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Kafka >> mail # user >> large amount of disk space freed on restart


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Re: large amount of disk space freed on restart
Yeah, that's what it looks like to me (looking at the code).  So, I'm
guessing it's some os level caching, resource recycling.  Have you ever
heard of this happening?  One thing that might be different in my usage
from the norm is a relatively large number of topics (e.g. ~2K topics).

Jason
On Thu, May 23, 2013 at 7:14 AM, Jun Rao <[EMAIL PROTECTED]> wrote:

> Jason,
>
> Kafka closes the handler of all delete files. Otherwise, the broker will
> run out of file handler quickly.
>
> Thanks,
>
> Jun
>
>
> On Wed, May 22, 2013 at 10:17 PM, Jason Rosenberg <[EMAIL PROTECTED]>
> wrote:
>
> > So, does this indicate kafka (or the jvm itself) is not aggressively
> > closing file handles of deleted files?  Is there a fix for this?  Or is
> > there not likely anything to be done?  What happens if the disk fills up
> > with file handles for phantom deleted files?
> >
> > Jason
> >
> >
> > On Wed, May 22, 2013 at 9:50 PM, Jonathan Creasy <[EMAIL PROTECTED]> wrote:
> >
> > > It isn't uncommon if a process has an open file handle on a file that
> is
> > > deleted, the space is not freed until the handle is closed. So
> restarting
> > > the process that has a handle on the file would cause the space to be
> > freed
> > > also.
> > >
> > > You can troubleshoot that with lsof.
> > > Normally, I see 2-4 log segments deleted every hour in my brokers.  I
> see
> > > log lines like this:
> > >
> > > 2013-05-23 04:40:06,857  INFO [kafka-logcleaner-0] log.LogManager -
> > > Deleting log segment 00000000035434043157.kafka from <redacted topic>
> > >
> > > However, it seems like if I restart the broker, a massive amount of
> disk
> > > space is freed (without a corresponding flood of these log segment
> > deleted
> > > messages).  Is there an explanation for this?  Does kafka keep
> reference
> > to
> > > file segments around, and reuse them as needed or something?  And then
> or
> > > restart, the references to those free segment files are dropped?
> > >
> > > Thoughts?
> > >
> > > This is with 0.7.2.
> > >
> > > Jason
> > >
> >
>

 
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB