Hi Kun Ren, You can follow the below steps. 1. configure HADOOP_NAMENODE_OPTS="-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=3988" in hadoop-env.sh 2. Start Namenode 3. Now Namenode will start debug port in 3988. 4. Configure Remote debug application to connect to <namenode_host>:3988 in eclipse 5. Now add a breakpoint in NameNodeRpcServer.java's any method you want to debug. NameNodeRpcServer.java is the gateway between NameNode and IPC Server Layer. 6. Now you can do step-by-step execution to observe the detailed executions.
Happy Debugging ;) -Vinay On Tue, Apr 19, 2016 at 8:46 PM, Kun Ren <[email protected]> wrote: > Hi All, > > Currently I used eclipse to compile/debug the source code, and I > configured the "remote Java application" to debug the source code in > eclipse, for example, I can debug the client side code when I run the > command "./bin/hdfs dfs -mkdir test", it goes through "FsShell---> > DistributedFileSystem---->DFSClient ....->send request to the server side. > Then it finish debugging, but I can not see how the server side handle the > request. > > > However, I want to debug and see how the server side(HDFS) handle the > request? Do you know how I can do this? Thanks so much. Also when I try to > add some debug information(such as print out something), but I can not see > anything printed out in eclipse, I don't know why. Thanks again. > > Best, > Kun >
