Commit | Line | Data |
2156bbdd |
1 | package DBIx::Class::Storage::DBI::Replicated; |
f5d3a5de |
2 | |
ecb65397 |
3 | BEGIN { |
a34b0c89 |
4 | use DBIx::Class; |
70c28808 |
5 | die('The following modules are required for Replication ' . DBIx::Class::Optional::Dependencies->req_missing_for ('replicated') . "\n" ) |
a34b0c89 |
6 | unless DBIx::Class::Optional::Dependencies->req_ok_for ('replicated'); |
ecb65397 |
7 | } |
8 | |
b2e4d522 |
9 | use Moose; |
26ab719a |
10 | use DBIx::Class::Storage::DBI; |
2bf79155 |
11 | use DBIx::Class::Storage::DBI::Replicated::Pool; |
26ab719a |
12 | use DBIx::Class::Storage::DBI::Replicated::Balancer; |
6a151f58 |
13 | use DBIx::Class::Storage::DBI::Replicated::Types qw/BalancerClassNamePart DBICSchema DBICStorageDBI/; |
41916570 |
14 | use MooseX::Types::Moose qw/ClassName HashRef Object/; |
b2e4d522 |
15 | use Scalar::Util 'reftype'; |
e666c5fd |
16 | use Hash::Merge; |
7da56142 |
17 | use List::Util qw/min max reduce/; |
ed7ab0f4 |
18 | use Try::Tiny; |
fd323bf1 |
19 | use namespace::clean; |
9901aad7 |
20 | |
21 | use namespace::clean -except => 'meta'; |
2bf79155 |
22 | |
23 | =head1 NAME |
24 | |
ecb65397 |
25 | DBIx::Class::Storage::DBI::Replicated - BETA Replicated database support |
2bf79155 |
26 | |
27 | =head1 SYNOPSIS |
28 | |
29 | The Following example shows how to change an existing $schema to a replicated |
48580715 |
30 | storage type, add some replicated (read-only) databases, and perform reporting |
955a6df6 |
31 | tasks. |
2bf79155 |
32 | |
3da4f736 |
33 | You should set the 'storage_type attribute to a replicated type. You should |
d4daee7b |
34 | also define your arguments, such as which balancer you want and any arguments |
3da4f736 |
35 | that the Pool object should get. |
36 | |
ce854fd3 |
37 | my $schema = Schema::Class->clone; |
64cdad22 |
38 | $schema->storage_type( ['::DBI::Replicated', {balancer=>'::Random'}] ); |
ce854fd3 |
39 | $schema->connection(...); |
d4daee7b |
40 | |
fd323bf1 |
41 | Next, you need to add in the Replicants. Basically this is an array of |
3da4f736 |
42 | arrayrefs, where each arrayref is database connect information. Think of these |
43 | arguments as what you'd pass to the 'normal' $schema->connect method. |
d4daee7b |
44 | |
64cdad22 |
45 | $schema->storage->connect_replicants( |
46 | [$dsn1, $user, $pass, \%opts], |
47 | [$dsn2, $user, $pass, \%opts], |
48 | [$dsn3, $user, $pass, \%opts], |
49 | ); |
d4daee7b |
50 | |
3da4f736 |
51 | Now, just use the $schema as you normally would. Automatically all reads will |
52 | be delegated to the replicants, while writes to the master. |
53 | |
7e38d850 |
54 | $schema->resultset('Source')->search({name=>'etc'}); |
d4daee7b |
55 | |
3da4f736 |
56 | You can force a given query to use a particular storage using the search |
57 | attribute 'force_pool'. For example: |
d4daee7b |
58 | |
7e38d850 |
59 | my $RS = $schema->resultset('Source')->search(undef, {force_pool=>'master'}); |
3da4f736 |
60 | |
61 | Now $RS will force everything (both reads and writes) to use whatever was setup |
fd323bf1 |
62 | as the master storage. 'master' is hardcoded to always point to the Master, |
3da4f736 |
63 | but you can also use any Replicant name. Please see: |
212cc5c2 |
64 | L<DBIx::Class::Storage::DBI::Replicated::Pool> and the replicants attribute for more. |
3da4f736 |
65 | |
66 | Also see transactions and L</execute_reliably> for alternative ways to |
67 | force read traffic to the master. In general, you should wrap your statements |
68 | in a transaction when you are reading and writing to the same tables at the |
69 | same time, since your replicants will often lag a bit behind the master. |
212cc5c2 |
70 | |
71 | See L<DBIx::Class::Storage::DBI::Replicated::Instructions> for more help and |
72 | walkthroughs. |
d4daee7b |
73 | |
2bf79155 |
74 | =head1 DESCRIPTION |
75 | |
7e38d850 |
76 | Warning: This class is marked BETA. This has been running a production |
ccb3b897 |
77 | website using MySQL native replication as its backend and we have some decent |
7e38d850 |
78 | test coverage but the code hasn't yet been stressed by a variety of databases. |
48580715 |
79 | Individual DBs may have quirks we are not aware of. Please use this in first |
7e38d850 |
80 | development and pass along your experiences/bug fixes. |
2bf79155 |
81 | |
82 | This class implements replicated data store for DBI. Currently you can define |
83 | one master and numerous slave database connections. All write-type queries |
84 | (INSERT, UPDATE, DELETE and even LAST_INSERT_ID) are routed to master |
85 | database, all read-type queries (SELECTs) go to the slave database. |
86 | |
87 | Basically, any method request that L<DBIx::Class::Storage::DBI> would normally |
bca099a3 |
88 | handle gets delegated to one of the two attributes: L</read_handler> or to |
89 | L</write_handler>. Additionally, some methods need to be distributed |
2bf79155 |
90 | to all existing storages. This way our storage class is a drop in replacement |
91 | for L<DBIx::Class::Storage::DBI>. |
92 | |
48580715 |
93 | Read traffic is spread across the replicants (slaves) occurring to a user |
2bf79155 |
94 | selected algorithm. The default algorithm is random weighted. |
95 | |
bca099a3 |
96 | =head1 NOTES |
97 | |
48580715 |
98 | The consistency between master and replicants is database specific. The Pool |
faaba25f |
99 | gives you a method to validate its replicants, removing and replacing them |
7e38d850 |
100 | when they fail/pass predefined criteria. Please make careful use of the ways |
ecb65397 |
101 | to force a query to run against Master when needed. |
102 | |
103 | =head1 REQUIREMENTS |
104 | |
a34b0c89 |
105 | Replicated Storage has additional requirements not currently part of |
aa8b2277 |
106 | L<DBIx::Class>. See L<DBIx::Class::Optional::Dependencies> for more details. |
2bf79155 |
107 | |
108 | =head1 ATTRIBUTES |
109 | |
110 | This class defines the following attributes. |
111 | |
2ce6e9a6 |
112 | =head2 schema |
113 | |
114 | The underlying L<DBIx::Class::Schema> object this storage is attaching |
115 | |
116 | =cut |
117 | |
118 | has 'schema' => ( |
119 | is=>'rw', |
6a151f58 |
120 | isa=>DBICSchema, |
2ce6e9a6 |
121 | weak_ref=>1, |
122 | required=>1, |
123 | ); |
124 | |
26ab719a |
125 | =head2 pool_type |
2bf79155 |
126 | |
fd323bf1 |
127 | Contains the classname which will instantiate the L</pool> object. Defaults |
26ab719a |
128 | to: L<DBIx::Class::Storage::DBI::Replicated::Pool>. |
2bf79155 |
129 | |
130 | =cut |
131 | |
26ab719a |
132 | has 'pool_type' => ( |
dcdf7b2c |
133 | is=>'rw', |
41916570 |
134 | isa=>ClassName, |
2ce6e9a6 |
135 | default=>'DBIx::Class::Storage::DBI::Replicated::Pool', |
64cdad22 |
136 | handles=>{ |
137 | 'create_pool' => 'new', |
138 | }, |
2bf79155 |
139 | ); |
140 | |
f068a139 |
141 | =head2 pool_args |
142 | |
143 | Contains a hashref of initialized information to pass to the Balancer object. |
212cc5c2 |
144 | See L<DBIx::Class::Storage::DBI::Replicated::Pool> for available arguments. |
f068a139 |
145 | |
146 | =cut |
147 | |
148 | has 'pool_args' => ( |
dcdf7b2c |
149 | is=>'rw', |
41916570 |
150 | isa=>HashRef, |
64cdad22 |
151 | lazy=>1, |
64cdad22 |
152 | default=>sub { {} }, |
f068a139 |
153 | ); |
154 | |
155 | |
26ab719a |
156 | =head2 balancer_type |
2bf79155 |
157 | |
158 | The replication pool requires a balance class to provider the methods for |
159 | choose how to spread the query load across each replicant in the pool. |
160 | |
161 | =cut |
162 | |
26ab719a |
163 | has 'balancer_type' => ( |
dcdf7b2c |
164 | is=>'rw', |
9901aad7 |
165 | isa=>BalancerClassNamePart, |
2ce6e9a6 |
166 | coerce=>1, |
167 | required=>1, |
168 | default=> 'DBIx::Class::Storage::DBI::Replicated::Balancer::First', |
64cdad22 |
169 | handles=>{ |
170 | 'create_balancer' => 'new', |
171 | }, |
2bf79155 |
172 | ); |
173 | |
17b05c13 |
174 | =head2 balancer_args |
175 | |
176 | Contains a hashref of initialized information to pass to the Balancer object. |
212cc5c2 |
177 | See L<DBIx::Class::Storage::DBI::Replicated::Balancer> for available arguments. |
17b05c13 |
178 | |
179 | =cut |
180 | |
181 | has 'balancer_args' => ( |
dcdf7b2c |
182 | is=>'rw', |
41916570 |
183 | isa=>HashRef, |
64cdad22 |
184 | lazy=>1, |
185 | required=>1, |
186 | default=>sub { {} }, |
17b05c13 |
187 | ); |
188 | |
26ab719a |
189 | =head2 pool |
2bf79155 |
190 | |
370f78d4 |
191 | Is a L<DBIx::Class::Storage::DBI::Replicated::Pool> or derived class. This is a |
26ab719a |
192 | container class for one or more replicated databases. |
2bf79155 |
193 | |
194 | =cut |
195 | |
26ab719a |
196 | has 'pool' => ( |
64cdad22 |
197 | is=>'ro', |
198 | isa=>'DBIx::Class::Storage::DBI::Replicated::Pool', |
199 | lazy_build=>1, |
200 | handles=>[qw/ |
6f7344b8 |
201 | connect_replicants |
64cdad22 |
202 | replicants |
203 | has_replicants |
204 | /], |
2bf79155 |
205 | ); |
206 | |
26ab719a |
207 | =head2 balancer |
2bf79155 |
208 | |
370f78d4 |
209 | Is a L<DBIx::Class::Storage::DBI::Replicated::Balancer> or derived class. This |
210 | is a class that takes a pool (L<DBIx::Class::Storage::DBI::Replicated::Pool>) |
2bf79155 |
211 | |
26ab719a |
212 | =cut |
2bf79155 |
213 | |
26ab719a |
214 | has 'balancer' => ( |
dcdf7b2c |
215 | is=>'rw', |
64cdad22 |
216 | isa=>'DBIx::Class::Storage::DBI::Replicated::Balancer', |
217 | lazy_build=>1, |
218 | handles=>[qw/auto_validate_every/], |
26ab719a |
219 | ); |
2bf79155 |
220 | |
cb6ec758 |
221 | =head2 master |
222 | |
223 | The master defines the canonical state for a pool of connected databases. All |
224 | the replicants are expected to match this databases state. Thus, in a classic |
225 | Master / Slaves distributed system, all the slaves are expected to replicate |
