Don…the bellow code will return leader node for mesos & marathon framework.
import …
public class SomeClass {
CuratorFramework client;
public void init(){
client = CuratorFrameworkFactory.newClient(connectionString, new
ExponentialBackoffRetry(1000, 3))
}
public String getMasterNodeIP(){
if(client!=null){
client.start();
LeaderSelectorListener listener = new LeaderSelectorListenerAdapter() {
public void takeLeadership(CuratorFramework client) throws
Exception {
}
};
LeaderSelector selector = new LeaderSelector(client, path, listener);
selector.autoRequeue();
selector.start();
Participant participant = selector.getLeader();
String id =
participant.getId().substring(participant.getId().indexOf("@") + 1,
participant.getId().indexOf("*"));
masterNode.add(id);
}
} catch (Exception e) {
logger.error("Failed find out master node", e.getCause());
}
}
}
Nikolaos Ballas | Software Development Manager
Technology Nexus S.a.r.l.
2-4 Rue Eugene Rupert
2453 Luxembourg
Delivery address: 2-3 Rue Eugene Rupert,Vertigo Polaris Building
Tel: + 3522619113580
[email protected]<mailto:[email protected]> |
nexusgroup.com<http://www.nexusgroup.com/>
LinkedIn.com<http://www.linkedin.com/company/nexus-technology> |
Twitter<http://www.twitter.com/technologynexus> |
Facebook.com<https://www.facebook.com/pages/Technology-Nexus/133756470003189>
[cid:19B646FC-B8E7-4F77-BBD3-75DD7B4B5BF7]
On 08 Jul 2015, at 16:27, Donald Laidlaw
<[email protected]<mailto:[email protected]>> wrote:
@Nikolaos Ballas neXus
I can see no way to instantiate the Curator LeaderSelector without actually
becoming a participant in leader election. If I do instantiate that class, it
does not accept a null value for the LeaderSelectorListener and so anything
instantiating LeaderSelector must also become a participant.
Even then, that class provides no way to listen for leadership change. The only
listening it does is to discover when it itself becomes the leader. I suppose
it would be possible to participate in the leadership election, but immediately
relinquish leadership causing a real mesos master to become the leader, but
that seems a little too invasive to do.
The only solution I can see is to monitor the children of the mesos leader
node, and parse through the contents of the ones whose name begins with “info”
as per @Marco Massenzio.
Best regards,
-Don
On Jul 7, 2015, at 12:16 PM, Donald Laidlaw
<[email protected]<mailto:[email protected]>> wrote:
Thank you all.
I will use the Curator recipe, since I already use Curator for a bunch of other
things.
If curator can find the leader and the participants that is good enough.
Otherwise I will parse the protocol buffer contents, and provide a way to parse
the future son contents when that happens.
I’ll reply again with the results of using the Curator recipe to get the leader
and participants.
Best regards,
-Don
On Jul 7, 2015, at 11:04 AM, Dick Davies
<[email protected]<mailto:[email protected]>> wrote:
The active master has a flag set in /metrics/snapshot :
"master/elected" which is 1 for the active
master and 0 otherwise, so it's easy enough to only load the metrics
from the active master.
(I use the collectd plugin and push data rather than poll, but the
same principle should apply).
On 7 July 2015 at 14:02, Donald Laidlaw
<[email protected]<mailto:[email protected]>> wrote:
Has anyone ever developed Java code to detect the mesos masters and leader,
given a zookeeper connection?
The reason I ask is because I would like to monitor mesos to report various
metrics reported by the master. This requires detecting and tracking the
leading master to query its /metrics/snapshot REST endpoint.
Thanks,
-Don
