Ok, so very simple test, all running on a local machine, not across
networks and all in the hello-samza repo this time around.
I've got the datapusher.py file set up to push data into localhost. One
event per second.
And a modified hello-samza where I've modified the
WikipediaParserStreamTask.java class to simply read what's there.
Running them both now and I'm seeing in the stderr files
(deploy/yarn/logs/userlogs/application_XXXXX/container_YYYY/stderr) the
following:
Exception in thread "main"
org.apache.samza.system.SystemConsumersException: Cannot deserialize an
incoming message.
at
org.apache.samza.system.SystemConsumers.update(SystemConsumers.scala:293)
at org.apache.samza.system.SystemConsumers.org
$apache$samza$system$SystemConsumers$$poll(SystemConsumers.scala:260)
at
org.apache.samza.system.SystemConsumers$$anonfun$refresh$2.apply(SystemConsumers.scala:276)
at
org.apache.samza.system.SystemConsumers$$anonfun$refresh$2.apply(SystemConsumers.scala:276)
at
scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
at
scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
at scala.collection.MapLike$DefaultKeySet.foreach(MapLike.scala:174)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:244)
at
scala.collection.AbstractSet.scala$collection$SetLike$$super$map(Set.scala:47)
at scala.collection.SetLike$class.map(SetLike.scala:93)
at scala.collection.AbstractSet.map(Set.scala:47)
at
org.apache.samza.system.SystemConsumers.refresh(SystemConsumers.scala:276)
at
org.apache.samza.system.SystemConsumers.choose(SystemConsumers.scala:213)
at
org.apache.samza.container.RunLoop$$anonfun$process$2$$anonfun$2.apply(RunLoop.scala:81)
at
org.apache.samza.container.RunLoop$$anonfun$process$2$$anonfun$2.apply(RunLoop.scala:81)
at
org.apache.samza.util.TimerUtils$class.updateTimer(TimerUtils.scala:37)
at org.apache.samza.container.RunLoop.updateTimer(RunLoop.scala:36)
at
org.apache.samza.container.RunLoop$$anonfun$process$2.apply(RunLoop.scala:80)
at
org.apache.samza.util.TimerUtils$class.updateTimer(TimerUtils.scala:37)
at org.apache.samza.container.RunLoop.updateTimer(RunLoop.scala:36)
at org.apache.samza.container.RunLoop.process(RunLoop.scala:79)
at org.apache.samza.container.RunLoop.run(RunLoop.scala:65)
at
org.apache.samza.container.SamzaContainer.run(SamzaContainer.scala:556)
at
org.apache.samza.container.SamzaContainer$.safeMain(SamzaContainer.scala:108)
at
org.apache.samza.container.SamzaContainer$.main(SamzaContainer.scala:87)
at org.apache.samza.container.SamzaContainer.main(SamzaContainer.scala)
Caused by: org.codehaus.jackson.JsonParseException: Unexpected character
('M' (code 77)): expected a valid value (number, String, array, object,
'true', 'false' or 'null')
at [Source: [B@5454d285; line: 1, column: 2]
at org.codehaus.jackson.JsonParser._constructError(JsonParser.java:1291)
at
org.codehaus.jackson.impl.JsonParserMinimalBase._reportError(JsonParserMinimalBase.java:385)
at
org.codehaus.jackson.impl.JsonParserMinimalBase._reportUnexpectedChar(JsonParserMinimalBase.java:306)
at
org.codehaus.jackson.impl.Utf8StreamParser._handleUnexpectedValue(Utf8StreamParser.java:1581)
at
org.codehaus.jackson.impl.Utf8StreamParser._nextTokenNotInObject(Utf8StreamParser.java:436)
at
org.codehaus.jackson.impl.Utf8StreamParser.nextToken(Utf8StreamParser.java:322)
at
org.codehaus.jackson.map.ObjectMapper._initForReading(ObjectMapper.java:2432)
at
org.codehaus.jackson.map.ObjectMapper._readMapAndClose(ObjectMapper.java:2389)
at
org.codehaus.jackson.map.ObjectMapper.readValue(ObjectMapper.java:1667)
at org.apache.samza.serializers.JsonSerde.fromBytes(JsonSerde.scala:33)
at
org.apache.samza.serializers.SerdeManager.fromBytes(SerdeManager.scala:115)
at
org.apache.samza.system.SystemConsumers.update(SystemConsumers.scala:290)
I changed the systems.kafka.samza.msg.serde=json to 'string' a while back,
but that caused a separate exception. However that was many, MANY attempts
ago.
