Hello, My first time posting this in the news group. My question sounds more like a MapReduce question instead of Hadoop HDFS itself.
To my understanding, the JobClient will submit all Mapper and Reduce class in a uniform way to the cluster? Can I assume this is more like a uniform scheduler for all the task? For example, if I have a 100 node cluster, 1 master (namenode), 99 slaves (datanodes). When I do "JobClient.runJob(jconf)" the JobClient will uniformly distributes all Mapper and Reduce class to all 99 nodes. In the slaves, they will all have the same hadoop-site.xml and hadoop-default.xml. Here comes the main concern, what if some of the nodes don't have the same hardware spec such as memory or CPU speed? E.g. different batch purchase and repairment overtime that causes this. Is there any way that the JobClient can be aware of this and submit different number of tasks to different slaves during start-up? For example, for some slaves, it has 16 cores CPU instead of 8 cores. The problem I see here is that for the 16 cores, only 8 cores are used. P.S. I'm looking into the JobClient source code and JobProfile/JobTracker to see if this can be done. But not sure if I am on the right track. If this topic is more likely to be in the [EMAIL PROTECTED], please let me know. I'll send another one to that news group. Regards, -Andy TREND MICRO EMAIL NOTICE The information contained in this email and any attachments is confidential and may be subject to copyright or other intellectual property protection. If you are not the intended recipient, you are not authorized to use or disclose this information, and we request that you notify us by reply mail or telephone and delete the original message from your mail system.
