[Bugs] [Bug 1331289] New: glusterd memory overcommit

Thu Apr 28 08:27:27 UTC 2016

https://bugzilla.redhat.com/show_bug.cgi?id=1331289

            Bug ID: 1331289
           Summary: glusterd memory overcommit
           Product: GlusterFS
           Version: mainline
         Component: glusterd
          Keywords: Triaged
          Severity: medium
          Assignee: kaushal at redhat.com
          Reporter: kaushal at redhat.com
                CC: amukherj at redhat.com, bordas.csaba at gmail.com,
                    bugs at gluster.org, ryanlee at zepheira.com
            Blocks: 1268125, 1327751

+++ This bug was initially created as a clone of Bug #1268125 +++

Description of problem:

We were using Gluster 3.3 through 3.5 without issue but needed to add SSL
support.  Due to SSL bugs in earlier versions, the quickest path forward was to
upgrade the network to 3.7.  This generally appears to be fine as files added
are appearing where they should, except that it's caused glusterd to vastly
overcommit memory on both nodes where it runs.

On one (serverA, the 'master'), it had 4GB of RAM to work with, and the other
(serverB) 2GB.  Both got up to around 30GB of committed virtual memory in a
couple of weeks. When other processes were stopped on serverA and glusterd
restarted, the overcommit problem appeared to be alleviated and, if it was
growing at all, grew a lot slower.  We had to resize serverA and took it
offline; at the same time, serverB glusterd shot up to 140GB while it was
offline.  Both are currently at 2GB of RAM (for other reasons) and, after
restarting both daemons, appear to be growing in committed memory at around
4GB/day.

Version of GlusterFS package installed:

3.7.4-ubuntu1~trusty1

Location from which the packages are used:

Launchpad PPA

GlusterFS Cluster Information:

    Number of volumes: 2
    Volume Names: backup, other
    Volume on which the particular issue is seen: N/A
    Type of volumes: backup Replicate, other Distribute
    Volume options if available:

Volume Name: backup
Type: Replicate
Status: Started
Number of Bricks: 1 x 2 = 2
Transport-type: tcp
Bricks:
Brick1: serverA:/glusterfs/brick3/data
Brick2: serverB:/glusterfs/brick3/data
Options Reconfigured:
auth.ssl-allow: [names]
ssl.cipher-list: HIGH:!SSLv2
ssl.certificate-depth: 3
server.ssl: on
client.ssl: on

Volume Name: other
Type: Distribute
Status: Started
Number of Bricks: 1
Transport-type: tcp
Bricks:
Brick1: serverA:/glusterfs/brick4/data
Options Reconfigured:
[same as above]

    Client Information
        OS Type: Linux
        Mount type: GlusterFS

How reproducible:

Have not tried (sorry).

Steps to Reproduce:

    1.
    2.
    3.

Actual results:

Expected results:

Logs Information:

I stripped dates and did a uniq -n on the actual log messages for the glusterd
process.  server setup and SSL connect errors appear together.

  17299  E [socket.c:2863:socket_connect]
(-->/usr/lib/x86_64-linux-gnu/libglusterfs.so.0(gf_timer_proc+0xfb)
[0x7f57813d366b]
-->/usr/lib/x86_64-linux-gnu/libgfrpc.so.0(rpc_clnt_reconnect+0xb9)
[0x7f5781185c59]
-->/usr/lib/x86_64-linux-gnu/glusterfs/3.7.4/rpc-transport/socket.so(+0x755d)
[0x7f577a62255d] ) 0-socket: invalid argument: this->private [Invalid argument]
    400  W [dict.c:1452:dict_get_with_ref]
(-->/usr/lib/x86_64-linux-gnu/glusterfs/3.7.4/xlator/mgmt/glusterd.so(build_shd_graph+0x69)
[0x7f577c95ee99]
-->/usr/lib/x86_64-linux-gnu/libglusterfs.so.0(dict_get_str_boolean+0x22)
[0x7f57813af6a2] -->/usr/lib/x86_64-linux-gnu/libglusterfs.so.0(+0x19406)
[0x7f57813ad406] ) 0-dict: dict OR key (graph-check) is NULL [Invalid argument]
    217  E [socket.c:2388:socket_poller] 0-socket.management: server setup
failed
    217  E [socket.c:352:ssl_setup_connection] 0-socket.management: SSL connect
error
     16  W [dict.c:1452:dict_get_with_ref]
(-->/usr/lib/x86_64-linux-gnu/glusterfs/3.7.4/xlator/mgmt/glusterd.so(build_shd_graph+0x69)
[0x7f3c7c558e99]
-->/usr/lib/x86_64-linux-gnu/libglusterfs.so.0(dict_get_str_boolean+0x22)
[0x7f3c80fa96a2] -->/usr/lib/x86_64-linux-gnu/libglusterfs.so.0(+0x19406)
[0x7f3c80fa7406] ) 0-dict: dict OR key (graph-check) is NULL [Invalid argument]
     11  E [socket.c:2501:socket_poller] 0-socket.management: error in polling
loop

Additional info: 

This is totally unrelated (probably?), but in order to get glusterd to really
start, I had to ln
/usr/lib/x86_64-linux-gnu/glusterfs/3.7.4/xlator/rpc-transport -s
/usr/lib/x86_64-linux-gnu/glusterfs/3.7.4/rpc-transport as the logs were
essentially complaining about being unable to find
xlator/rpc-transport/socket.so.

