[SERVER-20193] Performance regression in Single-threaded MMS workloads from git: a7338c4 Created: 28/Aug/15 Updated: 07/Dec/15 Resolved: 11/Sep/15 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | WiredTiger |
| Affects Version/s: | None |
| Fix Version/s: | 3.1.8 |
| Type: | Bug | Priority: | Major - P3 |
| Reporter: | Chung-yen Chang | Assignee: | David Hows |
| Resolution: | Done | Votes: | 0 |
| Labels: | mpreg | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
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| Backwards Compatibility: | Fully Compatible | ||||||||||||||||||||||||||||
| Operating System: | ALL | ||||||||||||||||||||||||||||
| Participants: | |||||||||||||||||||||||||||||
| Description |
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Big performance drop (>80%) from git: a7338c4 on single-threaded MMS workloads. Same build was marked red for Geo and Misc cases but there only one test failed for single-threaded cases and the drop was much smaller. I think it's safe to ignore that and just focus on the MMS cases. The commit that caused this was a wiredTiger check-in. WT team is aware of this drop so I am putting WT as the component for this ticket so they can pick this ticket up. |
| Comments |
| Comment by Githook User [ 16/Sep/15 ] | |||||||||||||||||
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Author: {u'username': u'michaelcahill', u'name': u'Michael Cahill', u'email': u'michael.cahill@mongodb.com'}Message: Merge pull request #2188 from wiredtiger/visible_all_call
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| Comment by Githook User [ 16/Sep/15 ] | |||||||||||||||||
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Author: {u'username': u'michaelcahill', u'name': u'Michael Cahill', u'email': u'michael.cahill@mongodb.com'}Message: | |||||||||||||||||
| Comment by Githook User [ 10/Sep/15 ] | |||||||||||||||||
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Author: {u'username': u'agorrod', u'name': u'Alex Gorrod', u'email': u'alexander.gorrod@mongodb.com'}Message: Merge pull request #2177 from wiredtiger/
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| Comment by Githook User [ 10/Sep/15 ] | |||||||||||||||||
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Author: {u'username': u'agorrod', u'name': u'Alex Gorrod', u'email': u'alexander.gorrod@mongodb.com'}Message: Merge pull request #2177 from wiredtiger/
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| Comment by Githook User [ 10/Sep/15 ] | |||||||||||||||||
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Author: {u'username': u'daveh86', u'name': u'David Hows', u'email': u'howsdav@gmail.com'}Message: | |||||||||||||||||
| Comment by Githook User [ 10/Sep/15 ] | |||||||||||||||||
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Author: {u'username': u'daveh86', u'name': u'David Hows', u'email': u'howsdav@gmail.com'}Message: | |||||||||||||||||
| Comment by Michael Cahill (Inactive) [ 07/Sep/15 ] | |||||||||||||||||
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david.hows, I'm pretty sure my comment above explains what's going on here – can you please re-run this and make sure you can see the slowdown? The fix is to call __wt_txn_update_oldest more frequently in this workload, for some definition of "more frequently", so that obsolete updates can be freed before the page size hits memory_page_max. For example, we change the end of __wt_update_serial in btree.i to something like this:
Does that make sense? | |||||||||||||||||
| Comment by Michael Cahill (Inactive) [ 29/Aug/15 ] | |||||||||||||||||
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This is the same issue as |