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 | |
d7c37d66 |
59 | my $rs = $schema->resultset('Source')->search(undef, {force_pool=>'master'}); |
3da4f736 |
60 | |
d7c37d66 |
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 | |
d7c37d66 |
71 | If you have a multi-statement read only transaction you can force it to select |
72 | a random server in the pool by: |
73 | |
74 | my $rs = $schema->resultset('Source')->search( undef, |
75 | { force_pool => $db->storage->read_handler->next_storage } |
76 | ); |
d4daee7b |
77 | |
2bf79155 |
78 | =head1 DESCRIPTION |
79 | |
7e38d850 |
80 | Warning: This class is marked BETA. This has been running a production |
ccb3b897 |
81 | website using MySQL native replication as its backend and we have some decent |
7e38d850 |
82 | test coverage but the code hasn't yet been stressed by a variety of databases. |
48580715 |
83 | Individual DBs may have quirks we are not aware of. Please use this in first |
7e38d850 |
84 | development and pass along your experiences/bug fixes. |
2bf79155 |
85 | |
86 | This class implements replicated data store for DBI. Currently you can define |
87 | one master and numerous slave database connections. All write-type queries |
88 | (INSERT, UPDATE, DELETE and even LAST_INSERT_ID) are routed to master |
89 | database, all read-type queries (SELECTs) go to the slave database. |
90 | |
91 | Basically, any method request that L<DBIx::Class::Storage::DBI> would normally |
bca099a3 |
92 | handle gets delegated to one of the two attributes: L</read_handler> or to |
93 | L</write_handler>. Additionally, some methods need to be distributed |
2bf79155 |
94 | to all existing storages. This way our storage class is a drop in replacement |
95 | for L<DBIx::Class::Storage::DBI>. |
96 | |
48580715 |
97 | Read traffic is spread across the replicants (slaves) occurring to a user |
2bf79155 |
98 | selected algorithm. The default algorithm is random weighted. |
99 | |
bca099a3 |
100 | =head1 NOTES |
101 | |
48580715 |
102 | The consistency between master and replicants is database specific. The Pool |
faaba25f |
103 | gives you a method to validate its replicants, removing and replacing them |
7e38d850 |
104 | when they fail/pass predefined criteria. Please make careful use of the ways |
ecb65397 |
105 | to force a query to run against Master when needed. |
106 | |
107 | =head1 REQUIREMENTS |
108 | |
a34b0c89 |
109 | Replicated Storage has additional requirements not currently part of |
aa8b2277 |
110 | L<DBIx::Class>. See L<DBIx::Class::Optional::Dependencies> for more details. |
2bf79155 |
111 | |
112 | =head1 ATTRIBUTES |
113 | |
114 | This class defines the following attributes. |
115 | |
2ce6e9a6 |
116 | =head2 schema |
117 | |
118 | The underlying L<DBIx::Class::Schema> object this storage is attaching |
119 | |
120 | =cut |
121 | |
122 | has 'schema' => ( |
123 | is=>'rw', |
6a151f58 |
124 | isa=>DBICSchema, |
2ce6e9a6 |
125 | weak_ref=>1, |
126 | required=>1, |
127 | ); |
128 | |
26ab719a |
129 | =head2 pool_type |
2bf79155 |
130 | |
fd323bf1 |
131 | Contains the classname which will instantiate the L</pool> object. Defaults |
26ab719a |
132 | to: L<DBIx::Class::Storage::DBI::Replicated::Pool>. |
2bf79155 |
133 | |
134 | =cut |
135 | |
26ab719a |
136 | has 'pool_type' => ( |
dcdf7b2c |
137 | is=>'rw', |
41916570 |
138 | isa=>ClassName, |
2ce6e9a6 |
139 | default=>'DBIx::Class::Storage::DBI::Replicated::Pool', |
64cdad22 |
140 | handles=>{ |
141 | 'create_pool' => 'new', |
142 | }, |
2bf79155 |
143 | ); |
144 | |
f068a139 |
145 | =head2 pool_args |
146 | |
147 | Contains a hashref of initialized information to pass to the Balancer object. |
212cc5c2 |
148 | See L<DBIx::Class::Storage::DBI::Replicated::Pool> for available arguments. |
f068a139 |
149 | |
150 | =cut |
151 | |
152 | has 'pool_args' => ( |
dcdf7b2c |
153 | is=>'rw', |
41916570 |
154 | isa=>HashRef, |
64cdad22 |
155 | lazy=>1, |
64cdad22 |
156 | default=>sub { {} }, |
f068a139 |
157 | ); |
158 | |
159 | |
26ab719a |
160 | =head2 balancer_type |
2bf79155 |
161 | |
162 | The replication pool requires a balance class to provider the methods for |
163 | choose how to spread the query load across each replicant in the pool. |
164 | |
165 | =cut |
166 | |
26ab719a |
167 | has 'balancer_type' => ( |
dcdf7b2c |
168 | is=>'rw', |
9901aad7 |
169 | isa=>BalancerClassNamePart, |
2ce6e9a6 |
170 | coerce=>1, |
171 | required=>1, |
172 | default=> 'DBIx::Class::Storage::DBI::Replicated::Balancer::First', |
64cdad22 |
173 | handles=>{ |
174 | 'create_balancer' => 'new', |
175 | }, |
2bf79155 |
176 | ); |
177 | |
17b05c13 |
178 | =head2 balancer_args |
179 | |
180 | Contains a hashref of initialized information to pass to the Balancer object. |
212cc5c2 |
181 | See L<DBIx::Class::Storage::DBI::Replicated::Balancer> for available arguments. |
17b05c13 |
182 | |
183 | =cut |
184 | |
185 | has 'balancer_args' => ( |
dcdf7b2c |
186 | is=>'rw', |
41916570 |
187 | isa=>HashRef, |
64cdad22 |
188 | lazy=>1, |
189 | required=>1, |
190 | default=>sub { {} }, |
17b05c13 |
191 | ); |
192 | |
26ab719a |
193 | =head2 pool |
2bf79155 |
194 | |
370f78d4 |
195 | Is a L<DBIx::Class::Storage::DBI::Replicated::Pool> or derived class. This is a |
26ab719a |
196 | container class for one or more replicated databases. |
2bf79155 |
197 | |
198 | =cut |
199 | |
26ab719a |
200 | has 'pool' => ( |
64cdad22 |
201 | is=>'ro', |
202 | isa=>'DBIx::Class::Storage::DBI::Replicated::Pool', |
203 | lazy_build=>1, |
204 | handles=>[qw/ |
6f7344b8 |
205 | connect_replicants |
64cdad22 |
206 | replicants |
207 | has_replicants |
208 | /], |
2bf79155 |
209 | ); |
210 | |
26ab719a |
211 | =head2 balancer |
2bf79155 |
212 | |
370f78d4 |
213 | Is a L<DBIx::Class::Storage::DBI::Replicated::Balancer> or derived class. This |
214 | is a class that takes a pool (L<DBIx::Class::Storage::DBI::Replicated::Pool>) |
2bf79155 |
215 | |
26ab719a |
216 | =cut |
2bf79155 |
217 | |
26ab719a |
218 | has 'balancer' => ( |
dcdf7b2c |
219 | is=>'rw', |
64cdad22 |
220 | isa=>'DBIx::Class::Storage::DBI::Replicated::Balancer', |
221 | lazy_build=>1, |
222 | handles=>[qw/auto_validate_every/], |
26ab719a |
223 | ); |
2bf79155 |
224 | |
cb6ec758 |
225 | =head2 master |
226 | |
227 | The master defines the canonical state for a pool of connected databases. All |
228 | the replicants are expected to match this databases state. Thus, in a classic |
229 | Master / Slaves distributed system, all the slaves are expected to replicate |
230 | the Master's state as quick as possible. This is the only database in the |
231 | pool of databases that is allowed to handle write traffic. |
232 | |
233 | =cut |
234 | |
235 | has 'master' => ( |
64cdad22 |
236 | is=> 'ro', |
6a151f58 |
237 | isa=>DBICStorageDBI, |
64cdad22 |
238 | lazy_build=>1, |
cb6ec758 |
239 | ); |
240 | |
cb6ec758 |
241 | =head1 ATTRIBUTES IMPLEMENTING THE DBIx::Storage::DBI INTERFACE |
242 | |
fd323bf1 |
243 | The following methods are delegated all the methods required for the |
cb6ec758 |
244 | L<DBIx::Class::Storage::DBI> interface. |
245 | |
cb6ec758 |
246 | =cut |
247 | |
4bea1fe7 |
248 | my $method_dispatch = { |
249 | writer => [qw/ |
64cdad22 |
250 | on_connect_do |
6f7344b8 |
251 | on_disconnect_do |
3244fdcc |
252 | on_connect_call |
253 | on_disconnect_call |
64cdad22 |
254 | connect_info |
3244fdcc |
255 | _connect_info |
64cdad22 |
256 | throw_exception |
257 | sql_maker |
258 | sqlt_type |
259 | create_ddl_dir |
260 | deployment_statements |
261 | datetime_parser |
6f7344b8 |
262 | datetime_parser_type |
263 | build_datetime_parser |
64cdad22 |
264 | last_insert_id |
265 | insert |
266 | insert_bulk |
267 | update |
268 | delete |
269 | dbh |
2ce6e9a6 |
270 | txn_begin |
64cdad22 |
271 | txn_do |
272 | txn_commit |
273 | txn_rollback |
2ce6e9a6 |
274 | txn_scope_guard |
90d7422f |
275 | _exec_txn_rollback |
276 | _exec_txn_begin |
277 | _exec_txn_commit |
64cdad22 |
278 | deploy |
0180bef9 |
279 | with_deferred_fk_checks |
6f7344b8 |
280 | dbh_do |
2ce6e9a6 |
281 | _prep_for_execute |
6f7344b8 |
282 | is_datatype_numeric |
283 | _count_select |
6f7344b8 |
284 | svp_rollback |
285 | svp_begin |
286 | svp_release |
e398f77e |
287 | relname_to_table_alias |
3244fdcc |
288 | _dbh_last_insert_id |
3244fdcc |
289 | _default_dbi_connect_attributes |
290 | _dbi_connect_info |
b9ca4ff1 |
291 | _dbic_connect_attributes |
3244fdcc |
292 | auto_savepoint |
0e773352 |
293 | _query_start |
3244fdcc |
294 | _query_end |
0e773352 |
295 | _format_for_trace |
296 | _dbi_attrs_for_bind |
3244fdcc |
297 | bind_attribute_by_data_type |
298 | transaction_depth |
299 | _dbh |
300 | _select_args |
52cef7e3 |
301 | _dbh_execute_for_fetch |
3244fdcc |
302 | _sql_maker |
3244fdcc |
303 | _dbh_execute_inserts_with_no_binds |
304 | _select_args_to_query |
5e782048 |
305 | _gen_sql_bind |
3244fdcc |
306 | _svp_generate_name |
3244fdcc |
