Commit | Line | Data |
2156bbdd |
1 | package DBIx::Class::Storage::DBI::Replicated; |
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2 | |
ecb65397 |
3 | BEGIN { |
4 | use Carp::Clan qw/^DBIx::Class/; |
a34b0c89 |
5 | use DBIx::Class; |
6 | croak('The following modules are required for Replication ' . DBIx::Class::Optional::Dependencies->req_missing_for ('replicated') ) |
7 | unless DBIx::Class::Optional::Dependencies->req_ok_for ('replicated'); |
ecb65397 |
8 | } |
9 | |
b2e4d522 |
10 | use Moose; |
26ab719a |
11 | use DBIx::Class::Storage::DBI; |
2bf79155 |
12 | use DBIx::Class::Storage::DBI::Replicated::Pool; |
26ab719a |
13 | use DBIx::Class::Storage::DBI::Replicated::Balancer; |
6a151f58 |
14 | use DBIx::Class::Storage::DBI::Replicated::Types qw/BalancerClassNamePart DBICSchema DBICStorageDBI/; |
41916570 |
15 | use MooseX::Types::Moose qw/ClassName HashRef Object/; |
b2e4d522 |
16 | use Scalar::Util 'reftype'; |
e666c5fd |
17 | use Hash::Merge; |
7da56142 |
18 | use List::Util qw/min max reduce/; |
ed7ab0f4 |
19 | use Try::Tiny; |
fd323bf1 |
20 | use namespace::clean; |
9901aad7 |
21 | |
22 | use namespace::clean -except => 'meta'; |
2bf79155 |
23 | |
24 | =head1 NAME |
25 | |
ecb65397 |
26 | DBIx::Class::Storage::DBI::Replicated - BETA Replicated database support |
2bf79155 |
27 | |
28 | =head1 SYNOPSIS |
29 | |
30 | The Following example shows how to change an existing $schema to a replicated |
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31 | storage type, add some replicated (read-only) databases, and perform reporting |
955a6df6 |
32 | tasks. |
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33 | |
3da4f736 |
34 | You should set the 'storage_type attribute to a replicated type. You should |
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35 | also define your arguments, such as which balancer you want and any arguments |
3da4f736 |
36 | that the Pool object should get. |
37 | |
ce854fd3 |
38 | my $schema = Schema::Class->clone; |
64cdad22 |
39 | $schema->storage_type( ['::DBI::Replicated', {balancer=>'::Random'}] ); |
ce854fd3 |
40 | $schema->connection(...); |
d4daee7b |
41 | |
fd323bf1 |
42 | Next, you need to add in the Replicants. Basically this is an array of |
3da4f736 |
43 | arrayrefs, where each arrayref is database connect information. Think of these |
44 | arguments as what you'd pass to the 'normal' $schema->connect method. |
d4daee7b |
45 | |
64cdad22 |
46 | $schema->storage->connect_replicants( |
47 | [$dsn1, $user, $pass, \%opts], |
48 | [$dsn2, $user, $pass, \%opts], |
49 | [$dsn3, $user, $pass, \%opts], |
50 | ); |
d4daee7b |
51 | |
3da4f736 |
52 | Now, just use the $schema as you normally would. Automatically all reads will |
53 | be delegated to the replicants, while writes to the master. |
54 | |
7e38d850 |
55 | $schema->resultset('Source')->search({name=>'etc'}); |
d4daee7b |
56 | |
3da4f736 |
57 | You can force a given query to use a particular storage using the search |
58 | attribute 'force_pool'. For example: |
d4daee7b |
59 | |
7e38d850 |
60 | my $RS = $schema->resultset('Source')->search(undef, {force_pool=>'master'}); |
3da4f736 |
61 | |
62 | Now $RS will force everything (both reads and writes) to use whatever was setup |
fd323bf1 |
63 | as the master storage. 'master' is hardcoded to always point to the Master, |
3da4f736 |
64 | but you can also use any Replicant name. Please see: |
212cc5c2 |
65 | L<DBIx::Class::Storage::DBI::Replicated::Pool> and the replicants attribute for more. |
3da4f736 |
66 | |
67 | Also see transactions and L</execute_reliably> for alternative ways to |
68 | force read traffic to the master. In general, you should wrap your statements |
69 | in a transaction when you are reading and writing to the same tables at the |
