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1 | package DBIx::Class::Storage::DBI::Replicated; |
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2 | |
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3 | BEGIN { |
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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 | |
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9 | use Moose; |
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10 | use DBIx::Class::Storage::DBI; |
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11 | use DBIx::Class::Storage::DBI::Replicated::Pool; |
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12 | use DBIx::Class::Storage::DBI::Replicated::Balancer; |
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13 | use DBIx::Class::Storage::DBI::Replicated::Types qw/BalancerClassNamePart DBICSchema DBICStorageDBI/; |
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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; |
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20 | |
21 | use namespace::clean -except => 'meta'; |
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22 | |
23 | =head1 NAME |
24 | |
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25 | DBIx::Class::Storage::DBI::Replicated - BETA Replicated database support |
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26 | |
27 | =head1 SYNOPSIS |
28 | |
29 | The Following example shows how to change an existing $schema to a replicated |
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30 | storage type, add some replicated (read-only) databases, and perform reporting |
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31 | tasks. |
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32 | |
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33 | You should set the 'storage_type attribute to a replicated type. You should |
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34 | also define your arguments, such as which balancer you want and any arguments |
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35 | that the Pool object should get. |
36 | |
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37 | my $schema = Schema::Class->clone; |
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38 | $schema->storage_type( ['::DBI::Replicated', {balancer=>'::Random'}] ); |
ce854fd3 |
39 | $schema->connection(...); |
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40 | |
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41 | Next, you need to add in the Replicants. Basically this is an array of |
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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. |
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44 | |
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45 | $schema->storage->connect_replicants( |
46 | [$dsn1, $user, $pass, \%opts], |
47 | [$dsn2, $user, $pass, \%opts], |
48 | [$dsn3, $user, $pass, \%opts], |
49 | ); |
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50 | |
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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'}); |
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55 | |
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56 | You can force a given query to use a particular storage using the search |
57 | attribute 'force_pool'. For example: |
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58 | |
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59 | my $RS = $schema->resultset('Source')->search(undef, {force_pool=>'master'}); |
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60 | |
61 | Now $RS will force everything (both reads and writes) to use whatever was setup |
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62 | as the master storage. 'master' is hardcoded to always point to the Master, |
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63 | but you can also use any Replicant name. Please see: |
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64 | L<DBIx::Class::Storage::DBI::Replicated::Pool> and the replicants attribute for more. |
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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. |
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70 | |
71 | See L<DBIx::Class::Storage::DBI::Replicated::Instructions> for more help and |
72 | walkthroughs. |
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73 | |
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74 | =head1 DESCRIPTION |
75 | |
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76 | Warning: This class is marked BETA. This has been running a production |
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77 | website using MySQL native replication as its backend and we have some decent |
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78 | test coverage but the code hasn't yet been stressed by a variety of databases. |
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79 | Individual DBs may have quirks we are not aware of. Please use this in first |
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80 | development and pass along your experiences/bug fixes. |
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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 |
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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 |
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90 | to all existing storages. This way our storage class is a drop in replacement |
91 | for L<DBIx::Class::Storage::DBI>. |
92 | |
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93 | Read traffic is spread across the replicants (slaves) occurring to a user |
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94 | selected algorithm. The default algorithm is random weighted. |
95 | |
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96 | =head1 NOTES |
97 | |
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98 | The consistency between master and replicants is database specific. The Pool |
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99 | gives you a method to validate its replicants, removing and replacing them |
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100 | when they fail/pass predefined criteria. Please make careful use of the ways |
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101 | to force a query to run against Master when needed. |
102 | |
103 | =head1 REQUIREMENTS |
104 | |
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105 | Replicated Storage has additional requirements not currently part of |
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106 | L<DBIx::Class>. See L<DBIx::Class::Optional::Dependencies> for more details. |
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107 | |
108 | =head1 ATTRIBUTES |
109 | |
110 | This class defines the following attributes. |
111 | |
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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', |
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120 | isa=>DBICSchema, |
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121 | weak_ref=>1, |
122 | required=>1, |
123 | ); |
124 | |
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125 | =head2 pool_type |
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126 | |
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127 | Contains the classname which will instantiate the L</pool> object. Defaults |
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128 | to: L<DBIx::Class::Storage::DBI::Replicated::Pool>. |
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129 | |
130 | =cut |
131 | |
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132 | has 'pool_type' => ( |
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133 | is=>'rw', |
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134 | isa=>ClassName, |
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135 | default=>'DBIx::Class::Storage::DBI::Replicated::Pool', |
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136 | handles=>{ |
137 | 'create_pool' => 'new', |
138 | }, |
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139 | ); |
140 | |
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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' => ( |
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149 | is=>'rw', |
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150 | isa=>HashRef, |
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151 | lazy=>1, |
64cdad22 |
152 | default=>sub { {} }, |
f068a139 |
153 | ); |
154 | |
155 | |
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156 | =head2 balancer_type |
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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 | |
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163 | has 'balancer_type' => ( |
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164 | is=>'rw', |
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165 | isa=>BalancerClassNamePart, |
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166 | coerce=>1, |
167 | required=>1, |
168 | default=> 'DBIx::Class::Storage::DBI::Replicated::Balancer::First', |
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169 | handles=>{ |
170 | 'create_balancer' => 'new', |
171 | }, |
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172 | ); |
173 | |
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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' => ( |
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182 | is=>'rw', |
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183 | isa=>HashRef, |
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184 | lazy=>1, |
185 | required=>1, |
186 | default=>sub { {} }, |
17b05c13 |
187 | ); |
188 | |
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189 | =head2 pool |
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190 | |
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191 | Is a L<DBIx::Class::Storage::DBI::Replicated::Pool> or derived class. This is a |
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192 | container class for one or more replicated databases. |
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193 | |
194 | =cut |
195 | |
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196 | has 'pool' => ( |
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197 | is=>'ro', |
198 | isa=>'DBIx::Class::Storage::DBI::Replicated::Pool', |
199 | lazy_build=>1, |
200 | handles=>[qw/ |
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201 | connect_replicants |
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202 | replicants |
203 | has_replicants |
204 | /], |
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205 | ); |
206 | |
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207 | =head2 balancer |
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208 | |
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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>) |
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211 | |
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212 | =cut |
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213 | |
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214 | has 'balancer' => ( |
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215 | is=>'rw', |
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216 | isa=>'DBIx::Class::Storage::DBI::Replicated::Balancer', |
217 | lazy_build=>1, |
218 | handles=>[qw/auto_validate_every/], |
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219 | ); |
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220 | |
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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' => ( |
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232 | is=> 'ro', |
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233 | isa=>DBICStorageDBI, |
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234 | lazy_build=>1, |
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235 | ); |
236 | |
cb6ec758 |
237 | =head1 ATTRIBUTES IMPLEMENTING THE DBIx::Storage::DBI INTERFACE |
238 | |
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239 | The following methods are delegated all the methods required for the |
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240 | L<DBIx::Class::Storage::DBI> interface. |
241 | |
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242 | =cut |
243 | |
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244 | my $method_dispatch = { |
245 | writer => [qw/ |
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246 | on_connect_do |
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247 | on_disconnect_do |
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248 | on_connect_call |
249 | on_disconnect_call |
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250 | connect_info |
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251 | _connect_info |
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252 | throw_exception |
253 | sql_maker |
254 | sqlt_type |
255 | create_ddl_dir |
256 | deployment_statements |
257 | datetime_parser |
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258 | datetime_parser_type |
259 | build_datetime_parser |
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260 | last_insert_id |
261 | insert |
262 | insert_bulk |
263 | update |
264 | delete |
265 | dbh |
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266 | txn_begin |
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267 | txn_do |
268 | txn_commit |
269 | txn_rollback |
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270 | txn_scope_guard |
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271 | _exec_txn_rollback |
272 | _exec_txn_begin |
273 | _exec_txn_commit |
64cdad22 |
274 | deploy |
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275 | with_deferred_fk_checks |
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276 | dbh_do |
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277 | _prep_for_execute |
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278 | is_datatype_numeric |
279 | _count_select |
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280 | _subq_update_delete |
281 | svp_rollback |
282 | svp_begin |
283 | svp_release |
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284 | relname_to_table_alias |
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285 | _dbh_last_insert_id |
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286 | _default_dbi_connect_attributes |
287 | _dbi_connect_info |
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288 | _dbic_connect_attributes |
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289 | auto_savepoint |
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290 | _query_start |
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291 | _query_end |
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292 | _format_for_trace |
293 | _dbi_attrs_for_bind |
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294 | bind_attribute_by_data_type |
295 | transaction_depth |
296 | _dbh |
297 | _select_args |
298 | _dbh_execute_array |
3244fdcc |
299 | _sql_maker |
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300 | _per_row_update_delete |
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301 | _dbh_execute_inserts_with_no_binds |
302 | _select_args_to_query |
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303 | _gen_sql_bind |
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304 | _svp_generate_name |
305 | _multipk_update_delete |
3244fdcc |