307 | _normalize_connect_info |
308 | _parse_connect_do |
3244fdcc |
309 | savepoints |
3244fdcc |
310 | _sql_maker_opts |
311 | _conn_pid |
3244fdcc |
312 | _dbh_autocommit |
313 | _native_data_type |
314 | _get_dbh |
315 | sql_maker_class |
3244fdcc |
316 | _execute |
317 | _do_query |
402ac1c9 |
318 | _sth |
3244fdcc |
319 | _dbh_sth |
320 | _dbh_execute |
5b4f3fd0 |
321 | /, Class::MOP::Class->initialize('DBIx::Class::Storage::DBIHacks')->get_method_list ], |
4bea1fe7 |
322 | reader => [qw/ |
323 | select |
324 | select_single |
325 | columns_info_for |
326 | _dbh_columns_info_for |
327 | _select |
328 | /], |
329 | unimplemented => [qw/ |
330 | _arm_global_destructor |
331 | _verify_pid |
332 | |
0e773352 |
333 | source_bind_attributes |
334 | |
4bea1fe7 |
335 | get_use_dbms_capability |
336 | set_use_dbms_capability |
337 | get_dbms_capability |
338 | set_dbms_capability |
339 | _dbh_details |
340 | _dbh_get_info |
341 | |
342 | sql_limit_dialect |
343 | sql_quote_char |
344 | sql_name_sep |
345 | |
4bea1fe7 |
346 | _prefetch_autovalues |
347 | |
eec07bca |
348 | _resolve_bindattrs |
349 | |
4bea1fe7 |
350 | _max_column_bytesize |
351 | _is_lob_type |
352 | _is_binary_lob_type |
353 | _is_text_lob_type |
402ac1c9 |
354 | |
355 | sth |
4bea1fe7 |
356 | /,( |
357 | # the capability framework |
358 | # not sure if CMOP->initialize does evil things to DBIC::S::DBI, fix if a problem |
359 | grep |
360 | { $_ =~ /^ _ (?: use | supports | determine_supports ) _ /x } |
361 | ( Class::MOP::Class->initialize('DBIx::Class::Storage::DBI')->get_all_method_names ) |
362 | )], |
363 | }; |
364 | |
365 | if (DBIx::Class::_ENV_::DBICTEST) { |
366 | |
367 | my $seen; |
368 | for my $type (keys %$method_dispatch) { |
369 | for (@{$method_dispatch->{$type}}) { |
370 | push @{$seen->{$_}}, $type; |
371 | } |
372 | } |
cb6ec758 |
373 | |
4bea1fe7 |
374 | if (my @dupes = grep { @{$seen->{$_}} > 1 } keys %$seen) { |
375 | die(join "\n", '', |
376 | 'The following methods show up multiple times in ::Storage::DBI::Replicated handlers:', |
377 | (map { "$_: " . (join ', ', @{$seen->{$_}}) } sort @dupes), |
378 | '', |
379 | ); |
380 | } |
bbdda281 |
381 | |
4bea1fe7 |
382 | if (my @cant = grep { ! DBIx::Class::Storage::DBI->can($_) } keys %$seen) { |
383 | die(join "\n", '', |
384 | '::Storage::DBI::Replicated specifies handling of the following *NON EXISTING* ::Storage::DBI methods:', |
385 | @cant, |
386 | '', |
387 | ); |
388 | } |
389 | } |
bbdda281 |
390 | |
4bea1fe7 |
391 | for my $method (@{$method_dispatch->{unimplemented}}) { |
392 | __PACKAGE__->meta->add_method($method, sub { |
70c28808 |
393 | my $self = shift; |
394 | $self->throw_exception("$method must not be called on ".(blessed $self).' objects'); |
4bea1fe7 |
395 | }); |
396 | } |
31a8aaaf |
397 | |
4bea1fe7 |
398 | =head2 read_handler |
584ea6e4 |
399 | |
4bea1fe7 |
400 | Defines an object that implements the read side of L<BIx::Class::Storage::DBI>. |
584ea6e4 |
401 | |
4bea1fe7 |
402 | =cut |
403 | |
404 | has 'read_handler' => ( |
405 | is=>'rw', |
406 | isa=>Object, |
407 | lazy_build=>1, |
408 | handles=>$method_dispatch->{reader}, |
e471ab87 |
409 | ); |
410 | |
4bea1fe7 |
411 | =head2 write_handler |
412 | |
413 | Defines an object that implements the write side of L<BIx::Class::Storage::DBI>, |
414 | as well as methods that don't write or read that can be called on only one |
415 | storage, methods that return a C<$dbh>, and any methods that don't make sense to |
416 | run on a replicant. |
417 | |
418 | =cut |
419 | |
420 | has 'write_handler' => ( |
421 | is=>'ro', |
422 | isa=>Object, |
423 | lazy_build=>1, |
424 | handles=>$method_dispatch->{writer}, |
7f4433eb |
425 | ); |
426 | |
4bea1fe7 |
427 | |
6d766626 |
428 | |
b2e4d522 |
429 | has _master_connect_info_opts => |
430 | (is => 'rw', isa => HashRef, default => sub { {} }); |
431 | |
432 | =head2 around: connect_info |
433 | |
48580715 |
434 | Preserves master's C<connect_info> options (for merging with replicants.) |
435 | Also sets any Replicated-related options from connect_info, such as |
dcdf7b2c |
436 | C<pool_type>, C<pool_args>, C<balancer_type> and C<balancer_args>. |
b2e4d522 |
437 | |
438 | =cut |
439 | |
440 | around connect_info => sub { |
441 | my ($next, $self, $info, @extra) = @_; |
442 | |
282a9a4f |
443 | my $merge = Hash::Merge->new('LEFT_PRECEDENT'); |
e666c5fd |
444 | |
b2e4d522 |
445 | my %opts; |
446 | for my $arg (@$info) { |
447 | next unless (reftype($arg)||'') eq 'HASH'; |
e666c5fd |
448 | %opts = %{ $merge->merge($arg, \%opts) }; |
b2e4d522 |
449 | } |
b2e4d522 |
450 | delete $opts{dsn}; |
451 | |
dcdf7b2c |
452 | if (@opts{qw/pool_type pool_args/}) { |
453 | $self->pool_type(delete $opts{pool_type}) |
454 | if $opts{pool_type}; |
455 | |
b88b85e7 |
456 | $self->pool_args( |
e666c5fd |
457 | $merge->merge((delete $opts{pool_args} || {}), $self->pool_args) |
b88b85e7 |
458 | ); |
dcdf7b2c |
459 | |
64ae1667 |
460 | ## Since we possibly changed the pool_args, we need to clear the current |
461 | ## pool object so that next time it is used it will be rebuilt. |
462 | $self->clear_pool; |
dcdf7b2c |
463 | } |
464 | |
465 | if (@opts{qw/balancer_type balancer_args/}) { |
466 | $self->balancer_type(delete $opts{balancer_type}) |
467 | if $opts{balancer_type}; |
468 | |
b88b85e7 |
469 | $self->balancer_args( |
e666c5fd |
470 | $merge->merge((delete $opts{balancer_args} || {}), $self->balancer_args) |
b88b85e7 |
471 | ); |
dcdf7b2c |
472 | |
67c43863 |
473 | $self->balancer($self->_build_balancer) |
6f7344b8 |
474 | if $self->balancer; |
dcdf7b2c |
475 | } |
476 | |
b2e4d522 |
477 | $self->_master_connect_info_opts(\%opts); |
478 | |
cca282b6 |
479 | my @res; |
480 | if (wantarray) { |
0ce2d0d5 |
481 | @res = $self->$next($info, @extra); |
482 | } else { |
cca282b6 |
483 | $res[0] = $self->$next($info, @extra); |
0ce2d0d5 |
484 | } |
485 | |
fd4eb9c2 |
486 | # Make sure master is blessed into the correct class and apply role to it. |
487 | my $master = $self->master; |
488 | $master->_determine_driver; |
489 | Moose::Meta::Class->initialize(ref $master); |
cea43436 |
490 | |
ec0946db |
491 | DBIx::Class::Storage::DBI::Replicated::WithDSN->meta->apply($master); |
cea43436 |
492 | |
493 | # link pool back to master |
494 | $self->pool->master($master); |
0ce2d0d5 |
495 | |
cca282b6 |
496 | wantarray ? @res : $res[0]; |
b2e4d522 |
497 | }; |
498 | |
26ab719a |
499 | =head1 METHODS |
2bf79155 |
500 | |
26ab719a |
501 | This class defines the following methods. |
2bf79155 |
502 | |
c354902c |
503 | =head2 BUILDARGS |
2bf79155 |
504 | |
faaba25f |
505 | L<DBIx::Class::Schema> when instantiating its storage passed itself as the |
2ce6e9a6 |
506 | first argument. So we need to massage the arguments a bit so that all the |
507 | bits get put into the correct places. |
2bf79155 |
508 | |
509 | =cut |
510 | |
c354902c |
511 | sub BUILDARGS { |
fd323bf1 |
512 | my ($class, $schema, $storage_type_args, @args) = @_; |
d4daee7b |
513 | |
c354902c |
514 | return { |
6f7344b8 |
515 | schema=>$schema, |
516 | %$storage_type_args, |
517 | @args |
c354902c |
518 | } |
519 | } |
2bf79155 |
520 | |
cb6ec758 |
521 | =head2 _build_master |
2bf79155 |
522 | |
cb6ec758 |
523 | Lazy builder for the L</master> attribute. |
2bf79155 |
524 | |
525 | =cut |
526 | |
cb6ec758 |
527 | sub _build_master { |
2ce6e9a6 |
528 | my $self = shift @_; |
ee356d00 |
529 | my $master = DBIx::Class::Storage::DBI->new($self->schema); |
ee356d00 |
530 | $master |
106d5f3b |
531 | } |
532 | |
26ab719a |
533 | =head2 _build_pool |
2bf79155 |
534 | |
26ab719a |
535 | Lazy builder for the L</pool> attribute. |
2bf79155 |
536 | |
537 | =cut |
538 | |
26ab719a |
539 | sub _build_pool { |
64cdad22 |
540 | my $self = shift @_; |
541 | $self->create_pool(%{$self->pool_args}); |
2bf79155 |
542 | } |
543 | |
26ab719a |
544 | =head2 _build_balancer |
2bf79155 |
545 | |
cb6ec758 |
546 | Lazy builder for the L</balancer> attribute. This takes a Pool object so that |
547 | the balancer knows which pool it's balancing. |
2bf79155 |
548 | |
549 | =cut |
550 | |
26ab719a |
551 | sub _build_balancer { |
64cdad22 |
552 | my $self = shift @_; |
553 | $self->create_balancer( |
6f7344b8 |
554 | pool=>$self->pool, |
64cdad22 |
555 | master=>$self->master, |
556 | %{$self->balancer_args}, |
557 | ); |
2bf79155 |
558 | } |
559 | |
cb6ec758 |
560 | =head2 _build_write_handler |
2bf79155 |
561 | |
cb6ec758 |
562 | Lazy builder for the L</write_handler> attribute. The default is to set this to |
563 | the L</master>. |
50336325 |
564 | |
565 | =cut |
566 | |
cb6ec758 |
567 | sub _build_write_handler { |
64cdad22 |
568 | return shift->master; |
cb6ec758 |
569 | } |
50336325 |
570 | |
cb6ec758 |
571 | =head2 _build_read_handler |
2bf79155 |
572 | |
cb6ec758 |
573 | Lazy builder for the L</read_handler> attribute. The default is to set this to |
574 | the L</balancer>. |
2bf79155 |
575 | |
576 | =cut |
577 | |
cb6ec758 |
578 | sub _build_read_handler { |
64cdad22 |
579 | return shift->balancer; |
cb6ec758 |
580 | } |
50336325 |
581 | |
cb6ec758 |
582 | =head2 around: connect_replicants |
2bf79155 |
583 | |
cb6ec758 |
584 | All calls to connect_replicants needs to have an existing $schema tacked onto |
b2e4d522 |
585 | top of the args, since L<DBIx::Storage::DBI> needs it, and any C<connect_info> |
586 | options merged with the master, with replicant opts having higher priority. |
955a6df6 |
587 | |
cb6ec758 |
588 | =cut |
955a6df6 |
589 | |
b2e4d522 |
590 | around connect_replicants => sub { |
591 | my ($next, $self, @args) = @_; |
592 | |
593 | for my $r (@args) { |
594 | $r = [ $r ] unless reftype $r eq 'ARRAY'; |
595 | |
1a58752c |
596 | $self->throw_exception('coderef replicant connect_info not supported') |
b2e4d522 |
597 | if ref $r->[0] && reftype $r->[0] eq 'CODE'; |
598 | |
599 | # any connect_info options? |
600 | my $i = 0; |
601 | $i++ while $i < @$r && (reftype($r->[$i])||'') ne 'HASH'; |
602 | |
6f7344b8 |
603 | # make one if none |
b2e4d522 |
604 | $r->[$i] = {} unless $r->[$i]; |
605 | |
606 | # merge if two hashes |
b88b85e7 |
607 | my @hashes = @$r[$i .. $#{$r}]; |
608 | |
1a58752c |
609 | $self->throw_exception('invalid connect_info options') |
b88b85e7 |
610 | if (grep { reftype($_) eq 'HASH' } @hashes) != @hashes; |
611 | |
1a58752c |
612 | $self->throw_exception('too many hashrefs in connect_info') |
b88b85e7 |
613 | if @hashes > 2; |
614 | |
282a9a4f |
615 | my $merge = Hash::Merge->new('LEFT_PRECEDENT'); |
e666c5fd |
616 | my %opts = %{ $merge->merge(reverse @hashes) }; |
b88b85e7 |
617 | |
618 | # delete them |
b2e4d522 |
619 | splice @$r, $i+1, ($#{$r} - $i), (); |
620 | |
0bd8e058 |
621 | # make sure master/replicants opts don't clash |
622 | my %master_opts = %{ $self->_master_connect_info_opts }; |
623 | if (exists $opts{dbh_maker}) { |
624 | delete @master_opts{qw/dsn user password/}; |
625 | } |
626 | delete $master_opts{dbh_maker}; |
627 | |
b2e4d522 |
628 | # merge with master |
e666c5fd |
629 | %opts = %{ $merge->merge(\%opts, \%master_opts) }; |
b2e4d522 |
630 | |
631 | # update |
632 | $r->[$i] = \%opts; |
633 | } |
634 | |
635 | $self->$next($self->schema, @args); |
955a6df6 |
636 | }; |
2bf79155 |
637 | |
2bf79155 |
638 | =head2 all_storages |
639 | |
640 | Returns an array of of all the connected storage backends. The first element |
641 | in the returned array is the master, and the remainings are each of the |
642 | replicants. |
643 | |
644 | =cut |
645 | |
646 | sub all_storages { |
64cdad22 |
647 | my $self = shift @_; |
648 | return grep {defined $_ && blessed $_} ( |
649 | $self->master, |
6412a592 |
650 | values %{ $self->replicants }, |
64cdad22 |
651 | ); |
2bf79155 |
652 | } |
653 | |
c4d3fae2 |
654 | =head2 execute_reliably ($coderef, ?@args) |
655 | |
656 | Given a coderef, saves the current state of the L</read_handler>, forces it to |
48580715 |
657 | use reliable storage (e.g. sets it to the master), executes a coderef and then |
c4d3fae2 |
658 | restores the original state. |
659 | |
660 | Example: |
661 | |
64cdad22 |
662 | my $reliably = sub { |
663 | my $name = shift @_; |
664 | $schema->resultset('User')->create({name=>$name}); |
fd323bf1 |
665 | my $user_rs = $schema->resultset('User')->find({name=>$name}); |
64cdad22 |
666 | return $user_rs; |
667 | }; |
c4d3fae2 |
668 | |
64cdad22 |
669 | my $user_rs = $schema->storage->execute_reliably($reliably, 'John'); |
c4d3fae2 |
670 | |
671 | Use this when you must be certain of your database state, such as when you just |
672 | inserted something and need to get a resultset including it, etc. |
673 | |
674 | =cut |
675 | |
676 | sub execute_reliably { |
64cdad22 |
677 | my ($self, $coderef, @args) = @_; |
d4daee7b |
678 | |
64cdad22 |
679 | unless( ref $coderef eq 'CODE') { |
680 | $self->throw_exception('Second argument must be a coderef'); |
681 | } |
d4daee7b |
682 | |
64cdad22 |
683 | ##Get copy of master storage |
684 | my $master = $self->master; |
d4daee7b |
685 | |
64cdad22 |
686 | ##Get whatever the current read hander is |
687 | my $current = $self->read_handler; |
d4daee7b |
688 | |
64cdad22 |
689 | ##Set the read handler to master |
690 | $self->read_handler($master); |
d4daee7b |
691 | |
64cdad22 |
692 | ## do whatever the caller needs |
693 | my @result; |
694 | my $want_array = wantarray; |
d4daee7b |
695 | |
ed7ab0f4 |
