[SERVER-19136] oplog seems to slow down everything Created: 25/Jun/15 Updated: 30/Jul/15 Resolved: 30/Jul/15 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Performance, WiredTiger |
| Affects Version/s: | 3.0.1, 3.0.3 |
| Fix Version/s: | None |
| Type: | Bug | Priority: | Major - P3 |
| Reporter: | Kay Agahd | Assignee: | Ramon Fernandez Marina |
| Resolution: | Duplicate | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Attachments: |
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| Operating System: | ALL | ||||||||
| Participants: | |||||||||
| Description |
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We are using mongodb v3.0.1 and v3.0.3 for two different replSets, each consisting of 3 physical members. Both are using wiredTiger with defaults settings. After some weeks of normal operation, we observed that queries became significantly slower. By analyzing the log files with mlogvis, we found an unusal high amount of operations on the oplog which did not exists before the slowdown. The longest oplog queries took up to 12 seconds! Please see attached two screenshots produced by mlogvis. On the first you can clearly see the long during queries on local.oplog.rs, the stepDown and the re-election. The second screenshot shows the analyzed log file of yesterday, where all was still normal as usual. |
| Comments |
| Comment by Kay Agahd [ 30/Jul/15 ] |
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This is great news, thanks Ramon & team! |
| Comment by Ramon Fernandez Marina [ 30/Jul/15 ] |
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Hi kay.agahd@idealo.de, this is to let you know that MongoDB 3.0.5 was released earlier this week; I'd encourage you to try using it and report back if the oplog performance issues persist. I'm going to close this ticket as a duplicate of Thanks, |
| Comment by Kay Agahd [ 02/Jul/15 ] |
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ramon.fernandez, good to know that this issue might be fixed already in the next release. Thanks! |
| Comment by Ramon Fernandez Marina [ 01/Jul/15 ] |
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Hi kay.agahd@idealo.de, thanks for your report. This may be the same issue reported in Thanks, |