--- Additional comment from Atin Mukherjee on 2015-10-06 09:11:53 IST ---

Thanks for reporting the issue, however we would need a statedump of running
glusterd instance once the hike is seen. Along with that cmd_history.log is
also expected as that tells the commands performed in the cluster. Otherwise
its almost impossible to analyze what has caused the memory leak.

--- Additional comment from  on 2015-10-07 01:50 IST ---

--- Additional comment from  on 2015-10-07 01:51 IST ---

--- Additional comment from  on 2015-10-07 01:52:21 IST ---

I've generated the statedump files and cut out 6336 sections named
xlator.features.locks.backup-locks.inode from backup.dump.  I'm hoping the
contents of the inode context and the specific names of clients aren't
necessary bits of info and have removed them from the dump files.

The cmd_history.log is pretty empty.  The memory starts leaking immediately on
start/restart.  We're currently mitigating by restarting the process once a
week, the growth rate is quite steady without having done anything else. 
cmd_history does contain successes for updating volume settings (specifically,
SSL allows) that our internal management system runs every half hour.  We could
probably stand to modify it to issue changes only if the values differ, but
that doesn't look to me to be the source of the issue.

--- Additional comment from Atin Mukherjee on 2015-10-07 11:08:33 IST ---

(In reply to ryanlee from comment #4)
> I've generated the statedump files and cut out 6336 sections named
> xlator.features.locks.backup-locks.inode from backup.dump.  I'm hoping the
> contents of the inode context and the specific names of clients aren't
> necessary bits of info and have removed them from the dump files.
> 
> The cmd_history.log is pretty empty.  The memory starts leaking immediately
> on start/restart.  We're currently mitigating by restarting the process once
> a week, the growth rate is quite steady without having done anything else. 
> cmd_history does contain successes for updating volume settings
> (specifically, SSL allows) that our internal management system runs every
> half hour.  We could probably stand to modify it to issue changes only if
> the values differ, but that doesn't look to me to be the source of the issue.

You would need to take a statedump for glusterd process, not the clients. The
attachment indicates the statedump is for clients. Would be able to provide
that?

--- Additional comment from  on 2015-10-07 21:43:10 IST ---

When I searched for gluster and statedump, I found info for running

% gluster volume statedump backup all
% gluster volume statedump other all

on the server, which is what's provided.  If you need something else, you're
going to have to be more precise about how I can make it for you, not just that
you need it.

--- Additional comment from Atin Mukherjee on 2015-10-08 09:55:33 IST ---

You could take a statedump of the glusterd instance with the following command:

kill -SIGUSR1 <pid of glusterd instance>

With that the statedump will be generated in /var/run/gluster with the name as
glusterdump.<pid of glusterd>.timestamp

Hope this clarifies the confusion.

--- Additional comment from  on 2015-10-09 01:33 IST ---

--- Additional comment from  on 2015-10-09 01:33 IST ---

--- Additional comment from  on 2015-10-09 01:34:49 IST ---

Great, thanks.  Perhaps the new attachments will be of more use.

--- Additional comment from Atin Mukherjee on 2015-10-09 11:08:20 IST ---

Statedump helps, however I did ask for the cmd_history.log & glusterd.log file
as well. Along with it could you also provide the output of gluster volume info
output?

--- Additional comment from  on 2015-10-10 00:33:15 IST ---

(In reply to Atin Mukherjee from comment #11)

> however I did ask for the ... glusterd.log file as well

No, you didn't.  But I already summarized the errors in it in the original bug
report.

> cmd_history.log

I've already mentioned it's effectively empty in comment #4.

> the output of gluster volume info output

I already provided it in the original bug report.

--- Additional comment from  on 2016-01-22 01:33:07 IST ---

Still present in 3.7.6.  I wonder if this is related to bug 1258931?

--- Additional comment from Atin Mukherjee on 2016-01-22 09:40:26 IST ---

(In reply to ryanlee from comment #13)
> Still present in 3.7.6.  I wonder if this is related to bug 1258931?

Not really IMO. There is no memory leak/over commit reported in that bug.

--- Additional comment from  on 2016-01-23 02:04:38 IST ---

Sorry, I should have added a bit more context.  Several months on, and the
overcommit spread to all Gluster clients and started forcing one particularly
small node offline due to resource exhaustion.  It maxed out at 1TB on serverA
(probably because the system didn't allow it to commit any more).  Our
requirement for SSL support was for secure access from an offsite Gluster
client, but while enabling SSL provided a way in from one angle, its apparent
memory-hogging side effects meant that client was nearly always disconnected
anyways, so it wasn't going to work.

We went to find a different solution so we could switch back to non-SSL mode
for everything else.  It may not be the same bug, certainly, but I turned off
SSL yesterday, and everything is back to normal - all of the memory overcommits
on the servers and the clients are mercifully gone, and there's no longer a
growth pattern in our  monitoring graphs.

Which is the type of related I meant.  If not the same, they're both rooted in
issues with SSL mode.  Is it possible the inability to connect to the self-heal
daemon manifests as a constantly growing memory overcommit over the course of
months?

Referenced Bugs:

https://bugzilla.redhat.com/show_bug.cgi?id=1268125
[Bug 1268125] glusterd memory overcommit
https://bugzilla.redhat.com/show_bug.cgi?id=1327751
[Bug 1327751] glusterd memory overcommit
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