The important bit there is actually near the end of the message output line, where the first says "ack" and the second says "ondisk". I assume you're using btrfs; the ack is returned after the write is applied in-memory and readable by clients. The ondisk (commit) message is returned after it's durable to the journal or the backing filesystem. -Greg On Wednesday, September 10, 2014, yuelongguang <fastsync at 163.com> wrote: > hi,all > i recently debug ceph rbd, the log tells that one write to osd can get > two if its reply. > the difference between them is seq. > why? > > thanks > ---log--------- > reader got message 6 0x7f58900010a0 osd_op_reply(15 > rbd_data.19d92ae8944a.0000000000000001 [set-alloc-hint object_size 4194304 > write_size 4194304,write 0~3145728] v211'518 uv518 ack = 0) v6 > 2014-09-10 08:47:32.348213 7f58bc16b700 20 -- 10.58.100.92:0/1047669 > queue 0x7f58900010a0 prio 127 > 2014-09-10 08:47:32.348230 7f58bc16b700 20 -- 10.58.100.92:0/1047669 >> > 10.154.249.4:6800/2473 pipe(0xfae6d0 sd=6 :64407 s=2 pgs=133 cs=1 l=1 > c=0xfae940).reader reading tag... > 2014-09-10 08:47:32.348245 7f58bc16b700 20 -- 10.58.100.92:0/1047669 >> > 10.154.249.4:6800/2473 pipe(0xfae6d0 sd=6 :64407 s=2 pgs=133 cs=1 l=1 > c=0xfae940).reader got MSG > 2014-09-10 08:47:32.348257 7f58bc16b700 20 -- 10.58.100.92:0/1047669 >> > 10.154.249.4:6800/2473 pipe(0xfae6d0 sd=6 :64407 s=2 pgs=133 cs=1 l=1 > c=0xfae940).reader got envelope type=43 src osd.1 front=247 data=0 off 0 > 2014-09-10 08:47:32.348269 7f58bc16b700 10 -- 10.58.100.92:0/1047669 >> > 10.154.249.4:6800/2473 pipe(0xfae6d0 sd=6 :64407 s=2 pgs=133 cs=1 l=1 > c=0xfae940).reader wants 247 from dispatch throttler 247/104857600 > 2014-09-10 08:47:32.348286 7f58bc16b700 20 -- 10.58.100.92:0/1047669 >> > 10.154.249.4:6800/2473 pipe(0xfae6d0 sd=6 :64407 s=2 pgs=133 cs=1 l=1 > c=0xfae940).reader got front 247 > 2014-09-10 08:47:32.348303 7f58bc16b700 10 -- 10.58.100.92:0/1047669 >> > 10.154.249.4:6800/2473 pipe(0xfae6d0 sd=6 :64407 s=2 pgs=133 cs=1 l=1 > c=0xfae940).aborted = 0 > 2014-09-10 08:47:32.348312 7f58bc16b700 20 -- 10.58.100.92:0/1047669 >> > 10.154.249.4:6800/2473 pipe(0xfae6d0 sd=6 :64407 s=2 pgs=133 cs=1 l=1 > c=0xfae940).reader got 247 + 0 + 0 byte message > 2014-09-10 08:47:32.348332 7f58bc16b700 10 check_message_signature: seq # > = 7 front_crc_ = 3699418201 middle_crc = 0 data_crc = 0 > 2014-09-10 08:47:32.348369 7f58bc16b700 10 -- 10.58.100.92:0/1047669 >> > 10.154.249.4:6800/2473 pipe(0xfae6d0 sd=6 :64407 s=2 pgs=133 cs=1 l=1 > c=0xfae940).reader got message 7 0x7f5890003660 osd_op_reply(15 > rbd_data.19d92ae8944a.0000000000000001 [set-alloc-hint object_size 4194304 > write_size 4194304,write 0~3145728] v211'518 uv518 ondisk = 0) v6 > > > -- Software Engineer #42 @ http://inktank.com | http://ceph.com -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.ceph.com/pipermail/ceph-users-ceph.com/attachments/20140910/e4ec8165/attachment.htm>
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