[jira] [Created] (SPARK-26082) Misnaming of spark.mesos.fetch(er)Cache.enable in MesosClusterScheduler

["Martin Loncaric (JIRA)" <ji...@apache.org>]

Martin Loncaric created SPARK-26082:
---------------------------------------

             Summary: Misnaming of spark.mesos.fetch(er)Cache.enable in MesosClusterScheduler
                 Key: SPARK-26082
                 URL: https://issues.apache.org/jira/browse/SPARK-26082
             Project: Spark
          Issue Type: Bug
          Components: Mesos
    Affects Versions: 2.3.2, 2.3.1, 2.3.0, 2.2.2, 2.2.1, 2.2.0, 2.1.3, 2.1.2, 2.1.1, 2.1.0, 2.0.2, 2.0.1, 2.0.0
            Reporter: Martin Loncaric


Currently in [docs|https://spark.apache.org/docs/latest/running-on-mesos.html]:
{quote}spark.mesos.fetcherCache.enable / false / If set to `true`, all URIs (example: `spark.executor.uri`, `spark.mesos.uris`) will be cached by the Mesos Fetcher Cache
{quote}

Currently in {{MesosClusterScheduler.scala}} (which passes parameter to driver):
{{private val useFetchCache = conf.getBoolean("spark.mesos.fetchCache.enable", false)}}

Currently in {{MesosCourseGrainedSchedulerBackend.scala}} (which passes mesos caching parameter to executors):
{{private val useFetcherCache = conf.getBoolean("spark.mesos.fetcherCache.enable", false)}}

This naming discrepancy dates back to version 2.0.0 ([jira|http://mail-archives.apache.org/mod_mbox/spark-issues/201606.mbox/%3CJIRA.12979909.1466099309000.9921.1466101026233@Atlassian.JIRA%3E]).

This means that when {{spark.mesos.fetcherCache.enable=true}} is specified, the Mesos cache will be used only for executors, and not for drivers.

IMPACT:
Not caching these driver files (typically including at least spark binaries, custom jar, and additional dependencies) adds considerable network traffic when frequently running spark Applications on a Mesos cluster. Additionally, since extracted files like {{spark-x.x.x-bin-*.tgz}} are additionally copied and left in the sandbox with the cache off (rather than extracted directly without an extra copy), this can considerably increase disk usage. Users CAN currently workaround by specifying the {{spark.mesos.fetchCache.enable}} option, but this should at least be specified in the documentation.

SUGGESTED FIX:
Add {{spark.mesos.fetchCache.enable}} to the documentation for versions 2 - 2.4, and update to {{spark.mesos.fetcherCache.enable}} going forward.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org