Return-Path: X-Original-To: apmail-curator-user-archive@minotaur.apache.org Delivered-To: apmail-curator-user-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 9220C17ED1 for ; Fri, 16 Jan 2015 00:09:52 +0000 (UTC) Received: (qmail 56258 invoked by uid 500); 16 Jan 2015 00:09:54 -0000 Delivered-To: apmail-curator-user-archive@curator.apache.org Received: (qmail 56217 invoked by uid 500); 16 Jan 2015 00:09:54 -0000 Mailing-List: contact user-help@curator.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@curator.apache.org Delivered-To: mailing list user@curator.apache.org Received: (qmail 56206 invoked by uid 99); 16 Jan 2015 00:09:54 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 16 Jan 2015 00:09:54 +0000 X-ASF-Spam-Status: No, hits=2.5 required=5.0 tests=FREEMAIL_REPLY,HTML_MESSAGE,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of mckenzie.cam@gmail.com designates 209.85.217.170 as permitted sender) Received: from [209.85.217.170] (HELO mail-lb0-f170.google.com) (209.85.217.170) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 16 Jan 2015 00:09:49 +0000 Received: by mail-lb0-f170.google.com with SMTP id 10so16028902lbg.1 for ; Thu, 15 Jan 2015 16:07:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=4O3paqjuPORN1gxsAuUpXO3g0b9TbBxstYPzWVAYmmA=; b=VRGvdLbwF+cyCmNUhAkEuzwkeJcRFj5E0B/Ak98xB4cCU9wmVvp6e8ssGhwnw7SGtO 2cWzh72hf51SyWcbdN77AdaiGqMd8aSuTEz6mnsabaqiiafgSHgbdWXmK3w/ipin095B xHlRwiJd2E8qxWGDZnZ+cOojhOjOuZNKEgNAqyKlrgC0cUdskHJAqK6GRafXnpRu4SsF TMpCFnUcLFAOsuqsp5sPHG/wf19bx6aPspMeO+8giZuDq5MZUwTkNYGi9Vn3RFdLgchr fkAnkVTN6ltDREv+NMRJumb7ZGHO96kMx3ztxlJpSL8IGujvsUizgMy2FeFHsgkdTQYy ETdA== MIME-Version: 1.0 X-Received: by 10.112.170.36 with SMTP id aj4mr12613902lbc.3.1421366833070; Thu, 15 Jan 2015 16:07:13 -0800 (PST) Received: by 10.112.19.99 with HTTP; Thu, 15 Jan 2015 16:07:12 -0800 (PST) In-Reply-To: References: Date: Fri, 16 Jan 2015 11:07:12 +1100 Message-ID: Subject: Re: Zookeeper Leadership election with curator From: Cameron McKenzie To: Jordan Zimmerman Cc: user@curator.apache.org Content-Type: multipart/alternative; boundary=001a11c261fc2e4662050cb9c1cd X-Virus-Checked: Checked by ClamAV on apache.org --001a11c261fc2e4662050cb9c1cd Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Yes, good point. On Fri, Jan 16, 2015 at 10:57 AM, Jordan Zimmerman < jordan@jordanzimmerman.com> wrote: > But if you go through that much trouble you might as well just use > InterProcessMutex. > > -JZ > > > > On January 15, 2015 at 6:54:30 PM, Cameron McKenzie ( > mckenzie.cam@gmail.com) wrote: > > If you use the callback as Jordan suggested, then you can just block on > a latch, and then get this latch to be updated by the callback when it is > notified that it's leader. Then you won't have to wait for some fixed > amount of time, it will just block until it's leader. > > > On Fri, Jan 16, 2015 at 10:48 AM, Check Peck > wrote: > >> As of now, I am adding a sleep of 1 minute and it works fine before I >> check whether I am a leader or not. >> >> On Thu, Jan 15, 2015 at 3:43 PM, Check Peck >> wrote: >> >>> Yes that makes sense that 1 client will be leader. But suppose I have >>> 5 background threads running in 5 different machines and each backgroun= d >>> thread is in different classes and I want to make sure that those 5 >>> background threads are running from a single machine who is the leader = so >>> that's why we are doing that check whether I am the leader then do this= . >>> >>> Will this work if we add a Listener to leaderlatch? >>> >>> On Thu, Jan 15, 2015 at 3:30 PM, Jordan Zimmerman < >>> jordan@jordanzimmerman.com> wrote: >>> >>>> The problem with that is you have to wait until you are the leader. >>>> The benefit of LeaderSelector is that it has a callback that is invoke= d >>>> when you are the leader. Remember, you are in a multithreaded, multi c= lient >>>> environment. Only 1 client is going to be the leader. Maybe what you a= re >>>> after is an InterProcessMutex? >>>> >>>> -JZ >>>> >>>> >>>> >>>> On January 15, 2015 at 6:24:06 PM, Check Peck (comptechgeeky@gmail.com= ) >>>> wrote: >>>> >>>> I saw the leader election code here - >>>> https://git-wip-us.apache.org/repos/asf?p=3Dcurator.git;a=3Dtree;f=3Dc= urator-examples/src/main/java/leader;h=3D73b547eadb98995c0ccbd06a5b76d0741f= fef263;hb=3DHEAD >>>> >>>> But didn't understand few things - How can I call something like this >>>> in my code - I want to do stuff in my code by just checking whether I= am >>>> the leader or not. And from the LeaderSelectorExample, I am not able t= o >>>> understand this. >>>> >>>> if (zookClient.isLeader()) { >>>> >>>> // then do stuff >>>> >>>> } >>>> >>>> >>>> On Thu, Jan 15, 2015 at 3:17 PM, Jordan Zimmerman < >>>> jordan@jordanzimmerman.com> wrote: >>>> >>>>> Oh - maybe I read the code too fast. I guess it doesn=E2=80=99t make= more >>>>> than one=E2=80=A6 >>>>> >>>>> There=E2=80=99s an example of LeaderSelector here: >>>>> http://curator.apache.org/curator-examples/index.html >>>>> >>>>> >>>>> On January 15, 2015 at 6:00:03 PM, Check