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Kafka, mail # user - Understanding how to monitor using JMX attributes


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Re: Understanding how to monitor using JMX attributes
Jun Rao 2012-11-20, 17:12
The tool gets the end offset of the log using getOffsetBefore and the
consumer offset from ZK. It then calculates the lag.

We do have a JMX for lag in ZookeeperConsumerConnector. The api is the
following, but you need to provide topic/brokerid/partitionid.

/**
 *  JMX interface for monitoring consumer
 */
trait ZookeeperConsumerConnectorMBean {
  def getPartOwnerStats: String
  def getConsumerGroup: String
  def getOffsetLag(topic: String, brokerId: Int, partitionId: Int): Long
  def getConsumedOffset(topic: String, brokerId: Int, partitionId: Int):
Long
  def getLatestOffset(topic: String, brokerId: Int, partitionId: Int): Long
}

Thanks

Jun

On Tue, Nov 20, 2012 at 8:03 AM, Mike Heffner <[EMAIL PROTECTED]> wrote:

> I have not tried that yet, I was hoping to use an existing Ruby monitoring
> process that we use to monitor several other existing resources.  I also
> don't want to make changes to the Kafka consumer code, as it's part of a
> bundled package (Storm).
>
> Where does ConsumerOffsetChecker pull its information from? Shouldn't the
> values from JMX match? Guess I might need to look at its source code to
> figure out what it's doing.
>
>
>
>
> On Tue, Nov 20, 2012 at 12:34 AM, Jun Rao <[EMAIL PROTECTED]> wrote:
>
> > Instead of using jmx, have you tried using ConsumerOffsetChecker to
> figure
> > out the consumer lag?
> >
> > Thanks,
> >
> > Jun
> >
> > On Mon, Nov 19, 2012 at 7:10 PM, Mike Heffner <[EMAIL PROTECTED]> wrote:
> >
> > > Hi,
> > >
> > > I am trying to write a custom monitoring script for our Kafka setup and
> > > would like some help understanding how to interpret the JMX attributes.
> > >
> > > In our setup, the consumers are writing their current offset to a path
> in
> > > ZK. This is the value they are getting back from a call
> > > to SimpleConsumer.getOffsetsBefore(). A snapshot of this value looks
> > like:
> > >
> > > {"offset"=>5338008447, "partition"=>2, "broker"=>{"host"=>"10.x.x.94",
> > > "port"=>9092}, "topic"=>"mcommits"}
> > >
> > > Using the MX4J interface, I poll the
> > > bean "kafka:type=kafka.logs.mcommits-2" on host 10.x.x.94 and get the
> > > attribute values:
> > >
> > > {"CurrentOffset"=>506171524, "Name"=>"mcommits-2",
> > > "NumAppendedMessages"=>10526508, "NumberOfSegments"=>4,
> > "Size"=>2116784530}
> > >
> > > At the time both of these values were snapshotted, this consumer was
> > close
> > > to the end of the log file. In that case, I would expect both offsets
> to
> > be
> > > fairly similar, however the consumer offset is >> the producer log
> > offset,
> > > which doesn't make sense.
> > >
> > > Clearly there is something I'm not understanding. How do I use the JMX
> > > attributes to calculate how far behind the consumer is from the end of
> > the
> > > log file? In this scenario the consumer offset is >> both the
> > CurrentOffset
> > > value and the Size value. Is there a way of interpreting these values
> > that
> > > I'm not seeing?
> > >
> > >
> > > Thanks,
> > >
> > > Mike
> > >
> > > --
> > >
> > >   Mike Heffner <[EMAIL PROTECTED]>
> > >   Librato, Inc.
> > >
> >
>
>
>
> --
>
>   Mike Heffner <[EMAIL PROTECTED]>
>   Librato, Inc.
>