get host from rdd map

[weoccc <we...@gmail.com>]

in rdd map function, is there a way i can know the list of host names where
the map runs ? any code sample would be appreciated ?

thx,

Weide

Re: get host from rdd map

[Deenar Toraskar <de...@gmail.com>]

   1. You can call any api that returns you the hostname in your map
   function. Here's a simplified example, You would generally use
   mapPartitions as it will save the overhead of retrieving hostname multiple
   times
   2.
   3. import scala.sys.process._
   4. val distinctHosts = sc.parallelize(0 to 100).map { _ =>
   5. val hostname = ("hostname".!!).trim
   6. // your code
   7. (hostname)
   8. }.collect.distinct
   9.


On 24 October 2015 at 01:41, weoccc <we...@gmail.com> wrote:

> yea,
>
> my use cases is that i want to have some external communications where rdd
> is being run in map. The external communication might be handled separately
> transparent to spark.  What will be the hacky way and nonhacky way to do
> that ? :)
>
> Weide
>
>
>
> On Fri, Oct 23, 2015 at 5:32 PM, Ted Yu <yu...@gmail.com> wrote:
>
>> Can you outline your use case a bit more ?
>>
>> Do you want to know all the hosts which would run the map ?
>>
>> Cheers
>>
>> On Fri, Oct 23, 2015 at 5:16 PM, weoccc <we...@gmail.com> wrote:
>>
>>> in rdd map function, is there a way i can know the list of host names
>>> where the map runs ? any code sample would be appreciated ?
>>>
>>> thx,
>>>
>>> Weide
>>>
>>>
>>>
>>
>

Re: get host from rdd map

[weoccc <we...@gmail.com>]

yea,

my use cases is that i want to have some external communications where rdd
is being run in map. The external communication might be handled separately
transparent to spark.  What will be the hacky way and nonhacky way to do
that ? :)

Weide



On Fri, Oct 23, 2015 at 5:32 PM, Ted Yu <yu...@gmail.com> wrote:

> Can you outline your use case a bit more ?
>
> Do you want to know all the hosts which would run the map ?
>
> Cheers
>
> On Fri, Oct 23, 2015 at 5:16 PM, weoccc <we...@gmail.com> wrote:
>
>> in rdd map function, is there a way i can know the list of host names
>> where the map runs ? any code sample would be appreciated ?
>>
>> thx,
>>
>> Weide
>>
>>
>>
>

Re: get host from rdd map

[Ted Yu <yu...@gmail.com>]

Can you outline your use case a bit more ?

Do you want to know all the hosts which would run the map ?

Cheers

On Fri, Oct 23, 2015 at 5:16 PM, weoccc <we...@gmail.com> wrote:

> in rdd map function, is there a way i can know the list of host names
> where the map runs ? any code sample would be appreciated ?
>
> thx,
>
> Weide
>
>
>