如何在rails 3.0.9中實現讀取從屬（mySql）？

Question

我正在使用Rails 3.0.9。 （使用紅寶石1.9.3） 我一直在尋找一些複製寶石（data_fabric，octopus，multi_db）。

想知道什麼是最好的解決方案。 生產準備，快速，AR3兼容...

我認爲這是章魚，直到我看到了這個問題： https://github.com/tchandy/octopus/issues/60

我沒有在這一點上需要分片，所有我需要的是送能力讀給奴隸，寫給主人。

上述需求的最佳解決方案是什麼？

Answer 1

儘管存在這個問題，八爪魚仍然是一個挑選的人。我們在Square使用它來描述您使用的用例。

提交的放鬆依賴V0.4.0後直接進去了，所以它的安全鎖定到一個Git版本：3.1主要規格和相關的主看

gem 'octopus', 
    :git => 'https://github.com/tchandy/octopus.git', 
    :ref => '7e585ecd35d3caf9b5d23a0265e709716740a3ce' 

其他的變化，再加上性能單一提交（我的提交），所以它可能也很好。

作爲參考，我們正在運行一個v0.4.0的分支，修正它以允許AR 2.3，以及現在掌握的與性能相關的提交（如果您沒有進行大量流量，但不錯，則不是關鍵）。

git diff v0.4.0..7e585ecd35d3caf9b5d23a0265e709716740a3ce

diff --git a/Gemfile b/Gemfile 
index e82375d..c3bcf77 100644 
--- a/Gemfile 
+++ b/Gemfile 
@@ -1,7 +1,7 @@ 
source :rubygems 

-gem 'activerecord', '3.0.6' 
-gem 'actionpack', '3.0.6' 
+gem 'activerecord', '~> 3.0' 
+gem 'actionpack', '~> 3.0' 

group :test do 
    gem "rake", ">= 0.8.7" 
diff --git a/Gemfile.lock b/Gemfile.lock 
index a80476c..a82c18f 100644 
--- a/Gemfile.lock 
+++ b/Gemfile.lock 
@@ -58,8 +58,8 @@ PLATFORMS 
    ruby 

DEPENDENCIES 
- actionpack (= 3.0.6) 
- activerecord (= 3.0.6) 
+ actionpack (~> 3.0) 
+ activerecord (~> 3.0) 
    jeweler (>= 1.4) 
    mysql2 
    pg (>= 0.9.0) 
diff --git a/ar-octopus.gemspec b/ar-octopus.gemspec 
index 9e5f73e..2b06df4 100644 
--- a/ar-octopus.gemspec 
+++ b/ar-octopus.gemspec 
@@ -171,8 +171,8 @@ Gem::Specification.new do |s| 
    s.specification_version = 3 

    if Gem::Version.new(Gem::VERSION) >= Gem::Version.new('1.2.0') then 
-  s.add_runtime_dependency(%q<activerecord>, ["= 3.0.6"]) 
-  s.add_runtime_dependency(%q<actionpack>, ["= 3.0.6"]) 
+  s.add_runtime_dependency(%q<activerecord>, ["~> 3.0"]) 
+  s.add_runtime_dependency(%q<actionpack>, ["~> 3.0"]) 
     s.add_development_dependency(%q<rspec>, [">= 2.0.0.beta.19"]) 
     s.add_development_dependency(%q<mysql2>, [">= 0"]) 
     s.add_development_dependency(%q<pg>, [">= 0.9.0"]) 
@@ -181,8 +181,8 @@ Gem::Specification.new do |s| 
     s.add_development_dependency(%q<actionpack>, [">= 2.3"]) 
     s.add_runtime_dependency(%q<activerecord>, [">= 2.3"]) 
    else 
-  s.add_dependency(%q<activerecord>, ["= 3.0.6"]) 
-  s.add_dependency(%q<actionpack>, ["= 3.0.6"]) 
+  s.add_dependency(%q<activerecord>, ["~> 3.0"]) 
+  s.add_dependency(%q<actionpack>, ["~> 3.0"]) 
     s.add_dependency(%q<rspec>, [">= 2.0.0.beta.19"]) 
     s.add_dependency(%q<mysql2>, [">= 0"]) 
     s.add_dependency(%q<pg>, [">= 0.9.0"]) 
@@ -192,8 +192,8 @@ Gem::Specification.new do |s| 
     s.add_dependency(%q<activerecord>, [">= 2.3"]) 
    end 
    else 
- s.add_dependency(%q<activerecord>, ["= 3.0.6"]) 
- s.add_dependency(%q<actionpack>, ["= 3.0.6"]) 
+ s.add_dependency(%q<activerecord>, ["~> 3.0"]) 
+ s.add_dependency(%q<actionpack>, ["~> 3.0"]) 
    s.add_dependency(%q<rspec>, [">= 2.0.0.beta.19"]) 
    s.add_dependency(%q<mysql2>, [">= 0"]) 
    s.add_dependency(%q<pg>, [">= 0.9.0"]) 
diff --git a/lib/octopus/association_collection.rb b/lib/octopus/association_collection.rb 
index 2dbff87..44d0f7a 100644 
--- a/lib/octopus/association_collection.rb 
+++ b/lib/octopus/association_collection.rb 
@@ -12,4 +12,8 @@ module Octopus::AssociationCollection 
    end 
end 

-ActiveRecord::Associations::AssociationCollection.send(:include, Octopus::AssociationCollection) 
\ No newline at end of file 
+if ActiveRecord::VERSION::MAJOR >= 3 && ActiveRecord::VERSION::MINOR >=1 
+ ActiveRecord::Associations::CollectionAssociation.send(:include, Octopus::AssociationCollection) 
+else 
+ ActiveRecord::Associations::AssociationCollection.send(:include, Octopus::AssociationCollection) 
+end 
diff --git a/lib/octopus/migration.rb b/lib/octopus/migration.rb 
index 70bd8bd..7d9fd90 100644 
--- a/lib/octopus/migration.rb 
+++ b/lib/octopus/migration.rb 
@@ -70,4 +70,8 @@ module Octopus::Migration 
    end 
end 

-ActiveRecord::Migration.extend(Octopus::Migration) 
+if ActiveRecord::VERSION::MAJOR >= 3 && ActiveRecord::VERSION::MINOR >=1 
+ ActiveRecord::Migration.send :include, Octopus::Migration 
+else 
+ ActiveRecord::Migration.extend(Octopus::Migration) 
+end 
```