[DOC 2.1.0] cbbackup loops infinitely

Steve Yen added a comment - 12/Nov/12 3:00 PM There's a couple things going on here that probably need documentation... - cbbackup first contacts the server to get the # of items. But, if the cluster is changing (there are item mutations), that # of items will just be an estimate. - then, cbbackup uses the TAP protocol to perform the backup. But, under some conditions (not all item values are resident in memory), the TAP protocol might actually send duplicate messages. That's why cbbackup reports "msgs" for progress instead of "items" in its numerator, but uses "items" in its denominator. That can lead to >100% in some cases. Whether it leads to >200% is somewhat unexpected, but it depends on the situation and what couchbase server is doing in generating the TAP stream.

Steve Yen added a comment - 12/Nov/12 3:02 PM The 2.0.2 filter isn't correct at the moment. Putting this into 2.0.1 for the moment as it'll be revisited again.

Michael L added a comment - 27/Nov/12 1:13 PM (I am the original poster) Changing the line above to use an IP address rather than hostname seems to have fixed the problem. My backups now run to 100% and then complete as expected. As for the root cause: I don't believe it has anything to do with the cluster changing, since I first encountered this when trying to backup an essentially idle cluster.

Bin Cui added a comment - 06/Dec/12 12:07 PM Verified on a multi-node cluster that cbtransfer get the total item number correctly. And fail to reproduce the bug on the idle cluster.

Mike Wiederhold added a comment - 06/Dec/12 12:53 PM I asked the user on the forums for more information to reproduce this issue. I will post the information here if and when he responds.

Farshid Ghods added a comment - 10/Dec/12 11:30 AM deferring to 2.1 per bug scrub meeting ( Dipti & Farshid -December 7th )

Paul Janssen added a comment - 04/Jan/13 2:24 AM I have the same problem. Observed progress over 32000%. The expected msgs to save is far less than the actual msgs saved. Restore will load the same number of msgs as were actually saved. This will impact backup and restore time. This will impact diskspace.

Paul Janssen added a comment - 04/Jan/13 2:45 AM - edited Using ip-address (local,external) or hostname (localhost) does not make any difference, issue remains.

Maria McDuff added a comment - 25/Mar/13 1:12 PM bug scrub: Bin -- have you had a chance to take a look? pls update. thanks.

Bin Cui added a comment - 25/Mar/13 1:15 PM Cannot reproduce it in house.

Maria McDuff added a comment - 01/Apr/13 5:23 PM per bug scrub: abhinav -- can you please repro in latest 2.0.2 build? thanks.

Abhinav Dangeti added a comment - 01/Apr/13 6:50 PM Cannot reproduce on 2.0.2-749-rel. - 3 nodes, 2 buckets [ root@orange-11601 ~]# /opt/couchbase/bin/cbbackup couchbase://Administrator: password@localhost :8091 ~/backup   [####################] 100.0% (8557766/8558766 msgs) bucket: default, msgs transferred...        : total | last | per sec  batch : 10657 | 10657 | 14.7  byte : 1131794345 | 1131794345 | 1562011.5  msg : 8558766 | 8558766 | 11812.1   [####################] 100.0% (2024739/2024739 msgs) bucket: saslbucket, msgs transferred...        : total | last | per sec  batch : 14775 | 14775 | 86.0  byte : 1367390279 | 1367390279 | 7955075.3  msg : 10583505 | 10583505 | 61571.7 done

Maria McDuff added a comment - 09/Apr/13 7:54 PM not reproducible.

Bin Cui added a comment - 17/May/13 4:18 PM First, the error itself is harmless. The tool tried to transfer design docs and the source cluster doesn't contain any. Since 2.0.2, customer can specify --data-only option for cbtransfer/cbback/cbrestore tool. But we still dont know the root cause why there is such a big difference between the initial msgs to be sent and the final msgs that are transferred.

Bin Cui added a comment - 17/May/13 4:36 PM - edited One possible explanation about the deviant number: 1. the estimate number is the total active item number 2. the actual msg tranferred = total(tap_mutations + tap_delete) For the above customer case where they have 2 million item deleted, we will transfer not only the current active items, but also any deleted items. At again, there will be more msgs transferred if any key will have repeated set/deletions.

Perry Krug added a comment - 18/May/13 5:59 AM Reopening for visibility. Whether the tool is doing the "right" thing or not, there is still a major impact to the user both in terms of disk space being taken up, time being taken and perception of confidence, etc in the backup.

Maria McDuff added a comment - 20/May/13 1:38 PM Anil to work with Bin on customer use case.

Anil Kumar added a comment - 20/May/13 5:59 PM - edited Talked to Bin, here's the update. There are 2 issues here… 1). In case of heavy DGM – tool only captures the 'total active items' in memory and not include the items on disk. Fix for this is to consider also resident-ratio to get the current_item. As per Bin, we have already the stats and this should be low-risk fix. He will be making this fix for 2.0.2. 2). In case of Deletes on items – tool currently only captures the snapshot of 'active items' and doesn't consider any items getting deleted. Hence when it transfers it not only transfers current active items but also any deleted items which is unnecessary. To fix this we require some changes in EP-Engine side to provide stats on deleted items so that tool can smartly ignore those. Considering the timeframe for release this won't make it for 2.0.2 but we will have documentation explaining this to users. [Doc ticket on Karen ]

Abhinav Dangeti added a comment - 20/May/13 6:58 PM When cbbackup was run on a node with 6104188 items (~45% active resident ratio), root@plum-009 :~# /opt/couchbase/bin/cbbackup http://localhost:8091 /data/backup   [##############################] 147.6% (9007021/6104188 msgs) bucket: default, msgs transferred...        : total | last | per sec  batch : 29230 | 29230 | 33.1  byte : 10030064183 | 10030064183 | 11365547.3  msg : 9007021 | 9007021 | 10206.3 done

Bin Cui added a comment - 20/May/13 7:24 PM http://review.couchbase.org/#/c/26431/

Maria McDuff added a comment - 21/May/13 1:05 PM per bug triage, this fix from bin only addresses item 1 (see below): 1). In case of heavy DGM – tool only captures the 'total active items' in memory and not include the items on disk. Fix for this is to consider also resident-ratio to get the current_item. As per Bin, we have already the stats and this should be low-risk fix. He will be making this fix for 2.0.2.

Anil Kumar added a comment - 30/May/13 4:05 PM - edited created new bug to track it here : http://www.couchbase.com/issues/browse/MB-8377