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/* Copyright (c) 2008 MySQL AB, 2009 Sun Microsystems, Inc.
Use is subject to license terms.
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 */
#include <my_global.h>
#include "semisync_slave.h"
Repl_semi_sync_slave repl_semisync_slave;
my_bool rpl_semi_sync_slave_enabled= 0;
char rpl_semi_sync_slave_delay_master;
my_bool rpl_semi_sync_slave_status= 0;
ulong rpl_semi_sync_slave_trace_level;
/*
indicate whether or not the slave should send a reply to the master.
This is set to true in repl_semi_slave_read_event if the current
event read is the last event of a transaction. And the value is
checked in repl_semi_slave_queue_event.
*/
bool semi_sync_need_reply= false;
unsigned int rpl_semi_sync_slave_kill_conn_timeout;
unsigned long long rpl_semi_sync_slave_send_ack = 0;
int Repl_semi_sync_slave::init_object()
{
int result= 0;
m_init_done = true;
/* References to the parameter works after set_options(). */
set_slave_enabled(rpl_semi_sync_slave_enabled);
set_trace_level(rpl_semi_sync_slave_trace_level);
set_delay_master(rpl_semi_sync_slave_delay_master);
set_kill_conn_timeout(rpl_semi_sync_slave_kill_conn_timeout);
return result;
}
int Repl_semi_sync_slave::slave_read_sync_header(const char *header,
unsigned long total_len,
int *semi_flags,
const char **payload,
unsigned long *payload_len)
{
int read_res = 0;
DBUG_ENTER("Repl_semi_sync_slave::slave_read_sync_header");
if (rpl_semi_sync_slave_status)
{
if (DBUG_EVALUATE_IF("semislave_corrupt_log", 0, 1)
&& (unsigned char)(header[0]) == k_packet_magic_num)
{
semi_sync_need_reply = (header[1] & k_packet_flag_sync);
*payload_len = total_len - 2;
*payload = header + 2;
DBUG_PRINT("semisync", ("%s: reply - %d",
"Repl_semi_sync_slave::slave_read_sync_header",
semi_sync_need_reply));
if (semi_sync_need_reply)
*semi_flags |= SEMI_SYNC_NEED_ACK;
if (is_delay_master())
*semi_flags |= SEMI_SYNC_SLAVE_DELAY_SYNC;
}
else
{
sql_print_error("Missing magic number for semi-sync packet, packet "
"len: %lu", total_len);
read_res = -1;
}
} else {
*payload= header;
*payload_len= total_len;
}
DBUG_RETURN(read_res);
}
int Repl_semi_sync_slave::slave_start(Master_info *mi)
{
bool semi_sync= get_slave_enabled();
sql_print_information("Slave I/O thread: Start %s replication to\
master '%s@%s:%d' in log '%s' at position %lu",
semi_sync ? "semi-sync" : "asynchronous",
const_cast<char *>(mi->user), mi->host, mi->port,
const_cast<char *>(mi->master_log_name),
(unsigned long)(mi->master_log_pos));
if (semi_sync && !rpl_semi_sync_slave_status)
rpl_semi_sync_slave_status= 1;
/*clear the counter*/
rpl_semi_sync_slave_send_ack= 0;
return 0;
}
int Repl_semi_sync_slave::slave_stop(Master_info *mi)
{
if (rpl_semi_sync_slave_status)
rpl_semi_sync_slave_status= 0;
if (get_slave_enabled())
kill_connection(mi->mysql);
return 0;
}
int Repl_semi_sync_slave::reset_slave(Master_info *mi)
{
return 0;
}
void Repl_semi_sync_slave::kill_connection(MYSQL *mysql)
{
if (!mysql)
return;
char kill_buffer[30];
MYSQL *kill_mysql = NULL;
kill_mysql = mysql_init(kill_mysql);
mysql_options(kill_mysql, MYSQL_OPT_CONNECT_TIMEOUT, &m_kill_conn_timeout);
