Commit | Line | Data |
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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 | |
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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 | |
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34 | You should set the 'storage_type attribute to a replicated type. You should |
d4daee7b |
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: |
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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 |
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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 |
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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 |
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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 |
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127 | |
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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 |
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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, |
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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 |
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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 |
227d8366 |
311 | _supports_insert_returning |
6f7344b8 |
312 | _count_select |
6f7344b8 |
313 | _subq_update_delete |
314 | svp_rollback |
315 | svp_begin |
316 | svp_release |
e398f77e |
317 | relname_to_table_alias |
318 | _straight_join_to_node |
3244fdcc |
319 | _dbh_last_insert_id |
320 | _fix_bind_params |
321 | _default_dbi_connect_attributes |
322 | _dbi_connect_info |
b9ca4ff1 |
323 | _dbic_connect_attributes |
3244fdcc |
324 | auto_savepoint |
325 | _sqlt_version_ok |
326 | _query_end |
327 | bind_attribute_by_data_type |
328 | transaction_depth |
329 | _dbh |
330 | _select_args |
331 | _dbh_execute_array |
332 | _sql_maker_args |
333 | _sql_maker |
334 | _query_start |
335 | _sqlt_version_error |
336 | _per_row_update_delete |
337 | _dbh_begin_work |
338 | _dbh_execute_inserts_with_no_binds |
339 | _select_args_to_query |
340 | _svp_generate_name |
341 | _multipk_update_delete |
342 | source_bind_attributes |
343 | _normalize_connect_info |
344 | _parse_connect_do |
345 | _dbh_commit |
346 | _execute_array |
347 | _placeholders_supported |
3244fdcc |
348 | savepoints |
349 | _sqlt_minimum_version |
350 | _sql_maker_opts |
351 | _conn_pid |
352 | _typeless_placeholders_supported |
353 | _conn_tid |
354 | _dbh_autocommit |
355 | _native_data_type |
356 | _get_dbh |
357 | sql_maker_class |
358 | _dbh_rollback |
359 | _adjust_select_args_for_complex_prefetch |
360 | _resolve_ident_sources |
361 | _resolve_column_info |
362 | _prune_unused_joins |
363 | _strip_cond_qualifiers |
364 | _parse_order_by |
365 | _resolve_aliastypes_from_select_args |
366 | _execute |
367 | _do_query |
368 | _dbh_sth |
369 | _dbh_execute |
6ed1cd2e |
370 | _prefetch_insert_auto_nextvals |
6d766626 |
371 | _server_info_hash |
64cdad22 |
372 | /], |
cb6ec758 |
373 | ); |
374 | |
e471ab87 |
375 | my @unimplemented = qw( |
376 | _arm_global_destructor |
377 | _preserve_foreign_dbh |