306 | _normalize_connect_info |
307 | _parse_connect_do |
3244fdcc |
308 | _execute_array |
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 |
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319 | _dbh_sth |
320 | _dbh_execute |
5b4f3fd0 |
321 | /, Class::MOP::Class->initialize('DBIx::Class::Storage::DBIHacks')->get_method_list ], |
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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 | |
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333 | source_bind_attributes |
334 | |
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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 | |
348 | _max_column_bytesize |
349 | _is_lob_type |
350 | _is_binary_lob_type |
351 | _is_text_lob_type |
402ac1c9 |
352 | |
353 | sth |
4bea1fe7 |
354 | /,( |
355 | # the capability framework |
356 | # not sure if CMOP->initialize does evil things to DBIC::S::DBI, fix if a problem |
357 | grep |
358 | { $_ =~ /^ _ (?: use | supports | determine_supports ) _ /x } |
359 | ( Class::MOP::Class->initialize('DBIx::Class::Storage::DBI')->get_all_method_names ) |
360 | )], |
361 | }; |
362 | |
363 | if (DBIx::Class::_ENV_::DBICTEST) { |
364 | |
365 | my $seen; |
366 | for my $type (keys %$method_dispatch) { |
367 | for (@{$method_dispatch->{$type}}) { |
368 | push @{$seen->{$_}}, $type; |
369 | } |
370 | } |
cb6ec758 |
371 | |
4bea1fe7 |
372 | if (my @dupes = grep { @{$seen->{$_}} > 1 } keys %$seen) { |
373 | die(join "\n", '', |
374 | 'The following methods show up multiple times in ::Storage::DBI::Replicated handlers:', |
375 | (map { "$_: " . (join ', ', @{$seen->{$_}}) } sort @dupes), |
376 | '', |
377 | ); |
378 | } |
bbdda281 |
379 | |
4bea1fe7 |
380 | if (my @cant = grep { ! DBIx::Class::Storage::DBI->can($_) } keys %$seen) { |
381 | die(join "\n", '', |
382 | '::Storage::DBI::Replicated specifies handling of the following *NON EXISTING* ::Storage::DBI methods:', |
383 | @cant, |
384 | '', |
385 | ); |
386 | } |
387 | } |
bbdda281 |
388 | |
4bea1fe7 |
389 | for my $method (@{$method_dispatch->{unimplemented}}) { |
390 | __PACKAGE__->meta->add_method($method, sub { |
70c28808 |
391 | my $self = shift; |
392 | $self->throw_exception("$method must not be called on ".(blessed $self).' objects'); |
4bea1fe7 |
393 | }); |
394 | } |
31a8aaaf |
395 | |
4bea1fe7 |
396 | =head2 read_handler |
584ea6e4 |
397 | |
4bea1fe7 |
398 | Defines an object that implements the read side of L<BIx::Class::Storage::DBI>. |
584ea6e4 |
399 | |
4bea1fe7 |
400 | =cut |
401 | |
402 | has 'read_handler' => ( |
403 | is=>'rw', |
404 | isa=>Object, |
405 | lazy_build=>1, |
406 | handles=>$method_dispatch->{reader}, |
e471ab87 |
407 | ); |
408 | |
4bea1fe7 |
409 | =head2 write_handler |
410 | |
411 | Defines an object that implements the write side of L<BIx::Class::Storage::DBI>, |
412 | as well as methods that don't write or read that can be called on only one |
413 | storage, methods that return a C<$dbh>, and any methods that don't make sense to |
414 | run on a replicant. |
415 | |
416 | =cut |
417 | |
418 | has 'write_handler' => ( |
419 | is=>'ro', |
420 | isa=>Object, |
421 | lazy_build=>1, |
422 | handles=>$method_dispatch->{writer}, |
7f4433eb |
423 | ); |
424 | |
4bea1fe7 |
425 | |
6d766626 |
426 | |
b2e4d522 |
427 | has _master_connect_info_opts => |
428 | (is => 'rw', isa => HashRef, default => sub { {} }); |
429 | |
430 | =head2 around: connect_info |
431 | |
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432 | Preserves master's C<connect_info> options (for merging with replicants.) |
433 | Also sets any Replicated-related options from connect_info, such as |
dcdf7b2c |
434 | C<pool_type>, C<pool_args>, C<balancer_type> and C<balancer_args>. |
b2e4d522 |
435 | |
436 | =cut |
437 | |
438 | around connect_info => sub { |
439 | my ($next, $self, $info, @extra) = @_; |
440 | |
282a9a4f |
441 | my $merge = Hash::Merge->new('LEFT_PRECEDENT'); |
e666c5fd |
442 | |
b2e4d522 |
443 | my %opts; |
444 | for my $arg (@$info) { |
445 | next unless (reftype($arg)||'') eq 'HASH'; |
e666c5fd |
446 | %opts = %{ $merge->merge($arg, \%opts) }; |
b2e4d522 |
447 | } |
b2e4d522 |
448 | delete $opts{dsn}; |
449 | |
dcdf7b2c |
450 | if (@opts{qw/pool_type pool_args/}) { |
451 | $self->pool_type(delete $opts{pool_type}) |
452 | if $opts{pool_type}; |
453 | |
b88b85e7 |
454 | $self->pool_args( |
e666c5fd |
455 | $merge->merge((delete $opts{pool_args} || {}), $self->pool_args) |
b88b85e7 |
456 | ); |
dcdf7b2c |
457 | |
64ae1667 |
458 | ## Since we possibly changed the pool_args, we need to clear the current |
459 | ## pool object so that next time it is used it will be rebuilt. |
460 | $self->clear_pool; |
dcdf7b2c |
461 | } |
462 | |
463 | if (@opts{qw/balancer_type balancer_args/}) { |
464 | $self->balancer_type(delete $opts{balancer_type}) |
465 | if $opts{balancer_type}; |
466 | |
b88b85e7 |
467 | $self->balancer_args( |
e666c5fd |
468 | $merge->merge((delete $opts{balancer_args} || {}), $self->balancer_args) |
b88b85e7 |
469 | ); |
dcdf7b2c |
470 | |
67c43863 |
471 | $self->balancer($self->_build_balancer) |
6f7344b8 |
472 | if $self->balancer; |
dcdf7b2c |
473 | } |
474 | |
b2e4d522 |
475 | $self->_master_connect_info_opts(\%opts); |
476 | |
cca282b6 |
477 | my @res; |
478 | if (wantarray) { |
0ce2d0d5 |
479 | @res = $self->$next($info, @extra); |
480 | } else { |
cca282b6 |
481 | $res[0] = $self->$next($info, @extra); |
0ce2d0d5 |
482 | } |
483 | |
fd4eb9c2 |
484 | # Make sure master is blessed into the correct class and apply role to it. |
485 | my $master = $self->master; |
486 | $master->_determine_driver; |
487 | Moose::Meta::Class->initialize(ref $master); |
cea43436 |
488 | |
ec0946db |
489 | DBIx::Class::Storage::DBI::Replicated::WithDSN->meta->apply($master); |
cea43436 |
490 | |
491 | # link pool back to master |
492 | $self->pool->master($master); |
0ce2d0d5 |
493 | |
cca282b6 |
494 | wantarray ? @res : $res[0]; |
b2e4d522 |
495 | }; |
496 | |
26ab719a |
497 | =head1 METHODS |
2bf79155 |
498 | |
26ab719a |
499 | This class defines the following methods. |
2bf79155 |
500 | |
c354902c |
501 | =head2 BUILDARGS |
2bf79155 |
502 | |
faaba25f |
503 | L<DBIx::Class::Schema> when instantiating its storage passed itself as the |
2ce6e9a6 |
504 | first argument. So we need to massage the arguments a bit so that all the |
505 | bits get put into the correct places. |
2bf79155 |
506 | |
507 | =cut |
508 | |
c354902c |
509 | sub BUILDARGS { |
fd323bf1 |
510 | my ($class, $schema, $storage_type_args, @args) = @_; |
d4daee7b |
511 | |
c354902c |
512 | return { |
6f7344b8 |
513 | schema=>$schema, |
514 | %$storage_type_args, |
515 | @args |
c354902c |
516 | } |
517 | } |
2bf79155 |
518 | |
cb6ec758 |
519 | =head2 _build_master |
2bf79155 |
520 | |
cb6ec758 |
521 | Lazy builder for the L</master> attribute. |
2bf79155 |
522 | |
523 | =cut |
524 | |
cb6ec758 |
525 | sub _build_master { |
2ce6e9a6 |
526 | my $self = shift @_; |
ee356d00 |
527 | my $master = DBIx::Class::Storage::DBI->new($self->schema); |
ee356d00 |
528 | $master |
106d5f3b |
529 | } |
530 | |
26ab719a |
531 | =head2 _build_pool |
2bf79155 |
532 | |
26ab719a |
533 | Lazy builder for the L</pool> attribute. |
2bf79155 |
534 | |
535 | =cut |
536 | |
26ab719a |
537 | sub _build_pool { |
64cdad22 |
538 | my $self = shift @_; |
539 | $self->create_pool(%{$self->pool_args}); |
2bf79155 |
540 | } |
541 | |
26ab719a |
542 | =head2 _build_balancer |
2bf79155 |
543 | |
cb6ec758 |
544 | Lazy builder for the L</balancer> attribute. This takes a Pool object so that |
545 | the balancer knows which pool it's balancing. |
2bf79155 |
546 | |
547 | =cut |
548 | |
26ab719a |
549 | sub _build_balancer { |
64cdad22 |
550 | my $self = shift @_; |
551 | $self->create_balancer( |
6f7344b8 |
552 | pool=>$self->pool, |
64cdad22 |
553 | master=>$self->master, |
554 | %{$self->balancer_args}, |
555 | ); |
2bf79155 |
556 | } |
557 | |
cb6ec758 |
558 | =head2 _build_write_handler |
2bf79155 |
559 | |
cb6ec758 |
560 | Lazy builder for the L</write_handler> attribute. The default is to set this to |
561 | the L</master>. |
50336325 |
562 | |
563 | =cut |
564 | |
cb6ec758 |
565 | sub _build_write_handler { |
64cdad22 |
566 | return shift->master; |
cb6ec758 |
567 | } |
50336325 |
568 | |
cb6ec758 |
569 | =head2 _build_read_handler |
2bf79155 |
570 | |
cb6ec758 |
571 | Lazy builder for the L</read_handler> attribute. The default is to set this to |
572 | the L</balancer>. |
2bf79155 |
573 | |
574 | =cut |
575 | |
cb6ec758 |
576 | sub _build_read_handler { |
64cdad22 |
577 | return shift->balancer; |
cb6ec758 |
578 | } |
50336325 |
579 | |
cb6ec758 |
580 | =head2 around: connect_replicants |
2bf79155 |
581 | |
cb6ec758 |
582 | All calls to connect_replicants needs to have an existing $schema tacked onto |
b2e4d522 |
583 | top of the args, since L<DBIx::Storage::DBI> needs it, and any C<connect_info> |
584 | options merged with the master, with replicant opts having higher priority. |
955a6df6 |
585 | |
cb6ec758 |
586 | =cut |
955a6df6 |
587 | |
b2e4d522 |
588 | around connect_replicants => sub { |
589 | my ($next, $self, @args) = @_; |
590 | |
591 | for my $r (@args) { |
592 | $r = [ $r ] unless reftype $r eq 'ARRAY'; |
593 | |
1a58752c |
594 | $self->throw_exception('coderef replicant connect_info not supported') |
b2e4d522 |
595 | if ref $r->[0] && reftype $r->[0] eq 'CODE'; |
596 | |
597 | # any connect_info options? |
598 | my $i = 0; |
599 | $i++ while $i < @$r && (reftype($r->[$i])||'') ne 'HASH'; |
600 | |
6f7344b8 |
601 | # make one if none |
b2e4d522 |
602 | $r->[$i] = {} unless $r->[$i]; |
603 | |
604 | # merge if two hashes |
b88b85e7 |
605 | my @hashes = @$r[$i .. $#{$r}]; |
606 | |
1a58752c |
607 | $self->throw_exception('invalid connect_info options') |
b88b85e7 |
608 | if (grep { reftype($_) eq 'HASH' } @hashes) != @hashes; |
609 | |
1a58752c |
610 | $self->throw_exception('too many hashrefs in connect_info') |
b88b85e7 |
611 | if @hashes > 2; |
612 | |
282a9a4f |
613 | my $merge = Hash::Merge->new('LEFT_PRECEDENT'); |
e666c5fd |
614 | my %opts = %{ $merge->merge(reverse @hashes) }; |
b88b85e7 |
615 | |
616 | # delete them |
b2e4d522 |
617 | splice @$r, $i+1, ($#{$r} - $i), (); |
618 | |
0bd8e058 |
619 | # make sure master/replicants opts don't clash |
620 | my %master_opts = %{ $self->_master_connect_info_opts }; |
621 | if (exists $opts{dbh_maker}) { |
622 | delete @master_opts{qw/dsn user password/}; |
623 | } |
624 | delete $master_opts{dbh_maker}; |
