Commit | Line | Data |
2156bbdd |
1 | package DBIx::Class::Storage::DBI::Replicated; |
f5d3a5de |
2 | |
ecb65397 |
3 | BEGIN { |
4 | use Carp::Clan qw/^DBIx::Class/; |
d4daee7b |
5 | |
ecb65397 |
6 | ## Modules required for Replication support not required for general DBIC |
7 | ## use, so we explicitly test for these. |
d4daee7b |
8 | |
ecb65397 |
9 | my %replication_required = ( |
ec0946db |
10 | 'Moose' => '0.98', |
6eca76d5 |
11 | 'MooseX::Types' => '0.21', |
bd5da369 |
12 | 'namespace::clean' => '0.11', |
13 | 'Hash::Merge' => '0.11' |
ecb65397 |
14 | ); |
d4daee7b |
15 | |
ecb65397 |
16 | my @didnt_load; |
d4daee7b |
17 | |
ecb65397 |
18 | for my $module (keys %replication_required) { |
1a58752c |
19 | eval "use $module $replication_required{$module}"; |
20 | push @didnt_load, "$module $replication_required{$module}" |
21 | if $@; |
ecb65397 |
22 | } |
d4daee7b |
23 | |
ecb65397 |
24 | croak("@{[ join ', ', @didnt_load ]} are missing and are required for Replication") |
d4daee7b |
25 | if @didnt_load; |
ecb65397 |
26 | } |
27 | |
b2e4d522 |
28 | use Moose; |
26ab719a |
29 | use DBIx::Class::Storage::DBI; |
2bf79155 |
30 | use DBIx::Class::Storage::DBI::Replicated::Pool; |
26ab719a |
31 | use DBIx::Class::Storage::DBI::Replicated::Balancer; |
6a151f58 |
32 | use DBIx::Class::Storage::DBI::Replicated::Types qw/BalancerClassNamePart DBICSchema DBICStorageDBI/; |
41916570 |
33 | use MooseX::Types::Moose qw/ClassName HashRef Object/; |
b2e4d522 |
34 | use Scalar::Util 'reftype'; |
b88b85e7 |
35 | use Hash::Merge 'merge'; |
3244fdcc |
36 | use List::Util qw/min max/; |
9901aad7 |
37 | |
38 | use namespace::clean -except => 'meta'; |
2bf79155 |
39 | |
40 | =head1 NAME |
41 | |
ecb65397 |
42 | DBIx::Class::Storage::DBI::Replicated - BETA Replicated database support |
2bf79155 |
43 | |
44 | =head1 SYNOPSIS |
45 | |
46 | The Following example shows how to change an existing $schema to a replicated |
47 | storage type, add some replicated (readonly) databases, and perform reporting |
955a6df6 |
48 | tasks. |
2bf79155 |
49 | |
3da4f736 |
50 | You should set the 'storage_type attribute to a replicated type. You should |
d4daee7b |
51 | also define your arguments, such as which balancer you want and any arguments |
3da4f736 |
52 | that the Pool object should get. |
53 | |
ce854fd3 |
54 | my $schema = Schema::Class->clone; |
64cdad22 |
55 | $schema->storage_type( ['::DBI::Replicated', {balancer=>'::Random'}] ); |
ce854fd3 |
56 | $schema->connection(...); |
d4daee7b |
57 | |
3da4f736 |
58 | Next, you need to add in the Replicants. Basically this is an array of |
59 | arrayrefs, where each arrayref is database connect information. Think of these |
60 | arguments as what you'd pass to the 'normal' $schema->connect method. |
d4daee7b |
61 | |
64cdad22 |
62 | $schema->storage->connect_replicants( |
63 | [$dsn1, $user, $pass, \%opts], |
64 | [$dsn2, $user, $pass, \%opts], |
65 | [$dsn3, $user, $pass, \%opts], |
66 | ); |
d4daee7b |
67 | |
3da4f736 |
68 | Now, just use the $schema as you normally would. Automatically all reads will |
69 | be delegated to the replicants, while writes to the master. |
70 | |
7e38d850 |
71 | $schema->resultset('Source')->search({name=>'etc'}); |
d4daee7b |
72 | |
3da4f736 |
73 | You can force a given query to use a particular storage using the search |
74 | attribute 'force_pool'. For example: |
d4daee7b |
75 | |
7e38d850 |
76 | my $RS = $schema->resultset('Source')->search(undef, {force_pool=>'master'}); |
3da4f736 |
77 | |
78 | Now $RS will force everything (both reads and writes) to use whatever was setup |
79 | as the master storage. 'master' is hardcoded to always point to the Master, |
80 | but you can also use any Replicant name. Please see: |
212cc5c2 |
81 | L<DBIx::Class::Storage::DBI::Replicated::Pool> and the replicants attribute for more. |
3da4f736 |
82 | |
83 | Also see transactions and L</execute_reliably> for alternative ways to |
84 | force read traffic to the master. In general, you should wrap your statements |
85 | in a transaction when you are reading and writing to the same tables at the |
86 | same time, since your replicants will often lag a bit behind the master. |
212cc5c2 |
87 | |
88 | See L<DBIx::Class::Storage::DBI::Replicated::Instructions> for more help and |
89 | walkthroughs. |
d4daee7b |
90 | |
2bf79155 |
91 | =head1 DESCRIPTION |
92 | |
7e38d850 |
93 | Warning: This class is marked BETA. This has been running a production |
ccb3b897 |
94 | website using MySQL native replication as its backend and we have some decent |
7e38d850 |
95 | test coverage but the code hasn't yet been stressed by a variety of databases. |
96 | Individual DB's may have quirks we are not aware of. Please use this in first |
97 | development and pass along your experiences/bug fixes. |
2bf79155 |
98 | |
99 | This class implements replicated data store for DBI. Currently you can define |
100 | one master and numerous slave database connections. All write-type queries |
101 | (INSERT, UPDATE, DELETE and even LAST_INSERT_ID) are routed to master |
102 | database, all read-type queries (SELECTs) go to the slave database. |
103 | |
104 | Basically, any method request that L<DBIx::Class::Storage::DBI> would normally |
bca099a3 |
105 | handle gets delegated to one of the two attributes: L</read_handler> or to |
106 | L</write_handler>. Additionally, some methods need to be distributed |
2bf79155 |
107 | to all existing storages. This way our storage class is a drop in replacement |
108 | for L<DBIx::Class::Storage::DBI>. |
109 | |
110 | Read traffic is spread across the replicants (slaves) occuring to a user |
111 | selected algorithm. The default algorithm is random weighted. |
112 | |
bca099a3 |
113 | =head1 NOTES |
114 | |
115 | The consistancy betweeen master and replicants is database specific. The Pool |
faaba25f |
116 | gives you a method to validate its replicants, removing and replacing them |
7e38d850 |
117 | when they fail/pass predefined criteria. Please make careful use of the ways |
ecb65397 |
118 | to force a query to run against Master when needed. |
119 | |
120 | =head1 REQUIREMENTS |
121 | |
122 | Replicated Storage has additional requirements not currently part of L<DBIx::Class> |
123 | |
ec0946db |
124 | Moose => '0.98', |
6eca76d5 |
125 | MooseX::Types => '0.21', |
62eabf11 |
126 | namespace::clean => '0.11', |
127 | Hash::Merge => '0.11' |
d4daee7b |
128 | |
ecb65397 |
129 | You will need to install these modules manually via CPAN or make them part of the |
130 | Makefile for your distribution. |
2bf79155 |
131 | |
132 | =head1 ATTRIBUTES |
133 | |
134 | This class defines the following attributes. |
135 | |
2ce6e9a6 |
136 | =head2 schema |
137 | |
138 | The underlying L<DBIx::Class::Schema> object this storage is attaching |
139 | |
140 | =cut |
141 | |
142 | has 'schema' => ( |
143 | is=>'rw', |
6a151f58 |
144 | isa=>DBICSchema, |
2ce6e9a6 |
145 | weak_ref=>1, |
146 | required=>1, |
147 | ); |
148 | |
26ab719a |
149 | =head2 pool_type |
2bf79155 |
150 | |
26ab719a |
151 | Contains the classname which will instantiate the L</pool> object. Defaults |
152 | to: L<DBIx::Class::Storage::DBI::Replicated::Pool>. |
2bf79155 |
153 | |
154 | =cut |
155 | |
26ab719a |
156 | has 'pool_type' => ( |
dcdf7b2c |
157 | is=>'rw', |
41916570 |
158 | isa=>ClassName, |
2ce6e9a6 |
159 | default=>'DBIx::Class::Storage::DBI::Replicated::Pool', |
64cdad22 |
160 | handles=>{ |
161 | 'create_pool' => 'new', |
162 | }, |
2bf79155 |
163 | ); |
164 | |
f068a139 |
165 | =head2 pool_args |
166 | |
167 | Contains a hashref of initialized information to pass to the Balancer object. |
212cc5c2 |
168 | See L<DBIx::Class::Storage::DBI::Replicated::Pool> for available arguments. |
f068a139 |
169 | |
170 | =cut |
171 | |
172 | has 'pool_args' => ( |
dcdf7b2c |
173 | is=>'rw', |
41916570 |
174 | isa=>HashRef, |
64cdad22 |
175 | lazy=>1, |
64cdad22 |
176 | default=>sub { {} }, |
f068a139 |
177 | ); |
178 | |
179 | |
26ab719a |
180 | =head2 balancer_type |
2bf79155 |
181 | |
182 | The replication pool requires a balance class to provider the methods for |
183 | choose how to spread the query load across each replicant in the pool. |
184 | |
185 | =cut |
186 | |
26ab719a |
187 | has 'balancer_type' => ( |
dcdf7b2c |
188 | is=>'rw', |
9901aad7 |
189 | isa=>BalancerClassNamePart, |
2ce6e9a6 |
190 | coerce=>1, |
191 | required=>1, |
192 | default=> 'DBIx::Class::Storage::DBI::Replicated::Balancer::First', |
64cdad22 |
193 | handles=>{ |
194 | 'create_balancer' => 'new', |
195 | }, |
2bf79155 |
196 | ); |
197 | |
17b05c13 |
198 | =head2 balancer_args |
199 | |
200 | Contains a hashref of initialized information to pass to the Balancer object. |
212cc5c2 |
201 | See L<DBIx::Class::Storage::DBI::Replicated::Balancer> for available arguments. |
17b05c13 |
202 | |
203 | =cut |
204 | |
205 | has 'balancer_args' => ( |
dcdf7b2c |
206 | is=>'rw', |
41916570 |
207 | isa=>HashRef, |
64cdad22 |
208 | lazy=>1, |
209 | required=>1, |
210 | default=>sub { {} }, |
17b05c13 |
211 | ); |
212 | |
26ab719a |
213 | =head2 pool |
2bf79155 |
214 | |
26ab719a |
215 | Is a <DBIx::Class::Storage::DBI::Replicated::Pool> or derived class. This is a |
216 | container class for one or more replicated databases. |
2bf79155 |
217 | |
218 | =cut |
219 | |
26ab719a |
220 | has 'pool' => ( |
64cdad22 |
221 | is=>'ro', |
222 | isa=>'DBIx::Class::Storage::DBI::Replicated::Pool', |
223 | lazy_build=>1, |
224 | handles=>[qw/ |
6f7344b8 |
225 | connect_replicants |
64cdad22 |
226 | replicants |
227 | has_replicants |
228 | /], |
2bf79155 |
229 | ); |
230 | |
26ab719a |
231 | =head2 balancer |
2bf79155 |
232 | |
26ab719a |
233 | Is a <DBIx::Class::Storage::DBI::Replicated::Balancer> or derived class. This |
234 | is a class that takes a pool (<DBIx::Class::Storage::DBI::Replicated::Pool>) |
2bf79155 |
235 | |
26ab719a |
236 | =cut |
2bf79155 |
237 | |
26ab719a |
238 | has 'balancer' => ( |
dcdf7b2c |
239 | is=>'rw', |
64cdad22 |
240 | isa=>'DBIx::Class::Storage::DBI::Replicated::Balancer', |
241 | lazy_build=>1, |
242 | handles=>[qw/auto_validate_every/], |
26ab719a |
243 | ); |
2bf79155 |
244 | |
cb6ec758 |
245 | =head2 master |
246 | |
247 | The master defines the canonical state for a pool of connected databases. All |
248 | the replicants are expected to match this databases state. Thus, in a classic |
249 | Master / Slaves distributed system, all the slaves are expected to replicate |
250 | the Master's state as quick as possible. This is the only database in the |
251 | pool of databases that is allowed to handle write traffic. |
252 | |
253 | =cut |
254 | |
255 | has 'master' => ( |
64cdad22 |
256 | is=> 'ro', |
6a151f58 |
257 | isa=>DBICStorageDBI, |
64cdad22 |
258 | lazy_build=>1, |
cb6ec758 |
259 | ); |
260 | |
cb6ec758 |
261 | =head1 ATTRIBUTES IMPLEMENTING THE DBIx::Storage::DBI INTERFACE |
262 | |
263 | The following methods are delegated all the methods required for the |
264 | L<DBIx::Class::Storage::DBI> interface. |
265 | |
266 | =head2 read_handler |
267 | |
268 | Defines an object that implements the read side of L<BIx::Class::Storage::DBI>. |
269 | |
270 | =cut |
271 | |
272 | has 'read_handler' => ( |
64cdad22 |
273 | is=>'rw', |
41916570 |
274 | isa=>Object, |
64cdad22 |
275 | lazy_build=>1, |
276 | handles=>[qw/ |
277 | select |
278 | select_single |
279 | columns_info_for |
3244fdcc |
280 | _dbh_columns_info_for |
281 | _select |
6f7344b8 |
282 | /], |
cb6ec758 |
283 | ); |
284 | |
cb6ec758 |
285 | =head2 write_handler |
286 | |
3244fdcc |
287 | Defines an object that implements the write side of L<BIx::Class::Storage::DBI>, |
288 | as well as methods that don't write or read that can be called on only one |
289 | storage, methods that return a C<$dbh>, and any methods that don't make sense to |
290 | run on a replicant. |
cb6ec758 |
291 | |
292 | =cut |
293 | |
294 | has 'write_handler' => ( |
64cdad22 |
295 | is=>'ro', |
41916570 |
296 | isa=>Object, |
64cdad22 |
297 | lazy_build=>1, |
6f7344b8 |
298 | handles=>[qw/ |
64cdad22 |
299 | on_connect_do |
6f7344b8 |
300 | on_disconnect_do |
3244fdcc |
301 | on_connect_call |
302 | on_disconnect_call |
64cdad22 |
303 | connect_info |
3244fdcc |
304 | _connect_info |
64cdad22 |
305 | throw_exception |
306 | sql_maker |
307 | sqlt_type |
308 | create_ddl_dir |
309 | deployment_statements |
310 | datetime_parser |
6f7344b8 |
311 | datetime_parser_type |
312 | build_datetime_parser |
64cdad22 |
313 | last_insert_id |
314 | insert |
315 | insert_bulk |
316 | update |
317 | delete |
318 | dbh |
2ce6e9a6 |
319 | txn_begin |
64cdad22 |
320 | txn_do |
321 | txn_commit |
322 | txn_rollback |
2ce6e9a6 |
323 | txn_scope_guard |
64cdad22 |
324 | sth |
325 | deploy |
0180bef9 |
326 | with_deferred_fk_checks |
6f7344b8 |
327 | dbh_do |
64cdad22 |
328 | reload_row |
6f7344b8 |
329 | with_deferred_fk_checks |
2ce6e9a6 |
330 | _prep_for_execute |
7fb60fb1 |
331 | |
6f7344b8 |
332 | backup |
333 | is_datatype_numeric |
334 | _count_select |
335 | _subq_count_select |
336 | _subq_update_delete |
337 | svp_rollback |
338 | svp_begin |
339 | svp_release |
e398f77e |
340 | relname_to_table_alias |
341 | _straight_join_to_node |
3244fdcc |
342 | _dbh_last_insert_id |
343 | _fix_bind_params |
344 | _default_dbi_connect_attributes |
345 | _dbi_connect_info |
346 | auto_savepoint |
347 | _sqlt_version_ok |
348 | _query_end |
349 | bind_attribute_by_data_type |
350 | transaction_depth |
351 | _dbh |
352 | _select_args |
353 | _dbh_execute_array |
354 | _sql_maker_args |
355 | _sql_maker |
356 | _query_start |
357 | _sqlt_version_error |
358 | _per_row_update_delete |
359 | _dbh_begin_work |
360 | _dbh_execute_inserts_with_no_binds |
361 | _select_args_to_query |
362 | _svp_generate_name |
363 | _multipk_update_delete |
364 | source_bind_attributes |
365 | _normalize_connect_info |
366 | _parse_connect_do |
367 | _dbh_commit |
368 | _execute_array |
369 | _placeholders_supported |
370 | _verify_pid |
371 | savepoints |
372 | _sqlt_minimum_version |
373 | _sql_maker_opts |
374 | _conn_pid |
375 | _typeless_placeholders_supported |
376 | _conn_tid |
377 | _dbh_autocommit |
378 | _native_data_type |
379 | _get_dbh |
380 | sql_maker_class |
381 | _dbh_rollback |
382 | _adjust_select_args_for_complex_prefetch |
383 | _resolve_ident_sources |
384 | _resolve_column_info |
385 | _prune_unused_joins |
386 | _strip_cond_qualifiers |
387 | _parse_order_by |
388 | _resolve_aliastypes_from_select_args |
389 | _execute |
390 | _do_query |
391 | _dbh_sth |
392 | _dbh_execute |
64cdad22 |
393 | /], |
cb6ec758 |
394 | ); |
395 | |
b2e4d522 |
396 | has _master_connect_info_opts => |
397 | (is => 'rw', isa => HashRef, default => sub { {} }); |
398 | |
399 | =head2 around: connect_info |
400 | |
401 | Preserve master's C<connect_info> options (for merging with replicants.) |
dcdf7b2c |
402 | Also set any Replicated related options from connect_info, such as |
403 | C<pool_type>, C<pool_args>, C<balancer_type> and C<balancer_args>. |
b2e4d522 |
404 | |
405 | =cut |
406 | |
407 | around connect_info => sub { |
408 | my ($next, $self, $info, @extra) = @_; |
409 | |
0ce2d0d5 |
410 | my $wantarray = wantarray; |
411 | |
b2e4d522 |
412 | my %opts; |
413 | for my $arg (@$info) { |
414 | next unless (reftype($arg)||'') eq 'HASH'; |
b88b85e7 |
415 | %opts = %{ merge($arg, \%opts) }; |
b2e4d522 |
416 | } |
b2e4d522 |
417 | delete $opts{dsn}; |
418 | |
dcdf7b2c |
419 | if (@opts{qw/pool_type pool_args/}) { |
420 | $self->pool_type(delete $opts{pool_type}) |
421 | if $opts{pool_type}; |
422 | |
b88b85e7 |
423 | $self->pool_args( |
424 | merge((delete $opts{pool_args} || {}), $self->pool_args) |
425 | ); |
dcdf7b2c |
426 | |
67c43863 |
427 | $self->pool($self->_build_pool) |
6f7344b8 |
428 | if $self->pool; |
dcdf7b2c |
429 | } |
430 | |
431 | if (@opts{qw/balancer_type balancer_args/}) { |
432 | $self->balancer_type(delete $opts{balancer_type}) |
433 | if $opts{balancer_type}; |
434 | |
b88b85e7 |
435 | $self->balancer_args( |
436 | merge((delete $opts{balancer_args} || {}), $self->balancer_args) |
437 | ); |
dcdf7b2c |
438 | |
67c43863 |
439 | $self->balancer($self->_build_balancer) |
6f7344b8 |
440 | if $self->balancer; |
dcdf7b2c |
441 | } |
442 | |
b2e4d522 |
443 | $self->_master_connect_info_opts(\%opts); |
444 | |
0ce2d0d5 |
445 | my (@res, $res); |
446 | if ($wantarray) { |
447 | @res = $self->$next($info, @extra); |
448 | } else { |
449 | $res = $self->$next($info, @extra); |
450 | } |
451 | |
fd4eb9c2 |
452 | # Make sure master is blessed into the correct class and apply role to it. |
453 | my $master = $self->master; |
454 | $master->_determine_driver; |
455 | Moose::Meta::Class->initialize(ref $master); |
cea43436 |
456 | |
ec0946db |
457 | DBIx::Class::Storage::DBI::Replicated::WithDSN->meta->apply($master); |
cea43436 |
458 | |
459 | # link pool back to master |
460 | $self->pool->master($master); |
0ce2d0d5 |
461 | |
462 | $wantarray ? @res : $res; |
b2e4d522 |
463 | }; |
464 | |
26ab719a |
465 | =head1 METHODS |
2bf79155 |
466 | |
26ab719a |
467 | This class defines the following methods. |
2bf79155 |
468 | |
c354902c |
469 | =head2 BUILDARGS |
2bf79155 |
470 | |
faaba25f |
471 | L<DBIx::Class::Schema> when instantiating its storage passed itself as the |
2ce6e9a6 |
472 | first argument. So we need to massage the arguments a bit so that all the |
473 | bits get put into the correct places. |
2bf79155 |
474 | |
475 | =cut |
476 | |
c354902c |
477 | sub BUILDARGS { |
d7a58a29 |
478 | my ($class, $schema, $storage_type_args, @args) = @_; |
d4daee7b |
479 | |
c354902c |
480 | return { |
6f7344b8 |
481 | schema=>$schema, |
482 | %$storage_type_args, |
483 | @args |
c354902c |
484 | } |
485 | } |
2bf79155 |
486 | |
cb6ec758 |
487 | =head2 _build_master |
2bf79155 |
488 | |
cb6ec758 |
489 | Lazy builder for the L</master> attribute. |
2bf79155 |
490 | |
491 | =cut |
492 | |
cb6ec758 |
493 | sub _build_master { |
2ce6e9a6 |
494 | my $self = shift @_; |
ee356d00 |
495 | my $master = DBIx::Class::Storage::DBI->new($self->schema); |