572338e0 |
378 | _verify_pid |
379 | _verify_tid |
e471ab87 |
380 | ); |
381 | |
382 | for my $method (@unimplemented) { |
383 | __PACKAGE__->meta->add_method($method, sub { |
384 | croak "$method must not be called on ".(blessed shift).' objects'; |
385 | }); |
386 | } |
6d766626 |
387 | |
b2e4d522 |
388 | has _master_connect_info_opts => |
389 | (is => 'rw', isa => HashRef, default => sub { {} }); |
390 | |
391 | =head2 around: connect_info |
392 | |
48580715 |
393 | Preserves master's C<connect_info> options (for merging with replicants.) |
394 | Also sets any Replicated-related options from connect_info, such as |
dcdf7b2c |
395 | C<pool_type>, C<pool_args>, C<balancer_type> and C<balancer_args>. |
b2e4d522 |
396 | |
397 | =cut |
398 | |
399 | around connect_info => sub { |
400 | my ($next, $self, $info, @extra) = @_; |
401 | |
0ce2d0d5 |
402 | my $wantarray = wantarray; |
403 | |
282a9a4f |
404 | my $merge = Hash::Merge->new('LEFT_PRECEDENT'); |
e666c5fd |
405 | |
b2e4d522 |
406 | my %opts; |
407 | for my $arg (@$info) { |
408 | next unless (reftype($arg)||'') eq 'HASH'; |
e666c5fd |
409 | %opts = %{ $merge->merge($arg, \%opts) }; |
b2e4d522 |
410 | } |
b2e4d522 |
411 | delete $opts{dsn}; |
412 | |
dcdf7b2c |
413 | if (@opts{qw/pool_type pool_args/}) { |
414 | $self->pool_type(delete $opts{pool_type}) |
415 | if $opts{pool_type}; |
416 | |
b88b85e7 |
417 | $self->pool_args( |
e666c5fd |
418 | $merge->merge((delete $opts{pool_args} || {}), $self->pool_args) |
b88b85e7 |
419 | ); |
dcdf7b2c |
420 | |
67c43863 |
421 | $self->pool($self->_build_pool) |
6f7344b8 |
422 | if $self->pool; |
dcdf7b2c |
423 | } |
424 | |
425 | if (@opts{qw/balancer_type balancer_args/}) { |
426 | $self->balancer_type(delete $opts{balancer_type}) |
427 | if $opts{balancer_type}; |
428 | |
b88b85e7 |
429 | $self->balancer_args( |
e666c5fd |
430 | $merge->merge((delete $opts{balancer_args} || {}), $self->balancer_args) |
b88b85e7 |
431 | ); |
dcdf7b2c |
432 | |
67c43863 |
433 | $self->balancer($self->_build_balancer) |
6f7344b8 |
434 | if $self->balancer; |
dcdf7b2c |
435 | } |
436 | |
b2e4d522 |
437 | $self->_master_connect_info_opts(\%opts); |
438 | |
0ce2d0d5 |
439 | my (@res, $res); |
440 | if ($wantarray) { |
441 | @res = $self->$next($info, @extra); |
442 | } else { |
443 | $res = $self->$next($info, @extra); |
444 | } |
445 | |
fd4eb9c2 |
446 | # Make sure master is blessed into the correct class and apply role to it. |
447 | my $master = $self->master; |
448 | $master->_determine_driver; |
449 | Moose::Meta::Class->initialize(ref $master); |
cea43436 |
450 | |
ec0946db |
451 | DBIx::Class::Storage::DBI::Replicated::WithDSN->meta->apply($master); |
cea43436 |
452 | |
453 | # link pool back to master |
454 | $self->pool->master($master); |
0ce2d0d5 |
455 | |
456 | $wantarray ? @res : $res; |
b2e4d522 |
457 | }; |
458 | |
26ab719a |
459 | =head1 METHODS |
2bf79155 |
460 | |
26ab719a |
461 | This class defines the following methods. |
2bf79155 |
462 | |
c354902c |
463 | =head2 BUILDARGS |
2bf79155 |
464 | |
faaba25f |
465 | L<DBIx::Class::Schema> when instantiating its storage passed itself as the |
2ce6e9a6 |
466 | first argument. So we need to massage the arguments a bit so that all the |
467 | bits get put into the correct places. |
2bf79155 |
468 | |
469 | =cut |
470 | |
c354902c |
471 | sub BUILDARGS { |
fd323bf1 |
472 | my ($class, $schema, $storage_type_args, @args) = @_; |
d4daee7b |
473 | |
c354902c |
474 | return { |
6f7344b8 |
475 | schema=>$schema, |
476 | %$storage_type_args, |
477 | @args |
c354902c |
478 | } |
479 | } |
2bf79155 |
480 | |
cb6ec758 |
481 | =head2 _build_master |
2bf79155 |
482 | |
cb6ec758 |
483 | Lazy builder for the L</master> attribute. |
2bf79155 |
484 | |
485 | =cut |
486 | |
cb6ec758 |
487 | sub _build_master { |
2ce6e9a6 |
488 | my $self = shift @_; |
ee356d00 |
489 | my $master = DBIx::Class::Storage::DBI->new($self->schema); |
ee356d00 |
490 | $master |
106d5f3b |
491 | } |
492 | |
26ab719a |
493 | =head2 _build_pool |
2bf79155 |
494 | |
26ab719a |
495 | Lazy builder for the L</pool> attribute. |
2bf79155 |
496 | |
497 | =cut |
498 | |
26ab719a |
499 | sub _build_pool { |
64cdad22 |
500 | my $self = shift @_; |
501 | $self->create_pool(%{$self->pool_args}); |
2bf79155 |
502 | } |
503 | |
26ab719a |
504 | =head2 _build_balancer |
2bf79155 |
505 | |
cb6ec758 |
506 | Lazy builder for the L</balancer> attribute. This takes a Pool object so that |
507 | the balancer knows which pool it's balancing. |
2bf79155 |
508 | |
509 | =cut |
510 | |
26ab719a |
511 | sub _build_balancer { |
64cdad22 |
512 | my $self = shift @_; |
513 | $self->create_balancer( |
6f7344b8 |
514 | pool=>$self->pool, |
64cdad22 |
515 | master=>$self->master, |
516 | %{$self->balancer_args}, |
517 | ); |
2bf79155 |
518 | } |
519 | |
cb6ec758 |
520 | =head2 _build_write_handler |
2bf79155 |
521 | |
cb6ec758 |
522 | Lazy builder for the L</write_handler> attribute. The default is to set this to |
523 | the L</master>. |
50336325 |
524 | |
525 | =cut |
526 | |
cb6ec758 |
527 | sub _build_write_handler { |
64cdad22 |
528 | return shift->master; |
cb6ec758 |
529 | } |
50336325 |
530 | |
cb6ec758 |
531 | =head2 _build_read_handler |
2bf79155 |
532 | |
cb6ec758 |
533 | Lazy builder for the L</read_handler> attribute. The default is to set this to |
534 | the L</balancer>. |
2bf79155 |
535 | |
536 | =cut |
537 | |
cb6ec758 |
538 | sub _build_read_handler { |
64cdad22 |
539 | return shift->balancer; |
cb6ec758 |
540 | } |
50336325 |
541 | |
cb6ec758 |
542 | =head2 around: connect_replicants |
2bf79155 |
543 | |
cb6ec758 |
544 | All calls to connect_replicants needs to have an existing $schema tacked onto |
b2e4d522 |
545 | top of the args, since L<DBIx::Storage::DBI> needs it, and any C<connect_info> |
546 | options merged with the master, with replicant opts having higher priority. |
955a6df6 |
547 | |
cb6ec758 |
548 | =cut |
955a6df6 |
549 | |
b2e4d522 |
550 | around connect_replicants => sub { |
551 | my ($next, $self, @args) = @_; |
552 | |
553 | for my $r (@args) { |
554 | $r = [ $r ] unless reftype $r eq 'ARRAY'; |
555 | |
1a58752c |
556 | $self->throw_exception('coderef replicant connect_info not supported') |
b2e4d522 |
557 | if ref $r->[0] && reftype $r->[0] eq 'CODE'; |
558 | |
559 | # any connect_info options? |
560 | my $i = 0; |
561 | $i++ while $i < @$r && (reftype($r->[$i])||'') ne 'HASH'; |
562 | |
6f7344b8 |
563 | # make one if none |
b2e4d522 |
564 | $r->[$i] = {} unless $r->[$i]; |
565 | |
566 | # merge if two hashes |
b88b85e7 |
567 | my @hashes = @$r[$i .. $#{$r}]; |
568 | |
1a58752c |
569 | $self->throw_exception('invalid connect_info options') |
b88b85e7 |
570 | if (grep { reftype($_) eq 'HASH' } @hashes) != @hashes; |
571 | |
1a58752c |
572 | $self->throw_exception('too many hashrefs in connect_info') |
b88b85e7 |
573 | if @hashes > 2; |
574 | |
282a9a4f |
575 | my $merge = Hash::Merge->new('LEFT_PRECEDENT'); |
e666c5fd |
576 | my %opts = %{ $merge->merge(reverse @hashes) }; |
b88b85e7 |
577 | |
578 | # delete them |
b2e4d522 |
579 | splice @$r, $i+1, ($#{$r} - $i), (); |
580 | |
0bd8e058 |
581 | # make sure master/replicants opts don't clash |
582 | my %master_opts = %{ $self->_master_connect_info_opts }; |
583 | if (exists $opts{dbh_maker}) { |
584 | delete @master_opts{qw/dsn user password/}; |
585 | } |
586 | delete $master_opts{dbh_maker}; |
587 | |
b2e4d522 |
588 | # merge with master |
e666c5fd |
589 | %opts = %{ $merge->merge(\%opts, \%master_opts) }; |
b2e4d522 |
590 | |
591 | # update |
592 | $r->[$i] = \%opts; |
593 | } |
594 | |
595 | $self->$next($self->schema, @args); |
955a6df6 |
596 | }; |
2bf79155 |
597 | |
2bf79155 |
598 | =head2 all_storages |
599 | |
600 | Returns an array of of all the connected storage backends. The first element |
601 | in the returned array is the master, and the remainings are each of the |
602 | replicants. |
603 | |
604 | =cut |
605 | |
606 | sub all_storages { |
64cdad22 |
607 | my $self = shift @_; |
608 | return grep {defined $_ && blessed $_} ( |
609 | $self->master, |
6412a592 |
610 | values %{ $self->replicants }, |
64cdad22 |
611 | ); |
2bf79155 |
612 | } |
613 | |
c4d3fae2 |
614 | =head2 execute_reliably ($coderef, ?@args) |
615 | |
616 | Given a coderef, saves the current state of the L</read_handler>, forces it to |
48580715 |
617 | use reliable storage (e.g. sets it to the master), executes a coderef and then |
c4d3fae2 |
618 | restores the original state. |
619 | |
620 | Example: |
621 | |
64cdad22 |
622 | my $reliably = sub { |
623 | my $name = shift @_; |
624 | $schema->resultset('User')->create({name=>$name}); |
fd323bf1 |
625 | my $user_rs = $schema->resultset('User')->find({name=>$name}); |
64cdad22 |
626 | return $user_rs; |
627 | }; |
c4d3fae2 |
628 | |
64cdad22 |
629 | my $user_rs = $schema->storage->execute_reliably($reliably, 'John'); |
c4d3fae2 |
630 | |
631 | Use this when you must be certain of your database state, such as when you just |
632 | inserted something and need to get a resultset including it, etc. |
633 | |
634 | =cut |
635 | |
636 | sub execute_reliably { |
64cdad22 |
637 | my ($self, $coderef, @args) = @_; |
d4daee7b |
638 | |
64cdad22 |
639 | unless( ref $coderef eq 'CODE') { |
640 | $self->throw_exception('Second argument must be a coderef'); |
641 | } |
d4daee7b |
642 | |
64cdad22 |
643 | ##Get copy of master storage |
644 | my $master = $self->master; |
d4daee7b |
645 | |
64cdad22 |
646 | ##Get whatever the current read hander is |
647 | my $current = $self->read_handler; |
d4daee7b |
648 | |
64cdad22 |
649 | ##Set the read handler to master |
650 | $self->read_handler($master); |
d4daee7b |
651 | |
64cdad22 |
652 | ## do whatever the caller needs |
653 | my @result; |
654 | my $want_array = wantarray; |
d4daee7b |
655 | |
ed7ab0f4 |
656 | try { |
64cdad22 |
657 | if($want_array) { |
658 | @result = $coderef->(@args); |
659 | } elsif(defined $want_array) { |
660 | ($result[0]) = ($coderef->(@args)); |
ed213e85 |
661 | } else { |
64cdad22 |
662 | $coderef->(@args); |
6f7344b8 |
663 | } |
ed7ab0f4 |
664 | } catch { |
665 | $self->throw_exception("coderef returned an error: $_"); |
666 | } finally { |
667 | ##Reset to the original state |
668 | $self->read_handler($current); |
64cdad22 |
669 | }; |
d4daee7b |
670 | |
ed7ab0f4 |
671 | return $want_array ? @result : $result[0]; |
c4d3fae2 |
672 | } |
673 | |
cb6ec758 |
674 | =head2 set_reliable_storage |
675 | |
676 | Sets the current $schema to be 'reliable', that is all queries, both read and |
677 | write are sent to the master |
d4daee7b |
678 | |
cb6ec758 |
679 | =cut |
680 | |
681 | sub set_reliable_storage { |
64cdad22 |
682 | my $self = shift @_; |
683 | my $schema = $self->schema; |
684 | my $write_handler = $self->schema->storage->write_handler; |
d4daee7b |
685 | |
64cdad22 |
686 | $schema->storage->read_handler($write_handler); |
cb6ec758 |
687 | } |
688 | |
689 | =head2 set_balanced_storage |
690 | |
691 | Sets the current $schema to be use the </balancer> for all reads, while all |
48580715 |
692 | writes are sent to the master only |
d4daee7b |
693 | |
cb6ec758 |
694 | =cut |
695 | |
696 | sub set_balanced_storage { |
64cdad22 |
697 | my $self = shift @_; |
698 | my $schema = $self->schema; |
bd5da369 |
699 | my $balanced_handler = $self->schema->storage->balancer; |
d4daee7b |
700 | |
bd5da369 |
701 | $schema->storage->read_handler($balanced_handler); |
cb6ec758 |
702 | } |
2bf79155 |
703 | |
704 | =head2 connected |
705 | |
706 | Check that the master and at least one of the replicants is connected. |
707 | |
708 | =cut |
709 | |
710 | sub connected { |
64cdad22 |
711 | my $self = shift @_; |
712 | return |
713 | $self->master->connected && |
714 | $self->pool->connected_replicants; |
2bf79155 |
715 | } |
716 | |
2bf79155 |
717 | =head2 ensure_connected |
718 | |
719 | Make sure all the storages are connected. |
720 | |
721 | =cut |
722 | |
723 | sub ensure_connected { |
64cdad22 |
724 | my $self = shift @_; |
725 | foreach my $source ($self->all_storages) { |
726 | $source->ensure_connected(@_); |
727 | } |
2bf79155 |
728 | } |
729 | |
2bf79155 |
730 | =head2 limit_dialect |
731 | |
732 | Set the limit_dialect for all existing storages |
733 | |
734 | =cut |
735 | |
736 | sub limit_dialect { |
64cdad22 |
737 | my $self = shift @_; |
738 | foreach my $source ($self->all_storages) { |
739 | $source->limit_dialect(@_); |
740 | } |
3fbe08e3 |
741 | return $self->master->quote_char; |
2bf79155 |
742 | } |
743 | |
2bf79155 |
744 | =head2 quote_char |
745 | |
746 | Set the quote_char for all existing storages |
747 | |
748 | =cut |
749 | |
750 | sub quote_char { |
64cdad22 |
751 | my $self = shift @_; |
752 | foreach my $source ($self->all_storages) { |
753 | $source->quote_char(@_); |
754 | } |
3fbe08e3 |
755 | return $self->master->quote_char; |
2bf79155 |
756 | } |
757 | |
2bf79155 |
758 | =head2 name_sep |
759 | |
760 | Set the name_sep for all existing storages |
761 | |
762 | =cut |
763 | |
764 | sub name_sep { |
64cdad22 |
765 | my $self = shift @_; |
766 | foreach my $source ($self->all_storages) { |
767 | $source->name_sep(@_); |
768 | } |
