on the boxes, the disks are busy, but not constantly at 100% (they
> >>> cycle from <10% up to 100%, but not 100% for more than a few seconds
> >>> at a time). There seems to be no reasonable explanation why I/O is
> >>> blocked pretty frequently longer than 30 seconds. We have verified
> >>> Jumbo frames by pinging from/to each node with 9000 byte packets. The
> >>> network admins have verified that packets are not being dropped in the
> >>> switches for these nodes. We have tried different kernels including
> >>> the recent Google patch to cubic. This is showing up on three cluster
> >>> (two Ethernet and one IPoIB). I booted one cluster into Debian Jessie
> >>> (from CentOS 7.1) with similar results.
> >>>
> >>> The messages seem slightly different:
> >>> 2015-10-03 14:38:23.193082 osd.134 10.208.16.25:6800/1425 439 :
> >>> cluster [WRN] 14 slow requests, 1 included below; oldest blocked for >
> >>> 100.087155 secs
> >>> 2015-10-03 14:38:23.193090 osd.134 10.208.16.25:6800/1425 440 :
> >>> cluster [WRN] slow request 30.041999 seconds old, received at
> >>> 2015-10-03 14:37:53.151014: osd_op(client.1328605.0:7082862
> >>> rbd_data.13fdcb2ae8944a.000000000001264f [read 975360~4096]
> >>> 11.6d19c36f ack+read+known_if_redirected e10249) currently no flag
> >>> points reached
> >>>
> >>> I don't know what "no flag points reached" means.
> >>
> >> Just that the op hasn't been marked as reaching any interesting points
> >> (op->mark_*() calls).
> >>
> >> Is it possible to gather a lot with debug ms = 20 and debug osd = 20?
> >> It's extremely verbose but it'll let us see where the op is getting
> >> blocked.  If you see the "slow request" message it means the op in
> >> received by ceph (that's when the clock starts), so I suspect it's not
> >> something we can blame on the network stack.
> >>
> >> sage
> >>
> >>
> >>>
> >>> The problem is most pronounced when we have to reboot an OSD node (1
> >>> of 13), we will have hundreds of I/O blocked for some times up to 300
> >>> seconds. It takes a good 15 minutes for things to settle down. The
> >>> production cluster is very busy doing normally 8,000 I/O and peaking
> >>> at 15,000. This is all 4TB spindles with SSD journals and the disks
> >>> are between 25-50% full. We are currently splitting PGs to distribute
> >>> the load better across the disks, but we are having to do this 10 PGs
> >>> at a time as we get blocked I/O. We have max_backfills and
> >>> max_recovery set to 1, client op priority is set higher than recovery
> >>> priority. We tried increasing the number of op threads but this didn't
> >>> seem to help. It seems as soon as PGs are finished being checked, they
> >>> become active and could be the cause for slow I/O while the other PGs
> >>> are being checked.
> >>>
> >>> What I don't understand is that the messages are delayed. As soon as
> >>> the message is received by Ceph OSD process, it is very quickly
> >>> committed to the journal and a response is sent back to the primary
> >>> OSD which is received very quickly as well. I've adjust
> >>> min_free_kbytes and it seems to keep the OSDs from crashing, but
> >>> doesn't solve the main problem. We don't have swap and there is 64 GB
> >>> of RAM per nodes for 10 OSDs.
> >>>
> >>> Is there something that could cause the kernel to get a packet but not
> >>> be able to dispatch it to Ceph such that it could be explaining why we
> >>> are seeing these blocked I/O for 30+ seconds. Is there some pointers
> >>> to tracing Ceph messages from the network buffer through the kernel to
> >>> the Ceph process?
> >>>
> >>> We can really use some pointers no matter how outrageous. We've have
> >>> over 6 people looking into this for weeks now and just can't think of
> >>> anything else.
> >>>
> >>> Thanks,
> >>> -----BEGIN PGP SIGNATURE-----
> >>> Version: Mailvelope v1.1.0
> >>> Comment: https://www.mailvelope.com
> >>>
> >>> wsFcBAEBCAAQBQJWEDY1CRDmVDuy+mK58QAARgoP/RcoL1qVmg7qbQrzStar
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> >>> =OI++
> >>> -----END PGP SIGNATURE-----
> >>> ----------------
> >>> Robert LeBlanc
> >>> PGP Fingerprint 79A2 9CA4 6CC4 45DD A904  C70E E654 3BB2 FA62 B9F1
> >>>
> >>>
> >>> On Fri, Sep 25, 2015 at 2:40 PM, Robert LeBlanc <robert@xxxxxxxxxxxxx> wrote:
> >>> > We dropped the replication on our cluster from 4 to 3 and it looks
> >>> > like all the blocked I/O has stopped (no entries in the log for the
> >>> > last 12 hours). This makes me believe that there is some issue with
> >>> > the number of sockets or some other TCP issue. We have not messed with
> >>> > Ephemeral ports and TIME_WAIT at this point. There are 130 OSDs, 8 KVM
> >>> > hosts hosting about 150 VMs. Open files is set at 32K for the OSD
> >>> > processes and 16K system wide.
> >>> >
> >>> > Does this seem like the right spot to be looking? What are some
> >>> > configuration items we should be looking at?
> >>> >
> >>> > Thanks,
> >>> > ----------------
> >>> > Robert LeBlanc
> >>> > PGP Fingerprint 79A2 9CA4 6CC4 45DD A904  C70E E654 3BB2 FA62 B9F1
> >>> >
> >>> >
> >>> > On Wed, Sep 23, 2015 at 1:30 PM, Robert LeBlanc <robert@xxxxxxxxxxxxx> wrote:
> >>> >> -----BEGIN PGP SIGNED MESSAGE-----
> >>> >> Hash: SHA256
> >>> >>
> >>> >> We were able to only get ~17Gb out of the XL710 (heavily tweaked)
> >>> >> until we went to the 4.x kernel where we got ~36Gb (no tweaking). It
> >>> >> seems that there were some major reworks in the network handling in
> >>> >> the kernel to efficiently handle that network rate. If I remember
> >>> >> right we also saw a drop in CPU utilization. I'm starting to think
> >>> >> that we did see packet loss while congesting our ISLs in our initial
> >>> >> testing, but we could not tell where the dropping was happening. We
> >>> >> saw some on the switches, but it didn't seem to be bad if we weren't
> >>> >> trying to congest things. We probably already saw this issue, just
> >>> >> didn't know it.
> >>> >> - ----------------
> >>> >> Robert LeBlanc
> >>> >> PGP Fingerprint 79A2 9CA4 6CC4 45DD A904  C70E E654 3BB2 FA62 B9F1
> >>> >>
> >>> >>
> >>> >> On Wed, Sep 23, 2015 at 1:10 PM, Mark Nelson  wrote:
> >>> >>> FWIW, we've got some 40GbE Intel cards in the community performance cluster
> >>> >>> on a Mellanox 40GbE switch that appear (knock on wood) to be running fine
> >>> >>> with 3.10.0-229.7.2.el7.x86_64.  We did get feedback from Intel that older
> >>> >>> drivers might cause problems though.
> >>> >>>
> >>> >>> Here's ifconfig from one of the nodes:
> >>> >>>
> >>> >>> ens513f1: flags=4163  mtu 1500
> >>> >>>         inet 10.0.10.101  netmask 255.255.255.0  broadcast 10.0.10.255
> >>> >>>         inet6 fe80::6a05:caff:fe2b:7ea1  prefixlen 64  scopeid 0x20
> >>> >>>         ether 68:05:ca:2b:7e:a1  txqueuelen 1000  (Ethernet)
> >>> >>>         RX packets 169232242875  bytes 229346261232279 (208.5 TiB)
> >>> >>>         RX errors 0  dropped 0  overruns 0  frame 0
> >>> >>>         TX packets 153491686361  bytes 203976410836881 (185.5 TiB)
> >>> >>>         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
> >>> >>>
> >>> >>> Mark
> >>> >>>
> >>> >>>
> >>> >>> On 09/23/2015 01:48 PM, Robert LeBlanc wrote:
> >>> >>>>
> >>> >>>> -----BEGIN PGP SIGNED MESSAGE-----
> >>> >>>> Hash: SHA256
> >>> >>>>
> >>> >>>> OK, here is the update on the saga...
