On May 17, 2011, at 3:11 PM, Mark question wrote: > So what other memory consumption tools do you suggest? I don't want to do it > manually and dump statistics into file because IO will affect performance > too.
We watch memory with Ganglia. We also tune our systems such that a task will only take X amount. In other words, given an 8gb RAM: 1gb for the OS 1gb for the TT and DN 6gb for all tasks if we assume each task will take max 1gb, then we end up with 3 maps and 3 reducers. Keep in mind that the mem consumed is more than just JVM heap size.