RATIS-698. RaftServerImpl should not enforce minTimeout before first leaderElection cycle.

Author: szetszwo

ratis-server/src/main/java/org/apache/ratis/server/impl/RaftServerImpl.java

@@ -47,6 +47,7 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Function;
 import java.util.function.Supplier;
@@ -90,6 +91,8 @@ public class RaftServerImpl implements RaftServerProtocol, RaftServerAsynchronou
 
   private AtomicReference<TermIndex> inProgressInstallSnapshotRequest;
 
+  private final AtomicBoolean honorMinTimeoutMs = new AtomicBoolean();
+
   RaftServerImpl(RaftGroup group, StateMachine stateMachine, RaftServerProxy proxy) throws IOException {
     final RaftPeerId id = proxy.getId();
     LOG.info("{}: new RaftServerImpl for {} with {}", id, group, stateMachine);
@@ -141,8 +144,12 @@ int getMaxTimeoutMs() {
   }
 
   int getRandomTimeoutMs() {
-    return minTimeoutMs + ThreadLocalRandom.current().nextInt(
-        maxTimeoutMs - minTimeoutMs + 1);
+    return (honorMinTimeoutMs.get() ? minTimeoutMs : 0) +
+        ThreadLocalRandom.current().nextInt(maxTimeoutMs - minTimeoutMs + 1);
+  }
+
+  void honorMinTimeoutMs() {
+    honorMinTimeoutMs.set(Boolean.TRUE);
   }
 
   int getSleepDeviationThresholdMs() {

ratis-server/src/main/java/org/apache/ratis/server/impl/ServerState.java

@@ -251,6 +251,7 @@ void setLeader(RaftPeerId newLeaderId, String op) {
         lastNoLeaderTime = null;
         suffix = ", leader elected after " + previous.elapsedTimeMs() + "ms";
         server.getStateMachine().notifyLeaderChanged(getMemberId(), newLeaderId);
+        server.honorMinTimeoutMs();
       }
       LOG.info("{}: change Leader from {} to {} at term {} for {}{}",
           getMemberId(), leaderId, newLeaderId, getCurrentTerm(), op, suffix);

ratis-server/src/test/java/org/apache/ratis/statemachine/SimpleStateMachine4Testing.java

@@ -24,7 +24,6 @@
 import org.apache.ratis.proto.RaftProtos.RoleInfoProto;
 import org.apache.ratis.protocol.Message;
 import org.apache.ratis.protocol.RaftClientRequest;
-import org.apache.ratis.protocol.RaftGroup;
 import org.apache.ratis.protocol.RaftGroupId;
 import org.apache.ratis.protocol.RaftGroupMemberId;
 import org.apache.ratis.protocol.RaftPeerId;
@@ -428,7 +427,9 @@ public void notifyNotLeader(Collection<TransactionContext> pendingEntries)
 
   @Override
   public void notifyLeaderChanged(RaftGroupMemberId groupMemberId, RaftPeerId raftPeerId) {
-
+    if (groupMemberId.getPeerId().equals(raftPeerId)) {
+      notifiedAsLeader = true;
+    }
   }
 
   public boolean isNotifiedAsLeader() {