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1 | package DBIx::Class::Storage::DBI::Replicated; |
f5d3a5de |
2 | |
ecb65397 |
3 | BEGIN { |
4 | use Carp::Clan qw/^DBIx::Class/; |
5 | |
6 | ## Modules required for Replication support not required for general DBIC |
7 | ## use, so we explicitly test for these. |
8 | |
9 | my %replication_required = ( |
9901aad7 |
10 | Moose => '0.77', |
ecb65397 |
11 | MooseX::AttributeHelpers => '0.12', |
9901aad7 |
12 | MooseX::Types => '0.10', |
13 | namespace::clean => '0.11', |
ecb65397 |
14 | ); |
15 | |
16 | my @didnt_load; |
17 | |
18 | for my $module (keys %replication_required) { |
19 | eval "use $module $replication_required{$module}"; |
20 | push @didnt_load, "$module $replication_required{$module}" |
21 | if $@; |
22 | } |
23 | |
24 | croak("@{[ join ', ', @didnt_load ]} are missing and are required for Replication") |
25 | if @didnt_load; |
26 | } |
27 | |
b2e4d522 |
28 | use Moose; |
26ab719a |
29 | use DBIx::Class::Storage::DBI; |
2bf79155 |
30 | use DBIx::Class::Storage::DBI::Replicated::Pool; |
26ab719a |
31 | use DBIx::Class::Storage::DBI::Replicated::Balancer; |
9901aad7 |
32 | use DBIx::Class::Storage::DBI::Replicated::Types 'BalancerClassNamePart'; |
41916570 |
33 | use MooseX::Types::Moose qw/ClassName HashRef Object/; |
b2e4d522 |
34 | use Scalar::Util 'reftype'; |
35 | use Carp::Clan qw/^DBIx::Class/; |
9901aad7 |
36 | |
37 | use namespace::clean -except => 'meta'; |
2bf79155 |
38 | |
39 | =head1 NAME |
40 | |
ecb65397 |
41 | DBIx::Class::Storage::DBI::Replicated - BETA Replicated database support |
2bf79155 |
42 | |
43 | =head1 SYNOPSIS |
44 | |
45 | The Following example shows how to change an existing $schema to a replicated |
46 | storage type, add some replicated (readonly) databases, and perform reporting |
955a6df6 |
47 | tasks. |
2bf79155 |
48 | |
64cdad22 |
49 | ## Change storage_type in your schema class |
50 | $schema->storage_type( ['::DBI::Replicated', {balancer=>'::Random'}] ); |
51 | |
52 | ## Add some slaves. Basically this is an array of arrayrefs, where each |
53 | ## arrayref is database connect information |
54 | |
55 | $schema->storage->connect_replicants( |
56 | [$dsn1, $user, $pass, \%opts], |
57 | [$dsn2, $user, $pass, \%opts], |
58 | [$dsn3, $user, $pass, \%opts], |
59 | ); |
60 | |
7e38d850 |
61 | ## Now, just use the $schema as normal |
62 | $schema->resultset('Source')->search({name=>'etc'}); |
63 | |
64 | ## You can force a given query to use a particular storage using the search |
65 | ### attribute 'force_pool'. For example: |
66 | |
67 | my $RS = $schema->resultset('Source')->search(undef, {force_pool=>'master'}); |
68 | |
69 | ## Now $RS will force everything (both reads and writes) to use whatever was |
70 | ## setup as the master storage. 'master' is hardcoded to always point to the |
71 | ## Master, but you can also use any Replicant name. Please see: |
72 | ## L<DBIx::Class::Storage::Replicated::Pool> and the replicants attribute for |
73 | ## More. Also see transactions and L</execute_reliably> for alternative ways |
74 | ## to force read traffic to the master. |
75 | |
2bf79155 |
76 | =head1 DESCRIPTION |
77 | |
7e38d850 |
78 | Warning: This class is marked BETA. This has been running a production |
ccb3b897 |
79 | website using MySQL native replication as its backend and we have some decent |
7e38d850 |
80 | test coverage but the code hasn't yet been stressed by a variety of databases. |