ee356d00 |
496 | $master |
106d5f3b |
497 | } |
498 | |
26ab719a |
499 | =head2 _build_pool |
2bf79155 |
500 | |
26ab719a |
501 | Lazy builder for the L</pool> attribute. |
2bf79155 |
502 | |
503 | =cut |
504 | |
26ab719a |
505 | sub _build_pool { |
64cdad22 |
506 | my $self = shift @_; |
507 | $self->create_pool(%{$self->pool_args}); |
2bf79155 |
508 | } |
509 | |
26ab719a |
510 | =head2 _build_balancer |
2bf79155 |
511 | |
cb6ec758 |
512 | Lazy builder for the L</balancer> attribute. This takes a Pool object so that |
513 | the balancer knows which pool it's balancing. |
2bf79155 |
514 | |
515 | =cut |
516 | |
26ab719a |
517 | sub _build_balancer { |
64cdad22 |
518 | my $self = shift @_; |
519 | $self->create_balancer( |
6f7344b8 |
520 | pool=>$self->pool, |
64cdad22 |
521 | master=>$self->master, |
522 | %{$self->balancer_args}, |
523 | ); |
2bf79155 |
524 | } |
525 | |
cb6ec758 |
526 | =head2 _build_write_handler |
2bf79155 |
527 | |
cb6ec758 |
528 | Lazy builder for the L</write_handler> attribute. The default is to set this to |
529 | the L</master>. |
50336325 |
530 | |
531 | =cut |
532 | |
cb6ec758 |
533 | sub _build_write_handler { |
64cdad22 |
534 | return shift->master; |
cb6ec758 |
535 | } |
50336325 |
536 | |
cb6ec758 |
537 | =head2 _build_read_handler |
2bf79155 |
538 | |
cb6ec758 |
539 | Lazy builder for the L</read_handler> attribute. The default is to set this to |
540 | the L</balancer>. |
2bf79155 |
541 | |
542 | =cut |
543 | |
cb6ec758 |
544 | sub _build_read_handler { |
64cdad22 |
545 | return shift->balancer; |
cb6ec758 |
546 | } |
50336325 |
547 | |
cb6ec758 |
548 | =head2 around: connect_replicants |
2bf79155 |
549 | |
cb6ec758 |
550 | All calls to connect_replicants needs to have an existing $schema tacked onto |
b2e4d522 |
551 | top of the args, since L<DBIx::Storage::DBI> needs it, and any C<connect_info> |
552 | options merged with the master, with replicant opts having higher priority. |
955a6df6 |
553 | |
cb6ec758 |
554 | =cut |
955a6df6 |
555 | |
b2e4d522 |
556 | around connect_replicants => sub { |
557 | my ($next, $self, @args) = @_; |
558 | |
559 | for my $r (@args) { |
560 | $r = [ $r ] unless reftype $r eq 'ARRAY'; |
561 | |
1a58752c |
562 | $self->throw_exception('coderef replicant connect_info not supported') |
b2e4d522 |
563 | if ref $r->[0] && reftype $r->[0] eq 'CODE'; |
564 | |
565 | # any connect_info options? |
566 | my $i = 0; |
567 | $i++ while $i < @$r && (reftype($r->[$i])||'') ne 'HASH'; |
568 | |
6f7344b8 |
569 | # make one if none |
b2e4d522 |
570 | $r->[$i] = {} unless $r->[$i]; |
571 | |
572 | # merge if two hashes |
b88b85e7 |
573 | my @hashes = @$r[$i .. $#{$r}]; |
574 | |
1a58752c |
575 | $self->throw_exception('invalid connect_info options') |
b88b85e7 |
576 | if (grep { reftype($_) eq 'HASH' } @hashes) != @hashes; |
577 | |
1a58752c |
578 | $self->throw_exception('too many hashrefs in connect_info') |
b88b85e7 |
579 | if @hashes > 2; |
580 | |
581 | my %opts = %{ merge(reverse @hashes) }; |
582 | |
583 | # delete them |
b2e4d522 |
584 | splice @$r, $i+1, ($#{$r} - $i), (); |
585 | |
0bd8e058 |
586 | # make sure master/replicants opts don't clash |
587 | my %master_opts = %{ $self->_master_connect_info_opts }; |
588 | if (exists $opts{dbh_maker}) { |
589 | delete @master_opts{qw/dsn user password/}; |
590 | } |
591 | delete $master_opts{dbh_maker}; |
592 | |
b2e4d522 |
593 | # merge with master |
0bd8e058 |
594 | %opts = %{ merge(\%opts, \%master_opts) }; |
b2e4d522 |
595 | |
596 | # update |
597 | $r->[$i] = \%opts; |
598 | } |
599 | |
600 | $self->$next($self->schema, @args); |
955a6df6 |
601 | }; |
2bf79155 |
602 | |
2bf79155 |
603 | =head2 all_storages |
604 | |
605 | Returns an array of of all the connected storage backends. The first element |
606 | in the returned array is the master, and the remainings are each of the |
607 | replicants. |
608 | |
609 | =cut |
610 | |
611 | sub all_storages { |
64cdad22 |
612 | my $self = shift @_; |
613 | return grep {defined $_ && blessed $_} ( |
614 | $self->master, |
6412a592 |
615 | values %{ $self->replicants }, |
64cdad22 |
616 | ); |
2bf79155 |
617 | } |
618 | |
c4d3fae2 |
619 | =head2 execute_reliably ($coderef, ?@args) |
620 | |
621 | Given a coderef, saves the current state of the L</read_handler>, forces it to |
622 | use reliable storage (ie sets it to the master), executes a coderef and then |
623 | restores the original state. |
624 | |
625 | Example: |
626 | |
64cdad22 |
627 | my $reliably = sub { |
628 | my $name = shift @_; |
629 | $schema->resultset('User')->create({name=>$name}); |
630 | my $user_rs = $schema->resultset('User')->find({name=>$name}); |
631 | return $user_rs; |
632 | }; |
c4d3fae2 |
633 | |
64cdad22 |
634 | my $user_rs = $schema->storage->execute_reliably($reliably, 'John'); |
c4d3fae2 |
635 | |
636 | Use this when you must be certain of your database state, such as when you just |
637 | inserted something and need to get a resultset including it, etc. |
638 | |
639 | =cut |
640 | |
641 | sub execute_reliably { |
64cdad22 |
642 | my ($self, $coderef, @args) = @_; |
d4daee7b |
643 | |
64cdad22 |
644 | unless( ref $coderef eq 'CODE') { |
645 | $self->throw_exception('Second argument must be a coderef'); |
646 | } |
d4daee7b |
647 | |
64cdad22 |
648 | ##Get copy of master storage |
649 | my $master = $self->master; |
d4daee7b |
650 | |
64cdad22 |
651 | ##Get whatever the current read hander is |
652 | my $current = $self->read_handler; |
d4daee7b |
653 | |
64cdad22 |
654 | ##Set the read handler to master |
655 | $self->read_handler($master); |
d4daee7b |
656 | |
64cdad22 |
657 | ## do whatever the caller needs |
658 | my @result; |
659 | my $want_array = wantarray; |
d4daee7b |
660 | |
64cdad22 |
661 | eval { |
662 | if($want_array) { |
663 | @result = $coderef->(@args); |
664 | } elsif(defined $want_array) { |
665 | ($result[0]) = ($coderef->(@args)); |
ed213e85 |
666 | } else { |
64cdad22 |
667 | $coderef->(@args); |
6f7344b8 |
668 | } |
64cdad22 |
669 | }; |
d4daee7b |
670 | |
64cdad22 |
671 | ##Reset to the original state |
6f7344b8 |
672 | $self->read_handler($current); |
d4daee7b |
673 | |
64cdad22 |
674 | ##Exception testing has to come last, otherwise you might leave the |
675 | ##read_handler set to master. |
d4daee7b |
676 | |
64cdad22 |
677 | if($@) { |
678 | $self->throw_exception("coderef returned an error: $@"); |
679 | } else { |
680 | return $want_array ? @result : $result[0]; |
681 | } |
c4d3fae2 |
682 | } |
683 | |
cb6ec758 |
684 | =head2 set_reliable_storage |
685 | |
686 | Sets the current $schema to be 'reliable', that is all queries, both read and |
687 | write are sent to the master |
d4daee7b |
688 | |
cb6ec758 |
689 | =cut |
690 | |
691 | sub set_reliable_storage { |
64cdad22 |
692 | my $self = shift @_; |
693 | my $schema = $self->schema; |
694 | my $write_handler = $self->schema->storage->write_handler; |
d4daee7b |
695 | |
64cdad22 |
696 | $schema->storage->read_handler($write_handler); |
cb6ec758 |
697 | } |
698 | |
699 | =head2 set_balanced_storage |
700 | |
701 | Sets the current $schema to be use the </balancer> for all reads, while all |
702 | writea are sent to the master only |
d4daee7b |
703 | |
cb6ec758 |
704 | =cut |
705 | |
706 | sub set_balanced_storage { |
64cdad22 |
707 | my $self = shift @_; |
708 | my $schema = $self->schema; |
bd5da369 |
709 | my $balanced_handler = $self->schema->storage->balancer; |
d4daee7b |
710 | |
bd5da369 |
711 | $schema->storage->read_handler($balanced_handler); |
cb6ec758 |
712 | } |
2bf79155 |
713 | |
714 | =head2 connected |
715 | |
716 | Check that the master and at least one of the replicants is connected. |
717 | |
718 | =cut |
719 | |
720 | sub connected { |
64cdad22 |
721 | my $self = shift @_; |
722 | return |
723 | $self->master->connected && |
724 | $self->pool->connected_replicants; |
2bf79155 |
725 | } |
726 | |
2bf79155 |
727 | =head2 ensure_connected |
728 | |
729 | Make sure all the storages are connected. |
730 | |
731 | =cut |
732 | |
733 | sub ensure_connected { |
64cdad22 |
734 | my $self = shift @_; |
735 | foreach my $source ($self->all_storages) { |
736 | $source->ensure_connected(@_); |
737 | } |
2bf79155 |
738 | } |
739 | |
2bf79155 |
740 | =head2 limit_dialect |
741 | |
742 | Set the limit_dialect for all existing storages |
743 | |
744 | =cut |
745 | |
746 | sub limit_dialect { |
64cdad22 |
747 | my $self = shift @_; |
748 | foreach my $source ($self->all_storages) { |
749 | $source->limit_dialect(@_); |
750 | } |
3fbe08e3 |
751 | return $self->master->quote_char; |
2bf79155 |
752 | } |
753 | |
2bf79155 |
754 | =head2 quote_char |
755 | |
756 | Set the quote_char for all existing storages |
757 | |
758 | =cut |
759 | |
760 | sub quote_char { |
64cdad22 |
761 | my $self = shift @_; |
762 | foreach my $source ($self->all_storages) { |
763 | $source->quote_char(@_); |
764 | } |
3fbe08e3 |
765 | return $self->master->quote_char; |
2bf79155 |
766 | } |
767 | |
2bf79155 |
768 | =head2 name_sep |
769 | |
770 | Set the name_sep for all existing storages |
