[SERVER-33238] Prevent WiredTiger read ticket count from going negative Created: 09/Feb/18 Updated: 29/Oct/23 Resolved: 09/Feb/18 |
|
| Status: | Closed |
| Project: | Core Server |
| Component/s: | Concurrency, Diagnostics |
| Affects Version/s: | None |
| Fix Version/s: | 3.4.13 |
| Type: | Task | Priority: | Major - P3 |
| Reporter: | Kelsey Schubert | Assignee: | Ramon Fernandez Marina |
| Resolution: | Fixed | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
|
||||||||||||||||
| Backwards Compatibility: | Fully Compatible | ||||||||||||||||
| Participants: | |||||||||||||||||
| Case: | (copied to CRM) | ||||||||||||||||
| Description |
|
Issue Status as of Feb 09, 2018 ISSUE SUMMARY ISSUE IMPACT The default limit of 128 available read tickets becomes effectively larger, thus allowing more readers into the system. Workloads which hit the maximum read ticket limits and rely on this mechanism for back pressure may suffer performance degradation. AFFECTED VERSIONS FIXED VERSIONS |
| Comments |
| Comment by Ramon Fernandez Marina [ 11/Feb/18 ] |
|
aqueen, 3.4.13 is now available for download. |
| Comment by Kelsey Schubert [ 09/Feb/18 ] |
|
Hi aqueen, I've updated the ticket description to include more details about this issue and its severity. To reiterate the new description, I expect most users running on MongoDB 3.4.12 will only observe reporting irregularities that may cause false alarm. However, workloads which hit the maximum read ticket limits and rely on this mechanism for back pressure may suffer, since the server will not enforce this limit. We expect MongoDB 3.4.13 to be released soon, so I'd suggest waiting for it regardless of whether or not it's a significant issue for your workload. Kind regards, |
| Comment by Githook User [ 09/Feb/18 ] |
|
Author: {'email': 'ramon@mongodb.com', 'name': 'Ramon Fernandez'}Message: This reverts commit 4fa890fa8b6ba3b438213efcfab07b588fd58e63. |
| Comment by Aaron Queen [ 09/Feb/18 ] |
|
I had planned on upgrading some production servers soon to 3.4.12 and I'm worried about a potential issue. What is the severity of this problem? Is this issue something that could cause issues in production in 3.4.12 and should I hold off on upgrading until 3.4.13 is released with the change reverted or the underlying issue resolved? |