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From Nick Dimiduk <ndimi...@gmail.com>
Subject Re: oldWALs: what it is and how can I clean it?
Date Wed, 11 Mar 2015 22:27:49 GMT
Glad you were able to track down the issue, Liam.

-n

On Wed, Mar 11, 2015 at 1:58 PM, Liam Slusser <lslusser@gmail.com> wrote:

> I just wanted to update this thread as after more investigation I've
> figured out why my oldWALs folder wasn't being cleaned up.  I had a look at
> the code to ReplicationLogCleaner and it makes this call:
>
>  if (!config.getBoolean(HConstants.REPLICATION_ENABLE_KEY,
>         HConstants.REPLICATION_ENABLE_DEFAULT)) {
>       LOG.warn("Not configured - allowing all wals to be deleted");
>       return;
>     }
>
> I searched through my logs and was never able to find that line of text.
> So wrote a quick program to run that piece of code, and sure enough it came
> back as True.  getBoolean returns the value if it's been defined and if not
> returns the default.  And after reading HBASE-3489 replication is enabled
> by default these days, which I also verified by looking at
> HConstants.REPLICATION_ENABLE_DEFAULT.  I run cloudera CDH5.3 and in the
> user interface even with hbase replication set to false, wasn't putting
> "hbase.replication" false in the configuration file.  I manually added the
> hbase.replication to false in the advance configuration for hbase-site.xml
> and restarted hbase and sure enough it deleted all the logs!
>
> So this is probably a bug in CDH, at least in the version that I ran.  I'm
> running cloudera manger 5.2.1 with CDH5.3.0-1.cdh5.3.0.p0.30.
>
> thanks,
> liam
>
>
> On Wed, Mar 4, 2015 at 5:18 PM, Liam Slusser <lslusser@gmail.com> wrote:
>
> > So after removing all the replication peers hbase still doesn't want to
> > clean up the oldWALs folder.  In the master logs I don't see any errors
> > from ReplicationLogCleaner or LogCleaner.  I have my logging set to INFO
> so
> > I'd think I would see something.
> >
> > Is there anyway to run the ReplicationLogCleaner manually and see the
> > output?  Can I write something that calls the right API functions?
> >
> > thanks,
> > liam
> >
> >
> > On Fri, Feb 27, 2015 at 1:50 PM, Nick Dimiduk <ndimiduk@gmail.com>
> wrote:
> >
> >> I would let the cleaner chore handle the cleanup for you. You don't know
> >> the state of all entries in that folder. To that extent, I'd avoid
> making
> >> any direct changes to the content of HBase's working directory,
> especially
> >> while HBase is running...
> >>
> >> On Fri, Feb 27, 2015 at 1:29 PM, Liam Slusser <lslusser@gmail.com>
> wrote:
> >>
> >> > Once I disable/remove the replication, can I just blow away the
> oldWALs
> >> > folder safely?
> >> >
> >> > On Fri, Feb 27, 2015 at 3:10 AM, Madeleine Piffaretti <
> >> > mpiffaretti@powerspace.com> wrote:
> >> >
> >> > > Thanks a lot!
> >> > >
> >> > > Indeed, we had a replication enable in the past because we used the
> >> > > hbase-indexer from NgData (use to replicate data from Hbase to
> Solr).
> >> > > The replication was disable from a long time but the hbase-indexer
> >> peer
> >> > was
> >> > > still activated and so, as you mentioned, the data was keept  to
> >> > guarantee
> >> > > to not lose data between disable and enable.
> >> > >
> >> > > I have removed the peer and empty the oldWALs folder.
> >> > >
> >> > >
> >> > >
> >> > > 2015-02-27 1:42 GMT+01:00 Liam Slusser <lslusser@gmail.com>:
> >> > >
> >> > > > Huge thanks, Enis, that was the information I was looking for.
> >> > > >
> >> > > > Cheers!
> >> > > > liam
> >> > > >
> >> > > >
> >> > > > On Thu, Feb 26, 2015 at 3:48 PM, Enis Söztutar <
> enis.soz@gmail.com>
> >> > > wrote:
> >> > > >
> >> > > > > @Madeleine,
> >> > > > >
> >> > > > > The folder gets cleaned regularly by a chore in master.
When a
> WAL
> >> > file
> >> > > > is
> >> > > > > not needed any more for recovery purposes (when HBase can
> guaratee
> >> > > HBase
> >> > > > > has flushed all the data in the WAL file), it is moved to
the
> >> oldWALs
> >> > > > > folder for archival. The log stays there until all other
> >> references
> >> > to
> >> > > > the
> >> > > > > WAL file are finished. There is currently two services which
