diff options
Diffstat (limited to '')
| -rw-r--r-- | sql/semisync_slave.cc | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/sql/semisync_slave.cc b/sql/semisync_slave.cc new file mode 100644 index 00000000..df8baf04 --- /dev/null +++ b/sql/semisync_slave.cc @@ -0,0 +1,250 @@ +/* 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"); + 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); +} |