Flume 远程写HDFS

现在的需求是在一台Flume采集机器上，往Hadoop集群上写HDFS，该机器没有安装Hadoop。

这里的Flume版本是1.6.0，Hadoop版本是2.7.1.

把Hadoop集群的hdfs-site.xml、core-site.xml两个配置文件复制到 flume安装目录的conf目录去，把hadoop-hdfs-2.7.1.jar复制到 Flume  lib目录。

一、Flume配置文件：

a1.sources = r1
a1.channels = c1
a1.sinks = k1

a1.sources.r1.type = syslogtcp
a1.sources.r1.bind = 192.168.110.160 # 本机ip
a1.sources.r1.port = 23003
a1.sources.r1.workerThreads  = 10

a1.channels.c1.type = memory
a1.channels.c1.capacity = 1000000
a1.channels.c1.transactionCapacity = 100000
a1.channels.c1.keep-alive = 6
a1.channels.c1.byteCapacityBufferPercentage = 20

a1.sinks.k1.type = hdfs
a1.sinks.k1.hdfs.path = hdfs://clusterpc/test/flume/%y-%m-%d
a1.sinks.k1.hdfs.filePrefix = events-
a1.sinks.k1.hdfs.round = true
a1.sinks.k1.hdfs.roundValue = 10
a1.sinks.k1.hdfs.roundUnit = minute
a1.sinks.k1.hdfs.useLocalTimeStamp=true

a1.sources.r1.channels = c1
a1.sinks.k1.channel = c1

　　启动： bin/flume-ng agent --conf conf --conf-file conf/flume-tcp-memory-hdfs.conf --name a1 -Dflume.root.logger=info,console

二、错误集：

1、 找不到主机名

2016-09-19 16:15:48,518 (SinkRunner-PollingRunner-DefaultSinkProcessor) [ERROR - org.apache.flume.sink.hdfs.HDFSEventSink.process(HDFSEventSink.java:459)] process failed
java.lang.IllegalArgumentException: java.net.UnknownHostException: cluster
        at org.apache.hadoop.security.SecurityUtil.buildTokenService(SecurityUtil.java:378)
        at org.apache.hadoop.hdfs.NameNodeProxies.createNonHAProxy(NameNodeProxies.java:310)
        at org.apache.hadoop.hdfs.NameNodeProxies.createProxy(NameNodeProxies.java:176)
        at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:678)
        at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:619)
        at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:149)
        at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2653)
        at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:92)
        at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2687)
        at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2669)
        at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:371)
        at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:170)
        at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:355)
        at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
        at org.apache.flume.sink.hdfs.BucketWriter$1.call(BucketWriter.java:243)
        at org.apache.flume.sink.hdfs.BucketWriter$1.call(BucketWriter.java:235)
        at org.apache.flume.sink.hdfs.BucketWriter$9$1.run(BucketWriter.java:679)
        at org.apache.flume.auth.SimpleAuthenticator.execute(SimpleAuthenticator.java:50)
        at org.apache.flume.sink.hdfs.BucketWriter$9.call(BucketWriter.java:676)
        at java.util.concurrent.FutureTask.run(FutureTask.java:262)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:744)
Caused by: java.net.UnknownHostException: cluster

　　cluster是公司Hadoop集群NameService的名字，这个错误是由于找不到Hadoop集群NameService造成的，所以需要把hdfs-site.xml复制到flume/conf目录。

