hadoop的"mapred.ReduceTask:java.net.ConnectExceptio

集群某节点91有故障发生，出现 [plain] 2013-11-08 08:32:13,908 WARN org.apache.hadoop.mapred.ReduceTask: attempt_201311061017_102_r_000000_0 copy failed: attempt_201311061017_102_m_000003_0 from node-192 2013-11-08 08:32:13,921 WARN org.a

[plain]

2013-11-08 08:32:13,908 WARN org.apache.hadoop.mapred.ReduceTask: attempt_201311061017_102_r_000000_0 copy failed: attempt_201311061017_102_m_000003_0 from node-192

2013-11-08 08:32:13,921 WARN org.apache.hadoop.mapred.ReduceTask: java.net.ConnectException: Connection timed out

at java.net.PlainSocketImpl.socketConnect(Native Method)

at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)

at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)

at java.net.AbstractPlainSocketImpl.connect(Unknown Source)

at java.net.SocksSocketImpl.connect(Unknown Source)

at java.net.Socket.connect(Unknown Source)

at sun.net.NetworkClient.doConnect(Unknown Source)

at sun.net.www.http.HttpClient.openServer(Unknown Source)

at sun.net.www.http.HttpClient.openServer(Unknown Source)

at sun.net.www.http.HttpClient.(Unknown Source)

at sun.net.www.http.HttpClient.New(Unknown Source)

at sun.net.www.http.HttpClient.New(Unknown Source)

at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source)

at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)

at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)

at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.getInputStream(ReduceTask.java:1631)

at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.setupSecureConnection(ReduceTask.java:1588)

at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.getMapOutput(ReduceTask.java:1488)

at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.copyOutput(ReduceTask.java:1399)

at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.run(ReduceTask.java:1331)

分析hadoop代码:

[java]

localFs = FileSystem.getLocal(fConf);

if (fConf.get("slave.host.name") != null) {

this.localHostname = fConf.get("slave.host.name");

}

if (localHostname == null) {

this.localHostname =

DNS.getDefaultHost

(fConf.get("mapred.tasktracker.dns.interface","default"),

fConf.get("mapred.tasktracker.dns.nameserver","default"));

}

在该节点ping 下这个hostname:

[plain]

ping node-191

PING node-128-191.localhost (220.250..228) 56(84) bytes of data.

bytes from 220.250..228: icmp_seq=1 ttl=247 time=14.8 ms

bytes from 220.250..228: icmp_seq=2 ttl=247 time=14.3 ms

bytes from 220.250..228: icmp_seq=3 ttl=247 time=14.4 ms

发现压根不是191的ip。

到该节点的hosts里查看，也没有配置191的hostname。

问题得解。

将191的hostname添加到集群所有节点的hosts上。重启tasktracker搞定。