使用Kafka将apache服务器日志加载到HDFS

Question

我想使用Kafka将apache服务器日志加载到hdfs。

创建主题：

./kafka-topics.sh --create --zookeeper 10.25.3.207:2181 --replication-factor 1 --partitions 1 --topic lognew  

跟踪access日志目录：

tail -f  /var/log/httpd/access_log |./kafka-console-producer.sh --broker-list 10.25.3.207:6667 --topic lognew  

在另一个终端(卡夫卡仓)启动消费者：

./kafka-console-consumer.sh --zookeeper 10.25.3.207:2181 --topic lognew --from-beginning  

camus.properties文件配置为:

# Needed Camus properties, more cleanup to come  
# final top-level data output directory, sub-directory will be dynamically      created for each topic pulled
etl.destination.path=/user/root/topics
# HDFS location where you want to keep execution files, i.e. offsets, error logs, and count files
etl.execution.base.path=/user/root/exec
# where completed Camus job output directories are kept, usually a sub-dir in the base.path
etl.execution.history.path=/user/root/camus/exec/history

# Kafka-0.8 handles all zookeeper calls
#zookeeper.hosts=
#zookeeper.broker.topics=/brokers/topics
#zookeeper.broker.nodes=/brokers/ids

# Concrete implementation of the Encoder class to use (used by Kafka Audit, and thus optional for now)    `camus.message.encoder.class=com.linkedin.camus.etl.kafka.coders.DummyKafkaMessageEncoder`

# Concrete implementation of the Decoder class to use
  #camus.message.decoder.class=com.linkedin.camus.etl.kafka.coders.LatestSchemaKafkaAvroMessageDecoder

# Used by avro-based Decoders to use as their Schema Registry
 #kafka.message.coder.schema.registry.class=com.linkedin.camus.example.schemaregistry.DummySchemaRegistry

# Used by the committer to arrange .avro files into a partitioned scheme. This will be the default partitioner for all
# topic that do not have a partitioner specified
    #etl.partitioner.class=com.linkedin.camus.etl.kafka.coders.DefaultPartitioner

# Partitioners can also be set on a per-topic basis
#etl.partitioner.class.<topic-name>=com.your.custom.CustomPartitioner

# all files in this dir will be added to the distributed cache and placed on the classpath for hadoop tasks
# hdfs.default.classpath.dir=

# max hadoop tasks to use, each task can pull multiple topic partitions
mapred.map.tasks=30
# max historical time that will be pulled from each partition based on event timestamp
kafka.max.pull.hrs=1
# events with a timestamp older than this will be discarded.
kafka.max.historical.days=3
# Max minutes for each mapper to pull messages (-1 means no limit)
kafka.max.pull.minutes.per.task=-1

# if whitelist has values, only whitelisted topic are pulled.  nothing on the blacklist is pulled
#kafka.blacklist.topics=
kafka.whitelist.topics=lognew
log4j.configuration=true

# Name of the client as seen by kafka
kafka.client.name=camus
# Fetch Request Parameters
#kafka.fetch.buffer.size=
#kafka.fetch.request.correlationid=
#kafka.fetch.request.max.wait=
#kafka.fetch.request.min.bytes=
# Connection parameters.
kafka.brokers=10.25.3.207:6667
#kafka.timeout.value=


#Stops the mapper from getting inundated with Decoder exceptions for the same topic
#Default value is set to 10
max.decoder.exceptions.to.print=5

#Controls the submitting of counts to Kafka
#Default value set to true
post.tracking.counts.to.kafka=true
monitoring.event.class=class.that.generates.record.to.submit.counts.to.kafka

# everything below this point can be ignored for the time being, will provide   more documentation down the road
##########################
etl.run.tracking.post=false
#kafka.monitor.tier=
#etl.counts.path=
kafka.monitor.time.granularity=10

etl.hourly=hourly
etl.daily=daily
etl.ignore.schema.errors=false

# configure output compression for deflate or snappy. Defaults to deflate
etl.output.codec=deflate
etl.deflate.level=6
#etl.output.codec=snappy

etl.default.timezone=America/Los_Angeles
etl.output.file.time.partition.mins=60
etl.keep.count.files=false
etl.execution.history.max.of.quota=.8

mapred.output.compress=true
mapred.map.max.attempts=1

kafka.client.buffer.size=20971520
kafka.client.so.timeout=60000

#zookeeper.session.timeout=
#zookeeper.connection.timeout=

执行以下命令时会出现错误：

hadoop jar camus-example-0.1.0-SNAPSHOT-shaded.jar com.linkedin.camus.etl.kafka.CamusJob -P camus.properties

以下是错误：

[CamusJob] - Fetching metadata from broker 10.25.3.207:6667 with client id camus for 0 topic(s) []
[CamusJob] - failed to create decoder
com.linkedin.camus.coders.MessageDecoderException:     com.linkedin.camus.coders.MessageDecoderException:     java.lang.NullPointerException
    at     com.linkedin.camus.etl.kafka.coders.MessageDecoderFactory.createMessageDecoder(MessageDecoderFactory.java:28)
    at com.linkedin.camus.etl.kafka.mapred.EtlInputFormat.createMessageDecoder(EtlInputFormat.java:390)
    at com.linkedin.camus.etl.kafka.mapred.EtlInputFormat.getSplits(EtlInputFormat.java:264)
    at org.apache.hadoop.mapreduce.JobSubmitter.writeNewSplits(JobSubmitter.java:301)
    at org.apache.hadoop.mapreduce.JobSubmitter.writeSplits(JobSubmitter.java:318)
    at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:196)
    at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1290)
    at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1287)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:415)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
    at org.apache.hadoop.mapreduce.Job.submit(Job.java:1287)
    at com.linkedin.camus.etl.kafka.CamusJob.run(CamusJob.java:280)
    at com.linkedin.camus.etl.kafka.CamusJob.run(CamusJob.java:608)
    at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
    at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:84)
    at com.linkedin.camus.etl.kafka.CamusJob.main(CamusJob.java:572)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.hadoop.util.RunJar.run(RunJar.java:221)
    at org.apache.hadoop.util.RunJar.main(RunJar.java:136)
Caused by: com.linkedin.camus.coders.MessageDecoderException: java.lang.NullPointerException
    at com.linkedin.camus.etl.kafka.coders.KafkaAvroMessageDecoder.init(KafkaAvroMessageDecoder.java:40)
    at com.linkedin.camus.etl.kafka.coders.MessageDecoderFactory.createMessageDecoder(MessageDecoderFactory.java:24)
    ... 22 more
Caused by: java.lang.NullPointerException
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:195)
    at     com.linkedin.camus.etl.kafka.coders.KafkaAvroMessageDecoder.init(KafkaAvroMessageDecoder.java:31)
    ... 23 more
[CamusJob] - Discarding topic (Decoder generation failed) : avrotopic
[CamusJob] - failed to create decoder

请提出解决这个问题的方法。提前感谢

深沉

Answer 1

我从没用过加缪。但我相信这是一个与卡夫卡相关的错误，它与你如何编码/解码信息有关。我相信您的堆栈跟踪中的重要行是

Caused by: com.linkedin.camus.coders.MessageDecoderException: java.lang.NullPointerException
  at com.linkedin.camus.etl.kafka.coders.KafkaAvroMessageDecoder.init(KafkaAvroMessageDecoder.java:40)
  at com.linkedin.camus.etl.kafka.coders.MessageDecoderFactory.createMessageDecoder(MessageDecoderFactory.java:24)

你是怎么告诉卡夫卡使用你的阿夫罗编码的？您已经注释掉了配置中的下面一行，

#kafka.message.coder.schema.registry.class=com.linkedin.camus.example.schemaregistry.DummySchemaRegistry

你是在其他地方设置代码吗？如果不是，我建议取消注释该配置值，并将其设置为您试图解码/编码的任何avro类。

使用正确的类路径可能需要进行一些调试，但我相信这是一个很容易解决的问题。

编辑在回应您的评论，我有几个自己的评论。

1. ，我从来没有使用过加缪，所以调试你从加缪得到的错误不是我能做的很好或者根本不可能的事情。所以你必须花一些时间(也许几个小时)去研究和尝试不同的事情来让它发挥作用。
2. 我怀疑DummySchemaRegistry是否是您需要的正确配置值。从虚拟开始的任何东西都可能不是一个有效的配置选项。
3. 做一个简单的谷歌搜索有关加缪和模式注册表显示了一些有趣的链接，SchemaRegistry类，KafkaAvroMessageEncoder。这些更有可能是您需要的正确的配置值。我猜是因为我从来没有用过加缪。
4. 这对您也有一定的帮助。我不知道你有没有看过。但是如果没有，我很确定在进入Stack溢出之前，搜索得到的特定错误可能是应该做的事情。