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Flume >> mail # user >> HDFS Sink keeps .tmp files and closes with exception

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Re: HDFS Sink keeps .tmp files and closes with exception
There are 2 sides to this problem,
The flume side issue was fixed in 1.2.0, FLUME-1163.
But the solution in FLUME-1163, requires that the Hadoop Libraries
used with flume, support the 'fs.automatic.shutdown' flag.
Unfortunately hadoop 1.x branch, does not have that feature pulled in

So if you use flume with hadoop libs from 1.x series, you'll still get
the .tmp files leftover, and the exception mentioned.

CDH3u5, does indeed pull in HADOOP-4829, so flume + CDH3u5 works
correctly and the files get properly closed at flume shutdown.

Do note, that this is a Hadoop Client side problem, so on your hadoop
cluster you can use 1.x version, and connect to it using flume +
CDH3u5 combo, and that should work as long as CDH3u5 libs are able to
talk with Hadoop 1.x cluster. But usually hadoop even on client side
is very picky about versions.

Here's a mail thread, where I discussed this before.

I can say with certainty, that if you use HDFS 1.x client side, the
.tmp files will not be renamed at shutdown, and you will get
exceptions as mentioned in the original mail.


On Fri, Oct 19, 2012 at 4:37 PM, Hari Shreedharan
> Nishant,
> a: if CDH4 was working for you, you could use it with hadoop-2.x or CDH3u5
> with hadoop-1.x.
> b: Looks like your rollSize/rollCount/rollInterval are all 0. Can you
> increase rollCount to say 1000 or so? If you see here:
> http://flume.apache.org/FlumeUserGuide.html#hdfs-sink, if you set the roll*
> configuration params to 0, they would never roll the files. If files are not
> rolled, they are not closed, and HDFS will show those as 0-sized files. Once
> the roll happens, HDFS GUI will show you the real file size. You can use any
> one of the three roll* config parameters to roll the files.
> Thanks,
> Hari
> --
> Hari Shreedharan
> On Friday, October 19, 2012 at 1:29 PM, Nishant Neeraj wrote:
> Thanks for the responses.
> a: Got rid of all the CDH stuffs. (basically, started on a fresh AWS
> instance)
> b: Installed from binary files.
> It DID NOT work. Here is what I observed:
> flume-ng version: Flume 1.2.0
> Hadoop: 1.0.4
> This is what my configuration is:
> agent1.sinks.fileSink1.type = hdfs
> agent1.sinks.fileSink1.channel = memChannel1
> agent1.sinks.fileSink1.hdfs.path > hdfs://localhost:54310/flume/agg1/%y-%m-%d
> agent1.sinks.fileSink1.hdfs.filePrefix = agg2
> agent1.sinks.fileSink1.hdfs.rollInterval = 0
> agent1.sinks.fileSink1.hdfs.rollSize = 0
> agent1.sinks.fileSink1.hdfs.rollCount = 0
> agent1.sinks.fileSink1.hdfs.fileType = DataStream
> agent1.sinks.fileSink1.hdfs.writeFormat = Text
> #agent1.sinks.fileSink1.hdfs.batchSize = 10
> #1: startup error
> -----------------------------------
> With new intallation, I start to find this exception on start of Flume (it
> does not stop me from adding data to hdfs)
> 2012-10-19 19:48:32,191 (conf-file-poller-0) [INFO -
> org.apache.flume.sink.DefaultSinkFactory.create(DefaultSinkFactory.java:70)]
> Creating instance of sink: fileSink1, type: hdfs
> 2012-10-19 19:48:32,296 (conf-file-poller-0) [DEBUG -
> org.apache.hadoop.conf.Configuration.<init>(Configuration.java:227)]
> java.io.IOException: config()
> at org.apache.hadoop.conf.Configuration.<init>(Configuration.java:227)
> at org.apache.hadoop.conf.Configuration.<init>(Configuration.java:214)
> at
> org.apache.hadoop.security.UserGroupInformation.ensureInitialized(UserGroupInformation.java:184)
> at
> org.apache.hadoop.security.UserGroupInformation.isSecurityEnabled(UserGroupInformation.java:236)
> at
> org.apache.flume.sink.hdfs.HDFSEventSink.authenticate(HDFSEventSink.java:516)
> at
> org.apache.flume.sink.hdfs.HDFSEventSink.configure(HDFSEventSink.java:238)
> at org.apache.flume.conf.Configurables.configure(Configurables.java:41)