mariadb/plugin/semisync/semisync.h
He Zhenxing f8155de078 Backport BUG#45848 Semisynchronous replication internals are visible in SHOW PROCESSLIST and logs
Semi-sync uses an extra connection from slave to master to send
replies, this is a normal client connection, and used a normal
SET query to set the reply information on master, which is visible
to user and may cause some confusion and complaining.

This problem is fixed by using the method of sending reply by
using the same connection that is used by master dump thread to
send binlog to slave. Since now the semi-sync plugins are integrated
with the server code, it is not a problem to use the internal net
interfaces to do this.

The master dump thread will mark the event requires a reply and
wait for the reply when the event just sent is the last event
of a transaction and semi-sync status is ON; And the slave will
send a reply to master when it received such an event that requires
a reply.
2009-10-12 20:55:01 +08:00

91 lines
2.6 KiB
C++

/* Copyright (C) 2007 Google Inc.
Copyright (C) 2008 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
#ifndef SEMISYNC_H
#define SEMISYNC_H
#define MYSQL_SERVER
#define HAVE_REPLICATION
#include <mysql_priv.h>
#include <my_global.h>
#include <my_pthread.h>
#include <mysql/plugin.h>
#include <replication.h>
typedef struct st_mysql_show_var SHOW_VAR;
typedef struct st_mysql_sys_var SYS_VAR;
/**
This class is used to trace function calls and other process
information
*/
class Trace {
public:
static const unsigned long kTraceFunction;
static const unsigned long kTraceGeneral;
static const unsigned long kTraceDetail;
static const unsigned long kTraceNetWait;
unsigned long trace_level_; /* the level for tracing */
inline void function_enter(const char *func_name)
{
if (trace_level_ & kTraceFunction)
sql_print_information("---> %s enter", func_name);
}
inline int function_exit(const char *func_name, int exit_code)
{
if (trace_level_ & kTraceFunction)
sql_print_information("<--- %s exit (%d)", func_name, exit_code);
return exit_code;
}
Trace()
:trace_level_(0L)
{}
Trace(unsigned long trace_level)
:trace_level_(trace_level)
{}
};
/**
Base class for semi-sync master and slave classes
*/
class ReplSemiSyncBase
:public Trace {
public:
static const char kSyncHeader[2]; /* three byte packet header */
/* Constants in network packet header. */
static const unsigned char kPacketMagicNum;
static const unsigned char kPacketFlagSync;
};
/* The layout of a semisync slave reply packet:
1 byte for the magic num
8 bytes for the binlog positon
n bytes for the binlog filename, terminated with a '\0'
*/
#define REPLY_MAGIC_NUM_LEN 1
#define REPLY_BINLOG_POS_LEN 8
#define REPLY_BINLOG_NAME_LEN (FN_REFLEN + 1)
#define REPLY_MAGIC_NUM_OFFSET 0
#define REPLY_BINLOG_POS_OFFSET (REPLY_MAGIC_NUM_OFFSET + REPLY_MAGIC_NUM_LEN)
#define REPLY_BINLOG_NAME_OFFSET (REPLY_BINLOG_POS_OFFSET + REPLY_BINLOG_POS_LEN)
#endif /* SEMISYNC_H */