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apache访问日志目录：

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（Kafka垃圾箱）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=

执行以下命令时出现错误：

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

错误如下：

[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。提前谢谢
深沉的