> >>> >>>>
> >>> >>>> I traced some more of blocked I/Os and it seems that communication
> >>> >>>> between two hosts seemed worse than others. I did a two way ping flood
> >>> >>>> between the two hosts using max packet sizes (1500). After 1.5M
> >>> >>>> packets, no lost pings. Then then had the ping flood running while I
> >>> >>>> put Ceph load on the cluster and the dropped pings started increasing
> >>> >>>> after stopping the Ceph workload the pings stopped dropping.
> >>> >>>>
> >>> >>>> I then ran iperf between all the nodes with the same results, so that
> >>> >>>> ruled out Ceph to a large degree. I then booted in the the
> >>> >>>> 3.10.0-229.14.1.el7.x86_64 kernel and with an hour test so far there
> >>> >>>> hasn't been any dropped pings or blocked I/O. Our 40 Gb NICs really
> >>> >>>> need the network enhancements in the 4.x series to work well.
> >>> >>>>
> >>> >>>> Does this sound familiar to anyone? I'll probably start bisecting the
> >>> >>>> kernel to see where this issue in introduced. Both of the clusters
> >>> >>>> with this issue are running 4.x, other than that, they are pretty
> >>> >>>> differing hardware and network configs.
> >>> >>>>
> >>> >>>> Thanks,
> >>> >>>> -----BEGIN PGP SIGNATURE-----
> >>> >>>> Version: Mailvelope v1.1.0
> >>> >>>> Comment: https://www.mailvelope.com
> >>> >>>>
> >>> >>>> wsFcBAEBCAAQBQJWAvOzCRDmVDuy+mK58QAApOMP/1xmCtW++G11qcE8y/sr
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> >>> >>>> 4OEo
> >>> >>>> =P33I
> >>> >>>> -----END PGP SIGNATURE-----
> >>> >>>> ----------------
> >>> >>>> Robert LeBlanc
> >>> >>>> PGP Fingerprint 79A2 9CA4 6CC4 45DD A904  C70E E654 3BB2 FA62 B9F1
> >>> >>>>
> >>> >>>>
> >>> >>>> On Tue, Sep 22, 2015 at 4:15 PM, Robert LeBlanc
> >>> >>>> wrote:
> >>> >>>>>
> >>> >>>>> -----BEGIN PGP SIGNED MESSAGE-----
> >>> >>>>> Hash: SHA256
> >>> >>>>>
> >>> >>>>> This is IPoIB and we have the MTU set to 64K. There was some issues
> >>> >>>>> pinging hosts with "No buffer space available" (hosts are currently
> >>> >>>>> configured for 4GB to test SSD caching rather than page cache). I
> >>> >>>>> found that MTU under 32K worked reliable for ping, but still had the
> >>> >>>>> blocked I/O.
> >>> >>>>>
> >>> >>>>> I reduced the MTU to 1500 and checked pings (OK), but I'm still seeing
> >>> >>>>> the blocked I/O.
> >>> >>>>> - ----------------
> >>> >>>>> Robert LeBlanc
> >>> >>>>> PGP Fingerprint 79A2 9CA4 6CC4 45DD A904  C70E E654 3BB2 FA62 B9F1
> >>> >>>>>
> >>> >>>>>
> >>> >>>>> On Tue, Sep 22, 2015 at 3:52 PM, Sage Weil  wrote:
> >>> >>>>>>
> >>> >>>>>> On Tue, 22 Sep 2015, Samuel Just wrote:
> >>> >>>>>>>
> >>> >>>>>>> I looked at the logs, it looks like there was a 53 second delay
> >>> >>>>>>> between when osd.17 started sending the osd_repop message and when
> >>> >>>>>>> osd.13 started reading it, which is pretty weird.  Sage, didn't we
> >>> >>>>>>> once see a kernel issue which caused some messages to be mysteriously
> >>> >>>>>>> delayed for many 10s of seconds?
> >>> >>>>>>
> >>> >>>>>>
> >>> >>>>>> Every time we have seen this behavior and diagnosed it in the wild it
> >>> >>>>>> has
> >>> >>>>>> been a network misconfiguration.  Usually related to jumbo frames.
> >>> >>>>>>
> >>> >>>>>> sage
> >>> >>>>>>
> >>> >>>>>>
> >>> >>>>>>>
> >>> >>>>>>> What kernel are you running?
> >>> >>>>>>> -Sam
> >>> >>>>>>>
> >>> >>>>>>> On Tue, Sep 22, 2015 at 2:22 PM, Robert LeBlanc  wrote:
> >>> >>>>>>>>
> >>> >>>>>>>> -----BEGIN PGP SIGNED MESSAGE-----
> >>> >>>>>>>> Hash: SHA256
> >>> >>>>>>>>
> >>> >>>>>>>> OK, looping in ceph-devel to see if I can get some more eyes. I've
> >>> >>>>>>>> extracted what I think are important entries from the logs for the
> >>> >>>>>>>> first blocked request. NTP is running all the servers so the logs
> >>> >>>>>>>> should be close in terms of time. Logs for 12:50 to 13:00 are
> >>> >>>>>>>> available at http://162.144.87.113/files/ceph_block_io.logs.tar.xz
> >>> >>>>>>>>
> >>> >>>>>>>> 2015-09-22 12:55:06.500374 - osd.17 gets I/O from client
> >>> >>>>>>>> 2015-09-22 12:55:06.557160 - osd.17 submits I/O to osd.13
> >>> >>>>>>>> 2015-09-22 12:55:06.557305 - osd.17 submits I/O to osd.16
> >>> >>>>>>>> 2015-09-22 12:55:06.573711 - osd.16 gets I/O from osd.17
> >>> >>>>>>>> 2015-09-22 12:55:06.595716 - osd.17 gets ondisk result=0 from osd.16
> >>> >>>>>>>> 2015-09-22 12:55:06.640631 - osd.16 reports to osd.17 ondisk result=0
> >>> >>>>>>>> 2015-09-22 12:55:36.926691 - osd.17 reports slow I/O > 30.439150 sec
> >>> >>>>>>>> 2015-09-22 12:55:59.790591 - osd.13 gets I/O from osd.17
> >>> >>>>>>>> 2015-09-22 12:55:59.812405 - osd.17 gets ondisk result=0 from osd.13
> >>> >>>>>>>> 2015-09-22 12:56:02.941602 - osd.13 reports to osd.17 ondisk result=0
> >>> >>>>>>>>
> >>> >>>>>>>> In the logs I can see that osd.17 dispatches the I/O to osd.13 and
> >>> >>>>>>>> osd.16 almost silmutaniously. osd.16 seems to get the I/O right away,
> >>> >>>>>>>> but for some reason osd.13 doesn't get the message until 53 seconds
> >>> >>>>>>>> later. osd.17 seems happy to just wait and doesn't resend the data
> >>> >>>>>>>> (well, I'm not 100% sure how to tell which entries are the actual data
> >>> >>>>>>>> transfer).
> >>> >>>>>>>>
> >>> >>>>>>>> It looks like osd.17 is receiving responses to start the communication
> >>> >>>>>>>> with osd.13, but the op is not acknowledged until almost a minute
> >>> >>>>>>>> later. To me it seems that the message is getting received but not
> >>> >>>>>>>> passed to another thread right away or something. This test was done
> >>> >>>>>>>> with an idle cluster, a single fio client (rbd engine) with a single
> >>> >>>>>>>> thread.
> >>> >>>>>>>>
> >>> >>>>>>>> The OSD servers are almost 100% idle during these blocked I/O
> >>> >>>>>>>> requests. I think I'm at the end of my troubleshooting, so I can use
> >>> >>>>>>>> some help.
