ERROR:格式化hdfs時出現connection-refused__hdfs

解決方案：
(先確保你的每個節點網路設定中 勾選了 Available to all users)
重點來了!!!——> 先用./zkServer.sh start 啟動各個zookeeper，再用./ hadoop-daemon.sh start journalnode啟動各個NodeName上的 JournalNode進程。然後再進行格式化即可。

問題描述：

Re-format filesystem in Storage Directory /itcast/hadoop-2.6.0/tmp/dfs/name ? (Y or N) y16/04/17 10:47:26 INFO ipc.Client: Retrying connect to server: itcast05/192.168.1.205:8485. Already tried 0 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:26 INFO ipc.Client: Retrying connect to server: itcast06/192.168.1.206:8485. Already tried 0 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:26 INFO ipc.Client: Retrying connect to server: itcast07/192.168.1.207:8485. Already tried 0 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:27 INFO ipc.Client: Retrying connect to server: itcast06/192.168.1.206:8485. Already tried 1 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:27 INFO ipc.Client: Retrying connect to server: itcast05/192.168.1.205:8485. Already tried 1 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:27 INFO ipc.Client: Retrying connect to server: itcast07/192.168.1.207:8485. Already tried 1 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:28 INFO ipc.Client: Retrying connect to server: itcast06/192.168.1.206:8485. Already tried 2 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:28 INFO ipc.Client: Retrying connect to server: itcast05/192.168.1.205:8485. Already tried 2 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:28 INFO ipc.Client: Retrying connect to server: itcast07/192.168.1.207:8485. Already tried 2 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:29 INFO ipc.Client: Retrying connect to server: itcast06/192.168.1.206:8485. Already tried 3 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:29 INFO ipc.Client: Retrying connect to server: itcast05/192.168.1.205:8485. Already tried 3 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:29 INFO ipc.Client: Retrying connect to server: itcast07/192.168.1.207:8485. Already tried 3 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:30 INFO ipc.Client: Retrying connect to server: itcast06/192.168.1.206:8485. Already tried 4 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:30 INFO ipc.Client: Retrying connect to server: itcast05/192.168.1.205:8485. Already tried 4 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:30 INFO ipc.Client: Retrying connect to server: itcast07/192.168.1.207:8485. Already tried 4 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:31 INFO ipc.Client: Retrying connect to server: itcast06/192.168.1.206:8485. Already tried 5 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:31 INFO ipc.Client: Retrying connect to server: itcast05/192.168.1.205:8485. Already tried 5 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:31 INFO ipc.Client: Retrying connect to server: itcast07/192.168.1.207:8485. Already tried 5 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:32 INFO ipc.Client: Retrying connect to server: itcast06/192.168.1.206:8485. Already tried 6 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:32 INFO ipc.Client: Retrying connect to server: itcast05/192.168.1.205:8485. Already tried 6 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:32 INFO ipc.Client: Retrying connect to server: itcast07/192.168.1.207:8485. Already tried 6 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:33 INFO ipc.Client: Retrying connect to server: itcast06/192.168.1.206:8485. Already tried 7 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:33 INFO ipc.Client: Retrying connect to server: itcast05/192.168.1.205:8485. Already tried 7 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:33 INFO ipc.Client: Retrying connect to server: itcast07/192.168.1.207:8485. Already tried 7 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:34 INFO ipc.Client: Retrying connect to server: itcast06/192.168.1.206:8485. Already tried 8 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:34 INFO ipc.Client: Retrying connect to server: itcast05/192.168.1.205:8485. Already tried 8 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:34 INFO ipc.Client: Retrying connect to server: itcast07/192.168.1.207:8485. Already tried 8 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:35 INFO ipc.Client: Retrying connect to server: itcast06/192.168.1.206:8485. Already tried 9 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)16/04/17 10:47:35 WARN namenode.NameNode: Encountered exception during format: org.apache.hadoop.hdfs.qjournal.client.QuorumException: Unable to check if JNs are ready for formatting. 1 exceptions thrown:192.168.1.206:8485: Call From itcast01/192.168.1.201 to itcast06:8485 failed on connection exception: java.net.ConnectException: Connection refused; For more details see:  http://wiki.apache.org/hadoop/ConnectionRefused        at org.apache.hadoop.hdfs.qjournal.client.QuorumException.create(QuorumException.java:81)        at org.apache.hadoop.hdfs.qjournal.client.QuorumCall.rethrowException(QuorumCall.java:223)        at org.apache.hadoop.hdfs.qjournal.client.QuorumJournalManager.hasSomeData(QuorumJournalManager.java:232)        at org.apache.hadoop.hdfs.server.common.Storage.confirmFormat(Storage.java:884)        at org.apache.hadoop.hdfs.server.namenode.FSImage.confirmFormat(FSImage.java:171)        at org.apache.hadoop.hdfs.server.namenode.NameNode.format(NameNode.java:937)        at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1379)        at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1504)