Still use joint consensus when only one peer changed (sofastack#482)

* still use joint consensus when only one peer changed * fix ut: readCommittedUserLog
mathdata · Jul 7, 2020 · b6338f5 · b6338f5
1 parent 11e9406
commit b6338f5
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Showing 2 changed files with 6 additions and 9 deletions.
diff --git a/jraft-core/src/main/java/com/alipay/sofa/jraft/core/NodeImpl.java b/jraft-core/src/main/java/com/alipay/sofa/jraft/core/NodeImpl.java
@@ -468,15 +468,12 @@ void nextStage() {
             Requires.requireTrue(isBusy(), "Not in busy stage");
             switch (this.stage) {
                 case STAGE_CATCHING_UP:
-                    if (this.nchanges > 1) {
+                    if (this.nchanges > 0) {
                         this.stage = Stage.STAGE_JOINT;
                         this.node.unsafeApplyConfiguration(new Configuration(this.newPeers, this.newLearners),
                             new Configuration(this.oldPeers), false);
                         return;
                     }
-                    // Skip joint consensus since only one peers has been changed here. Make
-                    // it a one-stage change to be compatible with the legacy
-                    // implementation.
                 case STAGE_JOINT:
                     this.stage = Stage.STAGE_STABLE;
                     this.node.unsafeApplyConfiguration(new Configuration(this.newPeers, this.newLearners), null, false);

diff --git a/jraft-core/src/test/java/com/alipay/sofa/jraft/core/NodeTest.java b/jraft-core/src/test/java/com/alipay/sofa/jraft/core/NodeTest.java
@@ -2922,16 +2922,16 @@ public void readCommittedUserLog() throws Exception {
             assertEquals("User log is deleted at index: 5", e.getMessage());
         }
 
-        // index == 12 and index == 13 are 2 CONFIGURATION logs, so real_index will be 14 when returned.
+        // index == 12、index == 13、index=14、index=15 are 4 CONFIGURATION logs(joint consensus), so real_index will be 16 when returned.
         userLog = leader.readCommittedUserLog(12);
         assertNotNull(userLog);
-        assertEquals(14, userLog.getIndex());
+        assertEquals(16, userLog.getIndex());
         assertEquals("hello10", new String(userLog.getData().array()));
 
-        // now index == 15 is a user log
-        userLog = leader.readCommittedUserLog(15);
+        // now index == 17 is a user log
+        userLog = leader.readCommittedUserLog(17);
         assertNotNull(userLog);
-        assertEquals(15, userLog.getIndex());
+        assertEquals(17, userLog.getIndex());
         assertEquals("hello11", new String(userLog.getData().array()));
 
         cluster.ensureSame();