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Posted to yarn-dev@hadoop.apache.org by Steve Loughran <st...@hortonworks.com> on 2015/10/18 20:18:26 UTC
When does the RM ever send out node map updates?
I've been modifying the slider AM to wait for NM updates of node maps -but I'm not seeing any onNodesUpdated() callbacks, at least for an AM which doesn't instantiate any containers.
When/how do those updates come?
Re: When does the RM ever send out node map updates?
Posted by Steve Loughran <st...@hortonworks.com>.
> On 19 Oct 2015, at 12:04, Rohith Sharma K S <ro...@huawei.com> wrote:
>
>>>> how does the AM determine the map of nodes.
> IIUC, it is not possible now. Probably a bug which was missed till now!!
> OR
> Does all the applications need to know all the nodes updates in a cluster? It could be 1000 nodes , 10K nodes.
>
> And how about when node label is configured.?
my AM needs to know the map because it's trying to support anti-affinity in resource requests (SLIDER-82), with the plan being "ask for any node that isn't already in use by that component type"). Some people have suggested blacklisting, but that would block all the other outstanding requests for other components.
The AM would be happy with a node map and then update events as things change.
RE: When does the RM ever send out node map updates?
Posted by Rohith Sharma K S <ro...@huawei.com>.
>>> how does the AM determine the map of nodes.
IIUC, it is not possible now. Probably a bug which was missed till now!!
OR
Does all the applications need to know all the nodes updates in a cluster? It could be 1000 nodes , 10K nodes.
And how about when node label is configured.?
Thanks & Regards
Rohith Sharma K S
-----Original Message-----
From: Steve Loughran [mailto:stevel@hortonworks.com]
Sent: 19 October 2015 15:01
To: yarn-dev@hadoop.apache.org
Subject: Re: When does the RM ever send out node map updates?
Thanks for that snippet.
Which brings me back to a key question: how does the AM determine the map of nodes.
And before someone says "the yarn client lets you do that", bear in mind this is for a long-lived restartable AM; what may have been valid when the client launched it 3 weeks earlier may be invalid on restart.
If it were in the RegisterApplicationMasterResponse I'd pick it up there & wait for changes —but you don't get a nodemap then
Any suggestions?
> On 19 Oct 2015, at 06:25, Rohith Sharma K S <ro...@huawei.com> wrote:
>
> NM node updates are sent to ApplicationMaster only when NodeManager is added/removed/'change in NM state i.e Usable/Unusable'. Otherwise no updates are sent to AM even at least one time in application life time!!
>
> I believe it is implemented purposefully to intimate AM about only unusable nodes.
>
> Thanks & Regards
> Rohith Sharma K S
>
> -----Original Message-----
> From: Steve Loughran [mailto:stevel@hortonworks.com]
> Sent: 18 October 2015 23:48
> To: yarn-dev@hadoop.apache.org
> Subject: When does the RM ever send out node map updates?
>
>
> I've been modifying the slider AM to wait for NM updates of node maps -but I'm not seeing any onNodesUpdated() callbacks, at least for an AM which doesn't instantiate any containers.
>
> When/how do those updates come?
>
Re: When does the RM ever send out node map updates?
Posted by Steve Loughran <st...@hortonworks.com>.
Thanks for that snippet.
Which brings me back to a key question: how does the AM determine the map of nodes.
And before someone says "the yarn client lets you do that", bear in mind this is for a long-lived restartable AM; what may have been valid when the client launched it 3 weeks earlier may be invalid on restart.
If it were in the RegisterApplicationMasterResponse I'd pick it up there & wait for changes —but you don't get a nodemap then
Any suggestions?
> On 19 Oct 2015, at 06:25, Rohith Sharma K S <ro...@huawei.com> wrote:
>
> NM node updates are sent to ApplicationMaster only when NodeManager is added/removed/'change in NM state i.e Usable/Unusable'. Otherwise no updates are sent to AM even at least one time in application life time!!
>
> I believe it is implemented purposefully to intimate AM about only unusable nodes.
>
> Thanks & Regards
> Rohith Sharma K S
>
> -----Original Message-----
> From: Steve Loughran [mailto:stevel@hortonworks.com]
> Sent: 18 October 2015 23:48
> To: yarn-dev@hadoop.apache.org
> Subject: When does the RM ever send out node map updates?
>
>
> I've been modifying the slider AM to wait for NM updates of node maps -but I'm not seeing any onNodesUpdated() callbacks, at least for an AM which doesn't instantiate any containers.
>
> When/how do those updates come?
>
RE: When does the RM ever send out node map updates?
Posted by Rohith Sharma K S <ro...@huawei.com>.
NM node updates are sent to ApplicationMaster only when NodeManager is added/removed/'change in NM state i.e Usable/Unusable'. Otherwise no updates are sent to AM even at least one time in application life time!!
I believe it is implemented purposefully to intimate AM about only unusable nodes.
Thanks & Regards
Rohith Sharma K S
-----Original Message-----
From: Steve Loughran [mailto:stevel@hortonworks.com]
Sent: 18 October 2015 23:48
To: yarn-dev@hadoop.apache.org
Subject: When does the RM ever send out node map updates?
I've been modifying the slider AM to wait for NM updates of node maps -but I'm not seeing any onNodesUpdated() callbacks, at least for an AM which doesn't instantiate any containers.
When/how do those updates come?