70 | same time, since your replicants will often lag a bit behind the master. |
212cc5c2 |
71 | |
72 | See L<DBIx::Class::Storage::DBI::Replicated::Instructions> for more help and |
73 | walkthroughs. |
d4daee7b |
74 | |
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75 | =head1 DESCRIPTION |
76 | |
7e38d850 |
77 | Warning: This class is marked BETA. This has been running a production |
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78 | website using MySQL native replication as its backend and we have some decent |
7e38d850 |
79 | test coverage but the code hasn't yet been stressed by a variety of databases. |
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80 | Individual DBs may have quirks we are not aware of. Please use this in first |
7e38d850 |
81 | development and pass along your experiences/bug fixes. |
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82 | |
83 | This class implements replicated data store for DBI. Currently you can define |
84 | one master and numerous slave database connections. All write-type queries |
85 | (INSERT, UPDATE, DELETE and even LAST_INSERT_ID) are routed to master |
86 | database, all read-type queries (SELECTs) go to the slave database. |
87 | |
88 | Basically, any method request that L<DBIx::Class::Storage::DBI> would normally |
bca099a3 |
89 | handle gets delegated to one of the two attributes: L</read_handler> or to |
90 | L</write_handler>. Additionally, some methods need to be distributed |
2bf79155 |
91 | to all existing storages. This way our storage class is a drop in replacement |
92 | for L<DBIx::Class::Storage::DBI>. |
93 | |
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94 | Read traffic is spread across the replicants (slaves) occurring to a user |
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95 | selected algorithm. The default algorithm is random weighted. |
96 | |
bca099a3 |
97 | =head1 NOTES |
98 | |
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99 | The consistency between master and replicants is database specific. The Pool |
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100 | gives you a method to validate its replicants, removing and replacing them |
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101 | when they fail/pass predefined criteria. Please make careful use of the ways |
ecb65397 |
102 | to force a query to run against Master when needed. |
103 | |
104 | =head1 REQUIREMENTS |
105 | |
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106 | Replicated Storage has additional requirements not currently part of |
aa8b2277 |
107 | L<DBIx::Class>. See L<DBIx::Class::Optional::Dependencies> for more details. |
2bf79155 |
108 | |
109 | =head1 ATTRIBUTES |
110 | |
111 | This class defines the following attributes. |
112 | |
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113 | =head2 schema |
114 | |
115 | The underlying L<DBIx::Class::Schema> object this storage is attaching |
116 | |
117 | =cut |
118 | |
119 | has 'schema' => ( |
120 | is=>'rw', |
6a151f58 |
121 | isa=>DBICSchema, |
2ce6e9a6 |
122 | weak_ref=>1, |
123 | required=>1, |
124 | ); |
125 | |
26ab719a |
126 | =head2 pool_type |
2bf79155 |
127 | |
fd323bf1 |
128 | Contains the classname which will instantiate the L</pool> object. Defaults |
26ab719a |
129 | to: L<DBIx::Class::Storage::DBI::Replicated::Pool>. |
2bf79155 |
130 | |
131 | =cut |
132 | |
26ab719a |
133 | has 'pool_type' => ( |
dcdf7b2c |
134 | is=>'rw', |
41916570 |
135 | isa=>ClassName, |
2ce6e9a6 |
136 | default=>'DBIx::Class::Storage::DBI::Replicated::Pool', |
64cdad22 |
137 | handles=>{ |
138 | 'create_pool' => 'new', |
139 | }, |
2bf79155 |
140 | ); |
141 | |
f068a139 |
142 | =head2 pool_args |
143 | |
144 | Contains a hashref of initialized information to pass to the Balancer object. |
212cc5c2 |
