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 > > [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
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