Re: [Boost-bugs] [Boost C++ Libraries] #11016: Boost file logging misbehaves when file system is full

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #11016: Boost file logging misbehaves when file system is full
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2015-02-12 11:15:17

#11016: Boost file logging misbehaves when file system is full
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  Reporter:  michi@…           |      Owner:  andysem
      Type:  Bugs              |     Status:  new
 Milestone:  To Be Determined  |  Component:  log
   Version:  Boost 1.55.0      |   Severity:  Problem
Resolution:                    |   Keywords:
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Comment (by Michi Henning <michi.henning@…>):

 Eating up all available inodes (on top of the file system being full
 already) is not right. If any attempt to write a file returns ENOSPC, all
 write activity should be abandoned. In addition, I would unlink whichever
 file incurs that error. The file system is already full, and things are
 pretty much hopeless at that point anyway until someone comes along and
 makes more space available. So, losing whichever log file couldn't be
 written/appended to is not a big deal.

 I don't think throwing an exception would help, in the sense that no code
 that uses boost::log expects to get an exception from one of the API
 calls. Throwing from a logging library just doesn't make sense. What am I
 supposed to do? Catch the exception and log an error about it having
 happened? ;-)

 I suspect some sort of stateful error handling is necessary here. If any
 write returns ENOSPC, take note of that fact and remember it. Disable log
 rotation for a while. Occasionally, maybe every 10-60 seconds or so, check
 if there is space available again. If not, rinse and repeat. There is no
 point in continuously bashing away at a file system that is full already…

 Another check might be to test whether a file is newly-created and empty.
 If so, the first write to the file should immediately unlink it again.
 That way, at least there won't be the endless attempts to create more and
 more files that can't be written to anyway.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/11016#comment:4>
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