145 | See L<DBIx::Class::Storage::DBI::Replicated::Pool> for available arguments. |
f068a139 |
146 | |
147 | =cut |
148 | |
149 | has 'pool_args' => ( |
dcdf7b2c |
150 | is=>'rw', |
41916570 |
151 | isa=>HashRef, |
64cdad22 |
152 | lazy=>1, |
64cdad22 |
153 | default=>sub { {} }, |
f068a139 |
154 | ); |
155 | |
156 | |
26ab719a |
157 | =head2 balancer_type |
2bf79155 |
158 | |
159 | The replication pool requires a balance class to provider the methods for |
160 | choose how to spread the query load across each replicant in the pool. |
161 | |
162 | =cut |
163 | |
26ab719a |
164 | has 'balancer_type' => ( |
dcdf7b2c |
165 | is=>'rw', |
9901aad7 |
166 | isa=>BalancerClassNamePart, |
2ce6e9a6 |
167 | coerce=>1, |
168 | required=>1, |
169 | default=> 'DBIx::Class::Storage::DBI::Replicated::Balancer::First', |
64cdad22 |
170 | handles=>{ |
171 | 'create_balancer' => 'new', |
172 | }, |
2bf79155 |
173 | ); |
174 | |
17b05c13 |
175 | =head2 balancer_args |
176 | |
177 | Contains a hashref of initialized information to pass to the Balancer object. |
212cc5c2 |
178 | See L<DBIx::Class::Storage::DBI::Replicated::Balancer> for available arguments. |
17b05c13 |
179 | |
180 | =cut |
181 | |
182 | has 'balancer_args' => ( |
dcdf7b2c |
183 | is=>'rw', |
41916570 |
184 | isa=>HashRef, |
64cdad22 |
185 | lazy=>1, |
186 | required=>1, |
187 | default=>sub { {} }, |
17b05c13 |
188 | ); |
189 | |
26ab719a |
190 | =head2 pool |
2bf79155 |
191 | |
370f78d4 |
192 | Is a L<DBIx::Class::Storage::DBI::Replicated::Pool> or derived class. This is a |
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193 | container class for one or more replicated databases. |
2bf79155 |
194 | |
195 | =cut |
196 | |
26ab719a |
197 | has 'pool' => ( |
64cdad22 |
198 | is=>'ro', |
199 | isa=>'DBIx::Class::Storage::DBI::Replicated::Pool', |
200 | lazy_build=>1, |
201 | handles=>[qw/ |
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202 | connect_replicants |
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203 | replicants |
204 | has_replicants |
205 | /], |
2bf79155 |
206 | ); |
207 | |
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208 | =head2 balancer |
2bf79155 |
209 | |
370f78d4 |
210 | Is a L<DBIx::Class::Storage::DBI::Replicated::Balancer> or derived class. This |
211 | is a class that takes a pool (L<DBIx::Class::Storage::DBI::Replicated::Pool>) |
2bf79155 |
212 | |
26ab719a |
213 | =cut |
2bf79155 |
214 | |
26ab719a |
215 | has 'balancer' => ( |
dcdf7b2c |
216 | is=>'rw', |
64cdad22 |
217 | isa=>'DBIx::Class::Storage::DBI::Replicated::Balancer', |
218 | lazy_build=>1, |
219 | handles=>[qw/auto_validate_every/], |
26ab719a |
220 | ); |
2bf79155 |
221 | |
cb6ec758 |
222 | =head2 master |
223 | |
224 | The master defines the canonical state for a pool of connected databases. All |
225 | the replicants are expected to match this databases state. Thus, in a classic |
226 | Master / Slaves distributed system, all the slaves are expected to replicate |
227 | the Master's state as quick as possible. This is the only database in the |
228 | pool of databases that is allowed to handle write traffic. |
229 | |
230 | =cut |
231 | |
232 | has 'master' => ( |
64cdad22 |
233 | is=> 'ro', |
6a151f58 |
234 | isa=>DBICStorageDBI, |
64cdad22 |
235 | lazy_build=>1, |
cb6ec758 |
236 | ); |
237 | |
cb6ec758 |
238 | =head1 ATTRIBUTES IMPLEMENTING THE DBIx::Storage::DBI INTERFACE |
239 | |
fd323bf1 |
240 | The following methods are delegated all the methods required for the |
cb6ec758 |
241 | L<DBIx::Class::Storage::DBI> interface. |
242 | |
243 | =head2 read_handler |
244 | |
245 | Defines an object that implements the read side of L<BIx::Class::Storage::DBI>. |
246 | |
247 | =cut |
248 | |
249 | has 'read_handler' => ( |
64cdad22 |
250 | is=>'rw', |
41916570 |
251 | isa=>Object, |
64cdad22 |
252 | lazy_build=>1, |