81 | Individual DB's may have quirks we are not aware of. Please use this in first |
82 | development and pass along your experiences/bug fixes. |
2bf79155 |
83 | |
84 | This class implements replicated data store for DBI. Currently you can define |
85 | one master and numerous slave database connections. All write-type queries |
86 | (INSERT, UPDATE, DELETE and even LAST_INSERT_ID) are routed to master |
87 | database, all read-type queries (SELECTs) go to the slave database. |
88 | |
89 | Basically, any method request that L<DBIx::Class::Storage::DBI> would normally |
bca099a3 |
90 | handle gets delegated to one of the two attributes: L</read_handler> or to |
91 | L</write_handler>. Additionally, some methods need to be distributed |
2bf79155 |
92 | to all existing storages. This way our storage class is a drop in replacement |
93 | for L<DBIx::Class::Storage::DBI>. |
94 | |
95 | Read traffic is spread across the replicants (slaves) occuring to a user |
96 | selected algorithm. The default algorithm is random weighted. |
97 | |
bca099a3 |
98 | =head1 NOTES |
99 | |
100 | The consistancy betweeen master and replicants is database specific. The Pool |
101 | gives you a method to validate it's replicants, removing and replacing them |
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102 | when they fail/pass predefined criteria. Please make careful use of the ways |
ecb65397 |
103 | to force a query to run against Master when needed. |
104 | |
105 | =head1 REQUIREMENTS |
106 | |
107 | Replicated Storage has additional requirements not currently part of L<DBIx::Class> |
108 | |
9901aad7 |
109 | Moose => 0.77 |
ecb65397 |
110 | MooseX::AttributeHelpers => 0.12 |
9901aad7 |
111 | MooseX::Types => 0.10 |
112 | namespace::clean => 0.11 |
ecb65397 |
113 | |
114 | You will need to install these modules manually via CPAN or make them part of the |
115 | Makefile for your distribution. |
2bf79155 |
116 | |
117 | =head1 ATTRIBUTES |
118 | |
119 | This class defines the following attributes. |
120 | |
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121 | =head2 schema |
122 | |
123 | The underlying L<DBIx::Class::Schema> object this storage is attaching |
124 | |
125 | =cut |
126 | |
127 | has 'schema' => ( |
128 | is=>'rw', |
129 | isa=>'DBIx::Class::Schema', |
130 | weak_ref=>1, |
131 | required=>1, |
132 | ); |
133 | |
26ab719a |
134 | =head2 pool_type |
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135 | |
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136 | Contains the classname which will instantiate the L</pool> object. Defaults |
137 | to: L<DBIx::Class::Storage::DBI::Replicated::Pool>. |
2bf79155 |
138 | |
139 | =cut |
140 | |
26ab719a |
141 | has 'pool_type' => ( |
dcdf7b2c |
142 | is=>'rw', |
41916570 |
143 | isa=>ClassName, |
2ce6e9a6 |
144 | default=>'DBIx::Class::Storage::DBI::Replicated::Pool', |
64cdad22 |
145 | handles=>{ |
146 | 'create_pool' => 'new', |
147 | }, |
2bf79155 |
148 | ); |
149 | |
f068a139 |
150 | =head2 pool_args |
151 | |
152 | Contains a hashref of initialized information to pass to the Balancer object. |
153 | See L<DBIx::Class::Storage::Replicated::Pool> for available arguments. |
154 | |
155 | =cut |
156 | |
157 | has 'pool_args' => ( |
dcdf7b2c |
158 | is=>'rw', |
41916570 |
159 | isa=>HashRef, |
64cdad22 |
160 | lazy=>1, |
64cdad22 |
161 | default=>sub { {} }, |
f068a139 |
162 | ); |
163 | |
164 | |
26ab719a |
165 | =head2 balancer_type |
2bf79155 |
166 | |