2、

java.io.IOException: Mkdirs failed to create /test/flume/16-09-19 (exists=false, cwd=file:/data/apache-flume-1.6.0-bin)
        at org.apache.hadoop.fs.ChecksumFileSystem.create(ChecksumFileSystem.java:450)
        at org.apache.hadoop.fs.ChecksumFileSystem.create(ChecksumFileSystem.java:435)
        at org.apache.hadoop.fs.FileSystem.create(FileSystem.java:909)
        at org.apache.hadoop.fs.FileSystem.create(FileSystem.java:890)
        at org.apache.hadoop.fs.FileSystem.create(FileSystem.java:787)
        at org.apache.hadoop.fs.FileSystem.create(FileSystem.java:776)
        at org.apache.flume.sink.hdfs.HDFSSequenceFile.open(HDFSSequenceFile.java:96)
        at org.apache.flume.sink.hdfs.HDFSSequenceFile.open(HDFSSequenceFile.java:78)
        at org.apache.flume.sink.hdfs.HDFSSequenceFile.open(HDFSSequenceFile.java:69)
        at org.apache.flume.sink.hdfs.BucketWriter$1.call(BucketWriter.java:246)
        at org.apache.flume.sink.hdfs.BucketWriter$1.call(BucketWriter.java:235)
        at org.apache.flume.sink.hdfs.BucketWriter$9$1.run(BucketWriter.java:679)
        at org.apache.flume.auth.SimpleAuthenticator.execute(SimpleAuthenticator.java:50)
        at org.apache.flume.sink.hdfs.BucketWriter$9.call(BucketWriter.java:676)
        at java.util.concurrent.FutureTask.run(FutureTask.java:262)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:744)

　　把 core-site.xml复制到flume/conf目录

3、

java.io.IOException: No FileSystem for scheme: hdfs
        at org.apache.hadoop.fs.FileSystem.getFileSystemClass(FileSystem.java:2644)
        at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2651)
        at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:92)
        at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2687)
        at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2669)
        at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:371)
        at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:170)
        at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:355)
        at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
        at org.apache.flume.sink.hdfs.BucketWriter$1.call(BucketWriter.java:243)
        at org.apache.flume.sink.hdfs.BucketWriter$1.call(BucketWriter.java:235)
        at org.apache.flume.sink.hdfs.BucketWriter$9$1.run(BucketWriter.java:679)
        at org.apache.flume.auth.SimpleAuthenticator.execute(SimpleAuthenticator.java:50)
        at org.apache.flume.sink.hdfs.BucketWriter$9.call(BucketWriter.java:676)
        at java.util.concurrent.FutureTask.run(FutureTask.java:262)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:744)

　　把hadoop-hdfs-2.7.1.jar复制到flume/lib目录下

4、HDFS权限不足，这里往HDFS写文件的用户是登录Flume采集机器的用户。

org.apache.hadoop.security.AccessControlException: Permission denied: user=kafka, access=WRITE, inode="/test/flume/16-09-19/events-.1474268726127.tmp":hadoop:supergroup:drwxr-xr-x
        at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.check(FSPermissionChecker.java:319)
        at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.check(FSPermissionChecker.java:292)
        at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkPermission(FSPermissionChecker.java:213)
        at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkPermission(FSPermissionChecker.java:190)
        at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPermission(FSDirectory.java:1698)
        at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPermission(FSDirectory.java:1682)
        at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkAncestorAccess(FSDirectory.java:1665)
        at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.startFileInternal(FSNamesystem.java:2517)
        at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.startFileInt(FSNamesystem.java:2452)
        at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.startFile(FSNamesystem.java:2335)
        at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.create(NameNodeRpcServer.java:623)
        at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.create(ClientNamenodeProtocolServerSideTranslatorPB.java:397)
        at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
        at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:616)
        at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:969)
        at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2049)
        at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2045)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:415)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
        at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2043)

　　HDFS 权限不足，要授权。hadoop fs -chmod -R 777 /test/

5、时间戳

java.lang.NullPointerException: Expected timestamp in the Flume event headers, but it was null
        at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:204)
        at org.apache.flume.formatter.output.BucketPath.replaceShorthand(BucketPath.java:228)
        at org.apache.flume.formatter.output.BucketPath.escapeString(BucketPath.java:432)
        at org.apache.flume.sink.hdfs.HDFSEventSink.process(HDFSEventSink.java:380)
        at org.apache.flume.sink.DefaultSinkProcessor.process(DefaultSinkProcessor.java:68)
        at org.apache.flume.SinkRunner$PollingRunner.run(SinkRunner.java:147)
        at java.lang.Thread.run(Thread.java:744)

　　原因是Event对象headers没有设置timestamp造成的，解决办法：设置a1.sinks.k1.hdfs.useLocalTimeStamp=true，使用本地时间戳。