Flume1.5.2 throws无法使用com.frontier45.flume.sink.elasticsearch2.ElasticSearchSink传递事件

Question

我们正在使用Apache Flume将数据索引到Elasticsearch中。 Flume在启动时抛出异常

17 May 2016 17:57:30,121 ERROR [SinkRunner-PollingRunner-DefaultSinkProcessor] (com.frontier45.flume.sink.elasticsearch2.ElasticSearchSink.process:201)  - Failed to commit transaction. Transaction rolled back.
java.lang.NullPointerException
        at com.frontier45.flume.sink.elasticsearch2.ElasticSearchSink.process(ElasticSearchSink.java:169)
        at org.apache.flume.sink.DefaultSinkProcessor.process(DefaultSinkProcessor.java:68)
        at org.apache.flume.SinkRunner$PollingRunner.run(SinkRunner.java:147)
        at java.lang.Thread.run(Thread.java:745)
17 May 2016 17:57:30,124 ERROR [SinkRunner-PollingRunner-DefaultSinkProcessor] (org.apache.flume.SinkRunner$PollingRunner.run:160)  - Unable to deliver event. Exception follows.
java.lang.NullPointerException
        at com.frontier45.flume.sink.elasticsearch2.ElasticSearchSink.process(ElasticSearchSink.java:169)
        at org.apache.flume.sink.DefaultSinkProcessor.process(DefaultSinkProcessor.java:68)
        at org.apache.flume.SinkRunner$PollingRunner.run(SinkRunner.java:147)
        at java.lang.Thread.run(Thread.java:745)

Flume conf文件设置

a1.sources = r1
a1.sinks = k1
a1.channels = c1

# Describe/configure the source
a1.sources.r1.type=exec
a1.sources.r1.command=tail -f /tmp/storm/logs/perf.log

#interceptors
a1.sources.r1.interceptors = i1
a1.sources.r1.interceptors.i1.type = REGEX_EXTRACTOR 
#the following regexp parse a line like 
#2015.06.29 08:59:51,650 INFO perf-logger 76 pool-13-thread-1 Reducer-38:97177163
a1.sources.r1.interceptors.i1.regex = (\\d{4}-\\d{2}-\\d{2}\\s\\d{2}:\\d{2}:\\d{2},\\d{3})\\s*([A-Z]{4})\\s*([a-zA-Z-.]*)\\s(\\d+)\\s([a-zA-Z-.0.9]*)\\s([a-zA-Z-.0.9]*):(\\d*)
a1.sources.r1.interceptors.i1.serializers = s1 s2 s3 s4 s5 s6 s7
a1.sources.r1.interceptors.i1.serializers.s1.name = timestamp
a1.sources.r1.interceptors.i1.serializers.s1.type = org.apache.flume.interceptor.RegexExtractorInterceptorMillisSerializer
a1.sources.r1.interceptors.i1.serializers.s1.pattern = yyyy-MM-dd HH:mm:ss,SSS
a1.sources.r1.interceptors.i1.serializers.s2.name = level
a1.sources.r1.interceptors.i1.serializers.s3.name = logger
a1.sources.r1.interceptors.i1.serializers.s4.name = line
a1.sources.r1.interceptors.i1.serializers.s5.name = thread
a1.sources.r1.interceptors.i1.serializers.s6.name = component
a1.sources.r1.interceptors.i1.serializers.s7.name = value

# Describe the sink
a1.sinks.k1.type = com.frontier45.flume.sink.elasticsearch2.ElasticSearchSink 
a1.sinks.k1.hostNames = localhost:9300
a1.sinks.k1.indexName = storm_logs  
a1.sinks.k1.indexType = storm_logs
a1.sinks.k1.clusterName = log_cluster
a1.sinks.k1.batchSize = 500
a1.sinks.k1.ttl = 5d
a1.sinks.k1.serializer = com.frontier45.flume.sink.elasticsearch2.ElasticSearchDynamicSerializer 
a1.sinks.k1.indexNameBuilder = com.frontier45.flume.sink.elasticsearch2.TimeBasedIndexNameBuilder 

# Use a channel which buffers events in memory
a1.channels.c1.type = memory
a1.channels.c1.memoryCapacity=100
#a1.channels.c1.byteCapacity=5242880
a1.channels.c1.checkpointDir = /tmp/elasticsearch/log
a1.channels.c1.dataDirs = /tmp/elasticsearch/data
a1.channels.c1.use-fast-replay = false

# Bind the source and sink to the channel
a1.sources.r1.channels = c1
a1.sinks.k1.channel = c1

使用Flume1.5.0 Elasticsearch2.3.0

任何人都面临这种错误？请分享决议。