167 | The replication pool requires a balance class to provider the methods for |
168 | choose how to spread the query load across each replicant in the pool. |
169 | |
170 | =cut |
171 | |
26ab719a |
172 | has 'balancer_type' => ( |
dcdf7b2c |
173 | is=>'rw', |
9901aad7 |
174 | isa=>BalancerClassNamePart, |
2ce6e9a6 |
175 | coerce=>1, |
176 | required=>1, |
177 | default=> 'DBIx::Class::Storage::DBI::Replicated::Balancer::First', |
64cdad22 |
178 | handles=>{ |
179 | 'create_balancer' => 'new', |
180 | }, |
2bf79155 |
181 | ); |
182 | |
17b05c13 |
183 | =head2 balancer_args |
184 | |
185 | Contains a hashref of initialized information to pass to the Balancer object. |
f068a139 |
186 | See L<DBIx::Class::Storage::Replicated::Balancer> for available arguments. |
17b05c13 |
187 | |
188 | =cut |
189 | |
190 | has 'balancer_args' => ( |
dcdf7b2c |
191 | is=>'rw', |
41916570 |
192 | isa=>HashRef, |
64cdad22 |
193 | lazy=>1, |
194 | required=>1, |
195 | default=>sub { {} }, |
17b05c13 |
196 | ); |
197 | |
26ab719a |
198 | =head2 pool |
2bf79155 |
199 | |
26ab719a |
200 | Is a <DBIx::Class::Storage::DBI::Replicated::Pool> or derived class. This is a |
201 | container class for one or more replicated databases. |
2bf79155 |
202 | |
203 | =cut |
204 | |
26ab719a |
205 | has 'pool' => ( |
64cdad22 |
206 | is=>'ro', |
207 | isa=>'DBIx::Class::Storage::DBI::Replicated::Pool', |
208 | lazy_build=>1, |
209 | handles=>[qw/ |
210 | connect_replicants |
211 | replicants |
212 | has_replicants |
213 | /], |
2bf79155 |
214 | ); |
215 | |
26ab719a |
216 | =head2 balancer |
2bf79155 |
217 | |
26ab719a |
218 | Is a <DBIx::Class::Storage::DBI::Replicated::Balancer> or derived class. This |
219 | is a class that takes a pool (<DBIx::Class::Storage::DBI::Replicated::Pool>) |
2bf79155 |
220 | |
26ab719a |
221 | =cut |
2bf79155 |
222 | |
26ab719a |
223 | has 'balancer' => ( |
dcdf7b2c |
224 | is=>'rw', |
64cdad22 |
225 | isa=>'DBIx::Class::Storage::DBI::Replicated::Balancer', |
226 | lazy_build=>1, |
227 | handles=>[qw/auto_validate_every/], |
26ab719a |
228 | ); |
2bf79155 |
229 | |
cb6ec758 |
230 | =head2 master |
231 | |
232 | The master defines the canonical state for a pool of connected databases. All |
233 | the replicants are expected to match this databases state. Thus, in a classic |
234 | Master / Slaves distributed system, all the slaves are expected to replicate |
235 | the Master's state as quick as possible. This is the only database in the |
236 | pool of databases that is allowed to handle write traffic. |
237 | |
238 | =cut |
239 | |
240 | has 'master' => ( |
64cdad22 |
241 | is=> 'ro', |
242 | isa=>'DBIx::Class::Storage::DBI', |
243 | lazy_build=>1, |
cb6ec758 |
244 | ); |
245 | |
cb6ec758 |
246 | =head1 ATTRIBUTES IMPLEMENTING THE DBIx::Storage::DBI INTERFACE |
247 | |
248 | The following methods are delegated all the methods required for the |
249 | L<DBIx::Class::Storage::DBI> interface. |
250 | |
251 | =head2 read_handler |
252 | |
253 | Defines an object that implements the read side of L<BIx::Class::Storage::DBI>. |
254 | |
255 | =cut |
256 | |
257 | has 'read_handler' => ( |
64cdad22 |
258 | is=>'rw', |
41916570 |
259 | isa=>Object, |
64cdad22 |
260 | lazy_build=>1, |
261 | handles=>[qw/ |
262 | select |
263 | select_single |
264 | columns_info_for |
265 | /], |
cb6ec758 |
266 | ); |
267 | |
cb6ec758 |
268 | =head2 write_handler |
269 | |
270 | Defines an object that implements the write side of L<BIx::Class::Storage::DBI>. |
271 | |