226 | the Master's state as quick as possible. This is the only database in the |
227 | pool of databases that is allowed to handle write traffic. |
228 | |
229 | =cut |
230 | |
231 | has 'master' => ( |
64cdad22 |
232 | is=> 'ro', |
6a151f58 |
233 | isa=>DBICStorageDBI, |
64cdad22 |
234 | lazy_build=>1, |
cb6ec758 |
235 | ); |
236 | |
cb6ec758 |
237 | =head1 ATTRIBUTES IMPLEMENTING THE DBIx::Storage::DBI INTERFACE |
238 | |
fd323bf1 |
239 | The following methods are delegated all the methods required for the |
cb6ec758 |
240 | L<DBIx::Class::Storage::DBI> interface. |
241 | |
cb6ec758 |
242 | =cut |
243 | |
4bea1fe7 |
244 | my $method_dispatch = { |
245 | writer => [qw/ |
64cdad22 |
246 | on_connect_do |
6f7344b8 |
247 | on_disconnect_do |
3244fdcc |
248 | on_connect_call |
249 | on_disconnect_call |
64cdad22 |
250 | connect_info |
3244fdcc |
251 | _connect_info |
64cdad22 |
252 | throw_exception |
253 | sql_maker |
254 | sqlt_type |
255 | create_ddl_dir |
256 | deployment_statements |
257 | datetime_parser |
6f7344b8 |
258 | datetime_parser_type |
259 | build_datetime_parser |
64cdad22 |
260 | last_insert_id |
261 | insert |
262 | insert_bulk |
263 | update |
264 | delete |
265 | dbh |
2ce6e9a6 |
266 | txn_begin |
64cdad22 |
267 | txn_do |
268 | txn_commit |
269 | txn_rollback |
2ce6e9a6 |
270 | txn_scope_guard |
64cdad22 |
271 | deploy |
0180bef9 |
272 | with_deferred_fk_checks |
6f7344b8 |
273 | dbh_do |
2ce6e9a6 |
274 | _prep_for_execute |
6f7344b8 |
275 | is_datatype_numeric |
276 | _count_select |
6f7344b8 |
277 | _subq_update_delete |
278 | svp_rollback |
279 | svp_begin |
280 | svp_release |
e398f77e |
281 | relname_to_table_alias |
3244fdcc |
282 | _dbh_last_insert_id |
3244fdcc |
283 | _default_dbi_connect_attributes |
284 | _dbi_connect_info |
b9ca4ff1 |
285 | _dbic_connect_attributes |
3244fdcc |
286 | auto_savepoint |
0e773352 |
287 | _query_start |
3244fdcc |
288 | _query_end |
0e773352 |
289 | _format_for_trace |
290 | _dbi_attrs_for_bind |
3244fdcc |
291 | bind_attribute_by_data_type |
292 | transaction_depth |
293 | _dbh |
294 | _select_args |
295 | _dbh_execute_array |
3244fdcc |
296 | _sql_maker |
3244fdcc |
297 | _per_row_update_delete |
298 | _dbh_begin_work |
299 | _dbh_execute_inserts_with_no_binds |
300 | _select_args_to_query |
301 | _svp_generate_name |
302 | _multipk_update_delete |
3244fdcc |
303 | _normalize_connect_info |
304 | _parse_connect_do |
305 | _dbh_commit |
306 | _execute_array |
3244fdcc |
307 | savepoints |
3244fdcc |
308 | _sql_maker_opts |
309 | _conn_pid |
3244fdcc |
310 | _dbh_autocommit |
311 | _native_data_type |
312 | _get_dbh |
313 | sql_maker_class |
314 | _dbh_rollback |
315 | _adjust_select_args_for_complex_prefetch |
316 | _resolve_ident_sources |
317 | _resolve_column_info |
318 | _prune_unused_joins |
319 | _strip_cond_qualifiers |
61f031bf |
320 | _strip_cond_qualifiers_from_array |
3244fdcc |
321 | _resolve_aliastypes_from_select_args |
322 | _execute |
323 | _do_query |
402ac1c9 |
324 | _sth |
3244fdcc |
325 | _dbh_sth |
326 | _dbh_execute |
64cdad22 |
327 | /], |
4bea1fe7 |
328 | reader => [qw/ |
329 | select |
330 | select_single |
331 | columns_info_for |
332 | _dbh_columns_info_for |
333 | _select |
334 | /], |
335 | unimplemented => [qw/ |
336 | _arm_global_destructor |
337 | _verify_pid |
338 | |
0e773352 |
339 | source_bind_attributes |
340 | |
4bea1fe7 |
341 | get_use_dbms_capability |
342 | set_use_dbms_capability |
343 | get_dbms_capability |
344 | set_dbms_capability |
345 | _dbh_details |
346 | _dbh_get_info |
347 | |
348 | sql_limit_dialect |
349 | sql_quote_char |
350 | sql_name_sep |
351 | |
352 | _inner_join_to_node |
353 | _group_over_selection |
354 | _extract_order_criteria |
355 | |
356 | _prefetch_autovalues |
357 | |
358 | _max_column_bytesize |
359 | _is_lob_type |
360 | _is_binary_lob_type |
361 | _is_text_lob_type |
402ac1c9 |
362 | |
363 | sth |
4bea1fe7 |
364 | /,( |
365 | # the capability framework |
366 | # not sure if CMOP->initialize does evil things to DBIC::S::DBI, fix if a problem |
367 | grep |
368 | { $_ =~ /^ _ (?: use | supports | determine_supports ) _ /x } |
369 | ( Class::MOP::Class->initialize('DBIx::Class::Storage::DBI')->get_all_method_names ) |
370 | )], |
371 | }; |
372 | |
373 | if (DBIx::Class::_ENV_::DBICTEST) { |
374 | |
375 | my $seen; |
376 | for my $type (keys %$method_dispatch) { |
377 | for (@{$method_dispatch->{$type}}) { |
378 | push @{$seen->{$_}}, $type; |
379 | } |
380 | } |
cb6ec758 |
381 | |
4bea1fe7 |
382 | if (my @dupes = grep { @{$seen->{$_}} > 1 } keys %$seen) { |
383 | die(join "\n", '', |
384 | 'The following methods show up multiple times in ::Storage::DBI::Replicated handlers:', |
385 | (map { "$_: " . (join ', ', @{$seen->{$_}}) } sort @dupes), |
386 | '', |
387 | ); |
388 | } |
bbdda281 |
389 | |
4bea1fe7 |
390 | if (my @cant = grep { ! DBIx::Class::Storage::DBI->can($_) } keys %$seen) { |