696 | try { |
64cdad22 |
697 | if($want_array) { |
698 | @result = $coderef->(@args); |
699 | } elsif(defined $want_array) { |
700 | ($result[0]) = ($coderef->(@args)); |
ed213e85 |
701 | } else { |
64cdad22 |
702 | $coderef->(@args); |
6f7344b8 |
703 | } |
ed7ab0f4 |
704 | } catch { |
705 | $self->throw_exception("coderef returned an error: $_"); |
706 | } finally { |
707 | ##Reset to the original state |
708 | $self->read_handler($current); |
64cdad22 |
709 | }; |
d4daee7b |
710 | |
cca282b6 |
711 | return wantarray ? @result : $result[0]; |
c4d3fae2 |
712 | } |
713 | |
cb6ec758 |
714 | =head2 set_reliable_storage |
715 | |
716 | Sets the current $schema to be 'reliable', that is all queries, both read and |
717 | write are sent to the master |
d4daee7b |
718 | |
cb6ec758 |
719 | =cut |
720 | |
721 | sub set_reliable_storage { |
64cdad22 |
722 | my $self = shift @_; |
723 | my $schema = $self->schema; |
724 | my $write_handler = $self->schema->storage->write_handler; |
d4daee7b |
725 | |
64cdad22 |
726 | $schema->storage->read_handler($write_handler); |
cb6ec758 |
727 | } |
728 | |
729 | =head2 set_balanced_storage |
730 | |
731 | Sets the current $schema to be use the </balancer> for all reads, while all |
48580715 |
732 | writes are sent to the master only |
d4daee7b |
733 | |
cb6ec758 |
734 | =cut |
735 | |
736 | sub set_balanced_storage { |
64cdad22 |
737 | my $self = shift @_; |
738 | my $schema = $self->schema; |
bd5da369 |
739 | my $balanced_handler = $self->schema->storage->balancer; |
d4daee7b |
740 | |
bd5da369 |
741 | $schema->storage->read_handler($balanced_handler); |
cb6ec758 |
742 | } |
2bf79155 |
743 | |
744 | =head2 connected |
745 | |
746 | Check that the master and at least one of the replicants is connected. |
747 | |
748 | =cut |
749 | |
750 | sub connected { |
64cdad22 |
751 | my $self = shift @_; |
752 | return |
753 | $self->master->connected && |
754 | $self->pool->connected_replicants; |
2bf79155 |
755 | } |
756 | |
2bf79155 |
757 | =head2 ensure_connected |
758 | |
759 | Make sure all the storages are connected. |
760 | |
761 | =cut |
762 | |
763 | sub ensure_connected { |
64cdad22 |
764 | my $self = shift @_; |
765 | foreach my $source ($self->all_storages) { |
766 | $source->ensure_connected(@_); |
767 | } |
2bf79155 |
768 | } |
769 | |
2bf79155 |
770 | =head2 limit_dialect |
771 | |
772 | Set the limit_dialect for all existing storages |
773 | |
774 | =cut |
775 | |
776 | sub limit_dialect { |
64cdad22 |
777 | my $self = shift @_; |
778 | foreach my $source ($self->all_storages) { |
779 | $source->limit_dialect(@_); |
780 | } |
f3e9f010 |
781 | return $self->master->limit_dialect; |
2bf79155 |
782 | } |
783 | |
2bf79155 |
784 | =head2 quote_char |
785 | |
786 | Set the quote_char for all existing storages |
787 | |
788 | =cut |
789 | |
790 | sub quote_char { |
64cdad22 |
791 | my $self = shift @_; |
792 | foreach my $source ($self->all_storages) { |
793 | $source->quote_char(@_); |
794 | } |
3fbe08e3 |
795 | return $self->master->quote_char; |
2bf79155 |
796 | } |
797 | |
2bf79155 |
798 | =head2 name_sep |
799 | |
800 | Set the name_sep for all existing storages |
801 | |
802 | =cut |
803 | |
804 | sub name_sep { |
64cdad22 |
805 | my $self = shift @_; |
806 | foreach my $source ($self->all_storages) { |
807 | $source->name_sep(@_); |
808 | } |
3fbe08e3 |
809 | return $self->master->name_sep; |
2bf79155 |
810 | } |
811 | |
2bf79155 |
812 | =head2 set_schema |
813 | |
814 | Set the schema object for all existing storages |
815 | |
816 | =cut |
817 | |
818 | sub set_schema { |
64cdad22 |
819 | my $self = shift @_; |
820 | foreach my $source ($self->all_storages) { |
821 | $source->set_schema(@_); |
822 | } |
2bf79155 |
823 | } |
824 | |
2bf79155 |
825 | =head2 debug |
826 | |
827 | set a debug flag across all storages |
828 | |
829 | =cut |
830 | |
831 | sub debug { |
64cdad22 |
832 | my $self = shift @_; |
3fbe08e3 |
833 | if(@_) { |
834 | foreach my $source ($self->all_storages) { |
835 | $source->debug(@_); |
6f7344b8 |
836 | } |
64cdad22 |
837 | } |
3fbe08e3 |
838 | return $self->master->debug; |
2bf79155 |
839 | } |
840 | |
2bf79155 |
841 | =head2 debugobj |
842 | |
cea43436 |
843 | set a debug object |
2bf79155 |
844 | |
845 | =cut |
846 | |
847 | sub debugobj { |
64cdad22 |
848 | my $self = shift @_; |
cea43436 |
849 | return $self->master->debugobj(@_); |
2bf79155 |
850 | } |
851 | |
2bf79155 |
852 | =head2 debugfh |
853 | |