272 | =cut |
273 | |
274 | has 'write_handler' => ( |
64cdad22 |
275 | is=>'ro', |
41916570 |
276 | isa=>Object, |
64cdad22 |
277 | lazy_build=>1, |
64cdad22 |
278 | handles=>[qw/ |
279 | on_connect_do |
280 | on_disconnect_do |
281 | connect_info |
282 | throw_exception |
283 | sql_maker |
284 | sqlt_type |
285 | create_ddl_dir |
286 | deployment_statements |
287 | datetime_parser |
288 | datetime_parser_type |
289 | last_insert_id |
290 | insert |
291 | insert_bulk |
292 | update |
293 | delete |
294 | dbh |
2ce6e9a6 |
295 | txn_begin |
64cdad22 |
296 | txn_do |
297 | txn_commit |
298 | txn_rollback |
2ce6e9a6 |
299 | txn_scope_guard |
64cdad22 |
300 | sth |
301 | deploy |
0180bef9 |
302 | with_deferred_fk_checks |
2ce6e9a6 |
303 | |
64cdad22 |
304 | reload_row |
2ce6e9a6 |
305 | _prep_for_execute |
2ce6e9a6 |
306 | |
64cdad22 |
307 | /], |
cb6ec758 |
308 | ); |
309 | |
b2e4d522 |
310 | has _master_connect_info_opts => |
311 | (is => 'rw', isa => HashRef, default => sub { {} }); |
312 | |
313 | =head2 around: connect_info |
314 | |
315 | Preserve master's C<connect_info> options (for merging with replicants.) |
dcdf7b2c |
316 | Also set any Replicated related options from connect_info, such as |
317 | C<pool_type>, C<pool_args>, C<balancer_type> and C<balancer_args>. |
b2e4d522 |
318 | |
319 | =cut |
320 | |
321 | around connect_info => sub { |
322 | my ($next, $self, $info, @extra) = @_; |
323 | |
324 | my %opts; |
325 | for my $arg (@$info) { |
326 | next unless (reftype($arg)||'') eq 'HASH'; |
327 | %opts = (%opts, %$arg); |
328 | } |
b2e4d522 |
329 | delete $opts{dsn}; |
330 | |
dcdf7b2c |
331 | if (@opts{qw/pool_type pool_args/}) { |
332 | $self->pool_type(delete $opts{pool_type}) |
333 | if $opts{pool_type}; |
334 | |
335 | $self->pool_args({ |
336 | %{ $self->pool_args }, |
337 | %{ delete $opts{pool_args} || {} } |
338 | }); |
339 | |
340 | $self->pool($self->_build_pool); |
341 | } |
342 | |
343 | if (@opts{qw/balancer_type balancer_args/}) { |
344 | $self->balancer_type(delete $opts{balancer_type}) |
345 | if $opts{balancer_type}; |
346 | |
347 | $self->balancer_args({ |
348 | %{ $self->balancer_args }, |
349 | %{ delete $opts{balancer_args} || {} } |
350 | }); |
351 | |
352 | $self->balancer($self->_build_balancer); |
353 | } |
354 | |
b2e4d522 |
355 | $self->_master_connect_info_opts(\%opts); |
356 | |
357 | $self->$next($info, @extra); |
358 | }; |
359 | |
26ab719a |
360 | =head1 METHODS |
2bf79155 |
361 | |
26ab719a |
362 | This class defines the following methods. |
2bf79155 |
363 | |
c354902c |
364 | =head2 BUILDARGS |
2bf79155 |
365 | |
cb6ec758 |
366 | L<DBIx::Class::Schema> when instantiating it's storage passed itself as the |
2ce6e9a6 |
367 | first argument. So we need to massage the arguments a bit so that all the |
368 | bits get put into the correct places. |
2bf79155 |
369 | |
370 | =cut |
371 | |
c354902c |
372 | sub BUILDARGS { |
373 | my ($class, $schema, $storage_type_args, @args) = @_; |
374 | |
375 | return { |
376 | schema=>$schema, |
377 | %$storage_type_args, |
378 | @args |
379 | } |
380 | } |
2bf79155 |
381 | |
cb6ec758 |
382 | =head2 _build_master |
2bf79155 |
383 | |
cb6ec758 |
384 | Lazy builder for the L</master> attribute. |
2bf79155 |
385 | |
386 | =cut |
387 | |
cb6ec758 |
388 | sub _build_master { |
2ce6e9a6 |
389 | my $self = shift @_; |
ee356d00 |
390 | my $master = DBIx::Class::Storage::DBI->new($self->schema); |
391 | DBIx::Class::Storage::DBI::Replicated::WithDSN->meta->apply($master); |
