Zhu Zhu created FLINK-14974:
-------------------------------
Summary: Managed memory fractions should be rounded properly to
not summed up to be more than 1.0
Key: FLINK-14974
URL: https://issues.apache.org/jira/browse/FLINK-14974
Project: Flink
Issue Type: Sub-task
Components: Runtime / Coordination
Affects Versions: 1.10.0
Reporter: Zhu Zhu
Fix For: 1.10.0
Managed memory fractions should be rounded to floor at a certain precision when
divided by the number of operators, otherwise the fractions can be summed up to
be more than 1.0 due to the double precision issue, and the last operator may
fail to allocate managed memory it is supposed to be able to acquire.
To achieve that, I think we should change
{{StreamingJobGraphGenerator#setManagedMemoryFractionForOperator}} to use
BigDecimal#divide(otherValue, scale, RoundMode.ROUND_DOWN) to calculate the
fractions. In this way, the sum of the fractions will not exceed 1.0.
The scale can be a bit larger (maybe 16) so that we only lose little managed
memory.
cc [~chesnay]
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
