potiuk commented on issue #14924:
URL: https://github.com/apache/airflow/issues/14924#issuecomment-912479114


   I looked a bit more. I have a hypothesis what could be the problem - I 
looked at the possibility that we have growing "dirty" memory (i.e. not 
flushed/synchronised to disk).
   
   My hypothesis is that (at least some of) the logs are not flushed and they 
remain in "dirty" (or rather "unsynchronized") state. That would be fairly 
strange as usually "dirty" memory is synchronized after at most few seconds. 
And I believe that the standard "RotatingFileHandler" we use to write processor 
manager lgos should properly close and flush the streams anyway. But maybe you 
have some optimisatios/settings on your OS to prolong/disable auto-flushing 
(would be strange though) and maybe there is some special configuration/handler 
of logs that you write?
   
   I found this nice PDF describing how PageCache actually works (fascinating 
read) 
http://sylab-srv.cs.fiu.edu/lib/exe/fetch.php?media=paperclub:lkd3ch16.pdf - 
Linux uses "write-back" cache strategy where it first writes data to cache and 
then it is flushed to disk (and remains in cache as non-dirty). The os will 
mark the files as dirty (and thus you can see them in  
`Container_memory_working_set_bytes'). If for whatever reason those files would 
remain as "dirty" they will still be counted as "working_set" memory.  And that 
would also explain why the memory is freed after deleting the files - when the 
file gets deleted. 
   


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