[ https://issues.apache.org/jira/browse/ZOOKEEPER-1031?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13013972#comment-13013972 ]
Vishal K commented on ZOOKEEPER-1031: ------------------------------------- Yes, but which follower should start the IP? There needs to be some level of agreement (like election). So it is easier to run it on the leader. Also, the node running this IP should not be behind the leader. Otherwise, fetching administartive info (e.g., configruation info) may return stale results. > Introduce virtual cluster IP and start that cluster IP on the host running ZK > leader > ------------------------------------------------------------------------------------ > > Key: ZOOKEEPER-1031 > URL: https://issues.apache.org/jira/browse/ZOOKEEPER-1031 > Project: ZooKeeper > Issue Type: Wish > Components: leaderElection, quorum > Affects Versions: 3.3.3 > Reporter: Vishal K > Priority: Minor > Fix For: 4.0.0 > > > It would be useful to enable a way to specify a virtual (floating) IP for the > ZK cluster (say in zoo.cfg). The ZK leader will start this IP on one of its > interfaces. If the leadership changes, the cluster IP will be taken over by > the new leader. This IP can be used to identify the ZK leader and send > administrative commands/query to the leader. For example, > - a ZK client can get the list of ZK servers in the configuration by sending > a request to the server running this IP address. The client just needs to > know one IP address. Availability of cluster automatically ensures > availability of > the IP address. > - To reconfigure ZK configuration, a client can send reconfig request to the > server on this IP and keep retrying until the request succeeds or fails. > Implementation issues: > 1. The old ZK leader that has lost leadership should be able to somehow give > up the virtual IP address. Otherwise, it could lead to collisions. One > solution is to self reboot. A system property can be used to specify ways to > unplumb the cluster IP > 2. Cross-platform support. > 3. Refreshing ARP caches -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira