save_binary_logs (1p)

# Test

$ save_binary_logs --command=test --binlog_dir=/var/lib/mysql --start_file=mysqld-bin.000002

# Saving binary logs

$ save_binary_logs --command=save --binlog_dir=/var/lib/mysql --start_file=mysqld-bin.000002 --start_pos=312 --output_file=/var/tmp/aggregate.binlog

# Saving relay logs

$ save_binary_logs --command=save --start_file=mysqld-relay-bin.000002 --start_pos=312 --relay_log_info=/var/lib/mysql/relay-log.info --output_file=/var/tmp/aggregate.binlog

save_binary_logs concatenates binary or relay logs from the specified log file/position to the end of the log. This tool is intended to be invoked from the master failover script(\s-1MHA\s0 Manager), and manual execution is normally not needed.

Suppose that master is crashed and the latest slave server has received binary logs up to mysqld-bin.000002:312. It is likely that master has more binary logs. If it is not sent to the slave, slaves will lose all binlogs from mysqld-bin.000002:312. The purpose of the save_binary_logs is to save binary logs that are not replicated to slaves. If master is reachable through \s-1SSH\s0 and binary logs are readable, saving binary logs is possible.

Here is an example:

$ save_binary_logs --command=save --start_file=mysqld-bin.000002 --start_pos=312 --output_file=/var/tmp/aggregate.binlog

Then all binary logs starting from mysqld-bin.000002:312 are concatenated and stored into /var/tmp/aggregate.binlog. If you have binary logs up to mysqld-bin.000004, the following mysqlbinlog outputs are written.

mysqld-bin.000002:Format Description Event(\s-1FDE\s0), plus from 312 to the tail mysqld-bin.000003:from 0 to the tail, excluding \s-1FDE\s0 mysqld-bin.000004:from 0 to the tail, excluding \s-1FDE\s0