3fbe08e3 |
769 | return $self->master->name_sep; |
2bf79155 |
770 | } |
771 | |
2bf79155 |
772 | =head2 set_schema |
773 | |
774 | Set the schema object for all existing storages |
775 | |
776 | =cut |
777 | |
778 | sub set_schema { |
64cdad22 |
779 | my $self = shift @_; |
780 | foreach my $source ($self->all_storages) { |
781 | $source->set_schema(@_); |
782 | } |
2bf79155 |
783 | } |
784 | |
2bf79155 |
785 | =head2 debug |
786 | |
787 | set a debug flag across all storages |
788 | |
789 | =cut |
790 | |
791 | sub debug { |
64cdad22 |
792 | my $self = shift @_; |
3fbe08e3 |
793 | if(@_) { |
794 | foreach my $source ($self->all_storages) { |
795 | $source->debug(@_); |
6f7344b8 |
796 | } |
64cdad22 |
797 | } |
3fbe08e3 |
798 | return $self->master->debug; |
2bf79155 |
799 | } |
800 | |
2bf79155 |
801 | =head2 debugobj |
802 | |
cea43436 |
803 | set a debug object |
2bf79155 |
804 | |
805 | =cut |
806 | |
807 | sub debugobj { |
64cdad22 |
808 | my $self = shift @_; |
cea43436 |
809 | return $self->master->debugobj(@_); |
2bf79155 |
810 | } |
811 | |
2bf79155 |
812 | =head2 debugfh |
813 | |
cea43436 |
814 | set a debugfh object |
2bf79155 |
815 | |
816 | =cut |
817 | |
818 | sub debugfh { |
64cdad22 |
819 | my $self = shift @_; |
cea43436 |
820 | return $self->master->debugfh(@_); |
2bf79155 |
821 | } |
822 | |
2bf79155 |
823 | =head2 debugcb |
824 | |
cea43436 |
825 | set a debug callback |
2bf79155 |
826 | |
827 | =cut |
828 | |
829 | sub debugcb { |
64cdad22 |
830 | my $self = shift @_; |
cea43436 |
831 | return $self->master->debugcb(@_); |
2bf79155 |
832 | } |
833 | |
2bf79155 |
834 | =head2 disconnect |
835 | |
836 | disconnect everything |
837 | |
838 | =cut |
839 | |
840 | sub disconnect { |
64cdad22 |
841 | my $self = shift @_; |
842 | foreach my $source ($self->all_storages) { |
843 | $source->disconnect(@_); |
844 | } |
2bf79155 |
845 | } |
846 | |
b2e4d522 |
847 | =head2 cursor_class |
848 | |
849 | set cursor class on all storages, or return master's |
850 | |
851 | =cut |
852 | |
853 | sub cursor_class { |
854 | my ($self, $cursor_class) = @_; |
855 | |
856 | if ($cursor_class) { |
857 | $_->cursor_class($cursor_class) for $self->all_storages; |
858 | } |
859 | $self->master->cursor_class; |
860 | } |
d4daee7b |
861 | |
3244fdcc |
862 | =head2 cursor |
863 | |
864 | set cursor class on all storages, or return master's, alias for L</cursor_class> |
865 | above. |
866 | |
867 | =cut |
868 | |
869 | sub cursor { |
870 | my ($self, $cursor_class) = @_; |
871 | |
872 | if ($cursor_class) { |
873 | $_->cursor($cursor_class) for $self->all_storages; |
874 | } |
875 | $self->master->cursor; |
876 | } |
877 | |
878 | =head2 unsafe |
879 | |
880 | sets the L<DBIx::Class::Storage::DBI/unsafe> option on all storages or returns |
881 | master's current setting |
882 | |
883 | =cut |
884 | |
885 | sub unsafe { |
886 | my $self = shift; |
887 | |
888 | if (@_) { |
889 | $_->unsafe(@_) for $self->all_storages; |
890 | } |
891 | |
892 | return $self->master->unsafe; |
893 | } |
894 | |
895 | =head2 disable_sth_caching |
896 | |
897 | sets the L<DBIx::Class::Storage::DBI/disable_sth_caching> option on all storages |
898 | or returns master's current setting |
899 | |
900 | =cut |
901 | |
902 | sub disable_sth_caching { |