771 | |
772 | =cut |
773 | |
774 | sub name_sep { |
64cdad22 |
775 | my $self = shift @_; |
776 | foreach my $source ($self->all_storages) { |
777 | $source->name_sep(@_); |
778 | } |
3fbe08e3 |
779 | return $self->master->name_sep; |
2bf79155 |
780 | } |
781 | |
2bf79155 |
782 | =head2 set_schema |
783 | |
784 | Set the schema object for all existing storages |
785 | |
786 | =cut |
787 | |
788 | sub set_schema { |
64cdad22 |
789 | my $self = shift @_; |
790 | foreach my $source ($self->all_storages) { |
791 | $source->set_schema(@_); |
792 | } |
2bf79155 |
793 | } |
794 | |
2bf79155 |
795 | =head2 debug |
796 | |
797 | set a debug flag across all storages |
798 | |
799 | =cut |
800 | |
801 | sub debug { |
64cdad22 |
802 | my $self = shift @_; |
3fbe08e3 |
803 | if(@_) { |
804 | foreach my $source ($self->all_storages) { |
805 | $source->debug(@_); |
6f7344b8 |
806 | } |
64cdad22 |
807 | } |
3fbe08e3 |
808 | return $self->master->debug; |
2bf79155 |
809 | } |
810 | |
2bf79155 |
811 | =head2 debugobj |
812 | |
cea43436 |
813 | set a debug object |
2bf79155 |
814 | |
815 | =cut |
816 | |
817 | sub debugobj { |
64cdad22 |
818 | my $self = shift @_; |
cea43436 |
819 | return $self->master->debugobj(@_); |
2bf79155 |
820 | } |
821 | |
2bf79155 |
822 | =head2 debugfh |
823 | |
cea43436 |
824 | set a debugfh object |
2bf79155 |
825 | |
826 | =cut |
827 | |
828 | sub debugfh { |
64cdad22 |
829 | my $self = shift @_; |
cea43436 |
830 | return $self->master->debugfh(@_); |
2bf79155 |
831 | } |
832 | |
2bf79155 |
833 | =head2 debugcb |
834 | |
cea43436 |
835 | set a debug callback |
2bf79155 |
836 | |
837 | =cut |
838 | |
839 | sub debugcb { |
64cdad22 |
840 | my $self = shift @_; |
cea43436 |
841 | return $self->master->debugcb(@_); |
2bf79155 |
842 | } |
843 | |
2bf79155 |
844 | =head2 disconnect |
845 | |
846 | disconnect everything |
847 | |
848 | =cut |
849 | |
850 | sub disconnect { |
64cdad22 |
851 | my $self = shift @_; |
852 | foreach my $source ($self->all_storages) { |
853 | $source->disconnect(@_); |
854 | } |
2bf79155 |
855 | } |
856 | |
b2e4d522 |
857 | =head2 cursor_class |
858 | |
859 | set cursor class on all storages, or return master's |
860 | |
861 | =cut |
862 | |
863 | sub cursor_class { |
864 | my ($self, $cursor_class) = @_; |
865 | |
866 | if ($cursor_class) { |
867 | $_->cursor_class($cursor_class) for $self->all_storages; |
868 | } |
869 | $self->master->cursor_class; |
870 | } |
d4daee7b |
871 | |
3244fdcc |
872 | =head2 cursor |
873 | |
874 | set cursor class on all storages, or return master's, alias for L</cursor_class> |
875 | above. |
876 | |
877 | =cut |
878 | |
879 | sub cursor { |
880 | my ($self, $cursor_class) = @_; |
881 | |
882 | if ($cursor_class) { |
883 | $_->cursor($cursor_class) for $self->all_storages; |
884 | } |
885 | $self->master->cursor; |
886 | } |
887 | |
888 | =head2 unsafe |
889 | |
890 | sets the L<DBIx::Class::Storage::DBI/unsafe> option on all storages or returns |
891 | master's current setting |
892 | |
893 | =cut |
894 | |
895 | sub unsafe { |
896 | my $self = shift; |
897 | |
898 | if (@_) { |
899 | $_->unsafe(@_) for $self->all_storages; |
900 | } |
901 | |
902 | return $self->master->unsafe; |
903 | } |
904 | |
905 | =head2 disable_sth_caching |
906 | |
907 | sets the L<DBIx::Class::Storage::DBI/disable_sth_caching> option on all storages |
908 | or returns master's current setting |
909 | |
910 | =cut |
911 | |
912 | sub disable_sth_caching { |
913 | my $self = shift; |
914 | |
915 | if (@_) { |
916 | $_->disable_sth_caching(@_) for $self->all_storages; |
917 | } |
918 | |
919 | return $self->master->disable_sth_caching; |
920 | } |
921 | |
922 | =head2 lag_behind_master |
923 | |
924 | returns the highest Replicant L<DBIx::Class::Storage::DBI/lag_behind_master> |
925 | setting |
926 | |
927 | =cut |
928 | |
929 | sub lag_behind_master { |
930 | my $self = shift; |
931 | |
932 | return max map $_->lag_behind_master, $self->replicants; |
933 | } |
934 | |
935 | =head2 is_replicating |
936 | |
937 | returns true if all replicants return true for |
938 | L<DBIx::Class::Storage::DBI/is_replicating> |
939 | |
940 | =cut |
941 | |
942 | sub is_replicating { |
943 | my $self = shift; |
944 | |
945 | return (grep $_->is_replicating, $self->replicants) == ($self->replicants); |
946 | } |
947 | |
948 | =head2 connect_call_datetime_setup |
949 | |
950 | calls L<DBIx::Class::Storage::DBI/connect_call_datetime_setup> for all storages |
951 | |
952 | =cut |
953 | |
