Thomas Graves created SPARK-30417:
-------------------------------------
Summary: SPARK-29976 calculation of slots wrong for Standalone Mode
Key: SPARK-30417
URL: https://issues.apache.org/jira/browse/SPARK-30417
Project: Spark
Issue Type: Bug
Components: Spark Core
Affects Versions: 3.0.0
Reporter: Thomas Graves
In SPARK-29976 we added a config to determine if we should allow speculation
when the number of tasks is less then the number of slots on a single executor.
The problem is that for standalone mode (and mesos coarse grained) the
EXECUTOR_CORES config is not set properly by default. In those modes the number
of executor cores is all the cores of the Worker. The default of
EXECUTOR_CORES is 1.
The calculation:
{color:#000080}val {color}{color:#660e7a}speculationTasksLessEqToSlots {color}=
{color:#660e7a}numTasks {color}<=
({color:#660e7a}conf{color}.get({color:#660e7a}EXECUTOR_CORES{color}) /
sched.{color:#660e7a}CPUS_PER_TASK{color})
If someone set the cpus per task > 1 then this would end up being false even if
1 task. Note that the default case where cpus per task is 1 and executor cores
is 1 it works out ok but is only applied if 1 task vs number of slots on the
executor.
Here we really don't know the number of executor cores for standalone mode or
mesos so I think a decent solution is to just use 1 in those cases and document
the difference.
Something like
max({color:#660e7a}conf{color}.get({color:#660e7a}EXECUTOR_CORES{color}) /
sched.{color:#660e7a}CPUS_PER_TASK{color}, 1)
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org
For additional commands, e-mail: issues-h...@spark.apache.org
