Question

我们将一个150 MB的csv文件复制到了flume的假脱机目录中，当它被加载到hdfs中时，该文件被分成较小的文件，如80 kb＆s。有没有办法加载文件而不使用水槽拆分成较小的文件？因为在namenode中会生成更多关于较小文件的元数据，所以我们需要避免它。

我的流感代码看起来像这样

# Initialize agent's source, channel and sink
agent.sources = TwitterExampleDir
agent.channels = memoryChannel
agent.sinks = flumeHDFS

# Setting the source to spool directory where the file exists
agent.sources.TwitterExampleDir.type = spooldir
agent.sources.TwitterExampleDir.spoolDir = /usr/local/flume/live

# Setting the channel to memory
agent.channels.memoryChannel.type = memory
# Max number of events stored in the memory channel
agent.channels.memoryChannel.capacity = 10000
# agent.channels.memoryChannel.batchSize = 15000
agent.channels.memoryChannel.transactioncapacity = 1000000

# Setting the sink to HDFS
agent.sinks.flumeHDFS.type = hdfs
agent.sinks.flumeHDFS.hdfs.path = hdfs://info3s7:54310/spool5
agent.sinks.flumeHDFS.hdfs.fileType = DataStream

# Write format can be text or writable
agent.sinks.flumeHDFS.hdfs.writeFormat = Text

# use a single csv file at a time
agent.sinks.flumeHDFS.hdfs.maxOpenFiles = 1

# rollover file based on maximum size of 10 MB
agent.sinks.flumeHDFS.hdfs.rollCount=0
agent.sinks.flumeHDFS.hdfs.rollInterval=2000
agent.sinks.flumeHDFS.hdfs.rollSize = 0
agent.sinks.flumeHDFS.hdfs.batchSize =1000000

# never rollover based on the number of events
agent.sinks.flumeHDFS.hdfs.rollCount = 0

# rollover file based on max time of 1 min
#agent.sinks.flumeHDFS.hdfs.rollInterval = 0
# agent.sinks.flumeHDFS.hdfs.idleTimeout = 600

# Connect source and sink with channel
agent.sources.TwitterExampleDir.channels = memoryChannel
agent.sinks.flumeHDFS.channel = memoryChannel

Answer 1

你想要的是这个：

# rollover file based on maximum size of 10 MB
agent.sinks.flumeHDFS.hdfs.rollCount = 0
agent.sinks.flumeHDFS.hdfs.rollInterval = 0
agent.sinks.flumeHDFS.hdfs.rollSize = 10000000
agent.sinks.flumeHDFS.hdfs.batchSize = 10000

来自flume documentation

hdfs.rollSize: File size to trigger roll, in bytes (0: never roll based on file size)

在您的示例中，您使用2000的 rollInterval ，它将在2000秒后翻转文件，从而产生小文件。

另请注意， batchSize 反映了文件刷新到HDFS之前的事件数，不一定是文件关闭之前的事件数和创建的新事件数。您需要将其设置为足够小的值，以便不会超时写入大文件，但又足够大以避免许多HDFS请求的开销。

使用Flume（假脱机目录）将大文件加载到hdfs

1 个答案: