Hi, Yes the file has no contents until the page cache is flushed.
I will give the fuse client a try and report back. Thanks On Mon, Aug 29, 2016 at 7:11 PM, Gregory Farnum <[email protected]> wrote: > On Mon, Aug 29, 2016 at 7:14 AM, Sean Redmond <[email protected]> > 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 > > [email protected] > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > >
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