Maybe using LOG.warn("function name") will get your stuff into the
namenode log file.Thanks, Dhruba -----Original Message----- From: Zhu Huijun [mailto:[EMAIL PROTECTED] Sent: Monday, February 25, 2008 2:32 PM To: [email protected] Subject: Specifying the positions of replicas Hi, all, Currently our group want to try some new data layout schemes on Hadoop, but I encounter some problems. In Hadoop, each block has 3 replicas by default. It is said in the documents that two of them are put randomly in the same rack, and the third is put at another rack. This procedure is also clear in the source code of the class org.apache.hadoop.dfs.ReplicationTargetChooser. What I did was adding a simple System.out.println("function name") clause in each function in ReplicationTargetChooser, and intended to check which ones are called to select the target nodes for replicas. However, when I use "./bin/hadoop dfs -copyFromLocal" command to copy some files from the local file system to HDFS, it seems none of the functions in the ReplicationTargetChooser is called, because nothing is printed out on the screen or the log files. I preciate if someone can tell me where I can modify to control the target nodes of replicas. Thank you! Have a nice day! Huijun Zhu