391 | die(join "\n", '', |
392 | '::Storage::DBI::Replicated specifies handling of the following *NON EXISTING* ::Storage::DBI methods:', |
393 | @cant, |
394 | '', |
395 | ); |
396 | } |
397 | } |
bbdda281 |
398 | |
4bea1fe7 |
399 | for my $method (@{$method_dispatch->{unimplemented}}) { |
400 | __PACKAGE__->meta->add_method($method, sub { |
70c28808 |
401 | my $self = shift; |
402 | $self->throw_exception("$method must not be called on ".(blessed $self).' objects'); |
4bea1fe7 |
403 | }); |
404 | } |
31a8aaaf |
405 | |
4bea1fe7 |
406 | =head2 read_handler |
584ea6e4 |
407 | |
4bea1fe7 |
408 | Defines an object that implements the read side of L<BIx::Class::Storage::DBI>. |
584ea6e4 |
409 | |
4bea1fe7 |
410 | =cut |
411 | |
412 | has 'read_handler' => ( |
413 | is=>'rw', |
414 | isa=>Object, |
415 | lazy_build=>1, |
416 | handles=>$method_dispatch->{reader}, |
e471ab87 |
417 | ); |
418 | |
4bea1fe7 |
419 | =head2 write_handler |
420 | |
421 | Defines an object that implements the write side of L<BIx::Class::Storage::DBI>, |
422 | as well as methods that don't write or read that can be called on only one |
423 | storage, methods that return a C<$dbh>, and any methods that don't make sense to |
424 | run on a replicant. |
425 | |
426 | =cut |
427 | |
428 | has 'write_handler' => ( |
429 | is=>'ro', |
430 | isa=>Object, |
431 | lazy_build=>1, |
432 | handles=>$method_dispatch->{writer}, |
7f4433eb |
433 | ); |
434 | |
4bea1fe7 |
435 | |
6d766626 |
436 | |
b2e4d522 |
437 | has _master_connect_info_opts => |
438 | (is => 'rw', isa => HashRef, default => sub { {} }); |
439 | |
440 | =head2 around: connect_info |
441 | |
48580715 |
442 | Preserves master's C<connect_info> options (for merging with replicants.) |
443 | Also sets any Replicated-related options from connect_info, such as |
dcdf7b2c |
444 | C<pool_type>, C<pool_args>, C<balancer_type> and C<balancer_args>. |
b2e4d522 |
445 | |
446 | =cut |
447 | |
448 | around connect_info => sub { |
449 | my ($next, $self, $info, @extra) = @_; |
450 | |
282a9a4f |
451 | my $merge = Hash::Merge->new('LEFT_PRECEDENT'); |
e666c5fd |
452 | |
b2e4d522 |
453 | my %opts; |
454 | for my $arg (@$info) { |
455 | next unless (reftype($arg)||'') eq 'HASH'; |
e666c5fd |
456 | %opts = %{ $merge->merge($arg, \%opts) }; |
b2e4d522 |
457 | } |
b2e4d522 |
458 | delete $opts{dsn}; |
459 | |
dcdf7b2c |
460 | if (@opts{qw/pool_type pool_args/}) { |
461 | $self->pool_type(delete $opts{pool_type}) |
462 | if $opts{pool_type}; |
463 | |
b88b85e7 |
464 | $self->pool_args( |
e666c5fd |
465 | $merge->merge((delete $opts{pool_args} || {}), $self->pool_args) |
b88b85e7 |
466 | ); |
dcdf7b2c |
467 | |
64ae1667 |
468 | ## Since we possibly changed the pool_args, we need to clear the current |
469 | ## pool object so that next time it is used it will be rebuilt. |
470 | $self->clear_pool; |
dcdf7b2c |
471 | } |
472 | |
473 | if (@opts{qw/balancer_type balancer_args/}) { |
474 | $self->balancer_type(delete $opts{balancer_type}) |
475 | if $opts{balancer_type}; |
476 | |
b88b85e7 |
477 | $self->balancer_args( |
e666c5fd |
478 | $merge->merge((delete $opts{balancer_args} || {}), $self->balancer_args) |
b88b85e7 |
479 | ); |
dcdf7b2c |
480 | |
67c43863 |
481 | $self->balancer($self->_build_balancer) |
6f7344b8 |
482 | if $self->balancer; |
dcdf7b2c |
483 | } |
484 | |
b2e4d522 |
485 | $self->_master_connect_info_opts(\%opts); |
486 | |
cca282b6 |
487 | my @res; |
488 | if (wantarray) { |
0ce2d0d5 |
489 | @res = $self->$next($info, @extra); |
490 | } else { |
cca282b6 |
491 | $res[0] = $self->$next($info, @extra); |
0ce2d0d5 |
492 | } |
493 | |
fd4eb9c2 |
494 | # Make sure master is blessed into the correct class and apply role to it. |
495 | my $master = $self->master; |
496 | $master->_determine_driver; |
497 | Moose::Meta::Class->initialize(ref $master); |
cea43436 |
498 | |
ec0946db |
499 | DBIx::Class::Storage::DBI::Replicated::WithDSN->meta->apply($master); |
cea43436 |
500 | |
501 | # link pool back to master |
502 | $self->pool->master($master); |
0ce2d0d5 |
503 | |
cca282b6 |
504 | wantarray ? @res : $res[0]; |
b2e4d522 |
505 | }; |
506 | |
26ab719a |
507 | =head1 METHODS |
2bf79155 |
508 | |
26ab719a |
509 | This class defines the following methods. |
2bf79155 |
510 | |
c354902c |
511 | =head2 BUILDARGS |
2bf79155 |
512 | |
faaba25f |
513 | L<DBIx::Class::Schema> when instantiating its storage passed itself as the |
2ce6e9a6 |
514 | first argument. So we need to massage the arguments a bit so that all the |
515 | bits get put into the correct places. |
2bf79155 |
516 | |
517 | =cut |
518 | |
c354902c |
519 | sub BUILDARGS { |
fd323bf1 |
520 | my ($class, $schema, $storage_type_args, @args) = @_; |
d4daee7b |
521 | |
c354902c |
522 | return { |
6f7344b8 |
523 | schema=>$schema, |
524 | %$storage_type_args, |
525 | @args |
c354902c |
526 | } |
527 | } |
2bf79155 |
528 | |
