[
https://issues.apache.org/jira/browse/KYLIN-5739?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17795175#comment-17795175
]
zhong.zhu commented on KYLIN-5739:
----------------------------------
h1. Dev Degisn
First of all, it should be noted that *_kylin.jobs.max-concurrent-jobs_* can be
set to 0, with a range of values >= 0, with real use cases.
For example: when starting Kylin, not 0, created a batch of tasks, at this
time, I want to jam the task to prevent it from being adjusted up, so the
project-level configuration is set to 0, then if you reboot later, init
scheduler when the core size is 0.
h2. Root Cause
When +_{{NDefaultScheduler}}_+ is initialized for the first time,
{*}_kylin.job.max-concurrent-jobs_{*}=0 is configured, causing an invalid
parameter exception to be thrown during jobPool initialization.
This means that the following context is also null, and the fetcherPool's timed
scheduling task won't get up properly.
So when you subsequently want to schedule tasks via NDefaultScheduler, since
the internal jobPool and context are both null, you'll get NEP exceptions where
you use the context and thread pool.
h3. Problematic phenomena:
After startup, all the jobs are pending, even if you change the project level
configuration max job > 0, it doesn't work, because the thread pool is all null.
Clicking restart will report a null pointer because the context is null.
> The job concurrency number is set to 0, resulting in initialization failure,
> and clicking the restart job button will report an error
> -------------------------------------------------------------------------------------------------------------------------------------
>
> Key: KYLIN-5739
> URL: https://issues.apache.org/jira/browse/KYLIN-5739
> Project: Kylin
> Issue Type: Bug
> Affects Versions: 5.0-beta
> Reporter: zhong.zhu
> Assignee: zhong.zhu
> Priority: Major
> Fix For: 5.0.0
>
>
> Only one Kylin node was started and clicking the restart task button reported
> an error
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
