Ok, so this can happen, even if the node has not been placed back into
rotation, at the metadata vip?


On Tue, Nov 5, 2013 at 12:11 AM, Neha Narkhede <neha.narkh...@gmail.com>wrote:

> It is probably due to the same metadata propagation issue.
> https://issues.apache.org/jira/browse/KAFKA-1111 should fix that.
>
> Thanks,
> Neha
>
>
> On Mon, Nov 4, 2013 at 11:47 AM, Jason Rosenberg <j...@squareup.com> wrote:
>
> > Ok,
> >
> > After adding a delay before enabling a freshly started broker in the
> > metadata vip that clients use, it seems to have drastically reduced the
> > number of these topic creation requests.  However, not all of them.
> >
> > I still see (only some times) a handful of "Topic creation" log messages,
> > that happen on a freshly started broker, during the time kafka has
> started,
> > but before the broker has been enabled in the metadata VIP.  Is there an
> > explanation for this?
> >
> > Thanks!
> >
> > Jason
> >
> >
> > On Fri, Nov 1, 2013 at 4:45 PM, Neha Narkhede <neha.narkh...@gmail.com
> > >wrote:
> >
> > > The mbeans are explained here -
> > > http://kafka.apache.org/documentation.html#monitoring. Look for
> > > *QueueTimeMs
> > >
> > > Thanks,
> > > Neha
> > >
> > >
> > > On Fri, Nov 1, 2013 at 12:14 PM, Jason Rosenberg <j...@squareup.com>
> > wrote:
> > >
> > > > Neha,
> > > >
> > > > This cluster has on the order of 750 topics.
> > > >
> > > > It looks like if I add a 20 second delay before placing a broker into
> > the
> > > > vip for metadata requests, it never seems to have this issue.  So I'm
> > not
> > > > sure about the 104 seconds number, other than that was how long the
> > flood
> > > > of "Topic creation" log messages went on for (over 500 of these).
> > > >
> > > > Which metric should I look at for 'high queue time'?
> > > >
> > > > Jason
> > > >
> > > >
> > > > On Fri, Nov 1, 2013 at 5:54 AM, Neha Narkhede <
> neha.narkh...@gmail.com
> > > > >wrote:
> > > >
> > > > > It is proportional to the number of topics but still seems too
> long.
> > > Did
> > > > > the broker have high queue time on all requests? Also how many
> topics
> > > > > existed on this cluster?
> > > > >
> > > > > Thanks,
> > > > > Neha
> > > > > On Oct 31, 2013 10:56 PM, "Jason Rosenberg" <j...@squareup.com>
> > wrote:
> > > > >
> > > > > > In this case, it appears to have gone on for 104 seconds.  Should
> > it
> > > > take
> > > > > > that long?  It doesn't seem to always take this long.  I guess
> one
> > of
> > > > the
> > > > > > drawbacks of having a large number of topics (brings out the edge
> > > > cases).
> > > > > >
> > > > > > Filed: https://issues.apache.org/jira/browse/KAFKA-1111
> > > > > >
> > > > > >
> > > > > > On Fri, Nov 1, 2013 at 1:17 AM, Neha Narkhede <
> > > neha.narkh...@gmail.com
> > > > > > >wrote:
> > > > > >
> > > > > > > >> Would it be possible for the broker to make sure all
> metadata
> > is
> > > > > > > propagated, before completing the startup sequence, and taking
> on
> > > > > > metadata
> > > > > > > requests?
> > > > > > >
> > > > > > > Yes, that is the flaw I mentioned before. We need to fix it.
> > > > > > >
> > > > > > >
> > > > > > > On Thu, Oct 31, 2013 at 9:56 PM, Jason Rosenberg <
> > j...@squareup.com
> > > >
> > > > > > wrote:
> > > > > > >
> > > > > > > > Ok,
> > > > > > > >
> > > > > > > > So, I can safely ignore these, it sounds like.  I don't see
> any
> > > > > > > > corresponding logging around it subsequently not succeeding