903 | my $self = shift; |
904 | |
905 | if (@_) { |
906 | $_->disable_sth_caching(@_) for $self->all_storages; |
907 | } |
908 | |
909 | return $self->master->disable_sth_caching; |
910 | } |
911 | |
912 | =head2 lag_behind_master |
913 | |
914 | returns the highest Replicant L<DBIx::Class::Storage::DBI/lag_behind_master> |
915 | setting |
916 | |
917 | =cut |
918 | |
919 | sub lag_behind_master { |
920 | my $self = shift; |
921 | |
922 | return max map $_->lag_behind_master, $self->replicants; |
fd323bf1 |
923 | } |
3244fdcc |
924 | |
925 | =head2 is_replicating |
926 | |
927 | returns true if all replicants return true for |
928 | L<DBIx::Class::Storage::DBI/is_replicating> |
929 | |
930 | =cut |
931 | |
932 | sub is_replicating { |
933 | my $self = shift; |
934 | |
935 | return (grep $_->is_replicating, $self->replicants) == ($self->replicants); |
936 | } |
937 | |
938 | =head2 connect_call_datetime_setup |
939 | |
940 | calls L<DBIx::Class::Storage::DBI/connect_call_datetime_setup> for all storages |
941 | |
942 | =cut |
943 | |
944 | sub connect_call_datetime_setup { |
945 | my $self = shift; |
946 | $_->connect_call_datetime_setup for $self->all_storages; |
947 | } |
948 | |
949 | sub _populate_dbh { |
950 | my $self = shift; |
951 | $_->_populate_dbh for $self->all_storages; |
952 | } |
953 | |
954 | sub _connect { |
955 | my $self = shift; |
956 | $_->_connect for $self->all_storages; |
957 | } |
958 | |
959 | sub _rebless { |
960 | my $self = shift; |
961 | $_->_rebless for $self->all_storages; |
962 | } |
963 | |
964 | sub _determine_driver { |
965 | my $self = shift; |
966 | $_->_determine_driver for $self->all_storages; |
967 | } |
968 | |
969 | sub _driver_determined { |
970 | my $self = shift; |
fd323bf1 |
971 | |
3244fdcc |
972 | if (@_) { |
973 | $_->_driver_determined(@_) for $self->all_storages; |
974 | } |
975 | |
976 | return $self->master->_driver_determined; |
977 | } |
978 | |
979 | sub _init { |
980 | my $self = shift; |
fd323bf1 |
981 | |
3244fdcc |
982 | $_->_init for $self->all_storages; |
983 | } |
984 | |
985 | sub _run_connection_actions { |
986 | my $self = shift; |
fd323bf1 |
987 | |
3244fdcc |
988 | $_->_run_connection_actions for $self->all_storages; |
989 | } |
990 | |
991 | sub _do_connection_actions { |
992 | my $self = shift; |
fd323bf1 |
993 | |
3244fdcc |
994 | if (@_) { |
995 | $_->_do_connection_actions(@_) for $self->all_storages; |
996 | } |
997 | } |
998 | |
999 | sub connect_call_do_sql { |
1000 | my $self = shift; |
1001 | $_->connect_call_do_sql(@_) for $self->all_storages; |
1002 | } |
1003 | |
1004 | sub disconnect_call_do_sql { |
1005 | my $self = shift; |
1006 | $_->disconnect_call_do_sql(@_) for $self->all_storages; |
1007 | } |
1008 | |
1009 | sub _seems_connected { |
1010 | my $self = shift; |
1011 | |
1012 | return min map $_->_seems_connected, $self->all_storages; |
1013 | } |
1014 | |
1015 | sub _ping { |
1016 | my $self = shift; |
1017 | |
1018 | return min map $_->_ping, $self->all_storages; |
1019 | } |
1020 | |
7da56142 |
1021 | my $numify_ver = sub { |
1022 | my $ver = shift; |
1023 | my @numparts = split /\D+/, $ver; |
1024 | my $format = '%d.' . (join '', ('%05d') x (@numparts - 1)); |
1025 | |
1026 | return sprintf $format, @numparts; |
1027 | }; |
1028 | |