Peck (comptechgeeky@gmail.co= m) >>>>> wrote: >>>>> >>>>> Thanks Jordan for the input. >>>>> >>>>> * Where do you see that I am creating new Curator instance for each >>>>> Leader? I guess I am using one Curator instance for my application? >>>>> * Ok, I have commented out this line in ZookeeperClient class >>>>> * That's a good point, how would I use the listener or the >>>>> leaderselector in my code base? If possible, can you provide an examp= le? >>>>> >>>>> >>>>> On Thu, Jan 15, 2015 at 2:38 PM, Jordan Zimmerman < >>>>> jordan@jordanzimmerman.com> wrote: >>>>> >>>>>> A few things: >>>>>> >>>>>> * You don=E2=80=99t need to create a new Curator instance for each = Leader. >>>>>> One Curator instance can be used for an application. >>>>>> * Calling >>>>>> client.getZookeeperClient().blockUntilConnectedOrTimedOut(); is unne= cessary >>>>>> * Calling isLeader() immediately after starting the latch may not >>>>>> work. It takes time for the leader to get selected. LeaderLatch has = a >>>>>> listener if you want to get notified. Alternatively, you can use >>>>>> LeaderSelector. >>>>>> >>>>>> Hope this helps. >>>>>> >>>>>> -Jordan >>>>>> >>>>>> >>>>>> >>>>>> On January 15, 2015 at 5:25:26 PM, Check Peck ( >>>>>> comptechgeeky@gmail.com) wrote: >>>>>> >>>>>> I am using Zookeeper for the leadership election process. I have >>>>>> three nodes zookeeper ensemble. >>>>>> >>>>>> We have a node like this "/test/msn" on which we are doing the >>>>>> leadership election and it works fine and we have application server= s >>>>>> running it in production and using "/test/msn" node for leadership. = And >>>>>> this program is always running. >>>>>> >>>>>> Now we created another node like this "/testpnl" in the same >>>>>> zookeeper servers. And we have another set of machines which is tryi= ng to >>>>>> do the leadership election on that node and whenever I run my progra= m in >>>>>> production from one servers, it always returns back that the node is= not >>>>>> leader? And I can see only one node inside "/testpnl" and it is the = same >>>>>> node from which I am running my program? >>>>>> >>>>>> I am using Curator 2.7.0 and the zookeeper version is 3.4.5 Is there >>>>>> anything wrong with my setup or zookeeper has some bug which I am no= t aware? >>>>>> >>>>>> Is anything >>>>>> >>>>>> public class ZookeeperLeaderTester { >>>>>> >>>>>> private ZookeeperClient zookClient; >>>>>> >>>>>> private static final String ZOOK_PRODUCTION =3D >>>>>> "host1:2181,host2:2181,host3:2181"; >>>>>> private static final String LEADERSHIP_NODE =3D "/testpnl"; >>>>>> >>>>>> private static class Holder { >>>>>> static final ZookeeperLeaderTester INSTANCE =3D new >>>>>> ZookeeperLeaderTester(); >>>>>> } >>>>>> >>>>>> public static ZookeeperLeaderTester getInstance() { >>>>>> return Holder.INSTANCE; >>>>>> } >>>>>> >>>>>> private ZookeeperLeaderTester() { >>>>>> try { >>>>>> String hostname =3D getHostName(); >>>>>> >>>>>> zookClient =3D new ZookeeperClient(nodes, >>>>>> LEADERSHIP_NODE, hostname); >>>>>> zookClient.start(); >>>>>> >>>>>> } catch (Exception ex) { >>>>>> System.out.println (ex); >>>>>> System.exit(1); >>>>>> } >>>>>> } >>>>>> >>>>>> public ZookeeperClient getZookClient() { >>>>>> return zookClient; >>>>>> } >>>>>> } >>>>>> >>>>>> And here is my ZookeeperClient code - >>>>>> >>>>>> public class ZookeeperClient { >>>>>> >>>>>> private CuratorFramework client; >>>>>> private String latchPath; >>>>>> private String id; >>>>>> private LeaderLatch leaderLatch; >>>>>> >>>>>> public ZookeeperClient(String connString, String latchPath, >>>>>> String id) { >>>>>> client =3D CuratorFrameworkFactory.newClient(connString, >>>>>> new ExponentialBackoffRetry(1000, Integer.MAX_VALUE)); >>>>>> this.id =3D id; >>>>>> this.latchPath =3D latchPath; >>>>>> } >>>>>> >>>>>> public void start() throws Exception { >>>>>> client.start(); >>>>>> >>>>>> client.getZookeeperClient().blockUntilConnectedOrTimedOut(); >>>>>> leaderLatch =3D new LeaderLatch(client, latchPath, id); >>>>>> leaderLatch.start(); >>>>>> } >>>>>> >>>>>> public boolean isLeader() { >>>>>> return leaderLatch.hasLeadership(); >>>>>> } >>>>>> >>>>>> public Participant currentLeader() throws Exception { >>>>>> return leaderLatch.getLeader(); >>>>>> } >>>>>> >>>>>> public void close() throws IOException { >>>>>> leaderLatch.close(); >>>>>> client.close(); >>>>>> } >>>>>> >>>>>> public CuratorFramework getClient() { >>>>>> return client; >>>>>> } >>>>>> >>>>>> public String getLatchPath() { >>>>>> return latchPath; >>>>>> } >>>>>> >>>>>> public String getId() { >>>>>> return id; >>>>>> } >>>>>> >>>>>> public LeaderLatch getLeaderLatch() { >>>>>> return leaderLatch; >>>>>> } >>>>>> } >>>>>> >>>>>> And this is the way I am using it - >>>>>> >>>>>> ZookeeperLeaderTester zookClient =3D >>>>>> ZookeeperLeaderTester.getInstance().getZookClient(); >>>>>> if (zookClient.isLeader()) { >>>>>> // then do stuff >>>>>> } >>>>>> >>>>>> >>>>> >>>> >>> >> > --001a11c261fc2e4662050cb9c1cd Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Yes, good point.

