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Posted to user@curator.apache.org by Ricardo Ferreira <ri...@gmail.com> on 2014/10/26 23:04:30 UTC
Find current group leader
Hi,
I'm using the Leader Election recipe to manage leadership among some of my
nodes.
However, I need to find out the current leader of these nodes from another
client which is not
part of the same group.
I haven't found anything on the API to do this. So what's done is to
instantiate a new LeaderSelector
and a dummy LeaderSelectorListener that relinquishes leadership as soon as
it gets it (just in case).
>From this LeaderSelector I can find the ID of the group leader. Then I'll
query ServiceDiscovery for
the instance corresponding to this ID.
Is there a simpler (or better) way to this?
Re: Find current group leader
Posted by Ricardo Ferreira <ri...@gmail.com>.
Ah, thanks, that makes more sense to me. Having to be elegible for election
without wanting it wasn't making much sense.
I'll give it a go tomorrow. Thanks again!
On Sun, Oct 26, 2014 at 10:22 PM, Jordan Zimmerman <
jordan@jordanzimmerman.com> wrote:
> For both LeaderSelector and LeaderLatch, you don’t have to start them to
> call getParticipants(). Just allocate one, call getParticipants() and then
> you’re done.
>
>
> On October 26, 2014 at 5:20:46 PM, Ricardo Ferreira (
> ricardojsfer@gmail.com) wrote:
>
> I'm using the Leader Selector on my server nodes (that make up the
> cluster). Each node instantiates a new LeaderSelector instance, passing
> itself as a LeaderSelectorListener.
>
> I've just checked and it seems LeaderLatch doesn't require me to register
> a LeaderSelectorListener, which is good, because I have no purpose to do so
> on the client...
>
> So on my client, I can instantiate a LeaderLatch, start it, query for the
> leader and then close it. Is this an acceptable pattern?
>
> On Sun, Oct 26, 2014 at 10:09 PM, Cameron McKenzie <mckenzie.cam@gmail.com
> > wrote:
>
>> hey Ricardo,
>> You're using the LeaderLatch recipe?
>>
>> There should be a getLeader() method exposed by the LeaderLatch which you
>> can use to determine the current leader.
>> cheers
>> Cam
>>
>> On Mon, Oct 27, 2014 at 9:04 AM, Ricardo Ferreira <ricardojsfer@gmail.com
>> > wrote:
>>
>>> Hi,
>>>
>>> I'm using the Leader Election recipe to manage leadership among some of
>>> my nodes.
>>>
>>> However, I need to find out the current leader of these nodes from
>>> another client which is not
>>> part of the same group.
>>>
>>> I haven't found anything on the API to do this. So what's done is to
>>> instantiate a new LeaderSelector
>>> and a dummy LeaderSelectorListener that relinquishes leadership as soon
>>> as it gets it (just in case).
>>> From this LeaderSelector I can find the ID of the group leader. Then
>>> I'll query ServiceDiscovery for
>>> the instance corresponding to this ID.
>>>
>>> Is there a simpler (or better) way to this?
>>>
>>
>>
>
Re: Find current group leader
Posted by Jordan Zimmerman <jo...@jordanzimmerman.com>.
For both LeaderSelector and LeaderLatch, you don’t have to start them to call getParticipants(). Just allocate one, call getParticipants() and then you’re done.
On October 26, 2014 at 5:20:46 PM, Ricardo Ferreira (ricardojsfer@gmail.com) wrote:
I'm using the Leader Selector on my server nodes (that make up the cluster). Each node instantiates a new LeaderSelector instance, passing itself as a LeaderSelectorListener.
I've just checked and it seems LeaderLatch doesn't require me to register a LeaderSelectorListener, which is good, because I have no purpose to do so on the client...
So on my client, I can instantiate a LeaderLatch, start it, query for the leader and then close it. Is this an acceptable pattern?
On Sun, Oct 26, 2014 at 10:09 PM, Cameron McKenzie <mc...@gmail.com> wrote:
hey Ricardo,
You're using the LeaderLatch recipe?
There should be a getLeader() method exposed by the LeaderLatch which you can use to determine the current leader.
cheers
Cam
On Mon, Oct 27, 2014 at 9:04 AM, Ricardo Ferreira <ri...@gmail.com> wrote:
Hi,
I'm using the Leader Election recipe to manage leadership among some of my nodes.
However, I need to find out the current leader of these nodes from another client which is not
part of the same group.
I haven't found anything on the API to do this. So what's done is to instantiate a new LeaderSelector
and a dummy LeaderSelectorListener that relinquishes leadership as soon as it gets it (just in case).
From this LeaderSelector I can find the ID of the group leader. Then I'll query ServiceDiscovery for
the instance corresponding to this ID.
Is there a simpler (or better) way to this?
Re: Find current group leader
Posted by Ricardo Ferreira <ri...@gmail.com>.
I'm using the Leader Selector on my server nodes (that make up the
cluster). Each node instantiates a new LeaderSelector instance, passing
itself as a LeaderSelectorListener.
I've just checked and it seems LeaderLatch doesn't require me to register a
LeaderSelectorListener, which is good, because I have no purpose to do so
on the client...
So on my client, I can instantiate a LeaderLatch, start it, query for the
leader and then close it. Is this an acceptable pattern?
On Sun, Oct 26, 2014 at 10:09 PM, Cameron McKenzie <mc...@gmail.com>
wrote:
> hey Ricardo,
> You're using the LeaderLatch recipe?
>
> There should be a getLeader() method exposed by the LeaderLatch which you
> can use to determine the current leader.
> cheers
> Cam
>
> On Mon, Oct 27, 2014 at 9:04 AM, Ricardo Ferreira <ri...@gmail.com>
> wrote:
>
>> Hi,
>>
>> I'm using the Leader Election recipe to manage leadership among some of
>> my nodes.
>>
>> However, I need to find out the current leader of these nodes from
>> another client which is not
>> part of the same group.
>>
>> I haven't found anything on the API to do this. So what's done is to
>> instantiate a new LeaderSelector
>> and a dummy LeaderSelectorListener that relinquishes leadership as soon
>> as it gets it (just in case).
>> From this LeaderSelector I can find the ID of the group leader. Then I'll
>> query ServiceDiscovery for
>> the instance corresponding to this ID.
>>
>> Is there a simpler (or better) way to this?
>>
>
>
Re: Find current group leader
Posted by Cameron McKenzie <mc...@gmail.com>.
hey Ricardo,
You're using the LeaderLatch recipe?
There should be a getLeader() method exposed by the LeaderLatch which you
can use to determine the current leader.
cheers
Cam
On Mon, Oct 27, 2014 at 9:04 AM, Ricardo Ferreira <ri...@gmail.com>
wrote:
> Hi,
>
> I'm using the Leader Election recipe to manage leadership among some of my
> nodes.
>
> However, I need to find out the current leader of these nodes from another
> client which is not
> part of the same group.
>
> I haven't found anything on the API to do this. So what's done is to
> instantiate a new LeaderSelector
> and a dummy LeaderSelectorListener that relinquishes leadership as soon as
> it gets it (just in case).
> From this LeaderSelector I can find the ID of the group leader. Then I'll
> query ServiceDiscovery for
> the instance corresponding to this ID.
>
> Is there a simpler (or better) way to this?
>