cea43436 |
854 | set a debugfh object |
2bf79155 |
855 | |
856 | =cut |
857 | |
858 | sub debugfh { |
64cdad22 |
859 | my $self = shift @_; |
cea43436 |
860 | return $self->master->debugfh(@_); |
2bf79155 |
861 | } |
862 | |
2bf79155 |
863 | =head2 debugcb |
864 | |
cea43436 |
865 | set a debug callback |
2bf79155 |
866 | |
867 | =cut |
868 | |
869 | sub debugcb { |
64cdad22 |
870 | my $self = shift @_; |
cea43436 |
871 | return $self->master->debugcb(@_); |
2bf79155 |
872 | } |
873 | |
2bf79155 |
874 | =head2 disconnect |
875 | |
876 | disconnect everything |
877 | |
878 | =cut |
879 | |
880 | sub disconnect { |
64cdad22 |
881 | my $self = shift @_; |
882 | foreach my $source ($self->all_storages) { |
883 | $source->disconnect(@_); |
884 | } |
2bf79155 |
885 | } |
886 | |
b2e4d522 |
887 | =head2 cursor_class |
888 | |
889 | set cursor class on all storages, or return master's |
890 | |
891 | =cut |
892 | |
893 | sub cursor_class { |
894 | my ($self, $cursor_class) = @_; |
895 | |
896 | if ($cursor_class) { |
897 | $_->cursor_class($cursor_class) for $self->all_storages; |
898 | } |
899 | $self->master->cursor_class; |
900 | } |
d4daee7b |
901 | |
3244fdcc |
902 | =head2 cursor |
903 | |
904 | set cursor class on all storages, or return master's, alias for L</cursor_class> |
905 | above. |
906 | |
907 | =cut |
908 | |
909 | sub cursor { |
910 | my ($self, $cursor_class) = @_; |
911 | |
912 | if ($cursor_class) { |
913 | $_->cursor($cursor_class) for $self->all_storages; |
914 | } |
915 | $self->master->cursor; |
916 | } |
917 | |
918 | =head2 unsafe |
919 | |
920 | sets the L<DBIx::Class::Storage::DBI/unsafe> option on all storages or returns |
921 | master's current setting |
922 | |
923 | =cut |
924 | |
925 | sub unsafe { |
926 | my $self = shift; |
927 | |
928 | if (@_) { |
929 | $_->unsafe(@_) for $self->all_storages; |
930 | } |
931 | |
932 | return $self->master->unsafe; |
933 | } |
934 | |
935 | =head2 disable_sth_caching |
936 | |
937 | sets the L<DBIx::Class::Storage::DBI/disable_sth_caching> option on all storages |
938 | or returns master's current setting |
939 | |
940 | =cut |
941 | |
942 | sub disable_sth_caching { |
943 | my $self = shift; |
944 | |
945 | if (@_) { |
946 | $_->disable_sth_caching(@_) for $self->all_storages; |
947 | } |
948 | |
949 | return $self->master->disable_sth_caching; |
950 | } |
951 | |
952 | =head2 lag_behind_master |
953 | |
954 | returns the highest Replicant L<DBIx::Class::Storage::DBI/lag_behind_master> |
955 | setting |
956 | |
957 | =cut |
958 | |
959 | sub lag_behind_master { |
960 | my $self = shift; |
961 | |
962 | return max map $_->lag_behind_master, $self->replicants; |
fd323bf1 |
963 | } |
3244fdcc |
964 | |
965 | =head2 is_replicating |
966 | |
967 | returns true if all replicants return true for |
968 | L<DBIx::Class::Storage::DBI/is_replicating> |
969 | |
970 | =cut |
971 | |
972 | sub is_replicating { |
973 | my $self = shift; |
974 | |
975 | return (grep $_->is_replicating, $self->replicants) == ($self->replicants); |
976 | } |
977 | |
978 | =head2 connect_call_datetime_setup |
979 | |
980 | calls L<DBIx::Class::Storage::DBI/connect_call_datetime_setup> for all storages |
981 | |
982 | =cut |
983 | |
984 | sub connect_call_datetime_setup { |
985 | my $self = shift; |
986 | $_->connect_call_datetime_setup for $self->all_storages; |
987 | } |
988 | |
989 | sub _populate_dbh { |
990 | my $self = shift; |
991 | $_->_populate_dbh for $self->all_storages; |
992 | } |
993 | |
994 | sub _connect { |
995 | my $self = shift; |
996 | $_->_connect for $self->all_storages; |
997 | } |
998 | |
999 | sub _rebless { |
1000 | my $self = shift; |
1001 | $_->_rebless for $self->all_storages; |
1002 | } |
1003 | |
1004 | sub _determine_driver { |
1005 | my $self = shift; |
1006 | $_->_determine_driver for $self->all_storages; |
1007 | } |
1008 | |
1009 | sub _driver_determined { |
1010 | my $self = shift; |
fd323bf1 |
1011 | |
3244fdcc |
1012 | if (@_) { |
1013 | $_->_driver_determined(@_) for $self->all_storages; |
1014 | } |
1015 | |
1016 | return $self->master->_driver_determined; |
1017 | } |
1018 | |
1019 | sub _init { |
1020 | my $self = shift; |
fd323bf1 |
1021 | |
3244fdcc |
1022 | $_->_init for $self->all_storages; |
1023 | } |
1024 | |
1025 | sub _run_connection_actions { |
1026 | my $self = shift; |
fd323bf1 |
1027 | |
3244fdcc |
1028 | $_->_run_connection_actions for $self->all_storages; |
1029 | } |
1030 | |
