Hi Костарев, I don't think this issue relates to federation. It looks like a1 and a2 doesn't register to RM successfully. It would helpful if you can share NodeManager's log to see what's wrong with a1 and a2 nodes in registration.
Thanks, Junping ----- Original Message ----- From: "Костарев А.Ф." <[email protected]> To: "Jun Ping Du" <[email protected]> Cc: [email protected] Sent: Tuesday, July 16, 2013 6:43:45 PM Subject: Re: Algorithm of distribution Map and Reduce tasks at various topology of a network Hi Jun Ping Du! Do You use fedaration? Our cluster works in federation mode. Today we launched tests again. Input file had size 600 Mb and size of block 6. So, there were 100 map tasks. And we saw the same result: all map tasks were executed within one datacenter. In web-interfaces of HDFS and YARN we saw different information. Page of HDFS contained information, that there were 6 nodes in cluster, page of YARN said only ablout 3 nodes. Screenshots and configuration files are attached. What settings we need to change to execute tasks on all nodes? On 07/15/2013 05:52 PM, Jun Ping Du wrote: Hi Костарев, I tried to reproduce your case on my 5-nodes setup (with 2 nodes in dc1/rack1, 1 node in dc1/rack2 and 2 nodes in dc2/rack2) but didn't see anything unusual. In my test, even with 3 replicas, I saw job with 150 map tasks distributed across all nodes no matter what datacenter is. Can you try again with a job with more map tasks as it is pretty random in scheduling if your job only have 10 map tasks. In your case, it seems b1, b3 and b2 take 3-4 maps away in one heartbeat which is pretty normal case. Let me know the distribution and version you are using if it still not work with more tasks. btw, you can find history log for each job in application page. Isn't it? Thanks, Junping -- Консультант 1-й категории Костарев А.Ф.
