十字螺丝钉的DBA日记

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1.innodb_ruby 是什么

innodb_ruby是jeremycole的一个用于分析Innodb相关结构的一个程序，也是非常方便我们研究Innodb的结构工具。
用于研究InnoDB的结构，比如叶子数量、非叶子节点数量、填充因子、B+树高度。
不推荐在生产使用。

github 地址： https://github.com/jeremycole/innodb_ruby

2.安装ruby

版本要大于2.2.0

3.安装innodb_ruby

innodb_ruby安装后，使用的命令是innodb_space

4.使用innodb_ruby

命令参数：
-s 通过读取系统表空间（一般是ibdata1），加载表明、索引名等。
-T 表名，格式是库/表名。
space-indexes 表上所有索引的信息，包含page使用数量、分配数据、填充因子等。

结果解读：
id：表示此索引的id。
name：索引的名字。
root：索引中根节点的page number。这两个索引的根节点都在3号page中。
fseg：page的说明。internal表示根节点或者非叶子节点；leaf表示叶子节点。
used：索引使用了多少个page。
allocated：索引分配了多少个page。
fill_factor：索引填充因子（“填充度”更合适），used/allocated表示填充度，也就是实际使用的百分比，越高越好。

5.innodb_space相关参数

# innodb_space –help

 

Usage: innodb_space <options> <mode>

Invocation examples:

innodb_space -s ibdata1 [-T tname [-I iname]] [options] <mode>
Use ibdata1 as the system tablespace and load the tname table (and the
iname index for modes that require it) from data located in the system
tablespace data dictionary. This will automatically generate a record
describer for any indexes.

innodb_space -f tname.ibd [-r ./desc.rb -d DescClass] [options] <mode>
Use the tname.ibd table (and the DescClass describer where required).

The following options are supported:

–help, -?
Print this usage text.

–trace, -t
Enable tracing of all data read. Specify twice to enable even more
tracing (including reads during opening of the tablespace) which can
be quite noisy.

–system-space-file, -s <arg>
Load the system tablespace file or files <arg>: Either a single file e.g.
“ibdata1”, a comma-delimited list of files e.g. “ibdata1,ibdata1”, or a
directory name. If a directory name is provided, it will be scanned for all
files named “ibdata?” which will then be sorted alphabetically and used to
load the system tablespace.

–table-name, -T <name>
Use the table name <name>.

–index-name, -I <name>
Use the index name <name>.

–space-file, -f <file>
Load the tablespace file <file>.

–page, -p <page>
Operate on the page <page>.

–level, -l <level>
Operate on the level <level>.

–list, -L <list>
Operate on the list <list>.

–fseg-id, -F <fseg_id>
Operate on the file segment (fseg) <fseg_id>.

–require, -r <file>
Use Ruby’s “require” to load the file <file>. This is useful for loading
classes with record describers.

–describer, -d <describer>
Use the named record describer to parse records in index pages.

The following modes are supported:

system-spaces
Print a summary of all spaces in the system.

data-dictionary-tables
Print all records in the SYS_TABLES data dictionary table.

data-dictionary-columns
Print all records in the SYS_COLUMNS data dictionary table.

data-dictionary-indexes
Print all records in the SYS_INDEXES data dictionary table.

data-dictionary-fields
Print all records in the SYS_FIELDS data dictionary table.

space-summary
Summarize all pages within a tablespace. A starting page number can be
provided with the –page/-p argument.

space-index-pages-summary
Summarize all “INDEX” pages within a tablespace. This is useful to analyze
page fill rates and record counts per page. In addition to “INDEX” pages,
“ALLOCATED” pages are also printed and assumed to be completely empty.
A starting page number can be provided with the –page/-p argument.

space-index-fseg-pages-summary
The same as space-index-pages-summary but only iterate one fseg, provided
with the –fseg-id/-F argument.

space-index-pages-free-plot
Use Ruby’s gnuplot module to produce a scatterplot of page free space for
all “INDEX” and “ALLOCATED” pages in a tablespace. More aesthetically
pleasing plots can be produced with space-index-pages-summary output,
but this is a quick and easy way to produce a passable plot. A starting
page number can be provided with the –page/-p argument.

space-page-type-regions
Summarize all contiguous regions of the same page type. This is useful to
provide an overall view of the space and allocations within it. A starting
page number can be provided with the –page/-p argument.

space-page-type-summary
Summarize all pages by type. A starting page number can be provided with
the –page/-p argument.

space-indexes
Summarize all indexes (actually each segment of the indexes) to show
the number of pages used and allocated, and the segment fill factor.

space-lists
Print a summary of all lists in a space.

space-list-iterate
Iterate through the contents of a space list.

space-extents
Iterate through all extents, printing the extent descriptor bitmap.

space-extents-illustrate
Iterate through all extents, illustrating the extent usage using ANSI
color and Unicode box drawing characters to show page usage throughout
the space.

space-extents-illustrate-svg
Iterate through all extents, illustrating the extent usage in SVG format
printed to stdout to show page usage throughout the space.

space-lsn-age-illustrate
Iterate through all pages, producing a heat map colored by the page LSN
using ANSI color and Unicode box drawing characters, allowing the user to
get an overview of page modification recency.

space-lsn-age-illustrate-svg
Iterate through all pages, producing a heat map colored by the page LSN
producing SVG format output, allowing the user to get an overview of page
modification recency.

space-inodes-fseg-id
Iterate through all inodes, printing only the FSEG ID.

space-inodes-summary
Iterate through all inodes, printing a short summary of each FSEG.

space-inodes-detail
Iterate through all inodes, printing a detailed report of each FSEG.

index-recurse
Recurse an index, starting at the root (which must be provided in the first
–page/-p argument), printing the node pages, node pointers (links), leaf
pages. A record describer must be provided with the –describer/-d argument
to recurse indexes (in order to parse node pages).

index-record-offsets
Recurse an index as index-recurse does, but print the offsets of each
record within the page.

index-digraph
Recurse an index as index-recurse does, but print a dot-compatible digraph
instead of a human-readable summary.

index-level-summary
Print a summary of all pages at a given level (provided with the –level/-l
argument) in an index.

index-fseg-internal-lists
index-fseg-leaf-lists
Print a summary of all lists in an index file segment. Index root page must
be provided with –page/-p.

index-fseg-internal-list-iterate
index-fseg-leaf-list-iterate
Iterate the file segment list (whose name is provided in the first –list/-L
argument) for internal or leaf pages for a given index (whose root page
is provided in the first –page/-p argument). The lists used for each
index are “full”, “not_full”, and “free”.

index-fseg-internal-frag-pages
index-fseg-leaf-frag-pages
Print a summary of all fragment pages in an index file segment. Index root
page must be provided with –page/-p.

page-dump
Dump the contents of a page, using the Ruby pp (“pretty-print”) module.

page-account
Account for a page’s usage in FSEGs.

page-validate
Validate the contents of a page.

page-directory-summary
Summarize the record contents of the page directory in a page. If a record
describer is available, the key of each record will be printed.

page-records
Summarize all records within a page.

page-illustrate
Produce an illustration of the contents of a page.

record-dump
Dump a detailed description of a record and the data it contains. A record
offset must be provided with -R/–record.

record-history
Summarize the history (undo logs) for a record. A record offset must be
provided with -R/–record.

undo-history-summary
Summarize all records in the history list (undo logs).

undo-record-dump
Dump a detailed description of an undo record and the data it contains.
A record offset must be provided with -R/–record.