may
> >> keep
> >> > > the
> >> > > > > files in the archive dir. First is a TTL process, which
ensures
> >> that
> >> > > the
> >> > > > > WAL files are kept at least for 10 min. This is mainly for
> >> debugging.
> >> > > You
> >> > > > > can reduce this time by setting hbase.master.logcleaner.ttl
> >> > > configuration
> >> > > > > property in master. It is by default 600000. The other one
is
> >> > > > replication.
> >> > > > > If you have replication setup, the replication processes
will
> >> hang on
> >> > > to
> >> > > > > the WAL files until they are replicated. Even if you disabled
> the
> >> > > > > replication, the files are still referenced.
> >> > > > >
> >> > > > > You can look at the logs from master from classes (LogCleaner,
> >> > > > > TimeToLiveLogCleaner, ReplicationLogCleaner) to see whether
the
> >> > master
> >> > > is
> >> > > > > actually running this chore and whether it is getting any
> >> exceptions.
> >> > > > >
> >> > > > > @Liam,
> >> > > > > Disabled replication will still hold on to the WAL files
> because,
> >> > > because
> >> > > > > it has a guarantee to not lose data between disable and
enable.
> >> You
> >> > can
> >> > > > > remove_peer, which frees up the WAL files to be eligible
for
> >> > deletion.
> >> > > > When
> >> > > > > you re-add replication peer again, the replication will
start
> from
> >> > the
> >> > > > > current status, versus if you re-enable a peer, it will
continue
> >> from
> >> > > > where
> >> > > > > it left.
> >> > > > >
> >> > > > >
> >> > > > >
> >> > > > > On Thu, Feb 26, 2015 at 12:56 AM, Madeleine Piffaretti <
> >> > > > > mpiffaretti@powerspace.com> wrote:
> >> > > > >
> >> > > > > > Hi,
> >> > > > > >
> >> > > > > > The replication is not turned on HBase...
> >> > > > > > Does this folder should be clean regularly? Because
I have
> data
> >> > from
> >> > > > > > december 2014...
> >> > > > > >
> >> > > > > >
> >> > > > > > 2015-02-26 1:40 GMT+01:00 Liam Slusser <lslusser@gmail.com>:
> >> > > > > >
> >> > > > > > > I'm having this same problem.  I had replication
enabled but
> >> have
> >> > > > since
> >> > > > > > > been disabled.  However oldWALs still grows. 
There are so
> >> many
> >> > > files
> >> > > > > in
> >> > > > > > > there that running "hadoop fs -ls /hbase/oldWALs"
runs out
> of
> >> > > memory.
> >> > > > > > >
> >> > > > > > > On Wed, Feb 25, 2015 at 9:27 AM, Nishanth S <
> >> > > nishanth.2884@gmail.com
> >> > > > >
> >> > > > > > > wrote:
> >> > > > > > >
> >> > > > > > > > Do you have replication turned on in hbase
and  if so is
> >> your
> >> > > slave
> >> > > > > > > >  consuming the replicated data?.
> >> > > > > > > >
> >> > > > > > > > -Nishanth
> >> > > > > > > >
> >> > > > > > > > On Wed, Feb 25, 2015 at 10:19 AM, Madeleine
Piffaretti <
> >> > > > > > > > mpiffaretti@powerspace.com> wrote:
> >> > > > > > > >
> >> > > > > > > > > Hi all,
> >> > > > > > > > >
> >> > > > > > > > > We are running out of space in our small
hadoop cluster
> >> so I
> >> > > was
> >> > > > > > > checking
> >> > > > > > > > > disk usage on HDFS and I saw that most
of the space was
> >> > > occupied
> >> > > > by
> >> > > > > > > the*
> >> > > > > > > > > /hbase/oldWALs* folder.
> >> > > > > > > > >
> >> > > > > > > > > I have checked in the "HBase Definitive
Book" and others
> >> > books,
> >> > > > > > > web-site
> >> > > > > > > > > and I have also search my issue on google
but I didn't
> >> find a
> >> > > > > proper
> >> > > > > > > > > response...
> >> > > > > > > > >
> >> > > > > > > > > So I would like to know what does this
folder, what is
> use
> >> > for
> >> > > > and
> >> > > > > > also
> >> > > > > > > > how
> >> > > > > > > > > can I free space from this folder without
breaking
> >> > > everything...
> >> > > > > > > > >
> >> > > > > > > > >
> >> > > > > > > > > If it's related to a specific version...
our cluster is
> >> under
> >> > > > > > > > > 5.3.0-1.cdh5.3.0.p0.30 from cloudera
(hbase 0.98.6).
> >> > > > > > > > >
> >> > > > > > > > > Thx for your help!
> >> > > > > > > > >
> >> > > > > > > >
> >> > > > > > >
> >> > > > > >
> >> > > > >
> >> > > >
> >> > >
> >> >
> >>
> >
> >
>

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