[
https://issues.apache.org/jira/browse/YARN-3623?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15045609#comment-15045609
]
Sangjin Lee commented on YARN-3623:
-----------------------------------
{quote}
4. Can raise new jira and handle REST interface support to get the supported
ATS version and config from the server for ATS 1.5
5. Can raise new jira and handle version checking for the ATSv2 interface
methods in TimelineClient.and also fetching of version
{quote}
In my mind, trying to get the version by querying the REST interface seems
highly problematic. If we're going to have a configuration that clearly spells
out which version the cluster is running, why not rely on that config? Is there
a reason to believe that may not be correct?
In terms of issues of querying the REST interface for the version, first, the
write URLs are not really feasible. V.1.5 may not even have the write REST
endpoint up. For v.2, you really need to first discover the right URL (i.e.
server) to talk to. You do it anyway, but that's only to know which endpoint to
talk to, not to discover which version it needs to use.
Even if we were to use the read REST endpoint, it would mean that the timeline
client code would need to contact the list of all known version URLs one at a
time to see which read endpoint is up and running. It sounds to me that it can
be unnecessarily flaky and harder than it needs to be.
I think it makes sense to rely on the version config, and not worry about
querying it live. I don't see added value, and config will only be simpler and
more robust. Have I missed any important point?
> We should have a config to indicate the Timeline Service version
> ----------------------------------------------------------------
>
> Key: YARN-3623
> URL: https://issues.apache.org/jira/browse/YARN-3623
> Project: Hadoop YARN
> Issue Type: Bug
> Components: timelineserver
> Reporter: Zhijie Shen
> Assignee: Xuan Gong
> Attachments: YARN-3623-2015-11-19.1.patch
>
>
> So far RM, MR AM, DA AM added/changed new config to enable the feature to
> write the timeline data to v2 server. It's good to have a YARN
> timeline-service.version config like timeline-service.enable to indicate the
> version of the running timeline service with the given YARN cluster. It's
> beneficial for users to more smoothly move from v1 to v2, as they don't need
> to change the existing config, but switch this config from v1 to v2. And each
> framework doesn't need to have their own v1/v2 config.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