253 | handles=>[qw/ |
254 | select |
255 | select_single |
256 | columns_info_for |
fd323bf1 |
257 | _dbh_columns_info_for |
3244fdcc |
258 | _select |
6f7344b8 |
259 | /], |
cb6ec758 |
260 | ); |
261 | |
cb6ec758 |
262 | =head2 write_handler |
263 | |
3244fdcc |
264 | Defines an object that implements the write side of L<BIx::Class::Storage::DBI>, |
265 | as well as methods that don't write or read that can be called on only one |
266 | storage, methods that return a C<$dbh>, and any methods that don't make sense to |
267 | run on a replicant. |
cb6ec758 |
268 | |
269 | =cut |
270 | |
271 | has 'write_handler' => ( |
64cdad22 |
272 | is=>'ro', |
41916570 |
273 | isa=>Object, |
64cdad22 |
274 | lazy_build=>1, |
6f7344b8 |
275 | handles=>[qw/ |
64cdad22 |
276 | on_connect_do |
6f7344b8 |
277 | on_disconnect_do |
3244fdcc |
278 | on_connect_call |
279 | on_disconnect_call |
64cdad22 |
280 | connect_info |
3244fdcc |
281 | _connect_info |
64cdad22 |
282 | throw_exception |
283 | sql_maker |
284 | sqlt_type |
285 | create_ddl_dir |
286 | deployment_statements |
287 | datetime_parser |
6f7344b8 |
288 | datetime_parser_type |
289 | build_datetime_parser |
64cdad22 |
290 | last_insert_id |
291 | insert |
292 | insert_bulk |
293 | update |
294 | delete |
295 | dbh |
2ce6e9a6 |
296 | txn_begin |
64cdad22 |
297 | txn_do |
298 | txn_commit |
299 | txn_rollback |
2ce6e9a6 |
300 | txn_scope_guard |
64cdad22 |
301 | sth |
302 | deploy |
0180bef9 |
303 | with_deferred_fk_checks |
6f7344b8 |
304 | dbh_do |
64cdad22 |
305 | reload_row |
6f7344b8 |
306 | with_deferred_fk_checks |
2ce6e9a6 |
307 | _prep_for_execute |
7fb60fb1 |
308 | |
6f7344b8 |
309 | backup |
310 | is_datatype_numeric |
311 | _count_select |
6f7344b8 |
312 | _subq_update_delete |
313 | svp_rollback |
314 | svp_begin |
315 | svp_release |
e398f77e |
316 | relname_to_table_alias |
3244fdcc |
317 | _dbh_last_insert_id |
318 | _fix_bind_params |
319 | _default_dbi_connect_attributes |
320 | _dbi_connect_info |
b9ca4ff1 |
321 | _dbic_connect_attributes |
3244fdcc |
322 | auto_savepoint |
323 | _sqlt_version_ok |
324 | _query_end |
325 | bind_attribute_by_data_type |
326 | transaction_depth |
327 | _dbh |
328 | _select_args |
329 | _dbh_execute_array |
3244fdcc |
330 | _sql_maker |
331 | _query_start |
332 | _sqlt_version_error |
333 | _per_row_update_delete |
334 | _dbh_begin_work |
335 | _dbh_execute_inserts_with_no_binds |
336 | _select_args_to_query |
337 | _svp_generate_name |
338 | _multipk_update_delete |
339 | source_bind_attributes |
340 | _normalize_connect_info |
341 | _parse_connect_do |
342 | _dbh_commit |
343 | _execute_array |
3244fdcc |
344 | savepoints |
345 | _sqlt_minimum_version |
346 | _sql_maker_opts |
347 | _conn_pid |
3244fdcc |
348 | _dbh_autocommit |
349 | _native_data_type |
350 | _get_dbh |
351 | sql_maker_class |
352 | _dbh_rollback |
353 | _adjust_select_args_for_complex_prefetch |
354 | _resolve_ident_sources |
355 | _resolve_column_info |
356 | _prune_unused_joins |
357 | _strip_cond_qualifiers |
3244fdcc |
358 | _resolve_aliastypes_from_select_args |
359 | _execute |
360 | _do_query |
361 | _dbh_sth |
362 | _dbh_execute |
64cdad22 |
363 | /], |
cb6ec758 |
364 | ); |
365 | |
e471ab87 |
366 | my @unimplemented = qw( |
367 | _arm_global_destructor |
572338e0 |
368 | _verify_pid |
bbdda281 |
369 | |
370 | get_use_dbms_capability |
371 | set_use_dbms_capability |
372 | get_dbms_capability |
373 | set_dbms_capability |
bbdda281 |
374 | _dbh_details |
375 | |
7f4433eb |
376 | sql_limit_dialect |
31a8aaaf |
377 | |
378 | _inner_join_to_node |
0a3441ee |
379 | _group_over_selection |
e366f807 |
380 | _prefetch_autovalues |
bac358c9 |
381 | _extract_order_criteria |
bf51641f |
382 | _max_column_bytesize |
153a0398 |
383 | _is_lob_type |
e471ab87 |
384 | ); |