> to
> > > > > actually
> > > > > > > > create the topic in zk.
> > > > > > > >
> > > > > > > > Would it be possible for the broker to make sure all metadata
> > is
> > > > > > > > propagated, before completing the startup sequence, and
> taking
> > on
> > > > > > > metadata
> > > > > > > > requests?
> > > > > > > >
> > > > > > > > If I were to not place the newly started broker back into the
> > vip
> > > > > for a
> > > > > > > > delay period after the kafka broker has started, would that
> > solve
> > > > > this
> > > > > > > > issue?
> > > > > > > >
> > > > > > > > Jason
> > > > > > > >
> > > > > > > >
> > > > > > > > On Fri, Nov 1, 2013 at 12:39 AM, Jun Rao <jun...@gmail.com>
> > > wrote:
> > > > > > > >
> > > > > > > > > This is probably because some metadata requests were issued
> > to
> > > a
> > > > > > newly
> > > > > > > > > started broker before the controller has propagated the
> > > metadata.
> > > > > > Since
> > > > > > > > the
> > > > > > > > > broker doesn't have the metadata in the cache, it thinks
> the
> > > > topic
> > > > > > > > doesn't
> > > > > > > > > exist and tries to create the topic. The creation will fail
> > > > though
> > > > > > > since
> > > > > > > > > it's already registered in ZK. These INFO logging should be
> > > > > transient
> > > > > > > > > though.
> > > > > > > > >
> > > > > > > > > Thanks,
> > > > > > > > >
> > > > > > > > > Jun
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > On Thu, Oct 31, 2013 at 8:41 PM, Jason Rosenberg <
> > > > j...@squareup.com
> > > > > >
> > > > > > > > wrote:
> > > > > > > > >
> > > > > > > > > > Some times during a rolling restart, I see lots of these
> > > > messages
> > > > > > > > during
> > > > > > > > > > the restart (these happened in the logs of the 2nd server
> > in
> > > > the
> > > > > > > > cluster
> > > > > > > > > to
> > > > > > > > > > restart (broker 11), after having restarted started, and
> > > during
> > > > > the
> > > > > > > > time
> > > > > > > > > > the 3rd node (broker 9) is doing a controlled shutdown
> > before
> > > > > > > > stopping).
> > > > > > > > > >
> > > > > > > > > > Is it creating new topics (it shouldn't have been!).  Or
> is
> > > it
> > > > > > moving
> > > > > > > > > > topics around, or what?
> > > > > > > > > >
> > > > > > > > > > 2013-11-01 03:25:55,661  INFO [kafka-request-handler-7]
> > > > > > > > > admin.AdminUtils$ -
> > > > > > > > > > Topic creation { "partitions":{ "0":[ 9, 11 ] },
> > "version":1
> > > }
> > > > > > > > > > 2013-11-01 03:26:01,577  INFO [kafka-request-handler-0]
> > > > > > > > > admin.AdminUtils$ -
> > > > > > > > > > Topic creation { "partitions":{ "0":[ 9, 10 ] },
> > "version":1
> > > }
> > > > > > > > > > 2013-11-01 03:26:07,767  INFO [kafka-request-handler-1]
> > > > > > > > > admin.AdminUtils$ -
> > > > > > > > > > Topic creation { "partitions":{ "0":[ 9, 11 ] },
> > "version":1
> > > }
> > > > > > > > > > 2013-11-01 03:26:07,823  INFO [kafka-request-handler-1]
> > > > > > > > > admin.AdminUtils$ -
> > > > > > > > > > Topic creation { "partitions":{ "0":[ 10, 11 ] },
> > > "version":1 }
> > > > > > > > > > 2013-11-01 03:26:11,183  INFO [kafka-request-handler-2]
> > > > > > > > > admin.AdminUtils$ -
> > > > > > > > > > Topic creation { "partitions":{ "0":[ 10, 11 ] },
> > > "version":1 }
> > > > > > > > > > 20
> > > > > > > > > >
> > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>

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