Tukas, I am not able to completely understand the problem. What you are saying is if afr has 2 subvolumes things work fine. If it has more than 2 subvols then NS does unnecessary reads/writes? or does it do unnecessary mkdirs? After doing the setup what do I need to do to see the problem that you are seeing? Krishna On Fri, Aug 29, 2008 at 11:58 PM, Łukasz Mierzwa <l.mierzwa@xxxxxxxxx> wrote: > Friday 29 August 2008 20:21:57 Łukasz Mierzwa napisał(a): >> Friday 29 August 2008 20:13:45 Łukasz Mierzwa napisał(a): >> > Thursday 28 August 2008 15:29:06 Łukasz Mierzwa napisał(a): >> > > Thursday 28 of August 2008 12:39:03 napisałeś(-łaś): >> > > > On Thu, Aug 28, 2008 at 3:01 PM, Łukasz Mierzwa <l.mierzwa@xxxxxxxxx> >> > >> > wrote: >> > > > > Thursday 28 of August 2008 07:06:30 Krishna Srinivas napisał(a): >> > > > >> On Wed, Aug 27, 2008 at 10:55 PM, Łukasz Mierzwa >> > > > >> <l.mierzwa@xxxxxxxxx> >> > > > > >> > > > > wrote: >> > > > >> > Tuesday 26 August 2008 16:28:41 Łukasz Mierzwa napisał(a): >> > > > >> >> Hi, >> > > > >> >> >> > > > >> >> I testing glusterfs for small files storage, first I've setup a >> > > > >> >> single disk gluster server, connected to it from another >> > > > >> >> machine and served those files with nginx. That worked ok, I >> > > > >> >> got good performance, on average about +20ms slower for each >> > > > >> >> request but that's ok. Now I've setup unify over afr (2 afr >> > > > >> >> groups with 3 servers each, unify and afr on the client side, >> > > > >> >> namespace dir is on every server, as other stuff afr'ed on the >> > > > >> >> client side), this is mounted on one of those 6 servers. After >> > > > >> >> writing ~200GB files from production server I started to do >> > > > >> >> some tests and I've noticed that doing simple ls on that mount >> > > > >> >> point causes as many writes as reads, this has to do something >> > > > >> >> to either unify or afr, I suspect that those writes are do to >> > > > >> >> namespace but I need to do more debugging. It's very annoying >> > > > >> >> that simple reads are causing so many writes. All my servers >> > > > >> >> are in sync so there should not be any need for sealf-healing. >> > > > >> >> Before I start debugging it I wanted to ask if this is normal? >> > > > >> >> Shoud afr or unify generate so many writes to namespace or >> > > > >> >> maybe xattrs during reads (storage is on ext3 with users_xattrs >> > > > >> >> on)? >> > > > >> > >> > > > >> > I tested it a little bit today and I found out that if I got 1 >> > > > >> > or 2 nodes in my afr group for namespace there are no writes at >> > > > >> > all while doing ls, if I add one or more nodes they are starting >> > > > >> > to get writes. WTF? >> > > > >> >> > > > >> Do you mean that your NS is getting write() calls when you do >> > > > >> "ls"? >> > > > > >> > > > > It seems so. I will split my NS and DATA bricks to different disks >> > > > > today so I will be 100% sure. What I am sure now is that I am >> > > > > getting as many writes as reads when I do "ls" and have more than 2 >> > > > > NS bricks in AFR. >> > > > >> > > > reads/writes should not happen when you do an 'ls' where are you >> > > > seeing reads and writes being done? How are you seeing it? are you >> > > > strace'ing the glusterfsd? >> > > > >> > > > Krishna >> > > >> > > I first noticed them when I looked at rrd graphs for those machines, I >> > > wanted to see if AFR is balancing reads. I can see them in rrd graphs >> > > generated from collectd, dstat, iotop and iostat, they are happening. I >> > > first tried to find something in my config and forgot about such >> > > obvious step as straceing glusterfs. I attach log from one of the >> > > servers, I straced gluster-server on this machine, You can see that >> > > there is a lot of mkdir/chown/chmod on files that are already there, >> > > all bricks were online when I was writing files to gluster client so no >> > > self-heal should be needed. I've also attached client and server >> > > configs. >> > >> > I attached strace log from gluster-server, this time I removed all but >> > last two ns servers, I straced brick with ns, no mkdir/chmod this time. >> >> Missing attachment > > Hmm, something is eating my attachments. > Grab it from: > http://doc.grono.org/gl_2ns.log.bz2 > > -- > Łukasz Mierzwa > > Grono.net S.A. > ul. Szturmowa 2a, 02-678 Warszawa > Sąd Rejonowy dla m.st. Warszawy, XIII Wydział Gospodarczy; > Nr KRS 0000292169 , NIP: 929-173-90-15 Regon: 141197097 Kapitał > zakładowy: 550.000,00 zł > http://grono.net/ > > Treść tej wiadomości jest poufna i prawnie chroniona. Odbiorca może być > jedynie jej adresat z wyłączeniem dostępu osób trzecich. Jeżeli nie > jesteś adresatem niniejszej wiadomości, jej rozpowszechnianie, > kopiowanie, rozprowadzanie lub inne działanie o podobnym charakterze > jest prawnie zabronione i może by karalne. Jeżeli wiadomość ta trafiła > do Ciebie omyłkowo, uprzejmie prosimy o odesłanie jej na adres nadawcy i > usunięcie. > > _______________________________________________ > Gluster-devel mailing list > Gluster-devel@xxxxxxxxxx > http://lists.nongnu.org/mailman/listinfo/gluster-devel > >
