Merge branch '2.2' into develop

Documentation/Monitors/MariaDB-Monitor.md

@@ -296,6 +296,10 @@ the above requirements. Rejoin does not obey `failcount` and will attempt to
 rejoin any valid servers immediately. When activating rejoin manually, the
 user-designated server must fulfill the same requirements.
 
+The user can define files with SQL statements which are executed on any server
+being demoted or promoted by cluster manipulation commands. See the sections on
+`promotion_sql_file` and `demotion_sql_file` for more information.
+
 ### Limitations and requirements
 
 Switchover and failover only understand simple topologies. They will not work if
@@ -450,6 +454,41 @@ may fail if all valid promotion candidates are in the exclusion list.
 servers_no_promotion=backup_dc_server1,backup_dc_server2
 ```
 
+#### `promotion_sql_file` and `demotion_sql_file`
+
+These optional settings are paths to text files with SQL statements in them.
+During promotion or demotion, the contents are read line-by-line and executed on
+the backend. Use these settings to execute custom statements on the servers to
+complement the built-in operations.
+
+Empty lines or lines starting with '#' are ignored. Any results returned by the
+statements are ignored. All statements must succeed for the failover, switchover
+or rejoin to continue. The monitor user may require additional privileges and
+grants for the custom commands to succeed.
+
+When promoting a slave to master during switchover or failover, the
+`promotion_sql_file` is read and executed on the new master server after its
+read-only flag is disabled. The commands are ran *before* starting replication
+from an external master if any.
+
+`demotion_sql_file` is ran on an old master during demotion to slave, before the
+old master starts replicating from the new master. The file is also ran before
+rejoining a standalone server to the cluster, as the standalone server is
+typically a former master server. When redirecting a slave replicating from a
+wrong master, the sql-file is not executed.
+
+Since the queries in the files are ran during operations which modify
+replication topology, care is required. If `promotion_sql_file` contains data
+modification (DML) queries, the new master server may not be able to
+successfully replicate from an external master. `demotion_sql_file` should never
+contain DML queries, as these may not replicate to the slave servers before
+slave threads are stopped, breaking replication.
+
+```
+promotion_sql_file=/home/root/scripts/promotion.sql
+demotion_sql_file=/home/root/scripts/demotion.sql
+```
+
 ### Manual activation
 
 Failover, switchover and rejoin can be activated manually through the REST API

client/maxadmin.c

@@ -241,7 +241,7 @@ main(int argc, char **argv)
     bool use_unix_socket = false;
 
     int option_index = 0;
-    char c;
+    int c;
     while ((c = getopt_long(argc, argv, "h:p::P:u:S:v?ei",
                             long_options, &option_index)) >= 0)
     {

server/modules/monitor/mariadbmon/cluster_manipulation.cc

@@ -313,19 +313,21 @@ uint32_t MariaDBMonitor::do_rejoin(const ServerArray& joinable_servers, json_t**
         {
             MariaDBServer* joinable = *iter;
             const char* name = joinable->name();
+
+            bool op_success = false;
+            if (joinable->n_slaves_configured == 0)
+            {
                 if (!m_demote_sql_file.empty() && !joinable->run_sql_from_file(m_demote_sql_file, output))
                 {
                     PRINT_MXS_JSON_ERROR(output, "%s execution failed when attempting to rejoin server '%s'.",
                                          CN_DEMOTION_SQL_FILE, joinable->name());
                 }
                 else
-            {
-                bool op_success;
-                if (joinable->n_slaves_configured == 0)
                 {
                     MXS_NOTICE("Directing standalone server '%s' to replicate from '%s'.", name, master_name);
                     op_success = joinable->join_cluster(change_cmd);
                 }
+            }
             else
             {
                 MXS_NOTICE("Server '%s' is replicating from a server other than '%s', "
@@ -339,7 +341,6 @@ uint32_t MariaDBMonitor::do_rejoin(const ServerArray& joinable_servers, json_t**
             }
         }
     }
-    }
     return servers_joined;
 }
 

server/modules/monitor/mariadbmon/mariadbserver.cc

@@ -645,7 +645,7 @@ bool MariaDBServer::run_sql_from_file(const string& path, json_t** error_out)
     std::ifstream sql_file(path);
     if (sql_file.is_open())
     {
-        MXS_NOTICE("Executing sql queries from file '%s'.", path.c_str());
+        MXS_NOTICE("Executing sql queries from file '%s' on server '%s'.", path.c_str(), name());
         int lines_executed = 0;
 
         while (!sql_file.eof() && !error)
@@ -664,6 +664,12 @@ bool MariaDBServer::run_sql_from_file(const string& path, json_t** error_out)
                 if (mxs_mysql_query(conn, line.c_str()) == 0)
                 {
                     lines_executed++;
+                    // Discard results if any.
+                    MYSQL_RES* res = mysql_store_result(conn);
+                    if (res != NULL)
+                    {
+                        mysql_free_result(res);
+                    }
                 }
                 else
                 {

server/modules/monitor/mariadbmon/mariadbserver.hh

@@ -266,7 +266,8 @@ public:
     bool failover_wait_relay_log(int seconds_remaining, json_t** err_out);
 
     /**
-     * Read the file contents and send them as sql queries to the server. Queries should not return any data.
+     * Read the file contents and send them as sql queries to the server. Any data returned by the queries is
+     * discarded.
      *
      * @param server Server to send queries to
      * @param path Text file path.

server/modules/routing/binlogrouter/maxbinlogcheck.c

@@ -88,7 +88,7 @@ int main(int argc, char **argv)
     char *key_file = NULL;
     char *aes_algo = NULL;
     int report_header = 0;
-    char c;
+    int c;
     BINLOG_FILE_FIX binlog_file = {0, false, false};
 
 #ifdef HAVE_GLIBC