MDEV-4487 Allow replication from MySQL 5.6+ when GTID is enabled on the master

MDEV-8685 MariaDB fails to decode Anonymous_GTID entries
MDEV-5705 Replication testing: 5.6->10.0

- Ignoring GTID events from MySQL 5.6+ (Allows replication from MySQL 5.6+ with GTID enabled)
- Added ignorable events from MySQL 5.6
- mysqlbinlog now writes information about GTID and ignorable events.
- Added more information in error message when replication stops because of wrong information in binary log.
- Fixed wrong test when write_on_release() should flush cache.

sql/log_event.cc

@@ -305,7 +305,7 @@ public:
   ~Write_on_release_cache()
   {
     copy_event_cache_to_file_and_reinit(m_cache, m_file);
-    if (m_flags | FLUSH_F)
+    if (m_flags & FLUSH_F)
       fflush(m_file);
   }
 
@@ -813,6 +813,15 @@ const char* Log_event::get_type_str(Log_event_type type)
   case BINLOG_CHECKPOINT_EVENT: return "Binlog_checkpoint";
   case GTID_EVENT: return "Gtid";
   case GTID_LIST_EVENT: return "Gtid_list";
+
+  /* The following is only for mysqlbinlog */
+  case IGNORABLE_LOG_EVENT: return "Ignorable log event";
+  case ROWS_QUERY_LOG_EVENT: return "MySQL Rows_query";
+  case GTID_LOG_EVENT: return "MySQL Gtid";
+  case ANONYMOUS_GTID_LOG_EVENT: return "MySQL Anonymous_Gtid";
+  case PREVIOUS_GTIDS_LOG_EVENT: return "MySQL Previous_gtids";
+  case HEARTBEAT_LOG_EVENT: return "Heartbeat";
+
   default: return "Unknown";				/* impossible */
   }
 }
@@ -1416,6 +1425,8 @@ Log_event* Log_event::read_log_event(IO_CACHE* file,
   DBUG_ENTER("Log_event::read_log_event");
   DBUG_ASSERT(description_event != 0);
   char head[LOG_EVENT_MINIMAL_HEADER_LEN];
+  my_off_t position= my_b_tell(file);
+
   /*
     First we only want to read at most LOG_EVENT_MINIMAL_HEADER_LEN, just to
     check the event for sanity and to know its length; no need to really parse
@@ -1427,7 +1438,7 @@ Log_event* Log_event::read_log_event(IO_CACHE* file,
                         LOG_EVENT_MINIMAL_HEADER_LEN);
 
   LOCK_MUTEX;
-  DBUG_PRINT("info", ("my_b_tell: %lu", (ulong) my_b_tell(file)));
+  DBUG_PRINT("info", ("my_b_tell: %llu", (ulonglong) position));
   if (my_b_read(file, (uchar *) head, header_size))
   {
     DBUG_PRINT("info", ("Log_event::read_log_event(IO_CACHE*,Format_desc*) \
@@ -1484,8 +1495,9 @@ err:
   {
     DBUG_ASSERT(error != 0);
     sql_print_error("Error in Log_event::read_log_event(): "
-                    "'%s', data_len: %lu, event_type: %d",
-		    error,data_len,(uchar)(head[EVENT_TYPE_OFFSET]));
+                    "'%s' at offset: %llu  data_len: %lu  event_type: %d",
+		    error, position, data_len,
+                    (uchar)(head[EVENT_TYPE_OFFSET]));
     my_free(buf);
     /*
       The SQL slave thread will check if file->error<0 to know
@@ -1518,10 +1530,12 @@ Log_event* Log_event::read_log_event(const char* buf, uint event_len,
   DBUG_PRINT("info", ("binlog_version: %d", description_event->binlog_version));
   DBUG_DUMP("data", (unsigned char*) buf, event_len);
 
-  /* Check the integrity */
+  /*
+    Check the integrity; This is needed because handle_slave_io() doesn't
+    check if packet is of proper length.
+ */
   if (event_len < EVENT_LEN_OFFSET ||
-      (uchar)buf[EVENT_TYPE_OFFSET] >= ENUM_END_EVENT ||
-      (uint) event_len != uint4korr(buf+EVENT_LEN_OFFSET))
+      event_len != uint4korr(buf+EVENT_LEN_OFFSET))
   {
     *error="Sanity check failed";		// Needed to free buffer
     DBUG_RETURN(NULL); // general sanity check - will fail on a partial read
@@ -1703,6 +1717,15 @@ Log_event* Log_event::read_log_event(const char* buf, uint event_len,
     case DELETE_ROWS_EVENT:
       ev = new Delete_rows_log_event(buf, event_len, description_event);
       break;
+
+      /* MySQL GTID events are ignored */
+    case GTID_LOG_EVENT:
+    case ANONYMOUS_GTID_LOG_EVENT:
+    case PREVIOUS_GTIDS_LOG_EVENT:
+      ev= new Ignorable_log_event(buf, description_event,
+                                  get_type_str((Log_event_type) event_type));
+      break;
+
     case TABLE_MAP_EVENT:
       ev = new Table_map_log_event(buf, event_len, description_event);
       break;
@@ -1720,10 +1743,22 @@ Log_event* Log_event::read_log_event(const char* buf, uint event_len,
       ev = new Annotate_rows_log_event(buf, event_len, description_event);
       break;
     default:
-      DBUG_PRINT("error",("Unknown event code: %d",
-                          (int) buf[EVENT_TYPE_OFFSET]));
-      ev= NULL;
-      break;
+      /*
+        Create an object of Ignorable_log_event for unrecognized sub-class.
+        So that SLAVE SQL THREAD will only update the position and continue.
+      */
+      if (uint2korr(buf + FLAGS_OFFSET) & LOG_EVENT_IGNORABLE_F)
+      {
+        ev= new Ignorable_log_event(buf, description_event,
+                                    get_type_str((Log_event_type) event_type));
+      }
+      else
+      {
+        DBUG_PRINT("error",("Unknown event code: %d",
+                            (int) buf[EVENT_TYPE_OFFSET]));
+        ev= NULL;
+        break;
+      }
     }
   }
 
