[SERVER-30526] Pre-populating connections of TaskExecutorPool (mongos) Created: 07/Aug/17 Updated: 08/Feb/23 Resolved: 10/Aug/17 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Networking |
| Affects Version/s: | 3.4.4 |
| Fix Version/s: | None |
| Type: | Improvement | Priority: | Major - P3 |
| Reporter: | 아나 하리 | Assignee: | Kelsey Schubert |
| Resolution: | Duplicate | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
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| Description |
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After examining connections between mongos and mongod server, I've found these connections are created when they need even I added setParameter.ShardingTaskExecutorPoolMinSize on mongos.conf. Mongos does not make connections until mongos receives some requests from client. This leads lots of errors (like com.mongodb.MongoSocketReadTimeoutException and com.mongodb.MongoWaitQueueFullException) on client side. There's no easy way to warming-up connections between mongos and mongod because mongos maintains multi-layer connection pools (TaskExecutorPool and SpecificPool). So, I think it would be better that mongos prepare connections as many as "setParameter.ShardingTaskExecutorPoolMinSize" when they start. And then we can do rolling-restart app/web server and mongos smoothly. I've attached mongod connection graph(3 shard cluster, each line is for primary member of each shard) and client timeout (over 3 seconds) error graph. And I hope this could be fixed ASAP, because critical in our service. If this is not fixed, we need to deploy new service code at night. I think other users also experience the same case if they are using rolling deployment also. Regards, |
| Comments |
| Comment by Kelsey Schubert [ 10/Aug/17 ] |
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Thanks for the clarification, matt.lee. I'm closing this ticket in favor of SERVER-26720, which is already on our backlog. Kind regards, |
| Comment by 아나 하리 [ 08/Aug/17 ] |
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Hi Thomas. You right. I had forgotten that. Thanks. |
| Comment by Kelsey Schubert [ 07/Aug/17 ] |
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Hi matt.lee, Would you please clarify how this feature request differs from SERVER-26720? Thank you, |