[Gluster-users] Question about geo-replication and deletes in 3.5 beta train

CJ Beck chris.beck at workday.com
Thu May 1 17:52:57 UTC 2014


Ok, I have found a way to get back to “ChangeLog”…  This might be related to the similar thread that we have going regarding the method for setting up the initial geo-replication session. Seems as though when geo-repliation is set up on my cluster, it tried to open the changelog fifo, but it wasn’t there.

In order to fix this, I had to do the following:


  *   Stop geo-replication
  *   Stop volume
  *   Start volume
  *   Change geo-replication “change_detector” to changelog
  *   Start geo-replication

Once I did that, it went to Hybrid mode first, then changed to ChangeLog mode.

-CJ

From: CJ Beck <chris.beck at workday.com<mailto:chris.beck at workday.com>>
Date: Thursday, May 1, 2014 at 10:28 AM
To: Venky Shankar <yknev.shankar at gmail.com<mailto:yknev.shankar at gmail.com>>
Cc: "gluster-users at gluster.org<mailto:gluster-users at gluster.org>" <gluster-users at gluster.org<mailto:gluster-users at gluster.org>>
Subject: Re: [Gluster-users] Question about geo-replication and deletes in 3.5 beta train

I just noticed this, which might be related to the change to xsync?

[root at dev604 eafea2c974a3c29ecfbf48cea274dc23]# more changes.log
[2014-04-30 15:45:27.807181] I [gf-changelog.c:179:gf_changelog_notification_init] 0-glusterfs: connecting to changelog socket: /var/run/gluster/changelog-eafea2c974a3c29ecfbf48cea274dc23.sock (brick: /data/sac-poc)
[2014-04-30 15:45:27.807257] W [gf-changelog.c:189:gf_changelog_notification_init] 0-glusterfs: connection attempt 1/5...
[2014-04-30 15:45:29.807404] W [gf-changelog.c:189:gf_changelog_notification_init] 0-glusterfs: connection attempt 2/5...
[2014-04-30 15:45:31.807607] W [gf-changelog.c:189:gf_changelog_notification_init] 0-glusterfs: connection attempt 3/5...
[2014-04-30 15:45:33.807818] W [gf-changelog.c:189:gf_changelog_notification_init] 0-glusterfs: connection attempt 4/5...
[2014-04-30 15:45:35.808038] W [gf-changelog.c:189:gf_changelog_notification_init] 0-glusterfs: connection attempt 5/5...
[2014-04-30 15:45:37.808239] E [gf-changelog.c:204:gf_changelog_notification_init] 0-glusterfs: could not connect to changelog socket! bailing out...

From: CJ Beck <chris.beck at workday.com<mailto:chris.beck at workday.com>>
Date: Wednesday, April 30, 2014 at 2:50 PM
To: Venky Shankar <yknev.shankar at gmail.com<mailto:yknev.shankar at gmail.com>>
Cc: "gluster-users at gluster.org<mailto:gluster-users at gluster.org>" <gluster-users at gluster.org<mailto:gluster-users at gluster.org>>
Subject: Re: [Gluster-users] Question about geo-replication and deletes in 3.5 beta train

I just got back to testing this, and for some reason on my “freshly” created cluster and geo-replication session, it’s defaulting to “Hybrid Mode”. It also keeps bouncing back to xsync as the change method (it seems).

