[jira] [Updated] (BEAM-958) desiredNumWorkers in Dataflow is too low

["Raghu Angadi (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/BEAM-958?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Raghu Angadi updated BEAM-958:
------------------------------
    Labels: breaking_change  (was: )

> desiredNumWorkers in Dataflow is too low
> ----------------------------------------
>
>                 Key: BEAM-958
>                 URL: https://issues.apache.org/jira/browse/BEAM-958
>             Project: Beam
>          Issue Type: Improvement
>          Components: runner-dataflow
>    Affects Versions: 0.3.0-incubating
>            Reporter: Raghu Angadi
>            Assignee: Davor Bonaci
>              Labels: breaking_change
>
> {{desiredNumWorkers}} in [UnboundedSource API|https://github.com/apache/incubator-beam/blob/v0.3.0-incubating-RC1/sdks/java/core/src/main/java/org/apache/beam/sdk/io/UnboundedSource.java#L69] is a suggestion to a source about how many splits it should create. KafkaIO currently takes this literally and only creates up to this many splits.
> The main draw back is that it is very low in Dataflow. It is calculated as 
>   * {{1 * maxNumWorkers}} if {{--maxNumWorkers}} is specified, otherwise
>   * {{3 * numWorkers}}.
> That implies there is only single reader per worker (which is usually a 4 core VM). That can leave CPU under utilized on many pipelines.
> Even 3x in case of fixes number of workers seems low to me. 



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)