[ 
https://issues.apache.org/jira/browse/ZOOKEEPER-2554?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15466241#comment-15466241
 ] 

Arshad Mohammad commented on ZOOKEEPER-2554:
--------------------------------------------

# bq. any server not currently in the view should be a non-voting participant. 
AFAIK,  non-voting participant means observer but in the code observer is 
changed to participant(voting-participant). So code is doing just opposite of 
what is intended, isn't it
# Test case is testing the way new observer should get added.  It is not 
testing the way it is getting added
For observer, server 3, the type changes multiple times: OBSERVER 
-->PARTICIPANT -->OBSERVER
## initialized from configuration
{code}
2016-09-06 07:43:31,783 [myid:3] - INFO  [Thread-7:QuorumPeer@415] - learner 
type set to OBSERVER
java.lang.Exception: exceptionForStackTrace
        at 
org.apache.zookeeper.server.quorum.QuorumPeer.setLearnerType(QuorumPeer.java:416)
        at 
org.apache.zookeeper.server.quorum.QuorumPeerMain.runFromConfig(QuorumPeerMain.java:179)
        at 
org.apache.zookeeper.server.quorum.QuorumPeerMain.initializeAndRun(QuorumPeerMain.java:120)
        at 
org.apache.zookeeper.server.quorum.QuorumPeerTestBase$MainThread.run(QuorumPeerTestBase.java:245)
{code}
## updated during first leader election
{code}
2016-09-06 07:43:31,808 [myid:3] - INFO  
[WorkerReceiver[myid=3]:QuorumPeer@415] - learner type set to PARTICIPANT
java.lang.Exception: exceptionForStackTrace
        at 
org.apache.zookeeper.server.quorum.QuorumPeer.setLearnerType(QuorumPeer.java:416)
        at 
org.apache.zookeeper.server.quorum.QuorumPeer.updateLearnerType(QuorumPeer.java:1843)
        at 
org.apache.zookeeper.server.quorum.QuorumPeer.processReconfig(QuorumPeer.java:1762)
        at 
org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerReceiver.run(FastLeaderElection.java:299)
        at java.lang.Thread.run(Thread.java:745)
{code}
## During reconfig processing
{code}
2016-09-06 07:43:32,155 [myid:3] - INFO  
[QuorumPeer[myid=3](plain=/127.0.0.1:11231)(secure=disabled):QuorumPeer@415] - 
learner type set to OBSERVER
java.lang.Exception: exceptionForStackTrace
        at 
org.apache.zookeeper.server.quorum.QuorumPeer.setLearnerType(QuorumPeer.java:416)
        at 
org.apache.zookeeper.server.quorum.QuorumPeer.updateLearnerType(QuorumPeer.java:1824)
        at 
org.apache.zookeeper.server.quorum.QuorumPeer.processReconfig(QuorumPeer.java:1762)
        at 
org.apache.zookeeper.server.quorum.Follower.processPacket(Follower.java:151)
        at 
org.apache.zookeeper.server.quorum.Follower.followLeader(Follower.java:90)
        at 
org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:1113)
{code}
##  In reconfig when type is changed from PARTICIPANT to OBSERVER, it is major 
change and exception is thrown and leader election happens again.
# So overall procedure to add the observer becomes very lengthy unnecessarily. 
is the expected way to add observers?

> reconfig can not add new server as observer
> -------------------------------------------
>
>                 Key: ZOOKEEPER-2554
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-2554
>             Project: ZooKeeper
>          Issue Type: Bug
>          Components: server
>    Affects Versions: 3.5.0, 3.5.1, 3.5.2
>            Reporter: Arshad Mohammad
>            Assignee: Arshad Mohammad
>            Priority: Critical
>         Attachments: ReconfigObserverTest.java, ZOOKEEPER-2554-01.patch
>
>
> Try to add new observer server using reconfig API, server gets added as 
> participant.
> STEPS:
> # create 3 node cluster.
> {code}
> server.0=127.0.0.1:11223:11224:participant;127.0.0.1:11222
> server.1=127.0.0.1:11226:11227:participant;127.0.0.1:11225
> server.2=127.0.0.1:11229:11230:participant;127.0.0.1:11228
> {code}
> # Suppose the 2 is the leader in the above cluster. Configure the new server 
> as
> {code}
> server.2=127.0.0.1:11229:11230:participant;127.0.0.1:11228
> server.3=127.0.0.1:11232:11233:observer;127.0.0.1:11231
> {code}
> # Connect to 1 and execute the reconfig command
> {code}
> zkClient.reconfig("server.3=127.0.0.1:11232:11233:observer;127.0.0.1:11231", 
> null, null, -1, null, null);
> {code}
> # Verify sever 3. It was supposed to run as observer but it is running as 
> participant



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to