954 | sub connect_call_datetime_setup { |
955 | my $self = shift; |
956 | $_->connect_call_datetime_setup for $self->all_storages; |
957 | } |
958 | |
959 | sub _populate_dbh { |
960 | my $self = shift; |
961 | $_->_populate_dbh for $self->all_storages; |
962 | } |
963 | |
964 | sub _connect { |
965 | my $self = shift; |
966 | $_->_connect for $self->all_storages; |
967 | } |
968 | |
969 | sub _rebless { |
970 | my $self = shift; |
971 | $_->_rebless for $self->all_storages; |
972 | } |
973 | |
974 | sub _determine_driver { |
975 | my $self = shift; |
976 | $_->_determine_driver for $self->all_storages; |
977 | } |
978 | |
979 | sub _driver_determined { |
980 | my $self = shift; |
981 | |
982 | if (@_) { |
983 | $_->_driver_determined(@_) for $self->all_storages; |
984 | } |
985 | |
986 | return $self->master->_driver_determined; |
987 | } |
988 | |
989 | sub _init { |
990 | my $self = shift; |
991 | |
992 | $_->_init for $self->all_storages; |
993 | } |
994 | |
995 | sub _run_connection_actions { |
996 | my $self = shift; |
997 | |
998 | $_->_run_connection_actions for $self->all_storages; |
999 | } |
1000 | |
1001 | sub _do_connection_actions { |
1002 | my $self = shift; |
1003 | |
1004 | if (@_) { |
1005 | $_->_do_connection_actions(@_) for $self->all_storages; |
1006 | } |
1007 | } |
1008 | |
1009 | sub connect_call_do_sql { |
1010 | my $self = shift; |
1011 | $_->connect_call_do_sql(@_) for $self->all_storages; |
1012 | } |
1013 | |
1014 | sub disconnect_call_do_sql { |
1015 | my $self = shift; |
1016 | $_->disconnect_call_do_sql(@_) for $self->all_storages; |
1017 | } |
1018 | |
1019 | sub _seems_connected { |
1020 | my $self = shift; |
1021 | |
1022 | return min map $_->_seems_connected, $self->all_storages; |
1023 | } |
1024 | |
1025 | sub _ping { |
1026 | my $self = shift; |
1027 | |
1028 | return min map $_->_ping, $self->all_storages; |
1029 | } |
1030 | |
7e38d850 |
1031 | =head1 GOTCHAS |
1032 | |
1033 | Due to the fact that replicants can lag behind a master, you must take care to |
1034 | make sure you use one of the methods to force read queries to a master should |
1035 | you need realtime data integrity. For example, if you insert a row, and then |
1036 | immediately re-read it from the database (say, by doing $row->discard_changes) |
1037 | or you insert a row and then immediately build a query that expects that row |
1038 | to be an item, you should force the master to handle reads. Otherwise, due to |
1039 | the lag, there is no certainty your data will be in the expected state. |
1040 | |
1041 | For data integrity, all transactions automatically use the master storage for |
1042 | all read and write queries. Using a transaction is the preferred and recommended |
1043 | method to force the master to handle all read queries. |
1044 | |
1045 | Otherwise, you can force a single query to use the master with the 'force_pool' |
1046 | attribute: |
1047 | |
1048 | my $row = $resultset->search(undef, {force_pool=>'master'})->find($pk); |
1049 | |
1050 | This attribute will safely be ignore by non replicated storages, so you can use |
1051 | the same code for both types of systems. |
1052 | |
1053 | Lastly, you can use the L</execute_reliably> method, which works very much like |
1054 | a transaction. |
1055 | |
1056 | For debugging, you can turn replication on/off with the methods L</set_reliable_storage> |
1057 | and L</set_balanced_storage>, however this operates at a global level and is not |
1058 | suitable if you have a shared Schema object being used by multiple processes, |
1059 | such as on a web application server. You can get around this limitation by |
1060 | using the Schema clone method. |
1061 | |
1062 | my $new_schema = $schema->clone; |
1063 | $new_schema->set_reliable_storage; |
d4daee7b |
1064 | |
7e38d850 |
1065 | ## $new_schema will use only the Master storage for all reads/writes while |
1066 | ## the $schema object will use replicated storage. |
1067 | |
f5d3a5de |
1068 | =head1 AUTHOR |
1069 | |
64cdad22 |
1070 | John Napiorkowski <john.napiorkowski@takkle.com> |
f5d3a5de |
1071 | |
c4d3fae2 |
1072 | Based on code originated by: |
f5d3a5de |
1073 | |
64cdad22 |
1074 | Norbert Csongrádi <bert@cpan.org> |
1075 | Peter Siklósi <einon@einon.hu> |
2156bbdd |
1076 | |
f5d3a5de |
1077 | =head1 LICENSE |
1078 | |
1079 | You may distribute this code under the same terms as Perl itself. |
1080 | |
1081 | =cut |
1082 | |
c354902c |
1083 | __PACKAGE__->meta->make_immutable; |
1084 | |
f5d3a5de |
1085 | 1; |