-Re: Hadoop Installation Mappers setting
Jitendra Yadav 2013-05-23, 18:56
Thanks for your clarification.
I have one more question.
How does cores factor influence slots calculation?
On 5/23/13, Amal G Jose <[EMAIL PROTECTED]> wrote:
> I am explaining it more.
> If your machine have 8 GB of memory.
> After reserving to Operating system and all other processes except
> tasktracker, you have 4 GB remaining(assume).
> The remaining process running is tasktracker.
> If the child jvm size is 200 MB,
> Then you can define a maximum slots of 4*1024 MB/ 200 MB
> Which is approximately 20.
> You can divide the slots into mapper and reducer slots as per your
> This is just an example that I explained based on my knowledge.
> On Thu, May 23, 2013 at 7:48 PM, <[EMAIL PROTECTED]> wrote:
>> I assume the question is on how many slots.
>> It dependents on
>> - the child/task jvm size and the available memory.
>> - available number of cores
>> Your available memory for tasks is total memory - memory used for OS and
>> other services running on your box.
>> Other services include non hadoop services as well as hadoop daemons.
>> Divide the available memory with child jvm size and that would get the
>> num of slots.
>> Also check whether sufficient number of cores are available as well.
>> Bejoy KS
>> Sent from remote device, Please excuse typos
>> *From: * Jitendra Yadav <[EMAIL PROTECTED]>
>> *Date: *Thu, 23 May 2013 18:10:38 +0530
>> *To: *<[EMAIL PROTECTED]>
>> *ReplyTo: * [EMAIL PROTECTED]
>> *Subject: *Hadoop Installation Mappers setting
>> While installing hadoop cluster, how we can calculate the exact number of
>> mappers value.