On Fri, Jan 31, 2020 at 11:06 AM Dan van der Ster <dan@vanderster.com> wrote:
Hi all,
We are quite regularly (a couple times per week) seeing:
HEALTH_WARN 1 clients failing to respond to capability release; 1 MDSs report slow requests MDS_CLIENT_LATE_RELEASE 1 clients failing to respond to capability release mdshpc-be143(mds.0): Client hpc-be028.cern.ch: failing to respond to capability release client_id: 52919162 MDS_SLOW_REQUEST 1 MDSs report slow requests mdshpc-be143(mds.0): 1 slow requests are blocked > 30 secs
Which is being caused by osdc ops stuck in a kernel client, e.g.:
10:57:18 root hpc-be028 /root → cat /sys/kernel/debug/ceph/4da6fd06-b069-49af-901f-c9513baabdbd.client52919162/osdc REQUESTS 9 homeless 0 46559317 osd243 3.ee6ffcdb 3.cdb [243,501,92]/243 [243,501,92]/243 e678697 fsvolumens_355f485c-6319-4ffe-acd6-94a07f2a14b4/10003f09a01.00000057 0x400014 1 read 46559322 osd243 3.ee6ffcdb 3.cdb [243,501,92]/243 [243,501,92]/243 e678697 fsvolumens_355f485c-6319-4ffe-acd6-94a07f2a14b4/10003f09a01.00000057 0x400014 1 read 46559323 osd243 3.969cc573 3.573 [243,330,226]/243 [243,330,226]/243 e678697 fsvolumens_355f485c-6319-4ffe-acd6-94a07f2a14b4/10003f09a56.00000056 0x400014 1 read 46559341 osd243 3.969cc573 3.573 [243,330,226]/243 [243,330,226]/243 e678697 fsvolumens_355f485c-6319-4ffe-acd6-94a07f2a14b4/10003f09a56.00000056 0x400014 1 read 46559342 osd243 3.969cc573 3.573 [243,330,226]/243 [243,330,226]/243 e678697 fsvolumens_355f485c-6319-4ffe-acd6-94a07f2a14b4/10003f09a56.00000056 0x400014 1 read 46559345 osd243 3.969cc573 3.573 [243,330,226]/243 [243,330,226]/243 e678697 fsvolumens_355f485c-6319-4ffe-acd6-94a07f2a14b4/10003f09a56.00000056 0x400014 1 read 46559621 osd243 3.6313e8ef 3.8ef [243,330,521]/243 [243,330,521]/243 e678697 fsvolumens_355f485c-6319-4ffe-acd6-94a07f2a14b4/10003f09a45.0000007a 0x400014 1 read 46559629 osd243 3.b280c852 3.852 [243,113,539]/243 [243,113,539]/243 e678697 fsvolumens_355f485c-6319-4ffe-acd6-94a07f2a14b4/10003f09a3a.0000007f 0x400014 1 read 46559928 osd243 3.1ee7bab4 3.ab4 [243,332,94]/243 [243,332,94]/243 e678697 fsvolumens_355f485c-6319-4ffe-acd6-94a07f2a14b4/10003f099ff.0000073f 0x400024 1 write LINGER REQUESTS BACKOFFS
We can unblock those requests by doing `ceph osd down osd.243` (or restarting osd.243).
This is ceph v14.2.6 and the client kernel is el7 3.10.0-957.27.2.el7.x86_64.
Are there a better way to debug this?
Hi Dan, I assume that these ops don't show up as slow requests on the OSD side? How long did you see it stuck for before intervening? Do you happen to have "debug ms = 1" logs from osd243? Do you have PG autoscaler enabled? Any PG splits and/or merges at the time? Thanks, Ilya