Cluster: more reliable replicas migration test.

tests/cluster/tests/07-replica-migration.tcl

@@ -45,3 +45,78 @@ foreach_redis_id id {
         }
     }
 }
+
+# Now test the migration to a master which used to be a slave, after
+# a failver.
+
+source "../tests/includes/init-tests.tcl"
+
+# Create a cluster with 5 master and 10 slaves, so that we have 2
+# slaves for each master.
+test "Create a 5 nodes cluster" {
+    create_cluster 5 10
+}
+
+test "Cluster is up" {
+    assert_cluster_state ok
+}
+
+set failover_cycle 0
+set new_master 2
+
+while {$failover_cycle != 2} {
+    incr failover_cycle
+    set current_epoch [CI 1 cluster_current_epoch]
+
+    test "Wait for slave of #$new_master to sync" {
+        wait_for_condition 1000 50 {
+            [string match {*state=online*} [RI $new_master slave0]]
+        } else {
+            fail "Slave of node #$new_master is not ok"
+        }
+    }
+
+    test "Killing master node #$new_master" {
+        kill_instance redis $new_master
+    }
+
+    test "Wait for failover" {
+        wait_for_condition 1000 50 {
+            [CI 1 cluster_current_epoch] > $current_epoch
+        } else {
+            fail "No failover detected"
+        }
+    }
+
+    test "Cluster should eventually be up again" {
+        assert_cluster_state ok
+    }
+
+    test "Cluster is writable" {
+        cluster_write_test 1
+    }
+
+    test "Instance #7 or #12 is now a master" {
+        assert {
+            (![instance_is_killed redis 7] && [RI 7 role] eq {master}) ||
+            (![instance_is_killed redis 12] && [RI 12 role] eq {master})
+        }
+    }
+
+    if {![instance_is_killed redis 7] && [RI 7 role] eq {master}} {
+        set new_master 7
+    } else {
+        set new_master 12
+    }
+}
+
+# The remaining instance is now without slaves. Some other slave
+# should migrate to it.
+
+test "Master #$new_master should have at least one replica" {
+    wait_for_condition 1000 50 {
+        [llength [lindex [R $new_master role] 2]] >= 1
+    } else {
+        fail "Master #$new_master has no replicas"
+    }
+}