MariaDB 10之TokuDB存储引擎

TokuDB存储引擎，你可以把它看做是ARCHIVE存储引擎的升级版，它拥有了密集压缩，并且支持事务。

压缩比：

Engine	Compression	Table size [MB]
InnoDB	none	2272
InnoDB	KEY_BLOCK_SIZE=8	1144
InnoDB	KEY_BLOCK_SIZE=4	584
MyISAM	none	1810
MyISAM	compressed with myisampack	809
Archive	default	211
TokuDB	ZLIB	284
TokuDB	LZMA	208

特性：

Feature	Archive	MyISAM (compressed)	InnoDB	TokuDB
DML	only INSERTs	no	yes	yes
Transactions	no	no	yes	yes
ACID	no	no	yes	yes
Indexes	no	yes	yes	yes
Online DDL	no	no	yes *	yes **

MariaDB10，已经内嵌了TokuDB存储引擎，安装超简单，如下：

调优：

Configuration: what’s really important

As noted by Vadim long ago, “Tuning of TokuDB is much easier than InnoDB, there’re only a few parameters to change, and actually out-of-box things running pretty well“:
TokuDB调优比InnoDB简单的多，只是有一些参数变化，或者你直接使用默认参数，也运行的良好。

MariaDB [(none)]> show variables like '%tokudb%';
+---------------------------------+-------------+
| Variable_name                   | Value       |
+---------------------------------+-------------+
| tokudb_alter_print_error        | OFF         |
| tokudb_analyze_time             | 5           |
| tokudb_block_size               | 4194304     |
| tokudb_cache_size               | 120926208   |
| tokudb_checkpoint_lock          | OFF         |
| tokudb_checkpoint_on_flush_logs | OFF         |
| tokudb_checkpointing_period     | 60          |
| tokudb_cleaner_iterations       | 5           |
| tokudb_cleaner_period           | 1           |
| tokudb_commit_sync              | ON          |
| tokudb_create_index_online      | ON          |
| tokudb_data_dir                 |             |
| tokudb_debug                    | 0           |
| tokudb_directio                 | OFF         |
| tokudb_disable_hot_alter        | OFF         |
| tokudb_disable_prefetching      | OFF         |
| tokudb_disable_slow_alter       | OFF         |
| tokudb_empty_scan               | rl          |
| tokudb_fs_reserve_percent       | 5           |
| tokudb_fsync_log_period         | 0           |
| tokudb_hide_default_row_format  | ON          |
| tokudb_init_flags               | 11403457    |
| tokudb_killed_time              | 4000        |
| tokudb_last_lock_timeout        |             |
| tokudb_load_save_space          | ON          |
| tokudb_loader_memory_size       | 100000000   |
| tokudb_lock_timeout             | 4000        |
| tokudb_lock_timeout_debug       | 1           |
| tokudb_log_dir                  |             |
| tokudb_max_lock_memory          | 15115776    |
| tokudb_pk_insert_mode           | 1           |
| tokudb_prelock_empty            | ON          |
| tokudb_read_block_size          | 65536       |
| tokudb_read_buf_size            | 131072      |
| tokudb_read_status_frequency    | 10000       |
| tokudb_row_format               | tokudb_zlib |
| tokudb_tmp_dir                  |             |
| tokudb_version                  | 7.1.6       |
| tokudb_write_status_frequency   | 1000        |
+---------------------------------+-------------+
39 rows in set (0.01 sec)

The most important of the tokudb_ variables is arguably tokudb_cache_size. The test server where I ran those tests (test01) have a little less than 1G of memory and as you can see above TokuDB is “reserving” half (50%) of them to itself. That’s the default behavior but, of course, you can change it. And you must do it if you are also going to have InnoDB tables on your server – you should not overcommit memory between InnoDB and TokuDB engines. Shlomi Noach wrote a good post explaining the main TokuDB-specific variables and what they do. It’s definitely a worth read.
（最重要的参数是tokudb_cache_size，它类似innodb_buffer_pool_size，如果你的服务器跑着两种引擎InnoDB和TokuDB，那么你得小心点了，别把内存用光了。）

参考：http://www.mysqlperformanceblog.com/2014/06/26/percona-server-with-tokudb-beta-installation-configuration/

注：因此引擎比较新，没有任何生产经验，可以试图把一些LOG日志表改为TokuDB引擎，这样在性能和磁盘空间使用率上都有较大幅度的提升。此外，该引擎的备份工具是收费，所以备份的时候可以采取冷备份。

参考：http://www.mysqlperformanceblog.com/2014/06/23/getting-to-know-tokudb-for-mysql/