[DOCS-5701] Jumbo chunks are never cleared automatically Created: 23/Jun/15 Updated: 30/Oct/23 Resolved: 01/Nov/22 |
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| Status: | Closed |
| Project: | Documentation |
| Component/s: | manual, Server |
| Affects Version/s: | None |
| Fix Version/s: | Server_Docs_20231030 |
| Type: | Bug | Priority: | Major - P3 |
| Reporter: | Kevin Pulo | Assignee: | Unassigned |
| Resolution: | Won't Fix | Votes: | 2 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
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| Participants: | |||||||||||||
| Days since reply: | 1 year, 14 weeks, 1 day ago | ||||||||||||
| Epic Link: | DOCSP-1769 | ||||||||||||
| Description |
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This page: http://docs.mongodb.org/manual/tutorial/clear-jumbo-flag/ erroneously claims
This is not true. It looks like This ticket is to request that the above sentence be replaced by one that explains when jumbo is cleared (currently only on successful chunk split), and that this means sometimes it needs to be cleared manually. |
| Comments |
| Comment by Education Bot [ 01/Nov/22 ] |
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Hello! This ticket has been closed due to inactivity. If you believe this ticket is still important, please reopen it and leave a comment to explain why. Thank you! |
| Comment by Kevin Pulo [ 26/Jun/15 ] |
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Oops, sorry about this — my testing wasn't sufficient. The jumbo flag can be cleared in certain circumstances, which (at the moment) are independent of whether or not the chunk is still jumbo. However, if the flag gets cleared, and the chunk is still actually jumbo, then at some later time it'll get marked jumbo again. The circumstances when jumbo will or won't be cleared are pretty complicated, but I think that "when the mongos reloads or rewrites the chunk metadata" isn't terribly useful for most users. Based on this, my suggestion is to change the second paragraph to something like:
I think it's also worth mentioning on this page the implications of jumbo chunks, namely, that the balancer does not attempt to split or migrate them. EDIT: I also think it might be useful to specify in the first paragraph that one of the leading causes of large chunks that cannot be split is poor shard key cardinality (with a link to the Considerations for Selecting Shard Key). |