最近巡检发现生产环境hadoop的namenode日志一直报错，具体代码如下：

2012-08-21 09:20:24,486 WARN org.apache.hadoop.hdfs.server.namenode.FSNamesystem: Cannot roll edit log, edits.new files already exists in all healthy directories:
  /data/work/hdfs/name/current/edits.new
  /backup/current/edits.new
2012-08-21 09:20:25,357 ERROR org.apache.hadoop.security.UserGroupInformation: PriviledgedActionException as:hadoop cause:java.net.ConnectException: Connection refused
2012-08-21 09:20:25,357 ERROR org.apache.hadoop.security.UserGroupInformation: PriviledgedActionException as:hadoop cause:java.net.ConnectException: Connection refused
2012-08-21 09:20:25,359 WARN org.mortbay.log: /getimage: java.io.IOException: GetImage failed. java.net.ConnectException: Connection refused
        at java.net.PlainSocketImpl.socketConnect(Native Method)
        at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
        at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:193)
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
        at java.net.Socket.connect(Socket.java:519)
        at java.net.Socket.connect(Socket.java:469)
        at sun.net.NetworkClient.doConnect(NetworkClient.java:163)
        at sun.net.www.http.HttpClient.openServer(HttpClient.java:394)
        at sun.net.www.http.HttpClient.openServer(HttpClient.java:529)
        at sun.net.www.http.HttpClient.(HttpClient.java:233)
        at sun.net.www.http.HttpClient.New(HttpClient.java:306)
        at sun.net.www.http.HttpClient.New(HttpClient.java:323)
        at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:852)
        at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:793)
        at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:718)
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1041)
        at org.apache.hadoop.hdfs.server.namenode.TransferFsImage.getFileClient(TransferFsImage.java:160)
        at org.apache.hadoop.hdfs.server.namenode.GetImageServlet$1$1.run(GetImageServlet.java:88)
        at org.apache.hadoop.hdfs.server.namenode.GetImageServlet$1$1.run(GetImageServlet.java:85)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:396)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1121)
        at org.apache.hadoop.hdfs.server.namenode.GetImageServlet$1.run(GetImageServlet.java:85)
        at org.apache.hadoop.hdfs.server.namenode.GetImageServlet$1.run(GetImageServlet.java:70)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:396)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1121)
        at org.apache.hadoop.hdfs.server.namenode.GetImageServlet.doGet(GetImageServlet.java:70)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
        at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1221)
        at org.apache.hadoop.http.HttpServer$QuotingInputFilter.doFilter(HttpServer.java:835)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
        at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:399)
        at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
        at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
        at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
        at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)
        at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
        at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
        at org.mortbay.jetty.Server.handle(Server.java:326)
        at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
        at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:928)
        at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:549)
        at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
        at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
        at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
        at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
网上谷歌了一番，提示了secondarynamenode和namenode获取image出了问题，但是网上的文章说是secondarynamenode根本就无法获取image，但是我的生产环境secondarynamenode是可以从namenode获取日志和映像的，因为我secondarynamenode的hdfs-site.xml文件中配置了namenode的主机名，所以能获取，反而就是日志中一直报错，但是不影响hdfs的使用。按照网上的办法的解决步骤如下：

1、停止hbase、zookeeper、hadoop

2、修改namenode的hdfs-site.xml文件中的内容：

  dfs.secondary.http.address
  0.0.0.0:50090
 
    The secondary namenode http server address and port.
    If the port is 0 then the server will start on a free port.
 

将上述的0.0.0.0修改为你部署secondarynamenode的主机名就OK了！

3、同步到所有的节点中，记得部署secondarynamenode节点的hdfs-site.xml文件不要完全覆盖了，因为配置不一样。

4、启动hadoop、zookeeper、hbase。

再查看hadoop的namenode日志相关的报错就消失了！