[
https://issues.apache.org/jira/browse/FLINK-36022?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17872279#comment-17872279
]
Maximilian Michels commented on FLINK-36022:
--------------------------------------------
The idea of having the option to disable scaling execution was to have a
dry-run mode to test the behavior of the autoscaler with its current
configuration.
I understand the idea behind changing certain configuration values in the
dry-run mode, but it would also mean it’s not a pure dry-run mode anymore.
That’s why I would suggest to add a different setting for this kind of
behavior, but perhaps it’s easiest to just set the desired values alongside
with the scaling=false setting.
On another note, I’m not sure setting the rescale time to zero would be correct
even in a dedicated new mode for suggestions. Rescaling will always take some
time and not accounting for it could void the scaling suggestion we print.
> When scaling.enabled =false, adjust the values of some parameters to
> provide bette recommendation values.
> -------------------------------------------------------------------------------------------------------------
>
> Key: FLINK-36022
> URL: https://issues.apache.org/jira/browse/FLINK-36022
> Project: Flink
> Issue Type: Improvement
> Components: Autoscaler
> Reporter: yuanfenghu
> Priority: Major
>
> h1. Background
> We have enabled AUTOSCALER in some scenarios, but we have not enabled
> job.autoscaler.scaling.enabled because we only want to use AUTOSCALER to
> obtain resource recommendations for tasks, but some parameters can cause
> these recommendations to be inaccurate.
> example ：
> * job.autoscaler.scale-down.max-factor
> If set to 0.5, it means that the vertex can be reduced to up to 50% of the
> original value during scaling. If we do not turn on the
> job.autoscaler.scaling.enabled parameter, then the recommended value here
> will only be 100 for a vertex with 200 parallelism. But in fact, this may
> only require 50 or even lower resources during low periods.
> * job.autoscaler.restart.time
> This parameter will cause the restart event to be used to calculate the
> resources required to chase data during expansion, resulting in the
> recommended resources being too large. However, if
> job.autoscaler.scaling.enabled =false, the restart time will be 0
>
> h1. Solution:
>
> When job.autoscaler.scaling.enabled = false, actively modify the above
> parameters job.autoscaler.scale-down.max-factor=1,
> job.autoscaler.restart.time=0
>
>
>
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