cb6ec758 |
529 | =head2 _build_master |
2bf79155 |
530 | |
cb6ec758 |
531 | Lazy builder for the L</master> attribute. |
2bf79155 |
532 | |
533 | =cut |
534 | |
cb6ec758 |
535 | sub _build_master { |
2ce6e9a6 |
536 | my $self = shift @_; |
ee356d00 |
537 | my $master = DBIx::Class::Storage::DBI->new($self->schema); |
ee356d00 |
538 | $master |
106d5f3b |
539 | } |
540 | |
26ab719a |
541 | =head2 _build_pool |
2bf79155 |
542 | |
26ab719a |
543 | Lazy builder for the L</pool> attribute. |
2bf79155 |
544 | |
545 | =cut |
546 | |
26ab719a |
547 | sub _build_pool { |
64cdad22 |
548 | my $self = shift @_; |
549 | $self->create_pool(%{$self->pool_args}); |
2bf79155 |
550 | } |
551 | |
26ab719a |
552 | =head2 _build_balancer |
2bf79155 |
553 | |
cb6ec758 |
554 | Lazy builder for the L</balancer> attribute. This takes a Pool object so that |
555 | the balancer knows which pool it's balancing. |
2bf79155 |
556 | |
557 | =cut |
558 | |
26ab719a |
559 | sub _build_balancer { |
64cdad22 |
560 | my $self = shift @_; |
561 | $self->create_balancer( |
6f7344b8 |
562 | pool=>$self->pool, |
64cdad22 |
563 | master=>$self->master, |
564 | %{$self->balancer_args}, |
565 | ); |
2bf79155 |
566 | } |
567 | |
cb6ec758 |
568 | =head2 _build_write_handler |
2bf79155 |
569 | |
cb6ec758 |
570 | Lazy builder for the L</write_handler> attribute. The default is to set this to |
571 | the L</master>. |
50336325 |
572 | |
573 | =cut |
574 | |
cb6ec758 |
575 | sub _build_write_handler { |
64cdad22 |
576 | return shift->master; |
cb6ec758 |
577 | } |
50336325 |
578 | |
cb6ec758 |
579 | =head2 _build_read_handler |
2bf79155 |
580 | |
cb6ec758 |
581 | Lazy builder for the L</read_handler> attribute. The default is to set this to |
582 | the L</balancer>. |
2bf79155 |
583 | |
584 | =cut |
585 | |
cb6ec758 |
586 | sub _build_read_handler { |
64cdad22 |
587 | return shift->balancer; |
cb6ec758 |
588 | } |
50336325 |
589 | |
cb6ec758 |
590 | =head2 around: connect_replicants |
2bf79155 |
591 | |
cb6ec758 |
592 | All calls to connect_replicants needs to have an existing $schema tacked onto |
b2e4d522 |
593 | top of the args, since L<DBIx::Storage::DBI> needs it, and any C<connect_info> |
594 | options merged with the master, with replicant opts having higher priority. |
955a6df6 |
595 | |
cb6ec758 |
596 | =cut |
955a6df6 |
597 | |
b2e4d522 |
598 | around connect_replicants => sub { |
599 | my ($next, $self, @args) = @_; |
600 | |
601 | for my $r (@args) { |
602 | $r = [ $r ] unless reftype $r eq 'ARRAY'; |
603 | |
1a58752c |
604 | $self->throw_exception('coderef replicant connect_info not supported') |
b2e4d522 |
605 | if ref $r->[0] && reftype $r->[0] eq 'CODE'; |
606 | |
607 | # any connect_info options? |
608 | my $i = 0; |
609 | $i++ while $i < @$r && (reftype($r->[$i])||'') ne 'HASH'; |
610 | |
6f7344b8 |
611 | # make one if none |
b2e4d522 |
612 | $r->[$i] = {} unless $r->[$i]; |
613 | |
614 | # merge if two hashes |
b88b85e7 |
615 | my @hashes = @$r[$i .. $#{$r}]; |
616 | |
1a58752c |
617 | $self->throw_exception('invalid connect_info options') |
b88b85e7 |
618 | if (grep { reftype($_) eq 'HASH' } @hashes) != @hashes; |
619 | |
1a58752c |
620 | $self->throw_exception('too many hashrefs in connect_info') |
b88b85e7 |
621 | if @hashes > 2; |
622 | |
282a9a4f |
623 | my $merge = Hash::Merge->new('LEFT_PRECEDENT'); |
e666c5fd |
624 | my %opts = %{ $merge->merge(reverse @hashes) }; |
b88b85e7 |
625 | |
626 | # delete them |
b2e4d522 |
627 | splice @$r, $i+1, ($#{$r} - $i), (); |
628 | |
0bd8e058 |
629 | # make sure master/replicants opts don't clash |
630 | my %master_opts = %{ $self->_master_connect_info_opts }; |
631 | if (exists $opts{dbh_maker}) { |
632 | delete @master_opts{qw/dsn user password/}; |
633 | } |
634 | delete $master_opts{dbh_maker}; |
635 | |
b2e4d522 |
636 | # merge with master |
e666c5fd |
637 | %opts = %{ $merge->merge(\%opts, \%master_opts) }; |
b2e4d522 |
638 | |
639 | # update |
640 | $r->[$i] = \%opts; |
641 | } |
642 | |
643 | $self->$next($self->schema, @args); |
955a6df6 |
644 | }; |
2bf79155 |
645 | |
2bf79155 |
646 | =head2 all_storages |
647 | |
648 | Returns an array of of all the connected storage backends. The first element |
649 | in the returned array is the master, and the remainings are each of the |
650 | replicants. |
651 | |
652 | =cut |
653 | |
654 | sub all_storages { |
64cdad22 |
655 | my $self = shift @_; |
656 | return grep {defined $_ && blessed $_} ( |
657 | $self->master, |
6412a592 |
658 | values %{ $self->replicants }, |
64cdad22 |
659 | ); |
2bf79155 |
660 | } |
661 | |
c4d3fae2 |
662 | =head2 execute_reliably ($coderef, ?@args) |
663 | |
664 | Given a coderef, saves the current state of the L</read_handler>, forces it to |
48580715 |
665 | use reliable storage (e.g. sets it to the master), executes a coderef and then |
c4d3fae2 |
666 | restores the original state. |
667 | |
668 | Example: |
