README
1NAME
2 Class::DBI::Replication - Class::DBI for replicated database
3
4SYNOPSIS
5 package Film;
6 use base qw(Class::DBI::Replication);
7
8 Film->set_master('dbi:mysql:host=master', $user, $pw);
9 Film->set_slaves(
10 [ 'dbi:mysql:host=slave1', $user, $pw ],
11 [ 'dbi:mysql:host=slave2', $user, $pw ],
12 );
13
14DESCRIPTION
15 Classs::DBI::Replication extends Class::DBI's persistence for replicated
16 databases.
17
18 The idea is very simple. SELECT from slaves, INSERT/UPDATE/DELETE to
19 master.
20
21 From http://www.mysql.com/doc/R/e/Replication_FAQ.html,
22
23 Q: What should I do to prepare my client code to use
24 performance-enhancing replication?
25
26 A: If the part of your code that is responsible for database access
27 has been properly abstracted/modularized, converting it to run with
28 the replicated setup should be very smooth and easy - just change
29 the implementation of your database access to read from some slave
30 or the master, and to always write to the master.
31
32 With Class::DBI::Replication, it can be done easily!
33
34METHODS
35 set_master
36 Film->set_master($datasource, $user, $password, \%attr);
37
38 This spcifies your master database. INSERT/UPDATE/DELETE are done
39 only to this database. Some SELECT queries also done to master for
40 concurrency problem.
41
42 If you don't want master to be distinct from slaves in SELECT
43 queries, put master in slaves, too.
44
45 set_slaves
46 Film->set_slaves(
47 [ 'dbi:mysql:host=slave1', $user, $password, \%attr ],
48 [ 'dbi:mysql:host=slave2', $user, $password, \%attr ],
49 );
50
51 This specifies your slave databases. SELECT are done to these
52 databases randomly. If you don't specify slaves, all queries are
53 gone to master, as always.
54
55TODO
56 * More docs
57
58 * More testing
59
60 * retrieve() adter create() problem. Currently, SELECT calls inside
61 Class::DBI are done to master database.
62
63 * Concurrency problems
64
65 * Customizable slave picking algorithm like Round-Robin
66
67AUTHOR
68 Tatsuhiko Miyagawa <miyagawa@bulknews.net>
69
70 This library is free software; you can redistribute it and/or modify it
71 under the same terms as Perl itself.
72
73SEE ALSO
74 the Class::DBI manpage, the Class::DBI::mysql manpage
75
76