spark-instrumented-optimizer/resource-managers/yarn
Thomas Graves 878094f972 [SPARK-30689][CORE][YARN] Add resource discovery plugin api to support YARN versions with resource scheduling
### What changes were proposed in this pull request?

This change is to allow custom resource scheduler (GPUs,FPGAs,etc) resource discovery to be more flexible. Users are asking for it to work with hadoop 2.x versions that do not support resource scheduling in YARN and/or also they may not run in an isolated environment.
This change creates a plugin api that users can write their own resource discovery class that allows a lot more flexibility. The user can chain plugins for different resource types. The user specified plugins execute in the order specified and will fall back to use the discovery script plugin if they don't return information for a particular resource.

I had to open up a few of the classes to be public and change them to not be case classes and make them developer api in order for the the plugin to get enough information it needs.

I also relaxed the yarn side so that if yarn isn't configured for resource scheduling we just warn and go on. This helps users that have yarn 3.1 but haven't configured the resource scheduling side on their cluster yet, or aren't running in isolated environment.

The user would configured this like:
--conf spark.resources.discovery.plugin="org.apache.spark.resource.ResourceDiscoveryFPGAPlugin, org.apache.spark.resource.ResourceDiscoveryGPUPlugin"

Note the executor side had to be wrapped with a classloader to make sure we include the user classpath for jars they specified on submission.

Note this is more flexible because the discovery script has limitations such as spawning it in a separate process. This means if you are trying to allocate resources in that process they might be released when the script returns. Other things are the class makes it more flexible to be able to integrate with existing systems and solutions for assigning resources.

### Why are the changes needed?

to more easily use spark resource scheduling with older versions of hadoop or in non-isolated enivronments.

### Does this PR introduce any user-facing change?

Yes a plugin api

### How was this patch tested?

Unit tests added and manual testing done on yarn and standalone modes.

Closes #27410 from tgravescs/hadoop27spark3.

Lead-authored-by: Thomas Graves <tgraves@nvidia.com>
Co-authored-by: Thomas Graves <tgraves@apache.org>
Signed-off-by: Thomas Graves <tgraves@apache.org>
2020-01-31 22:20:28 -06:00
..
src [SPARK-30689][CORE][YARN] Add resource discovery plugin api to support YARN versions with resource scheduling 2020-01-31 22:20:28 -06:00
pom.xml [INFRA] Reverts commit 56dcd79 and c216ef1 2019-12-16 19:57:44 -07:00