669 | |
64cdad22 |
670 | my $reliably = sub { |
671 | my $name = shift @_; |
672 | $schema->resultset('User')->create({name=>$name}); |
fd323bf1 |
673 | my $user_rs = $schema->resultset('User')->find({name=>$name}); |
64cdad22 |
674 | return $user_rs; |
675 | }; |
c4d3fae2 |
676 | |
64cdad22 |
677 | my $user_rs = $schema->storage->execute_reliably($reliably, 'John'); |
c4d3fae2 |
678 | |
679 | Use this when you must be certain of your database state, such as when you just |
680 | inserted something and need to get a resultset including it, etc. |
681 | |
682 | =cut |
683 | |
684 | sub execute_reliably { |
64cdad22 |
685 | my ($self, $coderef, @args) = @_; |
d4daee7b |
686 | |
64cdad22 |
687 | unless( ref $coderef eq 'CODE') { |
688 | $self->throw_exception('Second argument must be a coderef'); |
689 | } |
d4daee7b |
690 | |
64cdad22 |
691 | ##Get copy of master storage |
692 | my $master = $self->master; |
d4daee7b |
693 | |
64cdad22 |
694 | ##Get whatever the current read hander is |
695 | my $current = $self->read_handler; |
d4daee7b |
696 | |
64cdad22 |
697 | ##Set the read handler to master |
698 | $self->read_handler($master); |
d4daee7b |
699 | |
64cdad22 |
700 | ## do whatever the caller needs |
701 | my @result; |
702 | my $want_array = wantarray; |
d4daee7b |
703 | |
ed7ab0f4 |
704 | try { |
64cdad22 |
705 | if($want_array) { |
706 | @result = $coderef->(@args); |
707 | } elsif(defined $want_array) { |
708 | ($result[0]) = ($coderef->(@args)); |
ed213e85 |
709 | } else { |
64cdad22 |
710 | $coderef->(@args); |
6f7344b8 |
711 | } |
ed7ab0f4 |
712 | } catch { |
713 | $self->throw_exception("coderef returned an error: $_"); |
714 | } finally { |
715 | ##Reset to the original state |
716 | $self->read_handler($current); |
64cdad22 |
717 | }; |
d4daee7b |
718 | |
cca282b6 |
719 | return wantarray ? @result : $result[0]; |
c4d3fae2 |
720 | } |
721 | |
cb6ec758 |
722 | =head2 set_reliable_storage |
723 | |
724 | Sets the current $schema to be 'reliable', that is all queries, both read and |
725 | write are sent to the master |
d4daee7b |
726 | |
cb6ec758 |
727 | =cut |
728 | |
729 | sub set_reliable_storage { |
64cdad22 |
730 | my $self = shift @_; |
731 | my $schema = $self->schema; |
732 | my $write_handler = $self->schema->storage->write_handler; |
d4daee7b |
733 | |
64cdad22 |
734 | $schema->storage->read_handler($write_handler); |
cb6ec758 |
735 | } |
736 | |
737 | =head2 set_balanced_storage |
738 | |
739 | Sets the current $schema to be use the </balancer> for all reads, while all |
48580715 |
740 | writes are sent to the master only |
d4daee7b |
741 | |
cb6ec758 |
742 | =cut |
743 | |
744 | sub set_balanced_storage { |
64cdad22 |
745 | my $self = shift @_; |
746 | my $schema = $self->schema; |
bd5da369 |
747 | my $balanced_handler = $self->schema->storage->balancer; |
d4daee7b |
748 | |
bd5da369 |
749 | $schema->storage->read_handler($balanced_handler); |
cb6ec758 |
750 | } |
2bf79155 |
751 | |
752 | =head2 connected |
753 | |
754 | Check that the master and at least one of the replicants is connected. |
755 | |
756 | =cut |
757 | |
758 | sub connected { |
64cdad22 |
759 | my $self = shift @_; |
760 | return |
761 | $self->master->connected && |
762 | $self->pool->connected_replicants; |
2bf79155 |
763 | } |
764 | |
2bf79155 |
765 | =head2 ensure_connected |
766 | |
767 | Make sure all the storages are connected. |
768 | |
769 | =cut |
770 | |
771 | sub ensure_connected { |
64cdad22 |
772 | my $self = shift @_; |
773 | foreach my $source ($self->all_storages) { |
774 | $source->ensure_connected(@_); |
775 | } |
2bf79155 |
776 | } |
777 | |
2bf79155 |
778 | =head2 limit_dialect |
779 | |
780 | Set the limit_dialect for all existing storages |
781 | |
782 | =cut |
783 | |
784 | sub limit_dialect { |
64cdad22 |
785 | my $self = shift @_; |
786 | foreach my $source ($self->all_storages) { |
787 | $source->limit_dialect(@_); |
788 | } |
f3e9f010 |
789 | return $self->master->limit_dialect; |
2bf79155 |
790 | } |
791 | |
2bf79155 |
792 | =head2 quote_char |
793 | |
794 | Set the quote_char for all existing storages |
795 | |
796 | =cut |
797 | |
798 | sub quote_char { |
64cdad22 |
799 | my $self = shift @_; |
800 | foreach my $source ($self->all_storages) { |
801 | $source->quote_char(@_); |
802 | } |
3fbe08e3 |
803 | return $self->master->quote_char; |
2bf79155 |
804 | } |
805 | |
2bf79155 |
806 | =head2 name_sep |
807 | |
808 | Set the name_sep for all existing storages |
809 | |
810 | =cut |
811 | |
812 | sub name_sep { |
64cdad22 |
813 | my $self = shift @_; |
814 | foreach my $source ($self->all_storages) { |
815 | $source->name_sep(@_); |
816 | } |
3fbe08e3 |
817 | return $self->master->name_sep; |
2bf79155 |
818 | } |
819 | |
2bf79155 |
820 | =head2 set_schema |
821 | |
822 | Set the schema object for all existing storages |
823 | |
824 | =cut |
825 | |
826 | sub set_schema { |