625 | |
b2e4d522 |
626 | # merge with master |
e666c5fd |
627 | %opts = %{ $merge->merge(\%opts, \%master_opts) }; |
b2e4d522 |
628 | |
629 | # update |
630 | $r->[$i] = \%opts; |
631 | } |
632 | |
633 | $self->$next($self->schema, @args); |
955a6df6 |
634 | }; |
2bf79155 |
635 | |
2bf79155 |
636 | =head2 all_storages |
637 | |
638 | Returns an array of of all the connected storage backends. The first element |
639 | in the returned array is the master, and the remainings are each of the |
640 | replicants. |
641 | |
642 | =cut |
643 | |
644 | sub all_storages { |
64cdad22 |
645 | my $self = shift @_; |
646 | return grep {defined $_ && blessed $_} ( |
647 | $self->master, |
6412a592 |
648 | values %{ $self->replicants }, |
64cdad22 |
649 | ); |
2bf79155 |
650 | } |
651 | |
c4d3fae2 |
652 | =head2 execute_reliably ($coderef, ?@args) |
653 | |
654 | Given a coderef, saves the current state of the L</read_handler>, forces it to |
48580715 |
655 | use reliable storage (e.g. sets it to the master), executes a coderef and then |
c4d3fae2 |
656 | restores the original state. |
657 | |
658 | Example: |
659 | |
64cdad22 |
660 | my $reliably = sub { |
661 | my $name = shift @_; |
662 | $schema->resultset('User')->create({name=>$name}); |
fd323bf1 |
663 | my $user_rs = $schema->resultset('User')->find({name=>$name}); |
64cdad22 |
664 | return $user_rs; |
665 | }; |
c4d3fae2 |
666 | |
64cdad22 |
667 | my $user_rs = $schema->storage->execute_reliably($reliably, 'John'); |
c4d3fae2 |
668 | |
669 | Use this when you must be certain of your database state, such as when you just |
670 | inserted something and need to get a resultset including it, etc. |
671 | |
672 | =cut |
673 | |
674 | sub execute_reliably { |
64cdad22 |
675 | my ($self, $coderef, @args) = @_; |
d4daee7b |
676 | |
64cdad22 |
677 | unless( ref $coderef eq 'CODE') { |
678 | $self->throw_exception('Second argument must be a coderef'); |
679 | } |
d4daee7b |
680 | |
64cdad22 |
681 | ##Get copy of master storage |
682 | my $master = $self->master; |
d4daee7b |
683 | |
64cdad22 |
684 | ##Get whatever the current read hander is |
685 | my $current = $self->read_handler; |
d4daee7b |
686 | |
64cdad22 |
687 | ##Set the read handler to master |
688 | $self->read_handler($master); |
d4daee7b |
689 | |
64cdad22 |
690 | ## do whatever the caller needs |
691 | my @result; |
692 | my $want_array = wantarray; |
d4daee7b |
693 | |
ed7ab0f4 |
694 | try { |
64cdad22 |
695 | if($want_array) { |
696 | @result = $coderef->(@args); |
697 | } elsif(defined $want_array) { |
698 | ($result[0]) = ($coderef->(@args)); |
ed213e85 |
699 | } else { |
64cdad22 |
700 | $coderef->(@args); |
6f7344b8 |
701 | } |
ed7ab0f4 |
702 | } catch { |
703 | $self->throw_exception("coderef returned an error: $_"); |
704 | } finally { |
705 | ##Reset to the original state |
706 | $self->read_handler($current); |
64cdad22 |
707 | }; |
d4daee7b |
708 | |
cca282b6 |
709 | return wantarray ? @result : $result[0]; |
c4d3fae2 |
710 | } |
711 | |
cb6ec758 |
712 | =head2 set_reliable_storage |
713 | |
714 | Sets the current $schema to be 'reliable', that is all queries, both read and |
715 | write are sent to the master |
d4daee7b |
716 | |
cb6ec758 |
717 | =cut |
718 | |
719 | sub set_reliable_storage { |
64cdad22 |
720 | my $self = shift @_; |
721 | my $schema = $self->schema; |
722 | my $write_handler = $self->schema->storage->write_handler; |
d4daee7b |
723 | |
64cdad22 |
724 | $schema->storage->read_handler($write_handler); |
cb6ec758 |
725 | } |
726 | |
727 | =head2 set_balanced_storage |
728 | |
729 | Sets the current $schema to be use the </balancer> for all reads, while all |
48580715 |
730 | writes are sent to the master only |
d4daee7b |
731 | |
cb6ec758 |
732 | =cut |
733 | |
734 | sub set_balanced_storage { |
64cdad22 |
735 | my $self = shift @_; |
736 | my $schema = $self->schema; |
bd5da369 |
737 | my $balanced_handler = $self->schema->storage->balancer; |
d4daee7b |
738 | |
bd5da369 |
739 | $schema->storage->read_handler($balanced_handler); |
cb6ec758 |
740 | } |
2bf79155 |
741 | |
742 | =head2 connected |
743 | |
744 | Check that the master and at least one of the replicants is connected. |
745 | |
746 | =cut |
747 | |
748 | sub connected { |
64cdad22 |
749 | my $self = shift @_; |
750 | return |
751 | $self->master->connected && |
752 | $self->pool->connected_replicants; |
2bf79155 |
753 | } |
754 | |
2bf79155 |
755 | =head2 ensure_connected |
756 | |
757 | Make sure all the storages are connected. |
758 | |
759 | =cut |
760 | |
761 | sub ensure_connected { |
64cdad22 |
762 | my $self = shift @_; |
763 | foreach my $source ($self->all_storages) { |
764 | $source->ensure_connected(@_); |
765 | } |
2bf79155 |
766 | } |
767 | |
2bf79155 |
768 | =head2 limit_dialect |
769 | |
770 | Set the limit_dialect for all existing storages |
771 | |
772 | =cut |
773 | |
774 | sub limit_dialect { |
64cdad22 |
775 | my $self = shift @_; |
776 | foreach my $source ($self->all_storages) { |
777 | $source->limit_dialect(@_); |
778 | } |
f3e9f010 |
779 | return $self->master->limit_dialect; |
2bf79155 |
780 | } |
781 | |
2bf79155 |
782 | =head2 quote_char |
783 | |
784 | Set the quote_char for all existing storages |
785 | |
786 | =cut |
787 | |
788 | sub quote_char { |