392 | $master |
106d5f3b |
393 | } |
394 | |
26ab719a |
395 | =head2 _build_pool |
2bf79155 |
396 | |
26ab719a |
397 | Lazy builder for the L</pool> attribute. |
2bf79155 |
398 | |
399 | =cut |
400 | |
26ab719a |
401 | sub _build_pool { |
64cdad22 |
402 | my $self = shift @_; |
403 | $self->create_pool(%{$self->pool_args}); |
2bf79155 |
404 | } |
405 | |
26ab719a |
406 | =head2 _build_balancer |
2bf79155 |
407 | |
cb6ec758 |
408 | Lazy builder for the L</balancer> attribute. This takes a Pool object so that |
409 | the balancer knows which pool it's balancing. |
2bf79155 |
410 | |
411 | =cut |
412 | |
26ab719a |
413 | sub _build_balancer { |
64cdad22 |
414 | my $self = shift @_; |
415 | $self->create_balancer( |
416 | pool=>$self->pool, |
417 | master=>$self->master, |
418 | %{$self->balancer_args}, |
419 | ); |
2bf79155 |
420 | } |
421 | |
cb6ec758 |
422 | =head2 _build_write_handler |
2bf79155 |
423 | |
cb6ec758 |
424 | Lazy builder for the L</write_handler> attribute. The default is to set this to |
425 | the L</master>. |
50336325 |
426 | |
427 | =cut |
428 | |
cb6ec758 |
429 | sub _build_write_handler { |
64cdad22 |
430 | return shift->master; |
cb6ec758 |
431 | } |
50336325 |
432 | |
cb6ec758 |
433 | =head2 _build_read_handler |
2bf79155 |
434 | |
cb6ec758 |
435 | Lazy builder for the L</read_handler> attribute. The default is to set this to |
436 | the L</balancer>. |
2bf79155 |
437 | |
438 | =cut |
439 | |
cb6ec758 |
440 | sub _build_read_handler { |
64cdad22 |
441 | return shift->balancer; |
cb6ec758 |
442 | } |
50336325 |
443 | |
cb6ec758 |
444 | =head2 around: connect_replicants |
2bf79155 |
445 | |
cb6ec758 |
446 | All calls to connect_replicants needs to have an existing $schema tacked onto |
b2e4d522 |
447 | top of the args, since L<DBIx::Storage::DBI> needs it, and any C<connect_info> |
448 | options merged with the master, with replicant opts having higher priority. |
955a6df6 |
449 | |
cb6ec758 |
450 | =cut |
955a6df6 |
451 | |
b2e4d522 |
452 | around connect_replicants => sub { |
453 | my ($next, $self, @args) = @_; |
454 | |
455 | for my $r (@args) { |
456 | $r = [ $r ] unless reftype $r eq 'ARRAY'; |
457 | |
458 | croak "coderef replicant connect_info not supported" |
459 | if ref $r->[0] && reftype $r->[0] eq 'CODE'; |
460 | |
461 | # any connect_info options? |
462 | my $i = 0; |
463 | $i++ while $i < @$r && (reftype($r->[$i])||'') ne 'HASH'; |
464 | |
465 | # make one if none |
466 | $r->[$i] = {} unless $r->[$i]; |
467 | |
468 | # merge if two hashes |
469 | my %opts = map %$_, @$r[$i .. $#{$r}]; |
470 | splice @$r, $i+1, ($#{$r} - $i), (); |
471 | |
472 | # merge with master |
473 | %opts = (%{ $self->_master_connect_info_opts }, %opts); |
474 | |
475 | # update |
476 | $r->[$i] = \%opts; |
477 | } |
478 | |
479 | $self->$next($self->schema, @args); |
955a6df6 |
480 | }; |
2bf79155 |
481 | |
2bf79155 |
482 | =head2 all_storages |
483 | |
484 | Returns an array of of all the connected storage backends. The first element |
485 | in the returned array is the master, and the remainings are each of the |
486 | replicants. |
487 | |
488 | =cut |
489 | |
490 | sub all_storages { |
64cdad22 |
491 | my $self = shift @_; |
492 | return grep {defined $_ && blessed $_} ( |
493 | $self->master, |
6412a592 |
494 | values %{ $self->replicants }, |
64cdad22 |
495 | ); |
2bf79155 |
496 | } |
497 | |
c4d3fae2 |
498 | =head2 execute_reliably ($coderef, ?@args) |
499 | |