64cdad22 |
827 | my $self = shift @_; |
828 | foreach my $source ($self->all_storages) { |
829 | $source->set_schema(@_); |
830 | } |
2bf79155 |
831 | } |
832 | |
2bf79155 |
833 | =head2 debug |
834 | |
835 | set a debug flag across all storages |
836 | |
837 | =cut |
838 | |
839 | sub debug { |
64cdad22 |
840 | my $self = shift @_; |
3fbe08e3 |
841 | if(@_) { |
842 | foreach my $source ($self->all_storages) { |
843 | $source->debug(@_); |
6f7344b8 |
844 | } |
64cdad22 |
845 | } |
3fbe08e3 |
846 | return $self->master->debug; |
2bf79155 |
847 | } |
848 | |
2bf79155 |
849 | =head2 debugobj |
850 | |
cea43436 |
851 | set a debug object |
2bf79155 |
852 | |
853 | =cut |
854 | |
855 | sub debugobj { |
64cdad22 |
856 | my $self = shift @_; |
cea43436 |
857 | return $self->master->debugobj(@_); |
2bf79155 |
858 | } |
859 | |
2bf79155 |
860 | =head2 debugfh |
861 | |
cea43436 |
862 | set a debugfh object |
2bf79155 |
863 | |
864 | =cut |
865 | |
866 | sub debugfh { |
64cdad22 |
867 | my $self = shift @_; |
cea43436 |
868 | return $self->master->debugfh(@_); |
2bf79155 |
869 | } |
870 | |
2bf79155 |
871 | =head2 debugcb |
872 | |
cea43436 |
873 | set a debug callback |
2bf79155 |
874 | |
875 | =cut |
876 | |
877 | sub debugcb { |
64cdad22 |
878 | my $self = shift @_; |
cea43436 |
879 | return $self->master->debugcb(@_); |
2bf79155 |
880 | } |
881 | |
2bf79155 |
882 | =head2 disconnect |
883 | |
884 | disconnect everything |
885 | |
886 | =cut |
887 | |
888 | sub disconnect { |
64cdad22 |
889 | my $self = shift @_; |
890 | foreach my $source ($self->all_storages) { |
891 | $source->disconnect(@_); |
892 | } |
2bf79155 |
893 | } |
894 | |
b2e4d522 |
895 | =head2 cursor_class |
896 | |
897 | set cursor class on all storages, or return master's |
898 | |
899 | =cut |
900 | |
901 | sub cursor_class { |
902 | my ($self, $cursor_class) = @_; |
903 | |
904 | if ($cursor_class) { |
905 | $_->cursor_class($cursor_class) for $self->all_storages; |
906 | } |
907 | $self->master->cursor_class; |
908 | } |
d4daee7b |
909 | |
3244fdcc |
910 | =head2 cursor |
911 | |
912 | set cursor class on all storages, or return master's, alias for L</cursor_class> |
913 | above. |
914 | |
915 | =cut |
916 | |
917 | sub cursor { |
918 | my ($self, $cursor_class) = @_; |
919 | |
920 | if ($cursor_class) { |
921 | $_->cursor($cursor_class) for $self->all_storages; |
922 | } |
923 | $self->master->cursor; |
924 | } |
925 | |
926 | =head2 unsafe |
927 | |
928 | sets the L<DBIx::Class::Storage::DBI/unsafe> option on all storages or returns |
929 | master's current setting |
930 | |
931 | =cut |
932 | |
933 | sub unsafe { |
934 | my $self = shift; |
935 | |
936 | if (@_) { |
937 | $_->unsafe(@_) for $self->all_storages; |
938 | } |
939 | |
940 | return $self->master->unsafe; |
941 | } |
942 | |
943 | =head2 disable_sth_caching |
944 | |
945 | sets the L<DBIx::Class::Storage::DBI/disable_sth_caching> option on all storages |
946 | or returns master's current setting |
947 | |
948 | =cut |
949 | |
950 | sub disable_sth_caching { |
951 | my $self = shift; |
952 | |
953 | if (@_) { |
954 | $_->disable_sth_caching(@_) for $self->all_storages; |
955 | } |
956 | |
957 | return $self->master->disable_sth_caching; |
958 | } |
959 | |
960 | =head2 lag_behind_master |
961 | |
962 | returns the highest Replicant L<DBIx::Class::Storage::DBI/lag_behind_master> |
963 | setting |
964 | |
965 | =cut |
966 | |
967 | sub lag_behind_master { |
968 | my $self = shift; |
969 | |
970 | return max map $_->lag_behind_master, $self->replicants; |
fd323bf1 |
971 | } |
3244fdcc |
972 | |
973 | =head2 is_replicating |
974 | |
975 | returns true if all replicants return true for |
976 | L<DBIx::Class::Storage::DBI/is_replicating> |
977 | |
978 | =cut |
979 | |
980 | sub is_replicating { |
981 | my $self = shift; |
982 | |
983 | return (grep $_->is_replicating, $self->replicants) == ($self->replicants); |
984 | } |
985 | |
986 | =head2 connect_call_datetime_setup |
987 | |
988 | calls L<DBIx::Class::Storage::DBI/connect_call_datetime_setup> for all storages |
989 | |
990 | =cut |
991 | |
992 | sub connect_call_datetime_setup { |
993 | my $self = shift; |
994 | $_->connect_call_datetime_setup for $self->all_storages; |
995 | } |
996 | |
997 | sub _populate_dbh { |
998 | my $self = shift; |
999 | $_->_populate_dbh for $self->all_storages; |
1000 | } |
1001 | |
1002 | sub _connect { |
1003 | my $self = shift; |
1004 | $_->_connect for $self->all_storages; |
1005 | } |
1006 | |
1007 | sub _rebless { |
1008 | my $self = shift; |
1009 | $_->_rebless for $self->all_storages; |
1010 | } |
1011 | |
1012 | sub _determine_driver { |
1013 | my $self = shift; |
1014 | $_->_determine_driver for $self->all_storages; |
1015 | } |
1016 | |
1017 | sub _driver_determined { |
1018 | my $self = shift; |
fd323bf1 |
1019 | |
3244fdcc |
1020 | if (@_) { |
1021 | $_->_driver_determined(@_) for $self->all_storages; |
