Add Active Replication tests

Former-commit-id: 528d10091fda0d2c56674e825c4f70467587955f

src/networking.cpp

@@ -2577,7 +2577,9 @@ void helloCommand(client *c) {
 
     if (!g_pserver->sentinel_mode) {
         addReplyBulkCString(c,"role");
-        addReplyBulkCString(c,listLength(g_pserver->masters) ? "replica" : "master");
+        addReplyBulkCString(c,listLength(g_pserver->masters) ? 
+            g_pserver->fActiveReplica ? "active-replica" : "replica" 
+            : "master");
     }
 
     addReplyBulkCString(c,"modules");

src/replication.cpp

@@ -2342,12 +2342,15 @@ void replicationUnsetMaster(redisMaster *mi) {
 /* This function is called when the slave lose the connection with the
  * master into an unexpected way. */
 void replicationHandleMasterDisconnection(redisMaster *mi) {
+    if (mi != nullptr)
+    {
         mi->master = NULL;
         mi->repl_state = REPL_STATE_CONNECT;
         mi->repl_down_since = g_pserver->unixtime;
         /* We lost connection with our master, don't disconnect slaves yet,
         * maybe we'll be able to PSYNC with our master later. We'll disconnect
         * the slaves only if we'll have to do a full resync with our master. */
+    }
 }
 
 void replicaofCommand(client *c) {
@@ -2449,6 +2452,9 @@ void roleCommand(client *c) {
             redisMaster *mi = (redisMaster*)listNodeValue(ln);
             const char *slavestate = NULL;
             addReplyArrayLen(c,5);
+            if (g_pserver->fActiveReplica)
+                addReplyBulkCBuffer(c,"active-replica",14);
+            else
                 addReplyBulkCBuffer(c,"slave",5);
             addReplyBulkCString(c,mi->masterhost);
             addReplyLongLong(c,mi->masterport);

tests/integration/replication-active.tcl

@@ -0,0 +1,83 @@
+start_server {tags {"active-repl"} overrides {active-replica yes}} {
+    set slave [srv 0 client]
+    set slave_host [srv 0 host]
+    set slave_port [srv 0 port]
+    set slave_log [srv 0 stdout]
+    set slave_pid [s process_id]
+    start_server {overrides {active-replica yes}} {
+        set master [srv 0 client]
+        set master_host [srv 0 host]
+        set master_port [srv 0 port]
+
+        # Use a short replication timeout on the slave, so that if there
+        # are no bugs the timeout is triggered in a reasonable amount
+        # of time.
+        $slave config set repl-timeout 5
+
+        # Start the replication process...
+        $slave slaveof $master_host $master_port
+        $master slaveof $slave_host $slave_port
+
+        test {Active replicas report the correct role} {
+            wait_for_condition 50 100 {
+                [string match *active-replica* [$slave role]]
+            } else {
+                fail "Replica0 does not report the correct role"
+            }
+            wait_for_condition 50 100 {
+                [string match *active-replica* [$master role]]
+            } else {
+                fail "Replica1 does not report the correct role"
+            }
+        }
+
+        test {Active replicas propogate} {
+            $master set testkey foo
+            wait_for_condition 50 500 {
+                [string match *foo* [$slave get testkey]]
+            } else {
+                fail "replication failed to propogate"
+            }
+
+            $slave set testkey bar
+            wait_for_condition 50 500 {
+                [string match bar [$master get testkey]]
+            } else {
+                fail "replication failed to propogate in the other direction"
+            }
+        }
+
+        test {Active replicas WAIT} {
+            # Test that wait succeeds since replicas should be syncronized
+            $master set testkey foo
+            $slave set testkey2 test
+            assert_equal {1} [$master wait 1 10]
+            assert_equal {1} [$slave wait 1 10]
+
+            # Now setup a situation where wait should fail
+            exec kill -SIGSTOP $slave_pid
+            $master set testkey fee
+            assert_equal {0} [$master wait 1 1]
+        }
+        # Resume the replica we paused in the prior test
+        exec kill -SIGCONT $slave_pid
+
+        test {Active replica expire propogates} {
+            $master set testkey1 foo
+            wait_for_condition 50 1000 {
+                [string match *foo* [$slave get testkey1]]
+            } else {
+                fail "Replication failed to propogate"
+            }
+            $master pexpire testkey1 200
+            after 1000
+            assert_equal {0} [$master del testkey1]
+            assert_equal {0} [$slave del testkey1]
+
+            $slave set testkey1 foo px 200
+            after 1000
+            assert_equal {0} [$master del testkey1]
+            assert_equal {0} [$slave del testkey1]
+        }
+    }
+}

tests/test_helper.tcl

@@ -41,6 +41,7 @@ set ::all_tests {
     integration/replication-3
     integration/replication-4
     integration/replication-psync
+    integration/replication-active
     integration/aof
     integration/rdb
     integration/convert-zipmap-hash-on-load