> >>> >>>>>>>>
> >>> >>>>>>>> Single Test started about
> >>> >>>>>>>> 2015-09-22 12:52:36
> >>> >>>>>>>>
> >>> >>>>>>>> 2015-09-22 12:55:36.926680 osd.17 192.168.55.14:6800/16726 56 :
> >>> >>>>>>>> cluster [WRN] 1 slow requests, 1 included below; oldest blocked for >
> >>> >>>>>>>> 30.439150 secs
> >>> >>>>>>>> 2015-09-22 12:55:36.926699 osd.17 192.168.55.14:6800/16726 57 :
> >>> >>>>>>>> cluster [WRN] slow request 30.439150 seconds old, received at
> >>> >>>>>>>> 2015-09-22 12:55:06.487451:
> >>> >>>>>>>>   osd_op(client.250874.0:1388 rbd_data.3380e2ae8944a.0000000000000545
> >>> >>>>>>>> [set-alloc-hint object_size 4194304 write_size 4194304,write
> >>> >>>>>>>> 0~4194304] 8.bbf3e8ff ack+ondisk+write+known_if_redirected e56785)
> >>> >>>>>>>>   currently waiting for subops from 13,16
> >>> >>>>>>>> 2015-09-22 12:55:36.697904 osd.16 192.168.55.13:6800/29410 7 : cluster
> >>> >>>>>>>> [WRN] 2 slow requests, 2 included below; oldest blocked for >
> >>> >>>>>>>> 30.379680 secs
> >>> >>>>>>>> 2015-09-22 12:55:36.697918 osd.16 192.168.55.13:6800/29410 8 : cluster
> >>> >>>>>>>> [WRN] slow request 30.291520 seconds old, received at 2015-09-22
> >>> >>>>>>>> 12:55:06.406303:
> >>> >>>>>>>>   osd_op(client.250874.0:1384 rbd_data.3380e2ae8944a.0000000000000541
> >>> >>>>>>>> [set-alloc-hint object_size 4194304 write_size 4194304,write
> >>> >>>>>>>> 0~4194304] 8.5fb2123f ack+ondisk+write+known_if_redirected e56785)
> >>> >>>>>>>>   currently waiting for subops from 13,17
> >>> >>>>>>>> 2015-09-22 12:55:36.697927 osd.16 192.168.55.13:6800/29410 9 : cluster
> >>> >>>>>>>> [WRN] slow request 30.379680 seconds old, received at 2015-09-22
> >>> >>>>>>>> 12:55:06.318144:
> >>> >>>>>>>>   osd_op(client.250874.0:1382 rbd_data.3380e2ae8944a.000000000000053f
> >>> >>>>>>>> [set-alloc-hint object_size 4194304 write_size 4194304,write
> >>> >>>>>>>> 0~4194304] 8.312e69ca ack+ondisk+write+known_if_redirected e56785)
> >>> >>>>>>>>   currently waiting for subops from 13,14
> >>> >>>>>>>> 2015-09-22 12:58:03.998275 osd.13 192.168.55.12:6804/4574 130 :
> >>> >>>>>>>> cluster [WRN] 1 slow requests, 1 included below; oldest blocked for >
> >>> >>>>>>>> 30.954212 secs
> >>> >>>>>>>> 2015-09-22 12:58:03.998286 osd.13 192.168.55.12:6804/4574 131 :
> >>> >>>>>>>> cluster [WRN] slow request 30.954212 seconds old, received at
> >>> >>>>>>>> 2015-09-22 12:57:33.044003:
> >>> >>>>>>>>   osd_op(client.250874.0:1873 rbd_data.3380e2ae8944a.000000000000070d
> >>> >>>>>>>> [set-alloc-hint object_size 4194304 write_size 4194304,write
> >>> >>>>>>>> 0~4194304] 8.e69870d4 ack+ondisk+write+known_if_redirected e56785)
> >>> >>>>>>>>   currently waiting for subops from 16,17
> >>> >>>>>>>> 2015-09-22 12:58:03.759826 osd.16 192.168.55.13:6800/29410 10 :
> >>> >>>>>>>> cluster [WRN] 1 slow requests, 1 included below; oldest blocked for >
> >>> >>>>>>>> 30.704367 secs
> >>> >>>>>>>> 2015-09-22 12:58:03.759840 osd.16 192.168.55.13:6800/29410 11 :
> >>> >>>>>>>> cluster [WRN] slow request 30.704367 seconds old, received at
> >>> >>>>>>>> 2015-09-22 12:57:33.055404:
