MariaDB Enterprise Server InnoDB Redo Log

Overview

In MariaDB Enterprise Server, the InnoDB storage engine uses a Redo Log. The Redo Log is a transaction log that InnoDB uses to write data to disk in a crash-safe manner.

Redo Log records are identified using the Log Sequence Number (LSN). The Redo Log is a circular log file that is a constant size. Old Redo Log records are frequently overwritten by new Redo Log records. InnoDB regularly performs checkpoints. During a checkpoint, InnoDB flushes Redo Log records to the InnoDB tablespace files.

When the server crashes, InnoDB performs crash recovery during server startup using the Redo Log. During crash recovery, InnoDB finds the last checkpoint in the Redo Log and flushes the Redo Log records since the last checkpoint to the InnoDB tablespace files.

Feature Summary

Feature

Detail

Resources

Transaction Log

InnoDB Redo Log

Storage Engine

InnoDB

Purpose

Crash Safety

Availability

All ES and CS versions

Location

Set by innodb_log_group_home_dir (Defaults to datadir)

Quantity

Size

Set by innodb_log_file_size (default varies)

Basic Configuration

[mariadb]
...
innodb_log_file_size=2G

SET GLOBAL innodb_log_file_size=(2 * 1024 * 1024 * 1024);

SHOW GLOBAL VARIABLES
   LIKE 'innodb_log_file_size';

+----------------------+------------+
| Variable_name        | Value      |
+----------------------+------------+
| innodb_log_file_size | 2147483648 |
+----------------------+------------+