fecb38cb |
1029 | sub _server_info { |
1030 | my $self = shift; |
1031 | |
1032 | if (not $self->_server_info_hash) { |
7da56142 |
1033 | my $min_version_info = ( |
fd323bf1 |
1034 | reduce { $a->[0] < $b->[0] ? $a : $b } |
7da56142 |
1035 | map [ $numify_ver->($_->{dbms_version}), $_ ], |
1036 | map $_->_server_info, $self->all_storages |
1037 | )->[1]; |
fecb38cb |
1038 | |
1039 | $self->_server_info_hash($min_version_info); # on master |
1040 | } |
1041 | |
1042 | return $self->_server_info_hash; |
1043 | } |
1044 | |
1045 | sub _get_server_version { |
1046 | my $self = shift; |
1047 | |
1048 | return $self->_server_info->{dbms_version}; |
1049 | } |
1050 | |
7e38d850 |
1051 | =head1 GOTCHAS |
1052 | |
1053 | Due to the fact that replicants can lag behind a master, you must take care to |
1054 | make sure you use one of the methods to force read queries to a master should |
1055 | you need realtime data integrity. For example, if you insert a row, and then |
1056 | immediately re-read it from the database (say, by doing $row->discard_changes) |
1057 | or you insert a row and then immediately build a query that expects that row |
1058 | to be an item, you should force the master to handle reads. Otherwise, due to |
1059 | the lag, there is no certainty your data will be in the expected state. |
1060 | |
1061 | For data integrity, all transactions automatically use the master storage for |
1062 | all read and write queries. Using a transaction is the preferred and recommended |
1063 | method to force the master to handle all read queries. |
1064 | |
1065 | Otherwise, you can force a single query to use the master with the 'force_pool' |
1066 | attribute: |
1067 | |
1068 | my $row = $resultset->search(undef, {force_pool=>'master'})->find($pk); |
1069 | |
1070 | This attribute will safely be ignore by non replicated storages, so you can use |
1071 | the same code for both types of systems. |
1072 | |
1073 | Lastly, you can use the L</execute_reliably> method, which works very much like |
1074 | a transaction. |
1075 | |
1076 | For debugging, you can turn replication on/off with the methods L</set_reliable_storage> |
1077 | and L</set_balanced_storage>, however this operates at a global level and is not |
1078 | suitable if you have a shared Schema object being used by multiple processes, |
1079 | such as on a web application server. You can get around this limitation by |
1080 | using the Schema clone method. |
1081 | |
1082 | my $new_schema = $schema->clone; |
1083 | $new_schema->set_reliable_storage; |
d4daee7b |
1084 | |
7e38d850 |
1085 | ## $new_schema will use only the Master storage for all reads/writes while |
1086 | ## the $schema object will use replicated storage. |
1087 | |
f5d3a5de |
1088 | =head1 AUTHOR |
1089 | |
64cdad22 |
1090 | John Napiorkowski <john.napiorkowski@takkle.com> |
f5d3a5de |
1091 | |
c4d3fae2 |
1092 | Based on code originated by: |
f5d3a5de |
1093 | |
64cdad22 |
1094 | Norbert Csongrádi <bert@cpan.org> |
1095 | Peter Siklósi <einon@einon.hu> |
2156bbdd |
1096 | |
f5d3a5de |
1097 | =head1 LICENSE |
1098 | |
1099 | You may distribute this code under the same terms as Perl itself. |
1100 | |
1101 | =cut |
1102 | |
c354902c |
1103 | __PACKAGE__->meta->make_immutable; |
1104 | |
f5d3a5de |
1105 | 1; |