> >>> >>>>>>>>   osd_op(client.250874.0:1874 rbd_data.3380e2ae8944a.000000000000070e
> >>> >>>>>>>> [set-alloc-hint object_size 4194304 write_size 4194304,write
> >>> >>>>>>>> 0~4194304] 8.f7635819 ack+ondisk+write+known_if_redirected e56785)
> >>> >>>>>>>>   currently waiting for subops from 13,17
> >>> >>>>>>>>
> >>> >>>>>>>> Server   IP addr              OSD
> >>> >>>>>>>> nodev  - 192.168.55.11 - 12
> >>> >>>>>>>> nodew  - 192.168.55.12 - 13
> >>> >>>>>>>> nodex  - 192.168.55.13 - 16
> >>> >>>>>>>> nodey  - 192.168.55.14 - 17
> >>> >>>>>>>> nodez  - 192.168.55.15 - 14
> >>> >>>>>>>> nodezz - 192.168.55.16 - 15
> >>> >>>>>>>>
> >>> >>>>>>>> fio job:
> >>> >>>>>>>> [rbd-test]
> >>> >>>>>>>> readwrite=write
> >>> >>>>>>>> blocksize=4M
> >>> >>>>>>>> #runtime=60
> >>> >>>>>>>> name=rbd-test
> >>> >>>>>>>> #readwrite=randwrite
> >>> >>>>>>>> #bssplit=4k/85:32k/11:512/3:1m/1,4k/89:32k/10:512k/1
> >>> >>>>>>>> #rwmixread=72
> >>> >>>>>>>> #norandommap
> >>> >>>>>>>> #size=1T
> >>> >>>>>>>> #blocksize=4k
> >>> >>>>>>>> ioengine=rbd
> >>> >>>>>>>> rbdname=test2
> >>> >>>>>>>> pool=rbd
> >>> >>>>>>>> clientname=admin
> >>> >>>>>>>> iodepth=8
> >>> >>>>>>>> #numjobs=4
> >>> >>>>>>>> #thread
> >>> >>>>>>>> #group_reporting
> >>> >>>>>>>> #time_based
> >>> >>>>>>>> #direct=1
> >>> >>>>>>>> #ramp_time=60
> >>> >>>>>>>>
> >>> >>>>>>>>
> >>> >>>>>>>> Thanks,
> >>> >>>>>>>> -----BEGIN PGP SIGNATURE-----
> >>> >>>>>>>> Version: Mailvelope v1.1.0
> >>> >>>>>>>> Comment: https://www.mailvelope.com
> >>> >>>>>>>>
> >>> >>>>>>>> wsFcBAEBCAAQBQJWAcaKCRDmVDuy+mK58QAAPMsQAKBnS94fwuw0OqpPU3/z
> >>> >>>>>>>> tL8Z6TVRxrNigf721+2ClIu4LIH71bupDc3DgrrysQmmqGuvEMn68spmasWu
> >>> >>>>>>>> h9I/CqqgRpHqe4lUVoUEjyWA9/6Dbb6NiHSdpJ6p5jpGc8kZCvNS+ocDgFOl
> >>> >>>>>>>> 903i0M0E9eEMeci5O/hrMrx1FG8SN2LS8nI261aNHMOwQK0bw8wWiCJEvqVB
> >>> >>>>>>>> sz1/+jK1BJoeIYfaT9HfUXBAvfo/W3tY/vj9KbJuZJ5AMpeYPvEHu/LAr1N7
> >>> >>>>>>>> FzzUc7a6EMlaxmSd0ML49JbV0cY9BMDjfrkKEQNKlzszlEHm3iif98QtsxbF
> >>> >>>>>>>> pPJ0hZ0G53BY3k976OWVMFm3WFRWUVOb/oiLF8H6PCm59b4LBNAg6iPNH1AI
> >>> >>>>>>>> 5XhEcPpg06M03vqUaIiY9P1kQlvnn0yCXf82IUEgmg///vhxDsHWmcwClLEn
> >>> >>>>>>>> B0VszouStTzlMYnc/2vlUiI4gFVeilWLMW00VGTWV+7V1oIzIYvWHyl2QpBq
> >>> >>>>>>>> 4/ZwVjQ43qLfuDTS4o+IJ4ztOMd26vIv6Mn6WVwKCjoCXJc8ajywR9Dy+6lL
> >>> >>>>>>>> o8oJ+tn7hMc9Qy1iBhu3/QIP4WCsUf9RVeu60oahNEpde89qW32S9CZlrJDO
> >>> >>>>>>>> gf4iTryRjkAhdmZIj9JiaE8jQ6dvN817D9cqs/CXKV9vhzYoM7p5YWHghBKB
> >>> >>>>>>>> J3hS
> >>> >>>>>>>> =0J7F
> >>> >>>>>>>> -----END PGP SIGNATURE-----
> >>> >>>>>>>> ----------------
> >>> >>>>>>>> Robert LeBlanc
> >>> >>>>>>>> PGP Fingerprint 79A2 9CA4 6CC4 45DD A904  C70E E654 3BB2 FA62 B9F1
> >>> >>>>>>>>
> >>> >>>>>>>>
> >>> >>>>>>>> On Tue, Sep 22, 2015 at 8:31 AM, Gregory Farnum  wrote:
> >>> >>>>>>>>>
> >>> >>>>>>>>> On Tue, Sep 22, 2015 at 7:24 AM, Robert LeBlanc  wrote:
> >>> >>>>>>>>>>
> >>> >>>>>>>>>> -----BEGIN PGP SIGNED MESSAGE-----
> >>> >>>>>>>>>> Hash: SHA256
> >>> >>>>>>>>>>
> >>> >>>>>>>>>> Is there some way to tell in the logs that this is happening?
