desaikomal commented on code in PR #2558:
URL: https://github.com/apache/helix/pull/2558#discussion_r1266163422
##########
meta-client/src/main/java/org/apache/helix/metaclient/recipes/leaderelection/LeaderElectionClient.java:
##########
@@ -91,10 +131,46 @@ public boolean joinLeaderElectionParticipantPool(String
leaderPath) {
*
* @param leaderPath The path for leader election.
* @param userInfo Any additional information to associate with this
participant.
- * @return boolean indicating if the operation is succeeded.
+ * @throws RuntimeException if the operation is not succeeded.
*/
- public boolean joinLeaderElectionParticipantPool(String leaderPath, Object
userInfo) {
- return false;
+ public void joinLeaderElectionParticipantPool(String leaderPath, LeaderInfo
userInfo) {
+ // TODO: create participant entry with info
+ subscribeAndTryCreateLeaderEntry(leaderPath);
+ }
+
+ private void subscribeAndTryCreateLeaderEntry(String leaderPath) {
+ _metaClient.subscribeDataChange(leaderPath + LEADER_ENTRY_KEY,
_reElectListener, false);
+ LeaderInfo leaderInfo = new LeaderInfo(LEADER_ENTRY_KEY);
+ leaderInfo.setLeaderName(_participant);
+
+ try {
+ // try to create leader entry, assuming leader election group node is
already there
+ _metaClient.create(leaderPath + LEADER_ENTRY_KEY, leaderInfo,
MetaClientInterface.EntryMode.EPHEMERAL);
+ } catch (MetaClientNodeExistsException ex) {
+ LOG.info("Already a leader for group {}" , leaderPath);
+ } catch (MetaClientNoNodeException ex) {
+ try {
+ // try to create leader path root entry
+ _metaClient.create(leaderPath, null);
Review Comment:
this makes it clear. Essentially, first one can fail but the second one is
the actual one.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
