8.5.4 Optimizing InnoDB Redo Logging

Consider the following guidelines for optimizing redo logging:

• Make your redo log files big, even as big as the buffer pool. When InnoDB has written the redo log files full, it must write the modified contents of the buffer pool to disk in a checkpoint. Small redo log files cause many unnecessary disk writes. Although historically big redo log files caused lengthy recovery times, recovery is now much faster and you can confidently use large redo log files.

  The size and number of redo log files are configured using the innodb_log_file_size and innodb_log_files_in_group configuration options. For information about modifying an existing redo log file configuration, see Section 14.7.2, “Changing the Number or Size of InnoDB Redo Log Files”.

• Consider increasing the size of the log buffer. A large log buffer enables large transactions to run without a need to write the log to disk before the transactions commit. Thus, if you have transactions that update, insert, or delete many rows, making the log buffer larger saves disk I/O. Log buffer size is configured using the innodb_log_buffer_size configuration option.