Liang-Chi Hsieh created SPARK-19244:
---------------------------------------
Summary: Sort MemoryConsumers according to their memory usage when
spilling
Key: SPARK-19244
URL: https://issues.apache.org/jira/browse/SPARK-19244
Project: Spark
Issue Type: Improvement
Components: Spark Core
Reporter: Liang-Chi Hsieh
In `TaskMemoryManager `, when we acquire memory by calling
`acquireExecutionMemory` and we can't acquire required memory, we will try to
spill other memory consumers.
Currently, we simply iterates the memory consumers in a hash set. Normally each
time the consumer will be iterated in the same order.
The first issue is that we might spill additional consumers. For example, if
consumer 1 uses 10MB, consumer 2 uses 50MB, then consumer 3 acquires 100MB but
we can only get 60MB and spilling is needed. We might spill both consumer 1 and
consumer 2. But we actually just need to spill consumer 2 and get the required
100MB.
The second issue is that if we spill consumer 1 in first time spilling. After a
while, consumer 1 now uses 5MB. Then consumer 4 may acquire some memory and
spilling is needed again. Because we iterate the memory consumers in the same
order, we will spill consumer 1 again. So for consumer 1, we will produce many
small spilling files.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
