Operational Defect Database

BugZero found this defect 2437 days ago.

MongoDB | 396869

[SERVER-29787] MongoDB allocate and free too much memory

Last update date:


Affected products:

MongoDB Server

Affected releases:


Fixed releases:

No fixed releases provided.



When few queries process many documents (for example, full collection scan), MongoDB allocate and deallocate too much memory. So after few full scan query, free memory of linux is decreased and eventually linux use swap space. Take a look at the attached graph. And this case happen very often. I think you can reproduce this case easily.

Top User Comments

mark.agarunov commented on Wed, 5 Jul 2017 15:14:18 +0000: Hello matt.lee, Thank you for the response. As this issue cannot currently be reproduced, I've closed this ticket. If this is an issue for you in the future, please let us know and we will reopen the ticket. Thanks, Mark sunguck.lee@gmail.com commented on Fri, 30 Jun 2017 08:50:20 +0000: Hi Mark. I have seen this case in quite a while, so diagnostics data is gone. So I have tried to reproduce it but I can't. I will get back again with diagnostics data when I see similar case. Thanks. mark.agarunov commented on Thu, 22 Jun 2017 15:34:20 +0000: Hello matt.lee, Thank you for the report. To better understand what may be causing the memory usage, could you please archive and upload the $dbPath/diagnostic.data directory and attach it to this ticket? This should give us a better idea of what may be using the memory. Thanks, Mark

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