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:
  1. look up agents log: cannot find any error or exception.
  2. look up agents monitor metrics: the events number that put and take from channel always equals
  3. 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

These are the two agents configuration:
#agent1
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 
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!