385 | |
7f4433eb |
386 | # the capability framework |
387 | # not sure if CMOP->initialize does evil things to DBIC::S::DBI, fix if a problem |
388 | push @unimplemented, ( grep |
389 | { $_ =~ /^ _ (?: use | supports | determine_supports ) _ /x } |
390 | ( Class::MOP::Class->initialize('DBIx::Class::Storage::DBI')->get_all_method_names ) |
391 | ); |
392 | |
e471ab87 |
393 | for my $method (@unimplemented) { |
394 | __PACKAGE__->meta->add_method($method, sub { |
395 | croak "$method must not be called on ".(blessed shift).' objects'; |
396 | }); |
397 | } |
6d766626 |
398 | |
b2e4d522 |
399 | has _master_connect_info_opts => |
400 | (is => 'rw', isa => HashRef, default => sub { {} }); |
401 | |
402 | =head2 around: connect_info |
403 | |
48580715 |
404 | Preserves master's C<connect_info> options (for merging with replicants.) |
405 | Also sets any Replicated-related options from connect_info, such as |
dcdf7b2c |
406 | C<pool_type>, C<pool_args>, C<balancer_type> and C<balancer_args>. |
b2e4d522 |
407 | |
408 | =cut |
409 | |
410 | around connect_info => sub { |
411 | my ($next, $self, $info, @extra) = @_; |
412 | |
282a9a4f |
413 | my $merge = Hash::Merge->new('LEFT_PRECEDENT'); |
e666c5fd |
414 | |
b2e4d522 |
415 | my %opts; |
416 | for my $arg (@$info) { |
417 | next unless (reftype($arg)||'') eq 'HASH'; |
e666c5fd |
418 | %opts = %{ $merge->merge($arg, \%opts) }; |
b2e4d522 |
419 | } |
b2e4d522 |
420 | delete $opts{dsn}; |
421 | |
dcdf7b2c |
422 | if (@opts{qw/pool_type pool_args/}) { |
423 | $self->pool_type(delete $opts{pool_type}) |
424 | if $opts{pool_type}; |
425 | |
b88b85e7 |
426 | $self->pool_args( |
e666c5fd |
427 | $merge->merge((delete $opts{pool_args} || {}), $self->pool_args) |
b88b85e7 |
428 | ); |
dcdf7b2c |
429 | |
64ae1667 |
430 | ## Since we possibly changed the pool_args, we need to clear the current |
431 | ## pool object so that next time it is used it will be rebuilt. |
432 | $self->clear_pool; |
dcdf7b2c |
433 | } |
434 | |
435 | if (@opts{qw/balancer_type balancer_args/}) { |
436 | $self->balancer_type(delete $opts{balancer_type}) |
437 | if $opts{balancer_type}; |
438 | |
b88b85e7 |
439 | $self->balancer_args( |
e666c5fd |
440 | $merge->merge((delete $opts{balancer_args} || {}), $self->balancer_args) |
b88b85e7 |
441 | ); |
dcdf7b2c |
442 | |
67c43863 |
443 | $self->balancer($self->_build_balancer) |
6f7344b8 |
444 | if $self->balancer; |
dcdf7b2c |
445 | } |
446 | |
b2e4d522 |
447 | $self->_master_connect_info_opts(\%opts); |
448 | |
cca282b6 |
449 | my @res; |
450 | if (wantarray) { |
0ce2d0d5 |
451 | @res = $self->$next($info, @extra); |
452 | } else { |
cca282b6 |
453 | $res[0] = $self->$next($info, @extra); |
0ce2d0d5 |
454 | } |
455 | |
fd4eb9c2 |
456 | # Make sure master is blessed into the correct class and apply role to it. |
457 | my $master = $self->master; |
458 | $master->_determine_driver; |
459 | Moose::Meta::Class->initialize(ref $master); |
cea43436 |
460 | |
ec0946db |
461 | DBIx::Class::Storage::DBI::Replicated::WithDSN->meta->apply($master); |
cea43436 |
462 | |
463 | # link pool back to master |
464 | $self->pool->master($master); |
0ce2d0d5 |
465 | |
cca282b6 |
466 | wantarray ? @res : $res[0]; |
b2e4d522 |
467 | }; |
468 | |
26ab719a |
469 | =head1 METHODS |
2bf79155 |
470 | |
26ab719a |
471 | This class defines the following methods. |
2bf79155 |
472 | |
c354902c |
473 | =head2 BUILDARGS |
2bf79155 |
474 | |
faaba25f |
475 | L<DBIx::Class::Schema> when instantiating its storage passed itself as the |
2ce6e9a6 |
476 | first argument. So we need to massage the arguments a bit so that all the |
477 | bits get put into the correct places. |
2bf79155 |
478 | |
479 | =cut |
480 | |
c354902c |
481 | sub BUILDARGS { |
fd323bf1 |
482 | my ($class, $schema, $storage_type_args, @args) = @_; |
d4daee7b |