mysql_options(kill_mysql, MYSQL_OPT_READ_TIMEOUT, &m_kill_conn_timeout);
mysql_options(kill_mysql, MYSQL_OPT_WRITE_TIMEOUT, &m_kill_conn_timeout);
bool ret= (!mysql_real_connect(kill_mysql, mysql->host,
mysql->user, mysql->passwd,0, mysql->port, mysql->unix_socket, 0));
if (DBUG_EVALUATE_IF("semisync_slave_failed_kill", 1, 0) || ret)
{
sql_print_information("cannot connect to master to kill slave io_thread's "
"connection");
if (!ret)
mysql_close(kill_mysql);
return;
}
size_t kill_buffer_length = my_snprintf(kill_buffer, 30, "KILL %lu",
mysql->thread_id);
mysql_real_query(kill_mysql, kill_buffer, (ulong)kill_buffer_length);
mysql_close(kill_mysql);
}
int Repl_semi_sync_slave::request_transmit(Master_info *mi)
{
MYSQL *mysql= mi->mysql;
MYSQL_RES *res= 0;
MYSQL_ROW row;
const char *query;
if (!get_slave_enabled())
return 0;
query= "SHOW VARIABLES LIKE 'rpl_semi_sync_master_enabled'";
if (mysql_real_query(mysql, query, (ulong)strlen(query)) ||
!(res= mysql_store_result(mysql)))
{
sql_print_error("Execution failed on master: %s, error :%s", query, mysql_error(mysql));
return 1;
}
row= mysql_fetch_row(res);
if (DBUG_EVALUATE_IF("master_not_support_semisync", 1, 0)
|| !row)
{
/* Master does not support semi-sync */
sql_print_warning("Master server does not support semi-sync, "
"fallback to asynchronous replication");
rpl_semi_sync_slave_status= 0;
mysql_free_result(res);
return 0;
}
mysql_free_result(res);
/*
Tell master dump thread that we want to do semi-sync
replication
*/
query= "SET @rpl_semi_sync_slave= 1";
if (mysql_real_query(mysql, query, (ulong)strlen(query)))
{
sql_print_error("Set 'rpl_semi_sync_slave=1' on master failed");
return 1;
}
mysql_free_result(mysql_store_result(mysql));
rpl_semi_sync_slave_status= 1;
return 0;
}
int Repl_semi_sync_slave::slave_reply(Master_info *mi)
{
MYSQL* mysql= mi->mysql;
const char *binlog_filename= const_cast<char *>(mi->master_log_name);
my_off_t binlog_filepos= mi->master_log_pos;
NET *net= &mysql->net;
uchar reply_buffer[REPLY_MAGIC_NUM_LEN
+ REPLY_BINLOG_POS_LEN
+ REPLY_BINLOG_NAME_LEN];
int reply_res = 0;
size_t name_len = strlen(binlog_filename);
DBUG_ENTER("Repl_semi_sync_slave::slave_reply");
if (rpl_semi_sync_slave_status && semi_sync_need_reply)
{
/* Prepare the buffer of the reply. */
reply_buffer[REPLY_MAGIC_NUM_OFFSET] = k_packet_magic_num;
int8store(reply_buffer + REPLY_BINLOG_POS_OFFSET, binlog_filepos);
memcpy(reply_buffer + REPLY_BINLOG_NAME_OFFSET,
binlog_filename,
name_len + 1 /* including trailing '\0' */);
DBUG_PRINT("semisync", ("%s: reply (%s, %lu)",
"Repl_semi_sync_slave::slave_reply",
binlog_filename, (ulong)binlog_filepos));
net_clear(net, 0);
/* Send the reply. */
reply_res = my_net_write(net, reply_buffer,
name_len + REPLY_BINLOG_NAME_OFFSET);
if (!reply_res)
{
reply_res = DBUG_EVALUATE_IF("semislave_failed_net_flush", 1, net_flush(net));
if (reply_res)
sql_print_error("Semi-sync slave net_flush() reply failed");
rpl_semi_sync_slave_send_ack++;
}
else
{
sql_print_error("Semi-sync slave send reply failed: %s (%d)",
net->last_error, net->last_errno);
}
}
DBUG_RETURN(reply_res);
}
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