flume loss data when collect online data to hdfs

Question

I used flume-ng 1.5 version to collect logs.

There are two agents in the data flow and they are on two hosts, respectively.

And the data is sended from agent1 to agent2.

The agents's component is as follows:

agent1: spooling dir source --> file channel --> avro sink

agent2: avro source --> file channel --> hdfs sink

But it seems to loss data about 1/1000 percentage of million data. To solve problem I tried these steps:

look up agents log: cannot find any error or exception.
look up agents monitor metrics: the events number that put and take from channel always equals
statistic the data number by hive query and hdfs file use shell, respectively: the two number is equal and less than the online data number

agent1's configuration:

#agent
agent1.sources = src_spooldir
agent1.channels = chan_file
agent1.sinks = sink_avro

#source
agent1.sources.src_spooldir.type = spooldir
agent1.sources.src_spooldir.spoolDir = /data/logs/flume-spooldir
agent1.sources.src_spooldir.interceptors=i1

#interceptors
agent1.sources.src_spooldir.interceptors.i1.type=regex_extractor
agent1.sources.src_spooldir.interceptors.i1.regex=(\\d{4}-\\d{2}-\\d{2}).*
agent1.sources.src_spooldir.interceptors.i1.serializers=s1
agent1.sources.src_spooldir.interceptors.i1.serializers.s1.name=dt

#sink
agent1.sinks.sink_avro.type = avro
agent1.sinks.sink_avro.hostname = 10.235.2.212
agent1.sinks.sink_avro.port = 9910

#channel
agent1.channels.chan_file.type = file
agent1.channels.chan_file.checkpointDir = /data/flume/agent1/checkpoint
agent1.channels.chan_file.dataDirs = /data/flume/agent1/data

agent1.sources.src_spooldir.channels = chan_file
agent1.sinks.sink_avro.channel = chan_file

agent2's configuration

# agent 
agent2.sources  = source1
agent2.channels = channel1 
agent2.sinks    = sink1 

# source
agent2.sources.source1.type     = avro
agent2.sources.source1.bind     = 10.235.2.212
agent2.sources.source1.port     = 9910

# sink
agent2.sinks.sink1.type= hdfs
agent2.sinks.sink1.hdfs.fileType = DataStream
agent2.sinks.sink1.hdfs.filePrefix = log
agent2.sinks.sink1.hdfs.path = hdfs://hnd.hadoop.jsh:8020/data/%{dt}
agent2.sinks.sink1.hdfs.rollInterval = 600
agent2.sinks.sink1.hdfs.rollSize = 0
agent2.sinks.sink1.hdfs.rollCount = 0
agent2.sinks.sink1.hdfs.idleTimeout = 300
agent2.sinks.sink1.hdfs.round = true
agent2.sinks.sink1.hdfs.roundValue = 10
agent2.sinks.sink1.hdfs.roundUnit = minute

# channel
agent2.channels.channel1.type   = file
agent2.channels.channel1.checkpointDir = /data/flume/agent2/checkpoint
agent2.channels.channel1.dataDirs = /data/flume/agent2/data

agent2.sinks.sink1.channel      = channel1
agent2.sources.source1.channels = channel1

Any suggestions are welcome!

Alex Alex · Accepted Answer · 2015-07-22T01:50:22

there is a bug in file line deseriazer when encounter some specific character of utf which point is between U+10000 and U+10FFFF, they represent in utf16 by two 16-bit code unit called surrogate pairs.

flume loss data when collect online data to hdfs

1 Answers