MXS-1678: Add test case

Added test case that checks that relay master status is not lost when IO
thread is stopped.

maxscale-system-test/CMakeLists.txt

@@ -530,6 +530,10 @@ add_test_executable(mxs1543.cpp mxs1543 avro LABELS REPL_BACKEND)
  # https://jira.mariadb.org/browse/MXS-1585
 add_test_executable(mxs1585.cpp mxs1585 mxs1585 LABELS REPL_BACKEND)
 
+# MXS-1678: Stopping IO thread on relay master causes it to be promoted as master
+# https://jira.mariadb.org/browse/MXS-1678
+add_test_executable(mxs1678_relay_master.cpp mxs1678_relay_master replication LABELS REPL_BACKEND)
+
 # 'namedserverfilter' test
 add_test_executable(namedserverfilter.cpp namedserverfilter namedserverfilter LABELS namedserverfilter LIGHT REPL_BACKEND)
 

maxscale-system-test/mxs1678_relay_master.cpp

@@ -0,0 +1,86 @@
+/**
+ * MXS-1678: Stopping IO thread on relay master causes it to be promoted as master
+ *
+ * https://jira.mariadb.org/browse/MXS-1678
+ */
+#include "testconnections.h"
+#include <set>
+#include <string>
+
+typedef std::set<std::string> StringSet;
+
+// Note: This is backported from 2.2 and can be replaced with MaxScales::get_server_status once merged
+StringSet state(TestConnections& test, const char* name)
+{
+    StringSet rval;
+    char* res = test.ssh_maxscale_output(true, "maxadmin list servers|grep \'%s\'", name);
+    char* pipe = strrchr(res, '|');
+
+    if (res && pipe)
+    {
+        pipe++;
+        char* tok = strtok(pipe, ",");
+
+        while (tok)
+        {
+            char* p = tok;
+            char *end = strchr(tok, '\n');
+            if (!end)
+            {
+                end = strchr(tok, '\0');
+            }
+
+            // Trim leading whitespace
+            while (p < end && isspace(*p))
+            {
+                p++;
+            }
+
+            // Trim trailing whitespace
+            while (end > tok && isspace(*end))
+            {
+                *end-- = '\0';
+            }
+
+            rval.insert(p);
+            tok = strtok(NULL, ",\n");
+        }
+    }
+
+    free(res);
+
+    return rval;
+}
+
+
+int main(int argc, char** argv)
+{
+    TestConnections test(argc, argv);
+    test.repl->connect();
+    execute_query(test.repl->nodes[3], "STOP SLAVE");
+    execute_query(test.repl->nodes[3], "CHANGE MASTER TO MASTER_HOST='%s', MASTER_PORT=%d",
+                  test.repl->IP_private[2], test.repl->port[2]);
+    execute_query(test.repl->nodes[3], "START SLAVE");
+
+    StringSet master = {"Master", "Running"};
+    StringSet slave = {"Slave", "Running"};
+    StringSet relay_master = {"Relay Master", "Slave", "Running"};
+
+    test.tprintf("Checking before stopping IO thread");
+    test.add_result(state(test, "server1") != master, "server1 is not a master");
+    test.add_result(state(test, "server2") != slave, "server2 is not a slave");
+    test.add_result(state(test, "server3") != relay_master, "server3 is not a relay master");
+    test.add_result(state(test, "server4") != slave, "server4 is not a slave");
+
+    execute_query(test.repl->nodes[2], "STOP SLAVE IO_THREAD");
+    sleep(10);
+
+    test.tprintf("Checking after stopping IO thread");
+    test.add_result(state(test, "server1") != master, "server1 is not a master");
+    test.add_result(state(test, "server2") != slave, "server2 is not a slave");
+    test.add_result(state(test, "server3") != relay_master, "server3 is not a relay master");
+    test.add_result(state(test, "server4") != slave, "server4 is not a slave");
+
+    test.repl->fix_replication();
+    return test.global_result;
+}