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Type:
Question
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Resolution: Done
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Priority:
Major - P3
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Affects Version/s: 2.6.6
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Component/s: Admin, Performance, Sharding
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3
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Dear MongoDB Support Team,
I have a problem that automatic migration process has taken a long time to distribute chunks to new shards. It actually took 35 days in my environment until the number of all chunks became even, with the default chunk size(64M). Please see the details below for what I have done on my sharded cluster.
| when | what |
|---|---|
| 11th, March | Cluster was running with 7 shards, 2186 chunks for each. |
| 12th, March | Added new 3 shards to cluster and auto migration started. 10 shards from then on. |
| 18th, April | Migration has completed. Now, cluster is running with 10 shards, 1828 chunks for each. |
My question is: would it be faster to process chunk migration if manually operated? If the manual migration will improve the speed of the entire migration process, I would opt for it when adding new shards next time.
I have had some tries at seeing how moveChunk() works with a couple of options such as `_secondaryThrottle` or `_waitForDelete` experimentally with the balancer temporarily off, however, I am not sure how it affects the whole performance.
It would be really appreciated if I could gain some of your insights about this.
Best Regards,
Kazuo Yagi