> >>> >>>>>>>>>
> >>> >>>>>>>>>
> >>> >>>>>>>>> You can search for the (mangled) name _split_collection
> >>> >>>>>>>>>>
> >>> >>>>>>>>>> I'm not
> >>> >>>>>>>>>> seeing much I/O, CPU usage during these times. Is there some way to
> >>> >>>>>>>>>> prevent the splitting? Is there a negative side effect to doing so?
> >>> >>>>>>>>>
> >>> >>>>>>>>>
> >>> >>>>>>>>> Bump up the split and merge thresholds. You can search the list for
> >>> >>>>>>>>> this, it was discussed not too long ago.
> >>> >>>>>>>>>
> >>> >>>>>>>>>> We've had I/O block for over 900 seconds and as soon as the sessions
> >>> >>>>>>>>>> are aborted, they are reestablished and complete immediately.
> >>> >>>>>>>>>>
> >>> >>>>>>>>>> The fio test is just a seq write, starting it over (rewriting from
> >>> >>>>>>>>>> the
> >>> >>>>>>>>>> beginning) is still causing the issue. I was suspect that it is not
> >>> >>>>>>>>>> having to create new file and therefore split collections. This is
> >>> >>>>>>>>>> on
> >>> >>>>>>>>>> my test cluster with no other load.
> >>> >>>>>>>>>
> >>> >>>>>>>>>
> >>> >>>>>>>>> Hmm, that does make it seem less likely if you're really not creating
> >>> >>>>>>>>> new objects, if you're actually running fio in such a way that it's
> >>> >>>>>>>>> not allocating new FS blocks (this is probably hard to set up?).
> >>> >>>>>>>>>
> >>> >>>>>>>>>>
> >>> >>>>>>>>>> I'll be doing a lot of testing today. Which log options and depths
> >>> >>>>>>>>>> would be the most helpful for tracking this issue down?
> >>> >>>>>>>>>
> >>> >>>>>>>>>
> >>> >>>>>>>>> If you want to go log diving "debug osd = 20", "debug filestore =
> >>> >>>>>>>>> 20",
> >>> >>>>>>>>> "debug ms = 1" are what the OSD guys like to see. That should spit
> >>> >>>>>>>>> out
> >>> >>>>>>>>> everything you need to track exactly what each Op is doing.
