flume：spooldir采集日志，kafka输出的配置问题

flume配置：

#DBFile
DBFile.sources = sources1
DBFile.sinks = sinks1
DBFile.channels = channels1  

# DBFile-DB-Source
DBFile.sources.sources1.type = spooldir
DBFile.sources.sources1.spoolDir =/var/log/apache/flumeSpool//db
DBFile.sources.sources1.inputCharset=utf-8

# DBFile-Sink
DBFile.sinks.sinks1.type = org.apache.flume.sink.kafka.KafkaSink
DBFile.sinks.sinks1.topic = DBFile
DBFile.sinks.sinks1.brokerList = hdp01:6667,hdp02:6667,hdp07:6667
DBFile.sinks.sinks1.requiredAcks = 1
DBFile.sinks.sinks1.batchSize = 2000  

# DBFile-Channel
DBFile.channels.channels1.type = memory
DBFile.channels.channels1.capacity = 10000
DBFile.channels.channels1.transactionCapacity = 1000

# DBFile-Source And Sink to the channel
DBFile.sources.sources1.channels = channels1
DBFile.sinks.sinks1.channel = channels1

故障现象：第一次上传文件时，flume能很快处理文件，后面上传还是显示文件未处理。如果重启flume服务，又能立刻处理。

经测试，问题的原因在这个配置上：DBFile.sinks.sinks1.requiredAcks = -1 。

requiredAcks 的官方解释：How many replicas must acknowledge a message before its considered successfully written. Accepted values are 0 (Never wait for acknowledgement),

1 (wait for leader only), -1 (wait for all replicas) Set this to -1 to avoid data loss in some cases of leader failure.

把这个值改为1就好了。