@@ -4891,6 +4926,9 @@ Format_description_log_event(uint8 binlog_ver, const char* server_ver)
       post_header_len[HEARTBEAT_LOG_EVENT-1]= 0;
       post_header_len[IGNORABLE_LOG_EVENT-1]= 0;
       post_header_len[ROWS_QUERY_LOG_EVENT-1]= 0;
+      post_header_len[GTID_LOG_EVENT-1]= 0;
+      post_header_len[ANONYMOUS_GTID_LOG_EVENT-1]= 0;
+      post_header_len[PREVIOUS_GTIDS_LOG_EVENT-1]= 0;
       post_header_len[WRITE_ROWS_EVENT-1]=  ROWS_HEADER_LEN_V2;
       post_header_len[UPDATE_ROWS_EVENT-1]= ROWS_HEADER_LEN_V2;
       post_header_len[DELETE_ROWS_EVENT-1]= ROWS_HEADER_LEN_V2;
@@ -12639,6 +12677,52 @@ Incident_log_event::write_data_body(IO_CACHE *file)
 }
 
 
+Ignorable_log_event::Ignorable_log_event(const char *buf,
+                                         const Format_description_log_event
+                                         *descr_event,
+                                         const char *event_name)
+  :Log_event(buf, descr_event), number((int) (uchar) buf[EVENT_TYPE_OFFSET]),
+   description(event_name)
+{
+  DBUG_ENTER("Ignorable_log_event::Ignorable_log_event");
+  DBUG_VOID_RETURN;
+}
+
+Ignorable_log_event::~Ignorable_log_event()
+{
+}
+
+#ifndef MYSQL_CLIENT
+/* Pack info for its unrecognized ignorable event */
+void Ignorable_log_event::pack_info(THD *thd, Protocol *protocol)
+{
+  char buf[256];
+  size_t bytes;
+  bytes= my_snprintf(buf, sizeof(buf), "# Ignorable event type %d (%s)",
+                     number, description);
+  protocol->store(buf, bytes, &my_charset_bin);
+}
+#endif
+
+#ifdef MYSQL_CLIENT
+/* Print for its unrecognized ignorable event */
+void
+Ignorable_log_event::print(FILE *file,
+                           PRINT_EVENT_INFO *print_event_info)
+{
+  if (print_event_info->short_form)
+    return;
+
+  print_header(&print_event_info->head_cache, print_event_info, FALSE);
+  my_b_printf(&print_event_info->head_cache, "\tIgnorable\n");
+  my_b_printf(&print_event_info->head_cache,
+              "# Ignorable event type %d (%s)\n", number, description);
+  copy_event_cache_to_file_and_reinit(&print_event_info->head_cache,
+                                      file);
+}
+#endif
+
+
 #ifdef MYSQL_CLIENT
 /**
   The default values for these variables should be values that are
@@ -12720,4 +12804,25 @@ bool rpl_get_position_info(const char **log_file_name, ulonglong *log_pos,
   return TRUE;
 #endif
 }
+
+/**
+   Check if we should write event to the relay log
+
+   This is used to skip events that is only supported by MySQL
+
+   Return:
+   0 ok
+   1 Don't write event
+*/
+
+bool event_that_should_be_ignored(const char *buf)
+{
+  uint event_type= (uchar)buf[EVENT_TYPE_OFFSET];
+  if (event_type == GTID_LOG_EVENT ||
+      event_type == ANONYMOUS_GTID_LOG_EVENT ||
+      event_type == PREVIOUS_GTIDS_LOG_EVENT ||
+      (uint2korr(buf + FLAGS_OFFSET) & LOG_EVENT_IGNORABLE_F))
+    return 1;
+  return 0;
+}
 #endif

sql/log_event.h

@@ -260,6 +260,7 @@ struct sql_ex_info
 #define EXECUTE_LOAD_QUERY_HEADER_LEN  (QUERY_HEADER_LEN + EXECUTE_LOAD_QUERY_EXTRA_HEADER_LEN)
 #define INCIDENT_HEADER_LEN    2
 #define HEARTBEAT_HEADER_LEN   0
+#define IGNORABLE_HEADER_LEN   0
 #define ROWS_HEADER_LEN_V2    10
 #define ANNOTATE_ROWS_HEADER_LEN  0
 #define BINLOG_CHECKPOINT_HEADER_LEN 4
@@ -519,6 +520,17 @@ struct sql_ex_info
 */
 #define LOG_EVENT_RELAY_LOG_F 0x40
 