On Mon, Mar 23, 2015 at 5:23 PM, Ash W Matheson <ash.mathe...@gmail.com>
wrote:
> Ahh, I was going to add it to the run-class.sh script.
>
> Yeah, it's already there by default:
>
>
> # Metrics
> metrics.reporters=snapshot,jmx
>
> metrics.reporter.snapshot.class=org.apache.samza.metrics.reporter.MetricsSnapshotReporterFactory
> metrics.reporter.snapshot.stream=kafka.metrics
>
> metrics.reporter.jmx.class=org.apache.samza.metrics.reporter.JmxReporterFactory
>
> So, where would I see those metrics?
>
> On Mon, Mar 23, 2015 at 5:15 PM, Ash W Matheson <ash.mathe...@gmail.com>
> wrote:
>
>> read: I'm a C++ programmer looking at Java for the first time in > 10
>> years
>>
>> On Mon, Mar 23, 2015 at 5:13 PM, Ash W Matheson <ash.mathe...@gmail.com>
>> wrote:
>>
>>> I'm assuming I have Jmx defined ... where would that get set?
>>>
>>> On Mon, Mar 23, 2015 at 5:08 PM, Chinmay Soman <
>>> chinmay.cere...@gmail.com> wrote:
>>>
>>>> Hey Ash,
>>>>
>>>> Can you see your job metrics (if you have the Jmx metrics defined) to
>>>> see
>>>> if your job is actually doing anything ? My only guess at this point is
>>>> the
>>>> process method is not being called because somehow there's no incoming
>>>> data. I could be totally wrong of course.
>>>>
>>>> On Mon, Mar 23, 2015 at 4:28 PM, Ash W Matheson <ash.mathe...@gmail.com
>>>> >
>>>> wrote:
>>>>
>>>> > Just to be clear, here's what's changed from the default hello-samza
>>>> repo:
>>>> >
>>>> > wikipedia-parser.properties==========================
>>>> > task.inputs=kafka.myTopic
>>>> > systems.kafka.consumer.zookeeper.connect=
>>>> > ec2-xxx-xxx-xxx-xxx.compute-1.amazonaws.com:2181/
>>>> > systems.kafka.consumer.auto.offset.reset=smallest
>>>> >
>>>> > WikipediaParserStreamTask.java =====================
>>>> > public void process(IncomingMessageEnvelope envelope,
>>>> MessageCollector
>>>> > collector, TaskCoordinator coordinator) {
>>>> > Map<String, Object> jsonObject = (Map<String, Object>)
>>>> > envelope.getMessage();
>>>> > WikipediaFeedEvent event = new WikipediaFeedEvent(jsonObject);
>>>> >
>>>> > try {
>>>> > System.out.println(event.getRawEvent());
>>>> > // Map<String, Object> parsedJsonObject =
>>>> parse(event.getRawEvent());
>>>> >
>>>> > // parsedJsonObject.put("channel", event.getChannel());
>>>> > // parsedJsonObject.put("source", event.getSource());
>>>> > // parsedJsonObject.put("time", event.getTime());
>>>> >
>>>> > // collector.send(new OutgoingMessageEnvelope(new
>>>> > SystemStream("kafka", "wikipedia-edits"), parsedJsonObject));
>>>> >
>>>> > as well as the aforementioned changes to the log4j.xml file.
>>>> >
>>>> > The data pushed into the 'myTopic' topic is nothing more than a
>>>> sentence.
>>>> >
>>>> >
>>>> > On Mon, Mar 23, 2015 at 4:16 PM, Ash W Matheson <
>>>> ash.mathe...@gmail.com>
>>>> > wrote:
>>>> >
>>>> > > yep, modified log4j.xml to look like this:
>>>> > >
>>>> > > <root>
>>>> > > <priority value="debug" />
>>>> > > <appender-ref ref="RollingAppender"/>
>>>> > > <appender-ref ref="jmx" />
>>>> > > </root>
>>>> > >
>>>> > > Not sure what you mean by #2.
