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
故障現象：第一次上傳文件時，flume能很快處理文件，后面上傳還是顯示文件未處理。如果重啟flume服務，又能立刻處理。
經測試，問題的原因在這個配置上：DBFile.sinks.sinks1.requiredAcks = -1 。
requiredAcks 的官方解釋：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.
把這個值改為1就好了。