> >>> >>>>>>>>> -Greg
> >>> >>>>>>>>
> >>> >>>>>>>> --
> >>> >>>>>>>> To unsubscribe from this list: send the line "unsubscribe ceph-devel"
> >>> >>>>>>>> in
> >>> >>>>>>>> the body of a message to majordomo@xxxxxxxxxxxxxxx
> >>> >>>>>>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >>> >>>>>>>
> >>> >>>>>>>
> >>> >>>>>>>
> >>> >>>>>
> >>> >>>>> -----BEGIN PGP SIGNATURE-----
> >>> >>>>> Version: Mailvelope v1.1.0
> >>> >>>>> Comment: https://www.mailvelope.com
> >>> >>>>>
> >>> >>>>> wsFcBAEBCAAQBQJWAdMSCRDmVDuy+mK58QAAoEgP/AqpH7i1BLpoz6fTlfWG
> >>> >>>>> a6swvF8xvsyR15PDiPINYT0N7MgoikikGrMmhWpJ6utEr1XPW0MPFgzvNIsf
> >>> >>>>> a1eMtNzyww4rAo6JCq6BtjmUsSKmOrBNhRNr6It9v4Nv+biqZHkiY8x/rRtV
> >>> >>>>> s9z0cv3Q9Wqa6y/zKZg3H1XtbtUAx0r/DUwzSsP3omupZgNyaKkCgdkil9Vc
> >>> >>>>> iyzBxFZU4+qXNT2FBG4dYDjxSHQv4psjvKR3AWXSN4yEn286KyMDjFrsDY5B
> >>> >>>>> izS3h603QPoErqsUQngDE8COcaTAHHrV7gNJTikmGoNW6oQBjFq/z/zindTz
> >>> >>>>> caXshVQQ+OTLo/qzJM8QPswh0TGU74SVbDkTq+eTOb5pBhQbp+42Pkkqh7jj
> >>> >>>>> efyyYgDzpB1WrWRbUlWMNqmnjq7DT3lnAtuHyKbkwVs8x3JMPEiCl6PBvJbx
> >>> >>>>> GnNSCqgDJrpb4fHQ2iqfQeh8Ai6AL1C1Ai19RZPrAUhpDW0/DbUvuoKSR8m7
> >>> >>>>> glYYuH3hpy+oPYRhFcHm2fpNJ3u9npyk2Dai9RpzQ+mWmp3xi7becYmL482H
> >>> >>>>> +WyvLeY+8AiJQDpA0CdD8KeSlOC9bw5TPmihAIn9dVTJ1O2RlapCLqL3YAJg
> >>> >>>>> pGyDs8ercTEJLmvEyElj5XWh5DarsGscd2LELNS/UpyuYurbPcyPKUQ0uPjp
> >>> >>>>> gcZm
> >>> >>>>> =CjwB
> >>> >>>>> -----END PGP SIGNATURE-----
> >>> >>>>
> >>> >>>> --
> >>> >>>> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
> >>> >>>> the body of a message to majordomo@xxxxxxxxxxxxxxx
> >>> >>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >>> >>>>
> >>> >>>
> >>> >>
> >>> >> -----BEGIN PGP SIGNATURE-----
> >>> >> Version: Mailvelope v1.1.0
> >>> >> Comment: https://www.mailvelope.com
> >>> >>
> >>> >> wsFcBAEBCAAQBQJWAv3QCRDmVDuy+mK58QAABr4QAJcQj8zjl606aMdkmQG7
> >>> >> S46iMXVav/Tv2os9GCUsQmMPx2u1w3/WmPfjByd6Divczfo0JLDDqrbsqre2
> >>> >> lq0GNK6e8fq6FXHhPpnL+t4uFV4UZ289cma3yklRqEBDXWHlP59Hu7VpxC5l
> >>> >> 0MIcCg4wM5VM/LkrfcMven5em5CnjyFJYbActGzw9043rZoyUwCM+eL7sotl
> >>> >> JYHMcNWnqwdt8TLFDhUfVGiAQyV8/6E33CuCNUEuFGdtiBKzs9IZadOI8Ce0
> >>> >> dod2DQNyFSvomqNq6t0DuTCSA+pT8uuks2O0NcrHjoqwIWVkxQGPYlpbpckf
> >>> >> nxQdVM7vkqapVeQ0qUZx43Db9A5wDTC3PaEfVJZPZzWsSDjh9z7o6qHs3Kvp
> >>> >> krfyS+dJaZ3tOYAP1VFDfasj06sOTFu3mfGYToKA75zz5HN7QZ13Zau/qhDu
> >>> >> FHxsgk4oIXJsjj22LiSpoiigH5Ls+aVqtIbg8/vWp+EO6pK1fovEtJVeGAfE
> >>> >> tLOdxfJJLVjMCAScFG9BRl1ePPLeptivKV0v9ruWsTpn+Q96VtqAR5GQCkYE
> >>> >> hFrlxM+oIzHeArhhiIxSPCYLlnzxoD5IYXmTrWUYBCGvlY1mrI3j80mZ4VTj
> >>> >> BErsSlqnjUyFKmaI7YNKyARCloMroz3wqdy/wpg/63Io62nmh5IyY+WO8hPo
> >>> >> ae22
> >>> >> =AX+L
> >>> >> -----END PGP SIGNATURE-----
> >>> _______________________________________________
> >>> 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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