[SERVER-53662] Investigate if slow DNS resolution warnings are a symptom of an internal slowdown Created: 08/Jan/21 Updated: 27/Oct/23 Resolved: 19/Nov/21 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Task | Priority: | Major - P3 |
| Reporter: | Jordi Serra Torrens | Assignee: | Backlog - Service Architecture |
| Resolution: | Gone away | Votes: | 0 |
| Labels: | servicearch-wfbf-day | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
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| Assigned Teams: |
Service Arch
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| Participants: | |||||
| Story Points: | 5 | ||||
| Description |
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We have recently seen a couple of HELP tickets (HELP-20454 and HELP-20891) where the mongos logs indicate very slow DNS resolutions:
Followed by:
In at least one of the tickets, these errors correlate exactly with a performance degradation in that mongos (https://jira.mongodb.org/browse/HELP-20454?focusedCommentId=3532624&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-3532624) where active sessions get backed up and accumulate. In both tickets, we believe that there was no real DNS infrastructure issue, as reported by the sys admins and also by the fact that no other node in the cluster showed the DNS warnings. In HELP-20891 they even added static entries so it should be resolved locally, but the warnings continue. We suspect that these "slow DNS resolutions" may perhaps actually be a symptom of something getting slowed down within the mongos itself. Both HELP tickets are running a 4.2 cluster. Acceptance Criteria: Generate a consistent repro or hypothesis for this issue and generate a SERVER ticket to fix it, if needed. |
| Comments |
| Comment by Amirsaman Memaripour [ 19/Nov/21 ] |
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This issue has already been investigated and fixed as part of |