>>>> > >
>>>> > > However, I'm running now, not seeing any exceptions, but still not
>>>> seeing
>>>> > > any output from System.out.println(...)
>>>> > >
>>>> > > On Mon, Mar 23, 2015 at 11:29 AM, Naveen Somasundaram <
>>>> > > nsomasunda...@linkedin.com.invalid> wrote:
>>>> > >
>>>> > >> Hey Ash,
>>>> > >> 1. Did you happen to modify your log4j.xml ?
>>>> > >> 2. Can you print the class path that was printed
>>>> when the
>>>> > >> job started ? I am wondering if log4j was not loaded or not
>>>> present in
>>>> > the
>>>> > >> path where it’s looking for. If you have been using hello samza, it
>>>> > should
>>>> > >> have pulled it from Maven.
>>>> > >>
>>>> > >> Thanks,
>>>> > >> Naveen
>>>> > >>
>>>> > >> On Mar 22, 2015, at 10:35 AM, Ash W Matheson <
>>>> ash.mathe...@gmail.com>
>>>> > >> wrote:
>>>> > >>
>>>> > >> > Hey all,
>>>> > >> >
>>>> > >> > Evaluating Samza currently and am running into some odd issues.
>>>> > >> >
>>>> > >> > I'm currently working off the 'hello-samza' repo and trying to
>>>> parse a
>>>> > >> > simple kafka topic that I've produced through an extenal java app
>>>> > >> (nothing
>>>> > >> > other than a series of sentences) and it's failing pretty hard
>>>> for me.
>>>> > >> The
>>>> > >> > base 'hello-samza' set of apps works fine, but as soon as I
>>>> change the
>>>> > >> > configuration to look at a different Kafka/zookeeper I get the
>>>> > >> following in
>>>> > >> > the userlogs:
>>>> > >> >
>>>> > >> > 2015-03-22 17:07:09 KafkaSystemAdmin [WARN] Unable to fetch last
>>>> > offsets
>>>> > >> > for streams [myTopic] due to kafka.common.KafkaException:
>>>> fetching
>>>> > topic
>>>> > >> > metadata for topics [Set(myTopic)] from broker
>>>> > >> > [ArrayBuffer(id:0,host:redacted,port:9092)] failed. Retrying.
>>>> > >> >
>>>> > >> >
>>>> > >> > The modifications are pretty straightforward. In the
>>>> > >> > Wikipedia-parser.properties, I've changed the following:
>>>> > >> > task.inputs=kafka.myTopic
>>>> > >> > systems.kafka.consumer.zookeeper.connect=redacted:2181/
>>>> > >> > systems.kafka.consumer.auto.offset.reset=smallest
>>>> > >> > systems.kafka.producer.metadata.broker.list=redacted:9092
>>>> > >> >
>>>> > >> > and in the actual java file WikipediaParserStreamTask.java
>>>> > >> > public void process(IncomingMessageEnvelope envelope,
>>>> > MessageCollector
>>>> > >> > collector, TaskCoordinator coordinator) {
>>>> > >> > Map<String, Object> jsonObject = (Map<String, Object>)
>>>> > >> > envelope.getMessage();
>>>> > >> > WikipediaFeedEvent event = new WikipediaFeedEvent(jsonObject);
>>>> > >> >
>>>> > >> > try {
>>>> > >> > System.out.println(event.getRawEvent());
>>>> > >> >
>>>> > >> > And then following the compile/extract/run process outlined in
>>>> the
>>>> > >> > hello-samza website.
>>>> > >> >
>>>> > >> > Any thoughts? I've looked online for any 'super simple'
>>>> examples of
>>>> > >> > ingesting kafka in samza with very little success.
>>>> > >>
>>>> > >>
>>>> > >
>>>> >
>>>>
>>>>
>>>>
>>>> --
>>>> Thanks and regards
>>>>
>>>> Chinmay Soman
>>>>
>>>
>>>
>>
>
