diff options
Diffstat (limited to 'sql/semisync_slave.cc')
-rw-r--r-- | sql/semisync_slave.cc | 152 |
1 files changed, 86 insertions, 66 deletions
diff --git a/sql/semisync_slave.cc b/sql/semisync_slave.cc index 788aab78..4314b116 100644 --- a/sql/semisync_slave.cc +++ b/sql/semisync_slave.cc @@ -20,20 +20,9 @@ Repl_semi_sync_slave repl_semisync_slave; -my_bool rpl_semi_sync_slave_enabled= 0; - +my_bool global_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; @@ -44,14 +33,26 @@ int Repl_semi_sync_slave::init_object() m_init_done = true; /* References to the parameter works after set_options(). */ - set_slave_enabled(rpl_semi_sync_slave_enabled); + set_slave_enabled(global_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; } +static bool local_semi_sync_enabled; + +int rpl_semi_sync_enabled(THD *thd, SHOW_VAR *var, void *buff, + system_status_var *status_var, + enum_var_type scope) +{ + local_semi_sync_enabled= repl_semisync_slave.get_slave_enabled(); + var->type= SHOW_BOOL; + var->value= (char*) &local_semi_sync_enabled; + return 0; +} + + int Repl_semi_sync_slave::slave_read_sync_header(const uchar *header, unsigned long total_len, int *semi_flags, @@ -61,12 +62,12 @@ int Repl_semi_sync_slave::slave_read_sync_header(const uchar *header, int read_res = 0; DBUG_ENTER("Repl_semi_sync_slave::slave_read_sync_header"); - if (rpl_semi_sync_slave_status) + if (get_slave_enabled()) { if (!DBUG_IF("semislave_corrupt_log") && header[0] == k_packet_magic_num) { - semi_sync_need_reply = (header[1] & k_packet_flag_sync); + bool semi_sync_need_reply = (header[1] & k_packet_flag_sync); *payload_len = total_len - 2; *payload = header + 2; @@ -85,7 +86,9 @@ int Repl_semi_sync_slave::slave_read_sync_header(const uchar *header, "len: %lu", total_len); read_res = -1; } - } else { + } + else + { *payload= header; *payload_len= total_len; } @@ -93,9 +96,23 @@ int Repl_semi_sync_slave::slave_read_sync_header(const uchar *header, DBUG_RETURN(read_res); } -int Repl_semi_sync_slave::slave_start(Master_info *mi) +/* + Set default semisync variables and print some replication info to the log + + Note that the main setup is done in request_transmit() +*/ + +void Repl_semi_sync_slave::slave_start(Master_info *mi) { - bool semi_sync= get_slave_enabled(); + + /* + Set semi_sync_enabled at slave start. This is not changed until next + slave start or reconnect. + */ + bool semi_sync= global_rpl_semi_sync_slave_enabled; + + set_slave_enabled(semi_sync); + mi->semi_sync_reply_enabled= 0; sql_print_information("Slave I/O thread: Start %s replication to\ master '%s@%s:%d' in log '%s' at position %lu", @@ -104,30 +121,29 @@ int Repl_semi_sync_slave::slave_start(Master_info *mi) 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) +void Repl_semi_sync_slave::slave_stop(Master_info *mi) { if (get_slave_enabled()) kill_connection(mi->mysql); - if (rpl_semi_sync_slave_status) - rpl_semi_sync_slave_status= 0; - - return 0; + set_slave_enabled(0); } -int Repl_semi_sync_slave::reset_slave(Master_info *mi) +void Repl_semi_sync_slave::slave_reconnect(Master_info *mi) { - return 0; + /* + Start semi-sync either if it globally enabled or if was enabled + before the reconnect. + */ + if (global_rpl_semi_sync_slave_enabled || get_slave_enabled()) + slave_start(mi); } + void Repl_semi_sync_slave::kill_connection(MYSQL *mysql) { if (!mysql) @@ -194,33 +210,43 @@ int Repl_semi_sync_slave::request_transmit(Master_info *mi) !(res= mysql_store_result(mysql))) { sql_print_error("Execution failed on master: %s, error :%s", query, mysql_error(mysql)); + set_slave_enabled(0); return 1; } row= mysql_fetch_row(res); - if (DBUG_IF("master_not_support_semisync") || !row) + if (DBUG_IF("master_not_support_semisync") || (!row || ! row[1])) { /* 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; + if (!row) + sql_print_warning("Master server does not support semi-sync, " + "fallback to asynchronous replication"); + set_slave_enabled(0); mysql_free_result(res); return 0; } + if (strcmp(row[1], "ON")) + sql_print_information("Slave has semi-sync enabled but master server does " + "not. Semi-sync will be activated when master " + "enables it"); mysql_free_result(res); /* Tell master dump thread that we want to do semi-sync - replication + replication. This is done by setting a thread local variable in + the master connection. */ 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"); + sql_print_error("%s on master failed", query); + set_slave_enabled(0); return 1; } + mi->semi_sync_reply_enabled= 1; + /* Inform net_server that pkt_nr can come out of order */ + mi->mysql->net.pkt_nr_can_be_reset= 1; mysql_free_result(mysql_store_result(mysql)); - rpl_semi_sync_slave_status= 1; return 0; } @@ -230,46 +256,40 @@ 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"); + DBUG_ASSERT(get_slave_enabled() && mi->semi_sync_reply_enabled); - 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)); + + /* + We have to do a net_clear() as with semi-sync the slave_reply's are + interleaved with data from the master and then the net->pkt_nr + cannot be kept in sync. Better to start pkt_nr from 0 again. + */ + net_clear(net, 0); + /* Send the reply. */ + reply_res = my_net_write(net, reply_buffer, + name_len + REPLY_BINLOG_NAME_OFFSET); + if (!reply_res) { - /* 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); + reply_res= DBUG_IF("semislave_failed_net_flush") || net_flush(net); if (!reply_res) - { - reply_res = (DBUG_IF("semislave_failed_net_flush") || 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); } |