<= div class=3D"gmail_quote">On Fri, Jan 16, 2015 at 10:57 AM, Jordan Zimmerma= n <jordan@jordanzimmerman.com> wrote:
But if you go through that much trouble you might as well ju= st use InterProcessMutex.

-JZ



On January 15, 2015 at 6:54:30 PM, Cameron McKenzie (mckenzie.cam@gmail.co= m) wrote:

If you use the callback as Jordan suggested, then you can just block on a latch, and then get this latch to be updated by the callback when it is notified that it's leader. Then you won't have to wait for some fixed amount of time, it will just block until it's leader.


On Fri, Jan 16, 2015 at 10:48 AM, Check Peck <comptechgeeky@gmail.com> wrote:
As of now, I am adding a sleep of 1 minute and it works fine before I check whether I am a leader or not.

On Thu, Jan 15, 2015 at 3:43 PM, Check Peck <comptechgeeky@gmail.com> wrote:
Yes that makes sense that 1 client will be leader. But suppose I have 5 background threads running in 5 different machines and each background thread is in different classes and I want to make sure that those 5 background threads are running from a single machine who is the leader so that's why we are doing that check whether I am the leader then do this.

Will this work if we add a Listener to leaderlatch?

On Thu, Jan 15, 2015 at 3:30 PM, Jordan Zimmerman <jordan@jordanzimmerman.com> wrote:
The problem with that is you have to wait until you are the leader. The benefit of LeaderSelector is that it has a callback that is invoked when you are the leader. Remember, you are in a multithreaded, multi client environment. Only 1 client is going to be the leader. Maybe what you are after is an InterProcessMutex?

-JZ



On January 15, 2015 at 6:24:06 PM, Check Peck (comptechgeeky= @gmail.com) wrote:

But didn't understand few things - How can I call something like this in my code=C2=A0 - I want to do stuff in my code by just checking whether I am the leader or not. And from the LeaderSelectorExample, I am not able to understand this.

if (zookClient.isLeader()) {

// then do stuff

}
On Thu, Jan 15, 2015 at 3:17 PM, Jordan Zimmerman <jordan@jordanzimmerman.com> wrote:
Oh - maybe I read the code too fast. I guess it doesn=E2=80=99t make more than one=E2=80=A6

There=E2=80=99s an example of LeaderSelector here:=C2=A0http://cur= ator.apache.org/curator-examples/index.html


On January 15, 2015 at 6:00:03 PM, Check Peck (comptechgeeky= @gmail.com) wrote:

Thanks Jordan for the input.

