[ratis] 04/18: RATIS-1808. Rerun PreVote when Vote is timed out (#846)

[szetszwo]

This is an automated email from the ASF dual-hosted git repository.

szetszwo pushed a commit to branch branch-2_readIndex
in repository https://gitbox.apache.org/repos/asf/ratis.git

commit 3ed7c481c068c0a1a1d67d3a32cdf28bc27e1ce8
Author: Kaijie Chen <c...@apache.org>
AuthorDate: Fri Mar 10 00:42:47 2023 +0800

    RATIS-1808. Rerun PreVote when Vote is timed out (#846)
    
    (cherry picked from commit 601d01deb517e7d7093fcafd91589aa14c2dd72d)
---
 .../apache/ratis/server/impl/LeaderElection.java   | 81 +++++++++++-----------
 1 file changed, 39 insertions(+), 42 deletions(-)

diff --git 
a/ratis-server/src/main/java/org/apache/ratis/server/impl/LeaderElection.java 
b/ratis-server/src/main/java/org/apache/ratis/server/impl/LeaderElection.java
index ced72604a..5f79940cb 100644
--- 
a/ratis-server/src/main/java/org/apache/ratis/server/impl/LeaderElection.java
+++ 
b/ratis-server/src/main/java/org/apache/ratis/server/impl/LeaderElection.java
@@ -234,11 +234,12 @@ class LeaderElection implements Runnable {
       return;
     }
 
-    final Timer.Context electionContext = 
server.getLeaderElectionMetrics().getLeaderElectionTimer().time();
-    try {
-      if (skipPreVote || askForVotes(Phase.PRE_VOTE)) {
-        if (askForVotes(Phase.ELECTION)) {
-          server.changeToLeader();
+    try (Timer.Context ignored = 
server.getLeaderElectionMetrics().getLeaderElectionTimer().time()) {
+      for (int round = 0; shouldRun(); round++) {
+        if (skipPreVote || askForVotes(Phase.PRE_VOTE, round)) {
+          if (askForVotes(Phase.ELECTION, round)) {
+            server.changeToLeader();
+          }
         }
       }
     } catch(Exception e) {
@@ -257,7 +258,6 @@ class LeaderElection implements Runnable {
       }
     } finally {
       // Update leader election completion metric(s).
-      electionContext.stop();
       server.getLeaderElectionMetrics().onNewLeaderElectionCompletion();
       lifeCycle.checkStateAndClose(() -> {});
     }
@@ -296,48 +296,45 @@ class LeaderElection implements Runnable {
   }
 
   /** Send requestVote rpc to all other peers for the given phase. */
-  private boolean askForVotes(Phase phase) throws InterruptedException, 
IOException {
-    for(int round = 0; shouldRun(); round++) {
-      final long electionTerm;
-      final RaftConfigurationImpl conf;
-      synchronized (server) {
-        if (!shouldRun()) {
-          return false;
-        }
-        final ConfAndTerm confAndTerm = server.getState().initElection(phase);
-        electionTerm = confAndTerm.getTerm();
-        conf = confAndTerm.getConf();
+  private boolean askForVotes(Phase phase, int round) throws 
InterruptedException, IOException {
+    final long electionTerm;
+    final RaftConfigurationImpl conf;
+    synchronized (server) {
+      if (!shouldRun()) {
+        return false;
       }
+      final ConfAndTerm confAndTerm = server.getState().initElection(phase);
+      electionTerm = confAndTerm.getTerm();
+      conf = confAndTerm.getConf();
+    }
 
-      LOG.info("{} {} round {}: submit vote requests at term {} for {}", this, 
phase, round, electionTerm, conf);
-      final ResultAndTerm r = submitRequestAndWaitResult(phase, conf, 
electionTerm);
-      LOG.info("{} {} round {}: result {}", this, phase, round, r);
+    LOG.info("{} {} round {}: submit vote requests at term {} for {}", this, 
phase, round, electionTerm, conf);
+    final ResultAndTerm r = submitRequestAndWaitResult(phase, conf, 
electionTerm);
+    LOG.info("{} {} round {}: result {}", this, phase, round, r);
 
-      synchronized (server) {
-        if (!shouldRun(electionTerm)) {
-          return false; // term already passed or this should not run anymore.
-        }
+    synchronized (server) {
+      if (!shouldRun(electionTerm)) {
+        return false; // term already passed or this should not run anymore.
+      }
 
-        switch (r.getResult()) {
-          case PASSED:
-            return true;
-          case NOT_IN_CONF:
-          case SHUTDOWN:
-            server.getRaftServer().close();
-            
server.getStateMachine().event().notifyServerShutdown(server.getRoleInfoProto());
-            return false;
-          case TIMEOUT:
-            continue; // should retry
-          case REJECTED:
-          case DISCOVERED_A_NEW_TERM:
-            final long term = r.maxTerm(server.getState().getCurrentTerm());
-            server.changeToFollowerAndPersistMetadata(term, false, r);
-            return false;
-          default: throw new IllegalArgumentException("Unable to process 
result " + r.result);
-        }
+      switch (r.getResult()) {
+        case PASSED:
+          return true;
+        case NOT_IN_CONF:
+        case SHUTDOWN:
+          server.getRaftServer().close();
+          
server.getStateMachine().event().notifyServerShutdown(server.getRoleInfoProto());
+          return false;
+        case TIMEOUT:
+          return false; // should retry
+        case REJECTED:
+        case DISCOVERED_A_NEW_TERM:
+          final long term = r.maxTerm(server.getState().getCurrentTerm());
+          server.changeToFollowerAndPersistMetadata(term, false, r);
+          return false;
+        default: throw new IllegalArgumentException("Unable to process result 
" + r.result);
       }
     }
-    return false;
   }
 
   private int submitRequests(Phase phase, long electionTerm, TermIndex 
lastEntry,