spark-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Saisai Shao <sai.sai.s...@gmail.com>
Subject Re: Re: Can we redirect Spark shuffle spill data to HDFS or Alluxio?
Date Wed, 24 Aug 2016 14:42:49 GMT
Based on my limited knowledge of Tachyon (Alluxio), it only provides a
layer of Hadoop compatible FileSystem API, which means it cannot be used in
shuffle data store. If it can be mounted as an OS supported FS layer, like
NFS or Fuse, then it can be used for shuffle data store.

But never neglect the overhead and stability of distributed FS (RPC
communication, network latency), since shuffle is quite critical.

On Wed, Aug 24, 2016 at 10:30 PM, tony.yan@tendcloud.com <
tony.yan@tendcloud.com> wrote:

> Hi, Saisai and Rui,
> Thanks a lot for your answer.  Alluxio tried to work as the middle layer
> between storage and Spark, so is it possible to use Alluxio to resolve the
> issue? We want to have 1 SSD for every datanode and use Alluxio to manage
> mem,ssd and hdd.
>
> Thanks and Regards,
> Tony
>
> ------------------------------
> tony.yan@tendcloud.com
>
>
> *From:* Sun Rui <sunrise_win@163.com>
> *Date:* 2016-08-24 22:17
> *To:* Saisai Shao <sai.sai.shao@gmail.com>
> *CC:* tony.yan@tendcloud.com; user <user@spark.apache.org>
> *Subject:* Re: Can we redirect Spark shuffle spill data to HDFS or
> Alluxio?
> Yes, I also tried FUSE before, it is not stable and I don’t recommend it
>
> On Aug 24, 2016, at 22:15, Saisai Shao <sai.sai.shao@gmail.com> wrote:
>
> Also fuse is another candidate (https://wiki.apache.org/
> hadoop/MountableHDFS), but not so stable as I tried before.
>
> On Wed, Aug 24, 2016 at 10:09 PM, Sun Rui <sunrise_win@163.com> wrote:
>
>> For HDFS, maybe you can try mount HDFS as NFS. But not sure about the
>> stability, and also there is additional overhead of network I/O and replica
>> of HDFS files.
>>
>> On Aug 24, 2016, at 21:02, Saisai Shao <sai.sai.shao@gmail.com> wrote:
>>
>> Spark Shuffle uses Java File related API to create local dirs and R/W
>> data, so it can only be worked with OS supported FS. It doesn't leverage
>> Hadoop FileSystem API, so writing to Hadoop compatible FS is not worked.
>>
>> Also it is not suitable to write temporary shuffle data into distributed
>> FS, this will bring unnecessary overhead. In you case if you have large
>> memory on each node, you could use ramfs instead to store shuffle data.
>>
>> Thanks
>> Saisai
>>
>> On Wed, Aug 24, 2016 at 8:11 PM, tony.yan@tendcloud.com <
>> tony.yan@tendcloud.com> wrote:
>>
>>> Hi, All,
>>> When we run Spark on very large data, spark will do shuffle and the
>>> shuffle data will write to local disk. Because we have limited capacity at
>>> local disk, the shuffled data will occupied all of the local disk and then
>>> will be failed.  So is there a way we can write the shuffle spill data to
>>> HDFS? Or if we introduce alluxio in our system, can the shuffled data write
>>> to alluxio?
>>>
>>> Thanks and Regards,
>>>
>>> ------------------------------
>>> 阎志涛(Tony)
>>>
>>> 北京腾云天下科技有限公司
>>> ------------------------------------------------------------
>>> --------------------------------------------
>>> 邮箱:tony.yan@tendcloud.com
>>> 电话:13911815695
>>> 微信: zhitao_yan
>>> QQ : 4707059
>>> 地址:北京市东城区东直门外大街39号院2号楼航空服务大厦602室
>>> 邮编:100027
>>> ------------------------------------------------------------
>>> --------------------------------------------
>>> TalkingData.com <http://talkingdata.com/> - 让数据说话
>>>
>>
>>
>>
>
>

Mime
View raw message