Geo-replication log:
[root at dev604 gluster-poc]# egrep -i 'changelog|xsync' *
ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc.log:[2014-04-30 15:45:27.763072] I [master(/data/gluster-poc):58:gmaster_builder] <top>: setting up xsync change detection mode
ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc.log:[2014-04-30 15:45:27.765294] I [master(/data/gluster-poc):58:gmaster_builder] <top>: setting up changelog change detection mode
ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc.log:[2014-04-30 15:45:27.768302] I [master(/data/gluster-poc):1103:register] _GMaster: xsync temp directory: /var/run/gluster/gluster-poc/ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc/eafea2c974a3c29ecfbf48cea274dc23/xsync
ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc.log:[2014-04-30 15:45:37.808617] I [master(/data/gluster-poc):682:fallback_xsync] _GMaster: falling back to xsync mode
ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc.log:[2014-04-30 15:45:52.113879] I [master(/data/gluster-poc):58:gmaster_builder] <top>: setting up xsync change detection mode
ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc.log:[2014-04-30 15:45:52.116525] I [master(/data/gluster-poc):58:gmaster_builder] <top>: setting up xsync change detection mode
ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc.log:[2014-04-30 15:45:52.120129] I [master(/data/gluster-poc):1103:register] _GMaster: xsync temp directory: /var/run/gluster/gluster-poc/ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc/eafea2c974a3c29ecfbf48cea274dc23/xsync
ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc.log:[2014-04-30 15:45:52.120604] I [master(/data/gluster-poc):1103:register] _GMaster: xsync temp directory: /var/run/gluster/gluster-poc/ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc/eafea2c974a3c29ecfbf48cea274dc23/xsync
ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc.log:[2014-04-30 15:45:54.146847] I [master(/data/gluster-poc):1133:crawl] _GMaster: processing xsync changelog /var/run/gluster/gluster-poc/ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc/eafea2c974a3c29ecfbf48cea274dc23/xsync/XSYNC-CHANGELOG.1398872752
ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc.log:[2014-04-30 15:47:08.204514] I [master(/data/gluster-poc):58:gmaster_builder] <top>: setting up xsync change detection mode
ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc.log:[2014-04-30 15:47:08.206767] I [master(/data/gluster-poc):58:gmaster_builder] <top>: setting up xsync change detection mode
ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc.log:[2014-04-30 15:47:08.210570] I [master(/data/gluster-poc):1103:register] _GMaster: xsync temp directory: /var/run/gluster/gluster-poc/ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc/eafea2c974a3c29ecfbf48cea274dc23/xsync
ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc.log:[2014-04-30 15:47:08.211069] I [master(/data/gluster-poc):1103:register] _GMaster: xsync temp directory: /var/run/gluster/gluster-poc/ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc/eafea2c974a3c29ecfbf48cea274dc23/xsync
ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc.log:[2014-04-30 15:47:09.247109] I [master(/data/gluster-poc):1133:crawl] _GMaster: processing xsync changelog /var/run/gluster/gluster-poc/ssh%3A%2F%2Froot%4010.10.10.120%3Agluster%3A%2F%2F127.0.0.1%3Agluster-poc/eafea2c974a3c29ecfbf48cea274dc23/xsync/XSYNC-CHANGELOG.1398872828


[root at dev604 gluster-poc]# gluster volume geo-replication gluster-poc 10.10.10.120::gluster-poc  status detail

MASTER NODE               MASTER VOL    MASTER BRICK     SLAVE                     STATUS     CHECKPOINT STATUS    CRAWL STATUS    FILES SYNCD    FILES PENDING    BYTES PENDING    DELETES PENDING    FILES SKIPPED
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
dev604.domain.com    gluster-poc       /data/gluster-poc    10.10.10.120::gluster-poc    Active     N/A                  Hybrid Crawl    0              323              0                0                  0
dev606.domain.com    gluster-poc       /data/gluster-poc    10.10.10.122::gluster-poc    Passive    N/A                  N/A             0              0                0                0                  0
dev605.domain.com    gluster-poc       /data/gluster-poc    10.10.10.121::gluster-poc    Passive    N/A                  N/A             0              0                0                0                  0



From: Venky Shankar <yknev.shankar at gmail.com<mailto:yknev.shankar at gmail.com>>
Date: Wednesday, April 23, 2014 at 12:09 PM
To: CJ Beck <chris.beck at workday.com<mailto:chris.beck at workday.com>>
Cc: "gluster-users at gluster.org<mailto:gluster-users at gluster.org>" <gluster-users at gluster.org<mailto:gluster-users at gluster.org>>
Subject: Re: [Gluster-users] Question about geo-replication and deletes in 3.5 beta train

That should not happen. After a replica failover the "now" active node should continue where the "old" active node left off.

Could you provide geo-replication logs from master and slave after reproducing this (with changelog mode).

Thanks,
-venky


On Thu, Apr 17, 2014 at 9:34 PM, CJ Beck <chris.beck at workday.com<mailto:chris.beck at workday.com>> wrote:
I did set it intentionally because I found a case where files would be missed during geo-replication. Xsync seemed to handle the case better. The issue was when you bring the “Active” node down that is handling the geo-replication session, and it’s set to ChangeLog as the change method. Any files that are written into the cluster while geo-replication is down (eg, while the geo-replication session is being failed to another node), are missed / skipped, and won’t ever be transferred to the other cluster.

Is this the expected behavior? If not, then I can open a bug on it.

