25.5.29 ndb_size.pl — NDBCLUSTER 大小需求估算器
This is a Perl script that can be used to estimate the amount of space that would be required by a MySQL database if it were converted to use the NDBCLUSTER
storage engine. Unlike the other utilities discussed in this section, it does not require access to an NDB Cluster (in fact, there is no reason for it to do so). However, it does need to access the MySQL server on which the database to be tested resides.
-
A running MySQL server. The server instance does not have to provide support for NDB Cluster.
-
A working installation of Perl.
-
The
DBI
module, which can be obtained from CPAN if it is not already part of your Perl installation. (Many Linux and other operating system distributions provide their own packages for this library.) -
A MySQL user account having the necessary privileges. If you do not wish to use an existing account, then creating one using
GRANT USAGE ON
—wheredb_name
.*db_name
is the name of the database to be examined—is sufficient for this purpose.
ndb_size.pl
can also be found in the MySQL sources in storage/ndb/tools
.
Options that can be used with ndb_size.pl are shown in the following table. Additional descriptions follow the table.
perl ndb_size.pl [--database={db_name|ALL}] [--hostname=host[:port]] [--socket=socket] \
[--user=user] [--password=password] \
[--help|-h] [--format={html|text}] \
[--loadqueries=file_name] [--savequeries=file_name]
By default, this utility attempts to analyze all databases on the server. You can specify a single database using the --database
option; the default behavior can be made explicit by using ALL
for the name of the database. You can also exclude one or more databases by using the --excludedbs
option with a comma-separated list of the names of the databases to be skipped. Similarly, you can cause specific tables to be skipped by listing their names, separated by commas, following the optional --excludetables
option. A host name can be specified using --hostname
; the default is localhost
. You can specify a port in addition to the host using host
:port
format for the value of --hostname
. The default port number is 3306. If necessary, you can also specify a socket; the default is /var/lib/mysql.sock
. A MySQL user name and password can be specified the corresponding options shown. It also possible to control the format of the output using the --format
option; this can take either of the values html
or text
, with text
being the default. An example of the text output is shown here:
$> ndb_size.pl --database=test --socket=/tmp/mysql.sock
ndb_size.pl report for database: 'test' (1 tables)
--------------------------------------------------
Connected to: DBI:mysql:host=localhost;mysql_socket=/tmp/mysql.sock
Including information for versions: 4.1, 5.0, 5.1
test.t1
-------
DataMemory for Columns (* means varsized DataMemory):
Column Name Type Varsized Key 4.1 5.0 5.1
HIDDEN_NDB_PKEY bigint PRI 8 8 8
c2 varchar(50) Y 52 52 4*
c1 int(11) 4 4 4
-- -- --
Fixed Size Columns DM/Row 64 64 12
Varsize Columns DM/Row 0 0 4
DataMemory for Indexes:
Index Name Type 4.1 5.0 5.1
PRIMARY BTREE 16 16 16
-- -- --
Total Index DM/Row 16 16 16
IndexMemory for Indexes:
Index Name 4.1 5.0 5.1
PRIMARY 33 16 16
-- -- --
Indexes IM/Row 33 16 16
Summary (for THIS table):
4.1 5.0 5.1
Fixed Overhead DM/Row 12 12 16
NULL Bytes/Row 4 4 4
DataMemory/Row 96 96 48
(Includes overhead, bitmap and indexes)
Varsize Overhead DM/Row 0 0 8
Varsize NULL Bytes/Row 0 0 4
Avg Varside DM/Row 0 0 16
No. Rows 0 0 0
Rows/32kb DM Page 340 340 680
Fixedsize DataMemory (KB) 0 0 0
Rows/32kb Varsize DM Page 0 0 2040
Varsize DataMemory (KB) 0 0 0
Rows/8kb IM Page 248 512 512
IndexMemory (KB) 0 0 0
Parameter Minimum Requirements
------------------------------
* indicates greater than default
Parameter Default 4.1 5.0 5.1
DataMemory (KB) 81920 0 0 0
NoOfOrderedIndexes 128 1 1 1
NoOfTables 128 1 1 1
IndexMemory (KB) 18432 0 0 0
NoOfUniqueHashIndexes 64 0 0 0
NoOfAttributes 1000 3 3 3
NoOfTriggers 768 5 5 5
For debugging purposes, the Perl arrays containing the queries run by this script can be read from the file specified using can be saved to a file using --savequeries
; a file containing such arrays to be read during script execution can be specified using --loadqueries
. Neither of these options has a default value.
To produce output in HTML format, use the --format
option and redirect the output to a file, as shown here:
$> ndb_size.pl --database=test --socket=/tmp/mysql.sock --format=html > ndb_size.html
(Without the redirection, the output is sent to stdout
.)
The output from this script includes the following information:
-
Minimum values for the
DataMemory
,IndexMemory
,MaxNoOfTables
,MaxNoOfAttributes
,MaxNoOfOrderedIndexes
, andMaxNoOfTriggers
configuration parameters required to accommodate the tables analyzed. -
Memory requirements for all of the tables, attributes, ordered indexes, and unique hash indexes defined in the database.
-
The
IndexMemory
andDataMemory
required per table and table row.