1022 | } |
1023 | |
1024 | return $self->master->_driver_determined; |
1025 | } |
1026 | |
1027 | sub _init { |
1028 | my $self = shift; |
fd323bf1 |
1029 | |
3244fdcc |
1030 | $_->_init for $self->all_storages; |
1031 | } |
1032 | |
1033 | sub _run_connection_actions { |
1034 | my $self = shift; |
fd323bf1 |
1035 | |
3244fdcc |
1036 | $_->_run_connection_actions for $self->all_storages; |
1037 | } |
1038 | |
1039 | sub _do_connection_actions { |
1040 | my $self = shift; |
fd323bf1 |
1041 | |
3244fdcc |
1042 | if (@_) { |
1043 | $_->_do_connection_actions(@_) for $self->all_storages; |
1044 | } |
1045 | } |
1046 | |
1047 | sub connect_call_do_sql { |
1048 | my $self = shift; |
1049 | $_->connect_call_do_sql(@_) for $self->all_storages; |
1050 | } |
1051 | |
1052 | sub disconnect_call_do_sql { |
1053 | my $self = shift; |
1054 | $_->disconnect_call_do_sql(@_) for $self->all_storages; |
1055 | } |
1056 | |
1057 | sub _seems_connected { |
1058 | my $self = shift; |
1059 | |
1060 | return min map $_->_seems_connected, $self->all_storages; |
1061 | } |
1062 | |
1063 | sub _ping { |
1064 | my $self = shift; |
1065 | |
1066 | return min map $_->_ping, $self->all_storages; |
1067 | } |
1068 | |
bbdda281 |
1069 | # not using the normalized_version, because we want to preserve |
1070 | # version numbers much longer than the conventional xxx.yyyzzz |
7da56142 |
1071 | my $numify_ver = sub { |
1072 | my $ver = shift; |
1073 | my @numparts = split /\D+/, $ver; |
bbdda281 |
1074 | my $format = '%d.' . (join '', ('%06d') x (@numparts - 1)); |
7da56142 |
1075 | |
1076 | return sprintf $format, @numparts; |
1077 | }; |
fecb38cb |
1078 | sub _server_info { |
1079 | my $self = shift; |
1080 | |
bbdda281 |
1081 | if (not $self->_dbh_details->{info}) { |
1082 | $self->_dbh_details->{info} = ( |
fd323bf1 |
1083 | reduce { $a->[0] < $b->[0] ? $a : $b } |
7da56142 |
1084 | map [ $numify_ver->($_->{dbms_version}), $_ ], |
1085 | map $_->_server_info, $self->all_storages |
1086 | )->[1]; |
fecb38cb |
1087 | } |
1088 | |
bbdda281 |
1089 | return $self->next::method; |
fecb38cb |
1090 | } |
1091 | |
1092 | sub _get_server_version { |
1093 | my $self = shift; |
1094 | |
1095 | return $self->_server_info->{dbms_version}; |
1096 | } |
1097 | |
7e38d850 |
1098 | =head1 GOTCHAS |
1099 | |
1100 | Due to the fact that replicants can lag behind a master, you must take care to |
1101 | make sure you use one of the methods to force read queries to a master should |
1102 | you need realtime data integrity. For example, if you insert a row, and then |
1103 | immediately re-read it from the database (say, by doing $row->discard_changes) |
1104 | or you insert a row and then immediately build a query that expects that row |
1105 | to be an item, you should force the master to handle reads. Otherwise, due to |
1106 | the lag, there is no certainty your data will be in the expected state. |
1107 | |
1108 | For data integrity, all transactions automatically use the master storage for |
1109 | all read and write queries. Using a transaction is the preferred and recommended |
1110 | method to force the master to handle all read queries. |
1111 | |
1112 | Otherwise, you can force a single query to use the master with the 'force_pool' |
1113 | attribute: |
1114 | |
1115 | my $row = $resultset->search(undef, {force_pool=>'master'})->find($pk); |
1116 | |
1117 | This attribute will safely be ignore by non replicated storages, so you can use |
1118 | the same code for both types of systems. |
1119 | |
1120 | Lastly, you can use the L</execute_reliably> method, which works very much like |
1121 | a transaction. |
1122 | |
1123 | For debugging, you can turn replication on/off with the methods L</set_reliable_storage> |
1124 | and L</set_balanced_storage>, however this operates at a global level and is not |
1125 | suitable if you have a shared Schema object being used by multiple processes, |
1126 | such as on a web application server. You can get around this limitation by |
1127 | using the Schema clone method. |
1128 | |
1129 | my $new_schema = $schema->clone; |
1130 | $new_schema->set_reliable_storage; |
d4daee7b |
1131 | |
7e38d850 |
1132 | ## $new_schema will use only the Master storage for all reads/writes while |
1133 | ## the $schema object will use replicated storage. |
1134 | |
f5d3a5de |
1135 | =head1 AUTHOR |
1136 | |
64cdad22 |
1137 | John Napiorkowski <john.napiorkowski@takkle.com> |
f5d3a5de |
1138 | |
c4d3fae2 |
1139 | Based on code originated by: |
f5d3a5de |
1140 | |
64cdad22 |
1141 | Norbert Csongrádi <bert@cpan.org> |
1142 | Peter Siklósi <einon@einon.hu> |
2156bbdd |
1143 | |
f5d3a5de |
1144 | =head1 LICENSE |
1145 | |
1146 | You may distribute this code under the same terms as Perl itself. |
1147 | |
1148 | =cut |
1149 | |
c354902c |
1150 | __PACKAGE__->meta->make_immutable; |
1151 | |
f5d3a5de |
1152 | 1; |