64cdad22 |
789 | my $self = shift @_; |
790 | foreach my $source ($self->all_storages) { |
791 | $source->quote_char(@_); |
792 | } |
3fbe08e3 |
793 | return $self->master->quote_char; |
2bf79155 |
794 | } |
795 | |
2bf79155 |
796 | =head2 name_sep |
797 | |
798 | Set the name_sep for all existing storages |
799 | |
800 | =cut |
801 | |
802 | sub name_sep { |
64cdad22 |
803 | my $self = shift @_; |
804 | foreach my $source ($self->all_storages) { |
805 | $source->name_sep(@_); |
806 | } |
3fbe08e3 |
807 | return $self->master->name_sep; |
2bf79155 |
808 | } |
809 | |
2bf79155 |
810 | =head2 set_schema |
811 | |
812 | Set the schema object for all existing storages |
813 | |
814 | =cut |
815 | |
816 | sub set_schema { |
64cdad22 |
817 | my $self = shift @_; |
818 | foreach my $source ($self->all_storages) { |
819 | $source->set_schema(@_); |
820 | } |
2bf79155 |
821 | } |
822 | |
2bf79155 |
823 | =head2 debug |
824 | |
825 | set a debug flag across all storages |
826 | |
827 | =cut |
828 | |
829 | sub debug { |
64cdad22 |
830 | my $self = shift @_; |
3fbe08e3 |
831 | if(@_) { |
832 | foreach my $source ($self->all_storages) { |
833 | $source->debug(@_); |
6f7344b8 |
834 | } |
64cdad22 |
835 | } |
3fbe08e3 |
836 | return $self->master->debug; |
2bf79155 |
837 | } |
838 | |
2bf79155 |
839 | =head2 debugobj |
840 | |
cea43436 |
841 | set a debug object |
2bf79155 |
842 | |
843 | =cut |
844 | |
845 | sub debugobj { |
64cdad22 |
846 | my $self = shift @_; |
cea43436 |
847 | return $self->master->debugobj(@_); |
2bf79155 |
848 | } |
849 | |
2bf79155 |
850 | =head2 debugfh |
851 | |
cea43436 |
852 | set a debugfh object |
2bf79155 |
853 | |
854 | =cut |
855 | |
856 | sub debugfh { |
64cdad22 |
857 | my $self = shift @_; |
cea43436 |
858 | return $self->master->debugfh(@_); |
2bf79155 |
859 | } |
860 | |
2bf79155 |
861 | =head2 debugcb |
862 | |
cea43436 |
863 | set a debug callback |
2bf79155 |
864 | |
865 | =cut |
866 | |
867 | sub debugcb { |
64cdad22 |
868 | my $self = shift @_; |
cea43436 |
869 | return $self->master->debugcb(@_); |
2bf79155 |
870 | } |
871 | |
2bf79155 |
872 | =head2 disconnect |
873 | |
874 | disconnect everything |
875 | |
876 | =cut |
877 | |
878 | sub disconnect { |
64cdad22 |
879 | my $self = shift @_; |
880 | foreach my $source ($self->all_storages) { |
881 | $source->disconnect(@_); |
882 | } |
2bf79155 |
883 | } |
884 | |
b2e4d522 |
885 | =head2 cursor_class |
886 | |
887 | set cursor class on all storages, or return master's |
888 | |
889 | =cut |
890 | |
891 | sub cursor_class { |
892 | my ($self, $cursor_class) = @_; |
893 | |
894 | if ($cursor_class) { |
895 | $_->cursor_class($cursor_class) for $self->all_storages; |
896 | } |
897 | $self->master->cursor_class; |
898 | } |
d4daee7b |
899 | |
3244fdcc |
900 | =head2 cursor |
901 | |
902 | set cursor class on all storages, or return master's, alias for L</cursor_class> |
903 | above. |
904 | |
905 | =cut |
906 | |
907 | sub cursor { |
908 | my ($self, $cursor_class) = @_; |
909 | |
910 | if ($cursor_class) { |
911 | $_->cursor($cursor_class) for $self->all_storages; |
912 | } |
913 | $self->master->cursor; |
914 | } |
915 | |
916 | =head2 unsafe |
917 | |
918 | sets the L<DBIx::Class::Storage::DBI/unsafe> option on all storages or returns |
919 | master's current setting |
920 | |
921 | =cut |
922 | |
923 | sub unsafe { |
924 | my $self = shift; |
925 | |
926 | if (@_) { |
927 | $_->unsafe(@_) for $self->all_storages; |
928 | } |
929 | |
930 | return $self->master->unsafe; |
931 | } |
932 | |
933 | =head2 disable_sth_caching |
934 | |
935 | sets the L<DBIx::Class::Storage::DBI/disable_sth_caching> option on all storages |
936 | or returns master's current setting |
937 | |
938 | =cut |
939 | |
940 | sub disable_sth_caching { |
941 | my $self = shift; |
942 | |
943 | if (@_) { |
944 | $_->disable_sth_caching(@_) for $self->all_storages; |
945 | } |
946 | |
947 | return $self->master->disable_sth_caching; |
948 | } |
949 | |
950 | =head2 lag_behind_master |
951 | |
952 | returns the highest Replicant L<DBIx::Class::Storage::DBI/lag_behind_master> |
953 | setting |
954 | |
955 | =cut |
956 | |
957 | sub lag_behind_master { |
958 | my $self = shift; |
959 | |
960 | return max map $_->lag_behind_master, $self->replicants; |
fd323bf1 |
961 | } |
3244fdcc |
962 | |
963 | =head2 is_replicating |
964 | |
965 | returns true if all replicants return true for |
966 | L<DBIx::Class::Storage::DBI/is_replicating> |
967 | |
968 | =cut |
969 | |
970 | sub is_replicating { |
971 | my $self = shift; |
972 | |
973 | return (grep $_->is_replicating, $self->replicants) == ($self->replicants); |
974 | } |
975 | |
976 | =head2 connect_call_datetime_setup |
977 | |
978 | calls L<DBIx::Class::Storage::DBI/connect_call_datetime_setup> for all storages |
979 | |
980 | =cut |
981 | |
982 | sub connect_call_datetime_setup { |
983 | my $self = shift; |
984 | $_->connect_call_datetime_setup for $self->all_storages; |
985 | } |
986 | |
987 | sub _populate_dbh { |
988 | my $self = shift; |
989 | $_->_populate_dbh for $self->all_storages; |
990 | } |
991 | |
992 | sub _connect { |
993 | my $self = shift; |
994 | $_->_connect for $self->all_storages; |
995 | } |
996 | |
997 | sub _rebless { |
998 | my $self = shift; |