483 | |
c354902c |
484 | return { |
6f7344b8 |
485 | schema=>$schema, |
486 | %$storage_type_args, |
487 | @args |
c354902c |
488 | } |
489 | } |
2bf79155 |
490 | |
cb6ec758 |
491 | =head2 _build_master |
2bf79155 |
492 | |
cb6ec758 |
493 | Lazy builder for the L</master> attribute. |
2bf79155 |
494 | |
495 | =cut |
496 | |
cb6ec758 |
497 | sub _build_master { |
2ce6e9a6 |
498 | my $self = shift @_; |
ee356d00 |
499 | my $master = DBIx::Class::Storage::DBI->new($self->schema); |
ee356d00 |
500 | $master |
106d5f3b |
501 | } |
502 | |
26ab719a |
503 | =head2 _build_pool |
2bf79155 |
504 | |
26ab719a |
505 | Lazy builder for the L</pool> attribute. |
2bf79155 |
506 | |
507 | =cut |
508 | |
26ab719a |
509 | sub _build_pool { |
64cdad22 |
510 | my $self = shift @_; |
511 | $self->create_pool(%{$self->pool_args}); |
2bf79155 |
512 | } |
513 | |
26ab719a |
514 | =head2 _build_balancer |
2bf79155 |
515 | |
cb6ec758 |
516 | Lazy builder for the L</balancer> attribute. This takes a Pool object so that |
517 | the balancer knows which pool it's balancing. |
2bf79155 |
518 | |
519 | =cut |
520 | |
26ab719a |
521 | sub _build_balancer { |
64cdad22 |
522 | my $self = shift @_; |
523 | $self->create_balancer( |
6f7344b8 |
524 | pool=>$self->pool, |
64cdad22 |
525 | master=>$self->master, |
526 | %{$self->balancer_args}, |
527 | ); |
2bf79155 |
528 | } |
529 | |
cb6ec758 |
530 | =head2 _build_write_handler |
2bf79155 |
531 | |
cb6ec758 |
532 | Lazy builder for the L</write_handler> attribute. The default is to set this to |
533 | the L</master>. |
50336325 |
534 | |
535 | =cut |
536 | |
cb6ec758 |
537 | sub _build_write_handler { |
64cdad22 |
538 | return shift->master; |
cb6ec758 |
539 | } |
50336325 |
540 | |
cb6ec758 |
541 | =head2 _build_read_handler |
2bf79155 |
542 | |
cb6ec758 |
543 | Lazy builder for the L</read_handler> attribute. The default is to set this to |
544 | the L</balancer>. |
2bf79155 |
545 | |
546 | =cut |
547 | |
cb6ec758 |
548 | sub _build_read_handler { |
64cdad22 |
549 | return shift->balancer; |
cb6ec758 |
550 | } |
50336325 |
551 | |
cb6ec758 |
552 | =head2 around: connect_replicants |
2bf79155 |
553 | |
cb6ec758 |
554 | All calls to connect_replicants needs to have an existing $schema tacked onto |
b2e4d522 |
555 | top of the args, since L<DBIx::Storage::DBI> needs it, and any C<connect_info> |
556 | options merged with the master, with replicant opts having higher priority. |
955a6df6 |
557 | |
cb6ec758 |
558 | =cut |
955a6df6 |
559 | |
b2e4d522 |
560 | around connect_replicants => sub { |
561 | my ($next, $self, @args) = @_; |
562 | |
563 | for my $r (@args) { |
564 | $r = [ $r ] unless reftype $r eq 'ARRAY'; |
565 | |
1a58752c |
566 | $self->throw_exception('coderef replicant connect_info not supported') |
b2e4d522 |
567 | if ref $r->[0] && reftype $r->[0] eq 'CODE'; |
568 | |
569 | # any connect_info options? |
570 | my $i = 0; |
571 | $i++ while $i < @$r && (reftype($r->[$i])||'') ne 'HASH'; |
572 | |
6f7344b8 |
573 | # make one if none |
b2e4d522 |
574 | $r->[$i] = {} unless $r->[$i]; |
575 | |
576 | # merge if two hashes |
b88b85e7 |
577 | my @hashes = @$r[$i .. $#{$r}]; |
578 | |
1a58752c |
579 | $self->throw_exception('invalid connect_info options') |
b88b85e7 |
580 | if (grep { reftype($_) eq 'HASH' } @hashes) != @hashes; |
581 | |
1a58752c |
582 | $self->throw_exception('too many hashrefs in connect_info') |
b88b85e7 |
583 | if @hashes > 2; |
584 | |
282a9a4f |
585 | my $merge = Hash::Merge->new('LEFT_PRECEDENT'); |
e666c5fd |
586 | my %opts = %{ $merge->merge(reverse @hashes) }; |
b88b85e7 |
587 | |
588 | # delete them |
b2e4d522 |
589 | splice @$r, $i+1, ($#{$r} - $i), (); |
590 | |
0bd8e058 |
591 | # make sure master/replicants opts don't clash |
592 | my %master_opts = %{ $self->_master_connect_info_opts }; |