* Where do you see that I am creating new Curator instance for each Leader? I guess I am using one Curator instance for my application?
* Ok, I have commented out this line in ZookeeperClient class
* That's a good point, how would I use the listener or the leaderselector in my code base? If possible, can you provide an example?
On Thu, Jan 15, 2015 at 2:38 PM, Jordan Zimmerman <jordan@jordanzimmerman.com> wrote:
A few things:

* You don=E2=80=99t need to create a new Curator instance for each Leader. One Curator instance can be used for an application.
* Calling client.getZookeeperClient().blockUntilConnectedOrTimedOut(); is unnecessary
* Calling isLeader() immediately after starting the latch may not work. It takes time for the leader to get selected. LeaderLatch has a listener if you want to get notified. Alternatively, you can use LeaderSelector.

Hope this helps.

-Jordan



On January 15, 2015 at 5:25:26 PM, Check Peck (comptechgeeky= @gmail.com) wrote:

I am using Zookeeper for the leadership election process. I have three nodes zookeeper ensemble.

We have a node like this "/test/msn" on which we are doing the leadership election and it works fine and we have application servers running it in production and using "/test/msn" node for leadership. And this program is always running.

Now we created another node like this "/testpnl" in the same zookeeper servers. And we have another set of machines which is trying to do the leadership election on that node and whenever I run my program in production from one servers, it always returns back that the node is not leader? And I can see only one node inside "/testpnl" and it is the same node from which I am running my program?

I am using Curator 2.7.0 and the zookeeper version is 3.4.5 Is there anything wrong with my setup or zookeeper has some bug which I am not aware?

Is anything

=C2=A0=C2=A0=C2=A0 public class ZookeeperLeaderTester {

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 private ZookeeperClient zookClient;

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 private static final String ZOOK_PRODUCTION =3D "host1:2181,host2:2181,host3:2181";
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 private static final String LEADERSHIP_NODE =3D "/testpnl";

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 private static class Holder {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 static final ZookeeperLeaderTester INSTANCE =3D new ZookeeperLeaderTester();
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 public static ZookeeperLeaderTester getInstance() {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return Holder.INSTANCE;
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 private ZookeeperLeaderTester() {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 try {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 String hostname =3D getHostName();

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 zookClient =3D new ZookeeperClient(nodes, LEADERSHIP_NODE, hostname);
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 zookClient.start();

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 } catch (Exception ex) {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 System.out.println (ex);
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 System.exit(1);
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 public ZookeeperClient getZookClient() {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return zookClient;
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }
=C2=A0=C2=A0=C2=A0 }
=C2=A0=C2=A0=C2=A0
And here is my ZookeeperClient code -

=C2=A0=C2=A0=C2=A0 public class ZookeeperClient {

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 private CuratorFramework client;
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 private String latchPath;
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 private String id;
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 private LeaderLatch leaderLatch;

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 public ZookeeperClient(String connString, String latchPath, String id) {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 client =3D CuratorFrameworkFactory.newClient(connString, new ExponentialBackoffRetry(1000, Integer.MAX_VALUE));
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 this.id =3D id;
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 this.latchPath =3D latchPath;
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 public void start() throws Exception {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 client.start();
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 client.getZookeeperClient().blockUntilConnectedOrTimedOut();
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 leaderLatch =3D new LeaderLatch(client, latchPath, id);
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 leaderLatch.start();
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 public boolean isLeader() {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return leaderLatch.hasLeadership();
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 public Participant currentLeader() throws Exception {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return leaderLatch.getLeader();
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 public void close() throws IOException {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 leaderLatch.close();
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 client.close();
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 public CuratorFramework getClient() {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return client;
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 public String getLatchPath() {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return latchPath;
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 public String getId() {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return id;
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }

=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 public LeaderLatch getLeaderLatch() {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return leaderLatch;
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }
=C2=A0=C2=A0=C2=A0 }
=C2=A0=C2=A0=C2=A0
And this is the way I am using it -

=C2=A0=C2=A0=C2=A0 ZookeeperLeaderTester zookClient =3D ZookeeperLeaderTester.getInstance().getZookClient();
=C2=A0=C2=A0=C2=A0 if (zookClient.isLeader()) {
=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 // then do stuff
=C2=A0=C2=A0=C2=A0 }






--001a11c261fc2e4662050cb9c1cd--