999 | $_->_rebless for $self->all_storages; |
1000 | } |
1001 | |
1002 | sub _determine_driver { |
1003 | my $self = shift; |
1004 | $_->_determine_driver for $self->all_storages; |
1005 | } |
1006 | |
1007 | sub _driver_determined { |
1008 | my $self = shift; |
fd323bf1 |
1009 | |
3244fdcc |
1010 | if (@_) { |
1011 | $_->_driver_determined(@_) for $self->all_storages; |
1012 | } |
1013 | |
1014 | return $self->master->_driver_determined; |
1015 | } |
1016 | |
1017 | sub _init { |
1018 | my $self = shift; |
fd323bf1 |
1019 | |
3244fdcc |
1020 | $_->_init for $self->all_storages; |
1021 | } |
1022 | |
1023 | sub _run_connection_actions { |
1024 | my $self = shift; |
fd323bf1 |
1025 | |
3244fdcc |
1026 | $_->_run_connection_actions for $self->all_storages; |
1027 | } |
1028 | |
1029 | sub _do_connection_actions { |
1030 | my $self = shift; |
fd323bf1 |
1031 | |
3244fdcc |
1032 | if (@_) { |
1033 | $_->_do_connection_actions(@_) for $self->all_storages; |
1034 | } |
1035 | } |
1036 | |
1037 | sub connect_call_do_sql { |
1038 | my $self = shift; |
1039 | $_->connect_call_do_sql(@_) for $self->all_storages; |
1040 | } |
1041 | |
1042 | sub disconnect_call_do_sql { |
1043 | my $self = shift; |
1044 | $_->disconnect_call_do_sql(@_) for $self->all_storages; |
1045 | } |
1046 | |
1047 | sub _seems_connected { |
1048 | my $self = shift; |
1049 | |
1050 | return min map $_->_seems_connected, $self->all_storages; |
1051 | } |
1052 | |
1053 | sub _ping { |
1054 | my $self = shift; |
1055 | |
1056 | return min map $_->_ping, $self->all_storages; |
1057 | } |
1058 | |
bbdda281 |
1059 | # not using the normalized_version, because we want to preserve |
1060 | # version numbers much longer than the conventional xxx.yyyzzz |
7da56142 |
1061 | my $numify_ver = sub { |
1062 | my $ver = shift; |
1063 | my @numparts = split /\D+/, $ver; |
bbdda281 |
1064 | my $format = '%d.' . (join '', ('%06d') x (@numparts - 1)); |
7da56142 |
1065 | |
1066 | return sprintf $format, @numparts; |
1067 | }; |
fecb38cb |
1068 | sub _server_info { |
1069 | my $self = shift; |
1070 | |
bbdda281 |
1071 | if (not $self->_dbh_details->{info}) { |
1072 | $self->_dbh_details->{info} = ( |
fd323bf1 |
1073 | reduce { $a->[0] < $b->[0] ? $a : $b } |
7da56142 |
1074 | map [ $numify_ver->($_->{dbms_version}), $_ ], |
1075 | map $_->_server_info, $self->all_storages |
1076 | )->[1]; |
fecb38cb |
1077 | } |
1078 | |
bbdda281 |
1079 | return $self->next::method; |
fecb38cb |
1080 | } |
1081 | |
1082 | sub _get_server_version { |
1083 | my $self = shift; |
1084 | |
1085 | return $self->_server_info->{dbms_version}; |
1086 | } |
1087 | |
7e38d850 |
1088 | =head1 GOTCHAS |
1089 | |
1090 | Due to the fact that replicants can lag behind a master, you must take care to |
1091 | make sure you use one of the methods to force read queries to a master should |
1092 | you need realtime data integrity. For example, if you insert a row, and then |
1093 | immediately re-read it from the database (say, by doing $row->discard_changes) |
1094 | or you insert a row and then immediately build a query that expects that row |
1095 | to be an item, you should force the master to handle reads. Otherwise, due to |
1096 | the lag, there is no certainty your data will be in the expected state. |
1097 | |
1098 | For data integrity, all transactions automatically use the master storage for |
1099 | all read and write queries. Using a transaction is the preferred and recommended |
1100 | method to force the master to handle all read queries. |
1101 | |
1102 | Otherwise, you can force a single query to use the master with the 'force_pool' |
1103 | attribute: |
1104 | |
1105 | my $row = $resultset->search(undef, {force_pool=>'master'})->find($pk); |
1106 | |
1107 | This attribute will safely be ignore by non replicated storages, so you can use |
1108 | the same code for both types of systems. |
1109 | |
1110 | Lastly, you can use the L</execute_reliably> method, which works very much like |
1111 | a transaction. |
1112 | |
1113 | For debugging, you can turn replication on/off with the methods L</set_reliable_storage> |
1114 | and L</set_balanced_storage>, however this operates at a global level and is not |
1115 | suitable if you have a shared Schema object being used by multiple processes, |
1116 | such as on a web application server. You can get around this limitation by |
1117 | using the Schema clone method. |
1118 | |
1119 | my $new_schema = $schema->clone; |
1120 | $new_schema->set_reliable_storage; |
d4daee7b |
1121 | |
7e38d850 |
1122 | ## $new_schema will use only the Master storage for all reads/writes while |
1123 | ## the $schema object will use replicated storage. |
1124 | |
f5d3a5de |
1125 | =head1 AUTHOR |
1126 | |
64cdad22 |
1127 | John Napiorkowski <john.napiorkowski@takkle.com> |
f5d3a5de |
1128 | |
c4d3fae2 |
1129 | Based on code originated by: |
f5d3a5de |
1130 | |
64cdad22 |
1131 | Norbert Csongrádi <bert@cpan.org> |
1132 | Peter Siklósi <einon@einon.hu> |
2156bbdd |
1133 | |
f5d3a5de |
1134 | =head1 LICENSE |
1135 | |
1136 | You may distribute this code under the same terms as Perl itself. |
1137 | |
1138 | =cut |
1139 | |
c354902c |
1140 | __PACKAGE__->meta->make_immutable; |
1141 | |
f5d3a5de |
1142 | 1; |