593 | if (exists $opts{dbh_maker}) { |
594 | delete @master_opts{qw/dsn user password/}; |
595 | } |
596 | delete $master_opts{dbh_maker}; |
597 | |
b2e4d522 |
598 | # merge with master |
e666c5fd |
599 | %opts = %{ $merge->merge(\%opts, \%master_opts) }; |
b2e4d522 |
600 | |
601 | # update |
602 | $r->[$i] = \%opts; |
603 | } |
604 | |
605 | $self->$next($self->schema, @args); |
955a6df6 |
606 | }; |
2bf79155 |
607 | |
2bf79155 |
608 | =head2 all_storages |
609 | |
610 | Returns an array of of all the connected storage backends. The first element |
611 | in the returned array is the master, and the remainings are each of the |
612 | replicants. |
613 | |
614 | =cut |
615 | |
616 | sub all_storages { |
64cdad22 |
617 | my $self = shift @_; |
618 | return grep {defined $_ && blessed $_} ( |
619 | $self->master, |
6412a592 |
620 | values %{ $self->replicants }, |
64cdad22 |
621 | ); |
2bf79155 |
622 | } |
623 | |
c4d3fae2 |
624 | =head2 execute_reliably ($coderef, ?@args) |
625 | |
626 | Given a coderef, saves the current state of the L</read_handler>, forces it to |
48580715 |
627 | use reliable storage (e.g. sets it to the master), executes a coderef and then |
c4d3fae2 |
628 | restores the original state. |
629 | |
630 | Example: |
631 | |
64cdad22 |
632 | my $reliably = sub { |
633 | my $name = shift @_; |
634 | $schema->resultset('User')->create({name=>$name}); |
fd323bf1 |
635 | my $user_rs = $schema->resultset('User')->find({name=>$name}); |
64cdad22 |
636 | return $user_rs; |
637 | }; |
c4d3fae2 |
638 | |
64cdad22 |
639 | my $user_rs = $schema->storage->execute_reliably($reliably, 'John'); |
c4d3fae2 |
640 | |
641 | Use this when you must be certain of your database state, such as when you just |
642 | inserted something and need to get a resultset including it, etc. |
643 | |
644 | =cut |
645 | |
646 | sub execute_reliably { |
64cdad22 |
647 | my ($self, $coderef, @args) = @_; |
d4daee7b |
648 | |
64cdad22 |
649 | unless( ref $coderef eq 'CODE') { |
650 | $self->throw_exception('Second argument must be a coderef'); |
651 | } |
d4daee7b |
652 | |
64cdad22 |
653 | ##Get copy of master storage |
654 | my $master = $self->master; |
d4daee7b |
655 | |
64cdad22 |
656 | ##Get whatever the current read hander is |
657 | my $current = $self->read_handler; |
d4daee7b |
658 | |
64cdad22 |
659 | ##Set the read handler to master |
660 | $self->read_handler($master); |
d4daee7b |
661 | |
64cdad22 |
662 | ## do whatever the caller needs |
663 | my @result; |
664 | my $want_array = wantarray; |
d4daee7b |
665 | |
ed7ab0f4 |
666 | try { |
64cdad22 |
667 | if($want_array) { |
668 | @result = $coderef->(@args); |
669 | } elsif(defined $want_array) { |
670 | ($result[0]) = ($coderef->(@args)); |
ed213e85 |
671 | } else { |
64cdad22 |
672 | $coderef->(@args); |
6f7344b8 |
673 | } |
ed7ab0f4 |
674 | } catch { |
675 | $self->throw_exception("coderef returned an error: $_"); |
676 | } finally { |
677 | ##Reset to the original state |
678 | $self->read_handler($current); |
64cdad22 |
679 | }; |
d4daee7b |
680 | |
cca282b6 |
681 | return wantarray ? @result : $result[0]; |
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 |
48580715 |
702 | writes 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 | } |
f3e9f010 |
751 | return $self->master->limit_dialect; |
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; |
fd323bf1 |
933 | } |
3244fdcc |
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; |
fd323bf1 |
981 | |
3244fdcc |
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; |
fd323bf1 |
991 | |
3244fdcc |
992 | $_->_init for $self->all_storages; |
993 | } |
994 | |
995 | sub _run_connection_actions { |
996 | my $self = shift; |
fd323bf1 |
997 | |
3244fdcc |
998 | $_->_run_connection_actions for $self->all_storages; |
999 | } |
1000 | |