-CJ

From: Venky Shankar <yknev.shankar at gmail.com<mailto:yknev.shankar at gmail.com>>
Date: Wednesday, April 16, 2014 at 4:43 PM

To: CJ Beck <chris.beck at workday.com<mailto:chris.beck at workday.com>>
Cc: "gluster-users at gluster.org<mailto:gluster-users at gluster.org>" <gluster-users at gluster.org<mailto:gluster-users at gluster.org>>
Subject: Re: [Gluster-users] Question about geo-replication and deletes in 3.5 beta train


On Thu, Apr 17, 2014 at 3:01 AM, CJ Beck <chris.beck at workday.com<mailto:chris.beck at workday.com>> wrote:
I did have the “change_detector” set to xsync, which seems to be the issue (bypassing the changelog method). So I can fix that and see if the deletes are propagated.

​Was that set intentionally? Setting this as the main change detection mechanism would crawl the filesystem every 60 seconds to replicate the changes. Changelog mode handles live changes, so any deletes that were performed before this option was set would not be propagated.


Also, is there a way to tell the geo-replication to go ahead and walk the filesystems to do a “sync” so the remote side files are deleted, if they are not on the source?

​As of now, no. With distributed geo-replication, the geo-rep daemon crawls the bricks (instead of the mount). Since the brick would have a subset of the file system entities (for e.g. in a distributed volume), it's hard to find out purged entries without having to crawl the mount and comparing the entries b/w master and slave (which is slow). This is where changelog mode helps.


Thanks for the quick reply!

[root at host ~]# gluster volume geo-replication test-poc 10.10.1.120::test-poc status detail

MASTER NODE               MASTER VOL    MASTER BRICK     SLAVE                     STATUS     CHECKPOINT STATUS    CRAWL STATUS    FILES SYNCD    FILES PENDING    BYTES PENDING    DELETES PENDING    FILES SKIPPED
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
host1.com<http://host1.com>    test-poc       /data/test-poc    10.10.1.120::test-poc    Passive    N/A                  N/A             382            0                0                0                  0
host2.com<http://host2.com>    test-poc       /data/test-poc    10.10.1.122::test-poc    Passive    N/A                  N/A             0              0                0                0                  0
host3.com<http://host3.com>    test-poc       /data/test-poc    10.10.1.121::test-poc    Active     N/A                  Hybrid Crawl    10765          70               0                0                  0


From: Venky Shankar <yknev.shankar at gmail.com<mailto:yknev.shankar at gmail.com>>
Date: Wednesday, April 16, 2014 at 1:54 PM
To: CJ Beck <chris.beck at workday.com<mailto:chris.beck at workday.com>>
Cc: "gluster-users at gluster.org<mailto:gluster-users at gluster.org>" <gluster-users at gluster.org<mailto:gluster-users at gluster.org>>
Subject: Re: [Gluster-users] Question about geo-replication and deletes in 3.5 beta train

"ignore-deletes" is only valid in the initial crawl mode[1] where it does not propagate deletes to the slave (changelog mode does). Was the session restarted by any chance?

[1] Geo-replication now has two internal operations modes: a one shot filesystem crawl mode (used to replicate data already present in a volume) and the changelog mode (for replicating live changes).

Thanks,
-venky



On Thu, Apr 17, 2014 at 1:25 AM, CJ Beck <chris.beck at workday.com<mailto:chris.beck at workday.com>> wrote:
I have an issue where deletes are not being propagated to the slave cluster in a geo-replicated environment. I’ve looked through the code, and it appears as though this is something that might have been changed to be hard coded?

When I try to change it via a config option on the command line, it replies with a “reserved option” error:
[root at host ~]# gluster volume geo-replication test-poc 10.10.1.120::test-poc config ignore_deletes 1
Reserved option
geo-replication command failed
[root at host ~]# gluster volume geo-replication test-poc 10.10.1.120::test-poc config ignore-deletes 1
Reserved option
geo-replication command failed
[root at host ~]#

Looking at the source code (although, I’m not a C expert by any means), it seems as though it’s hard-coded to be “true” all the time?

(from glusterd-geo-rep.c):
4285         /* ignore-deletes */
4286         runinit_gsyncd_setrx (&runner, conf_path);
4287         runner_add_args (&runner, "ignore-deletes", "true", ".", ".", NULL);
4288         RUN_GSYNCD_CMD;

Any ideas how to get deletes propagated to the slave cluster?

Thanks!

-CJ

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