500 | Given a coderef, saves the current state of the L</read_handler>, forces it to |
501 | use reliable storage (ie sets it to the master), executes a coderef and then |
502 | restores the original state. |
503 | |
504 | Example: |
505 | |
64cdad22 |
506 | my $reliably = sub { |
507 | my $name = shift @_; |
508 | $schema->resultset('User')->create({name=>$name}); |
509 | my $user_rs = $schema->resultset('User')->find({name=>$name}); |
510 | return $user_rs; |
511 | }; |
c4d3fae2 |
512 | |
64cdad22 |
513 | my $user_rs = $schema->storage->execute_reliably($reliably, 'John'); |
c4d3fae2 |
514 | |
515 | Use this when you must be certain of your database state, such as when you just |
516 | inserted something and need to get a resultset including it, etc. |
517 | |
518 | =cut |
519 | |
520 | sub execute_reliably { |
64cdad22 |
521 | my ($self, $coderef, @args) = @_; |
522 | |
523 | unless( ref $coderef eq 'CODE') { |
524 | $self->throw_exception('Second argument must be a coderef'); |
525 | } |
526 | |
527 | ##Get copy of master storage |
528 | my $master = $self->master; |
529 | |
530 | ##Get whatever the current read hander is |
531 | my $current = $self->read_handler; |
532 | |
533 | ##Set the read handler to master |
534 | $self->read_handler($master); |
535 | |
536 | ## do whatever the caller needs |
537 | my @result; |
538 | my $want_array = wantarray; |
539 | |
540 | eval { |
541 | if($want_array) { |
542 | @result = $coderef->(@args); |
543 | } elsif(defined $want_array) { |
544 | ($result[0]) = ($coderef->(@args)); |
ed213e85 |
545 | } else { |
64cdad22 |
546 | $coderef->(@args); |
547 | } |
548 | }; |
549 | |
550 | ##Reset to the original state |
551 | $self->read_handler($current); |
552 | |
553 | ##Exception testing has to come last, otherwise you might leave the |
554 | ##read_handler set to master. |
555 | |
556 | if($@) { |
557 | $self->throw_exception("coderef returned an error: $@"); |
558 | } else { |
559 | return $want_array ? @result : $result[0]; |
560 | } |
c4d3fae2 |
561 | } |
562 | |
cb6ec758 |
563 | =head2 set_reliable_storage |
564 | |
565 | Sets the current $schema to be 'reliable', that is all queries, both read and |
566 | write are sent to the master |
64cdad22 |
567 | |
cb6ec758 |
568 | =cut |
569 | |
570 | sub set_reliable_storage { |
64cdad22 |
571 | my $self = shift @_; |
572 | my $schema = $self->schema; |
573 | my $write_handler = $self->schema->storage->write_handler; |
574 | |
575 | $schema->storage->read_handler($write_handler); |
cb6ec758 |
576 | } |
577 | |
578 | =head2 set_balanced_storage |
579 | |
580 | Sets the current $schema to be use the </balancer> for all reads, while all |
581 | writea are sent to the master only |
64cdad22 |
582 | |
cb6ec758 |
583 | =cut |
584 | |
585 | sub set_balanced_storage { |
64cdad22 |
586 | my $self = shift @_; |
587 | my $schema = $self->schema; |
588 | my $write_handler = $self->schema->storage->balancer; |
589 | |
590 | $schema->storage->read_handler($write_handler); |
cb6ec758 |
591 | } |
2bf79155 |
592 | |
6834cc1d |
593 | =head2 around: txn_do ($coderef) |
c4d3fae2 |
594 | |
595 | Overload to the txn_do method, which is delegated to whatever the |
596 | L<write_handler> is set to. We overload this in order to wrap in inside a |
597 | L</execute_reliably> method. |
598 | |
599 | =cut |
600 | |
6834cc1d |
601 | around 'txn_do' => sub { |
64cdad22 |
602 | my($txn_do, $self, $coderef, @args) = @_; |
603 | $self->execute_reliably(sub {$self->$txn_do($coderef, @args)}); |
