论述flume中batchSize,capacity,transactionCapacity参数之间的关系

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


##source
a1.sources.r1.type = exec
a1.sources.r1.command = tail -f /home/hadoop/test.txt

#sink
a1.sinks.k1.type = hdfs
a1.sinks.k1.hdfs.path=hdfs://192.168.156.65:9000/flume/events
a1.sinks.k1.hdfs.filePrefix=events 
a1.sinks.k1.hdfs.rollInterval=30
a1.sinks.k1.hdfs.rollSize=33554432
a1.sinks.k1.hdfs.rollCount=0
a1.sinks.k1.hdfs.batchSize=3000                   ##number of events written to file before it is flushed to HDFS,batchsize <=transactionCapacity<=capacity
a1.sinks.k1.hdfs.codeC=gzip
a1.sinks.k1.hdfs.fileType=CompressedStream 
#channel
a1.channels.c1.type = memory
a1.channels.c1.capacity=1000000             #The maximum number of events stored in the channel
a1.channels.c1.transactionCapacity=5000           #The maximum number of events the channel will take from a source or give to a sink per transaction


###bind the source and sink to the channel
a1.sources.r1.channels=c1

a1.sinks.k1.channel=c1 

a1.sinks.k1.hdfs.batchSize 官方解释:

 ##number of events written to file before it is flushed to HDFS  

a1.channels.c1.capacity  官方解释 :  

 #The maximum number of events stored in the channel

a1.channels.c1.transactionCapacity 官方解释 :   

 #The maximum number of events the channel will take from a source or give to a sink per transaction

这三者之间的关系:

,batchsize <=transactionCapacity<=capacity