+/**
+   @def LOG_EVENT_IGNORABLE_F
+
+   For an event, 'e', carrying a type code, that a slave,
+   's', does not recognize, 's' will check 'e' for
+   LOG_EVENT_IGNORABLE_F, and if the flag is set, then 'e'
+   is ignored. Otherwise, 's' acknowledges that it has
+   found an unknown event in the relay log.
+*/
+#define LOG_EVENT_IGNORABLE_F 0x80
+
 /**
    @def LOG_EVENT_SKIP_REPLICATION_F
 
@@ -697,6 +709,11 @@ enum Log_event_type
   UPDATE_ROWS_EVENT = 31,
   DELETE_ROWS_EVENT = 32,
  
+  /* MySQL 5.6 GTID events, ignored by MariaDB */
+  GTID_LOG_EVENT= 33,
+  ANONYMOUS_GTID_LOG_EVENT= 34,
+  PREVIOUS_GTIDS_LOG_EVENT= 35,
+
   /*
     Add new events here - right above this comment!
     Existing events (except ENUM_END_EVENT) should never change their numbers
@@ -4740,6 +4757,60 @@ private:
   LEX_STRING m_message;
 };
 
+/**
+  @class Ignorable_log_event
+
+  Base class for ignorable log events. Events deriving from
+  this class can be safely ignored by slaves that cannot
+  recognize them. Newer slaves, will be able to read and
+  handle them. This has been designed to be an open-ended
+  architecture, so adding new derived events shall not harm
+  the old slaves that support ignorable log event mechanism
+  (they will just ignore unrecognized ignorable events).
+
+  @note The only thing that makes an event ignorable is that it has
+  the LOG_EVENT_IGNORABLE_F flag set.  It is not strictly necessary
+  that ignorable event types derive from Ignorable_log_event; they may
+  just as well derive from Log_event and pass LOG_EVENT_IGNORABLE_F as
+  argument to the Log_event constructor.
+**/
+
+class Ignorable_log_event : public Log_event {
+public:
+  int number;
+  const char *description;
+
+#ifndef MYSQL_CLIENT
+  Ignorable_log_event(THD *thd_arg)
+    :Log_event(thd_arg, LOG_EVENT_IGNORABLE_F, FALSE),
+    number(0), description("internal")
+  {
+    DBUG_ENTER("Ignorable_log_event::Ignorable_log_event");
+    DBUG_VOID_RETURN;
+  }
+#endif
+
+  Ignorable_log_event(const char *buf,
+                      const Format_description_log_event *descr_event,
+                      const char *event_name);
+  virtual ~Ignorable_log_event();
+
+#ifndef MYSQL_CLIENT
+  void pack_info(THD *, Protocol*);
+#endif
+
+#ifdef MYSQL_CLIENT
+  virtual void print(FILE *file, PRINT_EVENT_INFO *print_event_info);
+#endif
+
+  virtual Log_event_type get_type_code() { return IGNORABLE_LOG_EVENT; }
+
+  virtual bool is_valid() const { return 1; }
+
+  virtual int get_data_size() { return IGNORABLE_HEADER_LEN; }
+};
+
+
 static inline bool copy_event_cache_to_file_and_reinit(IO_CACHE *cache,
                                                        FILE *file)
 {
@@ -4797,6 +4868,7 @@ bool rpl_get_position_info(const char **log_file_name, ulonglong *log_pos,
                            ulonglong *relay_log_pos);
 
 bool event_checksum_test(uchar *buf, ulong event_len, uint8 alg);
+bool event_that_should_be_ignored(const char *buf);
 uint8 get_checksum_alg(const char* buf, ulong len);
 extern TYPELIB binlog_checksum_typelib;
 

sql/slave.cc

@@ -5615,6 +5615,11 @@ static int queue_event(Master_info* mi,const char* buf, ulong event_len)
       error_msg.append(llbuf, strlen(llbuf));
       goto err;
     }
+
+    /*
+      Heartbeat events doesn't count in the binlog size, so we don't have to
+      increment mi->master_log_pos
+    */
     goto skip_relay_logging;
   }
   break;
@@ -5844,6 +5849,7 @@ static int queue_event(Master_info* mi,const char* buf, ulong event_len)
   else
   if ((s_id == global_system_variables.server_id &&
        !mi->rli.replicate_same_server_id) ||
+      event_that_should_be_ignored(buf) ||
       /*
         the following conjunction deals with IGNORE_SERVER_IDS, if set
         If the master is on the ignore list, execution of