6834cc1d |
604 | }; |
c4d3fae2 |
605 | |
2bf79155 |
606 | =head2 connected |
607 | |
608 | Check that the master and at least one of the replicants is connected. |
609 | |
610 | =cut |
611 | |
612 | sub connected { |
64cdad22 |
613 | my $self = shift @_; |
614 | return |
615 | $self->master->connected && |
616 | $self->pool->connected_replicants; |
2bf79155 |
617 | } |
618 | |
2bf79155 |
619 | =head2 ensure_connected |
620 | |
621 | Make sure all the storages are connected. |
622 | |
623 | =cut |
624 | |
625 | sub ensure_connected { |
64cdad22 |
626 | my $self = shift @_; |
627 | foreach my $source ($self->all_storages) { |
628 | $source->ensure_connected(@_); |
629 | } |
2bf79155 |
630 | } |
631 | |
2bf79155 |
632 | =head2 limit_dialect |
633 | |
634 | Set the limit_dialect for all existing storages |
635 | |
636 | =cut |
637 | |
638 | sub limit_dialect { |
64cdad22 |
639 | my $self = shift @_; |
640 | foreach my $source ($self->all_storages) { |
641 | $source->limit_dialect(@_); |
642 | } |
3fbe08e3 |
643 | return $self->master->quote_char; |
2bf79155 |
644 | } |
645 | |
2bf79155 |
646 | =head2 quote_char |
647 | |
648 | Set the quote_char for all existing storages |
649 | |
650 | =cut |
651 | |
652 | sub quote_char { |
64cdad22 |
653 | my $self = shift @_; |
654 | foreach my $source ($self->all_storages) { |
655 | $source->quote_char(@_); |
656 | } |
3fbe08e3 |
657 | return $self->master->quote_char; |
2bf79155 |
658 | } |
659 | |
2bf79155 |
660 | =head2 name_sep |
661 | |
662 | Set the name_sep for all existing storages |
663 | |
664 | =cut |
665 | |
666 | sub name_sep { |
64cdad22 |
667 | my $self = shift @_; |
668 | foreach my $source ($self->all_storages) { |
669 | $source->name_sep(@_); |
670 | } |
3fbe08e3 |
671 | return $self->master->name_sep; |
2bf79155 |
672 | } |
673 | |
2bf79155 |
674 | =head2 set_schema |
675 | |
676 | Set the schema object for all existing storages |
677 | |
678 | =cut |
679 | |
680 | sub set_schema { |
64cdad22 |
681 | my $self = shift @_; |
682 | foreach my $source ($self->all_storages) { |
683 | $source->set_schema(@_); |
684 | } |
2bf79155 |
685 | } |
686 | |
2bf79155 |
687 | =head2 debug |
688 | |
689 | set a debug flag across all storages |
690 | |
691 | =cut |
692 | |
693 | sub debug { |
64cdad22 |
694 | my $self = shift @_; |
3fbe08e3 |
695 | if(@_) { |
696 | foreach my $source ($self->all_storages) { |
697 | $source->debug(@_); |
698 | } |
64cdad22 |
699 | } |
3fbe08e3 |
700 | return $self->master->debug; |
2bf79155 |
701 | } |
702 | |
2bf79155 |
703 | =head2 debugobj |
704 | |
705 | set a debug object across all storages |
706 | |
707 | =cut |
708 | |
709 | sub debugobj { |
64cdad22 |
710 | my $self = shift @_; |
3fbe08e3 |
711 | if(@_) { |
712 | foreach my $source ($self->all_storages) { |
713 | $source->debugobj(@_); |
714 | } |
64cdad22 |
715 | } |
3fbe08e3 |
716 | return $self->master->debugobj; |
2bf79155 |
717 | } |
718 | |
2bf79155 |
719 | =head2 debugfh |
720 | |
721 | set a debugfh object across all storages |
722 | |
723 | =cut |
724 | |
725 | sub debugfh { |
64cdad22 |
726 | my $self = shift @_; |
3fbe08e3 |
727 | if(@_) { |
728 | foreach my $source ($self->all_storages) { |
729 | $source->debugfh(@_); |
730 | } |
64cdad22 |
731 | } |
3fbe08e3 |
732 | return $self->master->debugfh; |
2bf79155 |
733 | } |
734 | |
2bf79155 |
735 | =head2 debugcb |
736 | |
737 | set a debug callback across all storages |
738 | |
739 | =cut |
740 | |
