[SERVER-38085] mongod occupied a lot cpu without any workload Created: 12/Nov/18 Updated: 30/Nov/18 Resolved: 30/Nov/18 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Question | Priority: | Major - P3 |
| Reporter: | z dd | Assignee: | Danny Hatcher (Inactive) |
| Resolution: | Done | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Attachments: |
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| Participants: |
| Description |
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I install a community mongodb cluster for test. one of the mongod member eat a lot cpu and memory without any workload, my computer is 2U4G, from top command, cpu is 153%: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND from top -H: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND and I grap those 4 threads stack: Thread 76 (Thread 0x7f552fdb6700 (LWP 4642)):
Is it exepected? mongodb version is 3.4.14 |
| Comments |
| Comment by Danny Hatcher (Inactive) [ 30/Nov/18 ] |
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Hello, As I have not heard back from you and there does not appear to be a bug in the MongoDB server, I will now close this ticket. Thank you, Danny |
| Comment by Danny Hatcher (Inactive) [ 16/Nov/18 ] |
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Hello Zhang, Looking at the server status output, the server has been running for 5 months, it is a member of a sharded cluster, and there is significant load passing through it. Either the server status has come from the wrong server or this server is performing as expected. If you download a new MongoDB binary from our Download Center and run it on a server with no other traffic, I do not expect to see high CPU utilization. If you still do after following those steps, please upload the content of the diagnostic.data folder (from that new binary's dbpath) to this ticket. Thank you very much, Danny |
| Comment by z dd [ 16/Nov/18 ] |
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Hi, I create two instance with different MongoDB version, 3.2.18 and 3.4.14, and hit the same issue. At least, these phenomenon are the same. I am sorry for mismatch that info. "3.2.18.5" is corresponding 3.2.18 MongoDB release version. Thank you very much Zhang
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| Comment by Danny Hatcher (Inactive) [ 14/Nov/18 ] |
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Hello, You mentioned that you are running 3.4.14. However, the server status output returns "3.2.18.5" which is not a released version of MongoDB. Can you please confirm what version of MongoDB you are running? If it is a custom build, are you able to check against a standard release of MongoDB to see if the issue still occurs? Thank you very much, Danny |
| Comment by z dd [ 13/Nov/18 ] |
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from serverStatus command output, cache looks like abnormal "cache" : { ... but i can not find checkpoint thread with pstack command. |