On Tue, Aug 30, 2016 at 2:11 AM, Gregory Farnum <gfarnum@xxxxxxxxxx> wrote: > On Mon, Aug 29, 2016 at 7:14 AM, Sean Redmond <sean.redmond1@xxxxxxxxx> wrote: >> Hi, >> >> I am running cephfs (10.2.2) with kernel 4.7.0-1. I have noticed that >> frequently static files are showing empty when serviced via a web server >> (apache). I have tracked this down further and can see when running a >> checksum against the file on the cephfs file system on the node serving the >> empty http response the checksum is '00000' >> >> The below shows the checksum on a defective node. >> >> [root@server2]# ls -al /cephfs/webdata/static/456/JHL/66448H-755h.jpg >> -rw-r--r-- 1 apache apache 53317 Aug 28 23:46 >> /cephfs/webdata/static/456/JHL/66448H-755h.jpg It seems this file was modified recently. Maybe the web server silently modifies the files. Please check if this issue happens on older files. Regards Yan, Zheng >> >> [root@server2]# sum /cephfs/webdata/static/456/JHL/66448H-755h.jpg >> 00000 53 > > So can we presume there are no file contents, and it's just 53 blocks of zeros? > > This doesn't sound familiar to me; Zheng, do you have any ideas? > Anyway, ceph-fuse shouldn't be susceptible to this bug even with the > page cache enabled; if you're just serving stuff via the web it's > probably a better idea anyway (harder to break, easier to update, > etc). > -Greg > >> >> The below shows the checksum on a working node. >> >> [root@server1]# ls -al /cephfs/webdata/static/456/JHL/66448H-755h.jpg >> -rw-r--r-- 1 apache apache 53317 Aug 28 23:46 >> /cephfs/webdata/static/456/JHL/66448H-755h.jpg >> >> [root@server1]# sum /cephfs/webdata/static/456/JHL/66448H-755h.jpg >> 03620 53 >> [root@server1]# >> >> If I flush the cache as shown below the checksum returns as expected and the >> web server serves up valid content. >> >> [root@server2]# echo 3 > /proc/sys/vm/drop_caches >> [root@server2]# sum /cephfs/webdata/static/456/JHL/66448H-755h.jpg >> 03620 53 >> >> After some time typically less than 1hr the issue repeats, It seems to not >> repeat if I take any one of the servers out of the LB and only serve >> requests from one of the servers. >> >> I may try and use the FUSE client has has a mount option direct_io that >> looks to disable page cache. >> >> I have been hunting in the ML and tracker but could not see anything really >> close to this issue, Any input or feedback on similar experiences is >> welcome. >> >> Thanks >> >> >> _______________________________________________ >> 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 _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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