[SERVER-60374] Unique index performance degradation after upgrading from 4.4.3 to 5.0.3 Created: 01/Oct/21 Updated: 11/Jul/22 Resolved: 11/Jul/22 |
|
| Status: | Closed |
| Project: | Core Server |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Bug | Priority: | Major - P3 |
| Reporter: | Gábor Mező | Assignee: | Eric Sedor |
| Resolution: | Done | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Operating System: | ALL |
| Steps To Reproduce: |
The required time between 2-4 slowly increases with 5.0.3, but stay the same with 4.4.3. |
| Participants: |
| Description |
|
The issue is the following: I have a testing environment with bunch of integration tests running one after the other. They are using MongoDB, and using the same database and collections. I only have some unique indices there and there, there are no regular indices. Between fixtures I reset the database just by calling collection.deleteMany({}) in each collection. In 4.4.3 it was fine, but after 5.0.3 upgrade I noticed a serious performance degradation. After some investigation, I found that every test case took a slightly more time to run than the previous one, and it slowly added up, and to the end I can see test cases took 2x more time to finish than did with 4.4.3. What I ended up with, when I drop and recreate indices between fixtures, I get the same performance as it was with 4.4.3. So I suspect that somehow unique indices of deleted entries are not getting deleted automatically causing performance degradation for live data. |
| Comments |
| Comment by Eric Sedor [ 11/Jul/22 ] |
|
We haven’t heard back from you for some time, so I’m going to close this ticket. If this is still an issue for you, please provide additional information and we will reopen the ticket. Thank you! |
| Comment by Brooke Miller [ 12/May/22 ] |
|
We still need additional information to diagnose the problem. If this is still an issue for you, would you please provide the information Eric requested above? Regards, Brooke |
| Comment by Eric Sedor [ 04/Mar/22 ] |
|
Thanks gabor42mezo@gmail.com; Since I've been unable to reproduce this, would you be able archive (tar or zip) the $dbpath/diagnostic.data directory (the contents are described here) for this test on both 4.4.11 and 5.0.6, and attach them to this ticket? |
| Comment by Gábor Mező [ 04/Mar/22 ] |
|
| Comment by Gábor Mező [ 12/Feb/22 ] |
|
Hey, sorry, the notification got landed in my spam folder. I'm gonna get back to you on Monday. |
| Comment by Eric Sedor [ 31/Jan/22 ] |
|
Hi gabor42mezo@gmail.com, can I follow up with you on my questions above? |
| Comment by Eric Sedor [ 20/Oct/21 ] |
|
Hi gabor42mezo@gmail.com, and thank you so far. I've been investigating the possible relationship to I've also attempted an initial reproduction without much success. Can you please provide some additional information about your proposed reproduction:
|