1031 | sub _do_connection_actions { |
1032 | my $self = shift; |
fd323bf1 |
1033 | |
3244fdcc |
1034 | if (@_) { |
1035 | $_->_do_connection_actions(@_) for $self->all_storages; |
1036 | } |
1037 | } |
1038 | |
1039 | sub connect_call_do_sql { |
1040 | my $self = shift; |
1041 | $_->connect_call_do_sql(@_) for $self->all_storages; |
1042 | } |
1043 | |
1044 | sub disconnect_call_do_sql { |
1045 | my $self = shift; |
1046 | $_->disconnect_call_do_sql(@_) for $self->all_storages; |
1047 | } |
1048 | |
1049 | sub _seems_connected { |
1050 | my $self = shift; |
1051 | |
1052 | return min map $_->_seems_connected, $self->all_storages; |
1053 | } |
1054 | |
1055 | sub _ping { |
1056 | my $self = shift; |
1057 | |
1058 | return min map $_->_ping, $self->all_storages; |
1059 | } |
1060 | |
bbdda281 |
1061 | # not using the normalized_version, because we want to preserve |
1062 | # version numbers much longer than the conventional xxx.yyyzzz |
7da56142 |
1063 | my $numify_ver = sub { |
1064 | my $ver = shift; |
1065 | my @numparts = split /\D+/, $ver; |
bbdda281 |
1066 | my $format = '%d.' . (join '', ('%06d') x (@numparts - 1)); |
7da56142 |
1067 | |
1068 | return sprintf $format, @numparts; |
1069 | }; |
fecb38cb |
1070 | sub _server_info { |
1071 | my $self = shift; |
1072 | |
bbdda281 |
1073 | if (not $self->_dbh_details->{info}) { |
1074 | $self->_dbh_details->{info} = ( |
fd323bf1 |
1075 | reduce { $a->[0] < $b->[0] ? $a : $b } |
7da56142 |
1076 | map [ $numify_ver->($_->{dbms_version}), $_ ], |
1077 | map $_->_server_info, $self->all_storages |
1078 | )->[1]; |
fecb38cb |
1079 | } |
1080 | |
bbdda281 |
1081 | return $self->next::method; |
fecb38cb |
1082 | } |
1083 | |
1084 | sub _get_server_version { |
1085 | my $self = shift; |
1086 | |
1087 | return $self->_server_info->{dbms_version}; |
1088 | } |
1089 | |
7e38d850 |
1090 | =head1 GOTCHAS |
1091 | |
1092 | Due to the fact that replicants can lag behind a master, you must take care to |
1093 | make sure you use one of the methods to force read queries to a master should |
1094 | you need realtime data integrity. For example, if you insert a row, and then |
1095 | immediately re-read it from the database (say, by doing $row->discard_changes) |
1096 | or you insert a row and then immediately build a query that expects that row |
1097 | to be an item, you should force the master to handle reads. Otherwise, due to |
1098 | the lag, there is no certainty your data will be in the expected state. |
1099 | |
1100 | For data integrity, all transactions automatically use the master storage for |
1101 | all read and write queries. Using a transaction is the preferred and recommended |
1102 | method to force the master to handle all read queries. |
1103 | |
1104 | Otherwise, you can force a single query to use the master with the 'force_pool' |
1105 | attribute: |
1106 | |
1107 | my $row = $resultset->search(undef, {force_pool=>'master'})->find($pk); |
1108 | |
1109 | This attribute will safely be ignore by non replicated storages, so you can use |
1110 | the same code for both types of systems. |
1111 | |
1112 | Lastly, you can use the L</execute_reliably> method, which works very much like |
1113 | a transaction. |
1114 | |
1115 | For debugging, you can turn replication on/off with the methods L</set_reliable_storage> |
1116 | and L</set_balanced_storage>, however this operates at a global level and is not |
1117 | suitable if you have a shared Schema object being used by multiple processes, |
1118 | such as on a web application server. You can get around this limitation by |
1119 | using the Schema clone method. |
1120 | |
1121 | my $new_schema = $schema->clone; |
1122 | $new_schema->set_reliable_storage; |
d4daee7b |
1123 | |
7e38d850 |
1124 | ## $new_schema will use only the Master storage for all reads/writes while |
1125 | ## the $schema object will use replicated storage. |
1126 | |
f5d3a5de |
1127 | =head1 AUTHOR |
1128 | |
64cdad22 |
1129 | John Napiorkowski <john.napiorkowski@takkle.com> |
f5d3a5de |
1130 | |
c4d3fae2 |
1131 | Based on code originated by: |
f5d3a5de |
1132 | |
64cdad22 |
1133 | Norbert Csongrádi <bert@cpan.org> |
1134 | Peter Siklósi <einon@einon.hu> |
2156bbdd |
1135 | |
f5d3a5de |
1136 | =head1 LICENSE |
1137 | |
1138 | You may distribute this code under the same terms as Perl itself. |
1139 | |
1140 | =cut |
1141 | |
c354902c |
1142 | __PACKAGE__->meta->make_immutable; |
1143 | |
f5d3a5de |
1144 | 1; |