1001 | sub _do_connection_actions { |
1002 | my $self = shift; |
fd323bf1 |
1003 | |
3244fdcc |
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 | |
bbdda281 |
1031 | # not using the normalized_version, because we want to preserve |
1032 | # version numbers much longer than the conventional xxx.yyyzzz |
7da56142 |
1033 | my $numify_ver = sub { |
1034 | my $ver = shift; |
1035 | my @numparts = split /\D+/, $ver; |
bbdda281 |
1036 | my $format = '%d.' . (join '', ('%06d') x (@numparts - 1)); |
7da56142 |
1037 | |
1038 | return sprintf $format, @numparts; |
1039 | }; |
fecb38cb |
1040 | sub _server_info { |
1041 | my $self = shift; |
1042 | |
bbdda281 |
1043 | if (not $self->_dbh_details->{info}) { |
1044 | $self->_dbh_details->{info} = ( |
fd323bf1 |
1045 | reduce { $a->[0] < $b->[0] ? $a : $b } |
7da56142 |
1046 | map [ $numify_ver->($_->{dbms_version}), $_ ], |
1047 | map $_->_server_info, $self->all_storages |
1048 | )->[1]; |
fecb38cb |
1049 | } |
1050 | |
bbdda281 |
1051 | return $self->next::method; |
fecb38cb |
1052 | } |
1053 | |
1054 | sub _get_server_version { |
1055 | my $self = shift; |
1056 | |
1057 | return $self->_server_info->{dbms_version}; |
1058 | } |
1059 | |
7e38d850 |
1060 | =head1 GOTCHAS |
1061 | |
1062 | Due to the fact that replicants can lag behind a master, you must take care to |
1063 | make sure you use one of the methods to force read queries to a master should |
1064 | you need realtime data integrity. For example, if you insert a row, and then |
1065 | immediately re-read it from the database (say, by doing $row->discard_changes) |
1066 | or you insert a row and then immediately build a query that expects that row |
1067 | to be an item, you should force the master to handle reads. Otherwise, due to |
1068 | the lag, there is no certainty your data will be in the expected state. |
1069 | |
1070 | For data integrity, all transactions automatically use the master storage for |
1071 | all read and write queries. Using a transaction is the preferred and recommended |
1072 | method to force the master to handle all read queries. |
1073 | |
1074 | Otherwise, you can force a single query to use the master with the 'force_pool' |
1075 | attribute: |
1076 | |
1077 | my $row = $resultset->search(undef, {force_pool=>'master'})->find($pk); |
1078 | |
1079 | This attribute will safely be ignore by non replicated storages, so you can use |
1080 | the same code for both types of systems. |
1081 | |
1082 | Lastly, you can use the L</execute_reliably> method, which works very much like |
1083 | a transaction. |
1084 | |
1085 | For debugging, you can turn replication on/off with the methods L</set_reliable_storage> |
1086 | and L</set_balanced_storage>, however this operates at a global level and is not |
1087 | suitable if you have a shared Schema object being used by multiple processes, |
1088 | such as on a web application server. You can get around this limitation by |
1089 | using the Schema clone method. |
1090 | |
1091 | my $new_schema = $schema->clone; |
1092 | $new_schema->set_reliable_storage; |
d4daee7b |
1093 | |
7e38d850 |
1094 | ## $new_schema will use only the Master storage for all reads/writes while |
1095 | ## the $schema object will use replicated storage. |
1096 | |
f5d3a5de |
1097 | =head1 AUTHOR |
1098 | |
64cdad22 |
1099 | John Napiorkowski <john.napiorkowski@takkle.com> |
f5d3a5de |
1100 | |
c4d3fae2 |
1101 | Based on code originated by: |
f5d3a5de |
1102 | |
64cdad22 |
1103 | Norbert Csongrádi <bert@cpan.org> |
1104 | Peter Siklósi <einon@einon.hu> |
2156bbdd |
1105 | |
f5d3a5de |
1106 | =head1 LICENSE |
1107 | |
1108 | You may distribute this code under the same terms as Perl itself. |
1109 | |
1110 | =cut |
1111 | |
c354902c |
1112 | __PACKAGE__->meta->make_immutable; |
1113 | |
f5d3a5de |
1114 | 1; |