741 | sub debugcb { |
64cdad22 |
742 | my $self = shift @_; |
3fbe08e3 |
743 | if(@_) { |
744 | foreach my $source ($self->all_storages) { |
745 | $source->debugcb(@_); |
746 | } |
64cdad22 |
747 | } |
3fbe08e3 |
748 | return $self->master->debugcb; |
2bf79155 |
749 | } |
750 | |
2bf79155 |
751 | =head2 disconnect |
752 | |
753 | disconnect everything |
754 | |
755 | =cut |
756 | |
757 | sub disconnect { |
64cdad22 |
758 | my $self = shift @_; |
759 | foreach my $source ($self->all_storages) { |
760 | $source->disconnect(@_); |
761 | } |
2bf79155 |
762 | } |
763 | |
b2e4d522 |
764 | =head2 cursor_class |
765 | |
766 | set cursor class on all storages, or return master's |
767 | |
768 | =cut |
769 | |
770 | sub cursor_class { |
771 | my ($self, $cursor_class) = @_; |
772 | |
773 | if ($cursor_class) { |
774 | $_->cursor_class($cursor_class) for $self->all_storages; |
775 | } |
776 | $self->master->cursor_class; |
777 | } |
778 | |
7e38d850 |
779 | =head1 GOTCHAS |
780 | |
781 | Due to the fact that replicants can lag behind a master, you must take care to |
782 | make sure you use one of the methods to force read queries to a master should |
783 | you need realtime data integrity. For example, if you insert a row, and then |
784 | immediately re-read it from the database (say, by doing $row->discard_changes) |
785 | or you insert a row and then immediately build a query that expects that row |
786 | to be an item, you should force the master to handle reads. Otherwise, due to |
787 | the lag, there is no certainty your data will be in the expected state. |
788 | |
789 | For data integrity, all transactions automatically use the master storage for |
790 | all read and write queries. Using a transaction is the preferred and recommended |
791 | method to force the master to handle all read queries. |
792 | |
793 | Otherwise, you can force a single query to use the master with the 'force_pool' |
794 | attribute: |
795 | |
796 | my $row = $resultset->search(undef, {force_pool=>'master'})->find($pk); |
797 | |
798 | This attribute will safely be ignore by non replicated storages, so you can use |
799 | the same code for both types of systems. |
800 | |
801 | Lastly, you can use the L</execute_reliably> method, which works very much like |
802 | a transaction. |
803 | |
804 | For debugging, you can turn replication on/off with the methods L</set_reliable_storage> |
805 | and L</set_balanced_storage>, however this operates at a global level and is not |
806 | suitable if you have a shared Schema object being used by multiple processes, |
807 | such as on a web application server. You can get around this limitation by |
808 | using the Schema clone method. |
809 | |
810 | my $new_schema = $schema->clone; |
811 | $new_schema->set_reliable_storage; |
812 | |
813 | ## $new_schema will use only the Master storage for all reads/writes while |
814 | ## the $schema object will use replicated storage. |
815 | |
f5d3a5de |
816 | =head1 AUTHOR |
817 | |
64cdad22 |
818 | John Napiorkowski <john.napiorkowski@takkle.com> |
f5d3a5de |
819 | |
c4d3fae2 |
820 | Based on code originated by: |
f5d3a5de |
821 | |
64cdad22 |
822 | Norbert Csongrádi <bert@cpan.org> |
823 | Peter Siklósi <einon@einon.hu> |
2156bbdd |
824 | |
f5d3a5de |
825 | =head1 LICENSE |
826 | |
827 | You may distribute this code under the same terms as Perl itself. |
828 | |
829 | =cut |
830 | |
c354902c |
831 | __PACKAGE__->meta->make_immutable; |
832 | |
f5d3a5de |
833 | 1; |