如何优雅地处理Rails缓存失败？ （redis的高速缓冲存储器）

Question

我在我的应用中使用redis-cache进行片段缓存。当redis关闭或无法访问时，我会收到导致500错误的超时异常。

很少发生这种情况，但对于缓存，我希望rails将超时视为：

• no-op on write
• 读取缓存失败。

有什么建议吗？这是可以在rails缓存中配置的东西，还是我需要做一些猴子修补来优雅地处理这个案例？

我的stacktrace的相关部分在下面，以防它以任何方式帮助。 。

execution expired
 /opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/1.8/timeout.rb:60:in `new'
 bundle/gems/ruby/1.8/gems/redis-2.2.2/lib/redis/connection/ruby.rb:26:in `connect'
 bundle/gems/ruby/1.8/gems/redis-2.2.2/lib/redis/connection/ruby.rb:128:in `with_timeout'
 bundle/gems/ruby/1.8/gems/redis-2.2.2/lib/redis/connection/ruby.rb:25:in `connect'
 bundle/gems/ruby/1.8/gems/redis-2.2.2/lib/redis/client.rb:227:in `establish_connection'
 bundle/gems/ruby/1.8/gems/redis-2.2.2/lib/redis/client.rb:23:in `connect'
 bundle/gems/ruby/1.8/gems/redis-2.2.2/lib/redis/client.rb:247:in `ensure_connected'
 bundle/gems/ruby/1.8/gems/redis-2.2.2/lib/redis/client.rb:137:in `process'
 bundle/gems/ruby/1.8/gems/redis-2.2.2/lib/redis/client.rb:206:in `logging'
 bundle/gems/ruby/1.8/gems/redis-2.2.2/lib/redis/client.rb:136:in `process'
 bundle/gems/ruby/1.8/gems/redis-2.2.2/lib/redis/client.rb:46:in `call'
 bundle/gems/ruby/1.8/gems/redis-2.2.2/lib/redis.rb:157:in `get'
 /opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/1.8/monitor.rb:242:in `synchronize'
 bundle/gems/ruby/1.8/gems/redis-2.2.2/lib/redis.rb:156:in `get'
 bundle/gems/ruby/1.8/gems/redis-store-1.0.0.1/lib/redis/store/interface.rb:5:in `get'
 bundle/gems/ruby/1.8/gems/redis-store-1.0.0.1/lib/redis/store/marshalling.rb:13:in `get'
 bundle/gems/ruby/1.8/gems/redis-store-1.0.0.1/lib/active_support/cache/redis_store.rb:119:in `read_entry' 

Answer 1

凯文，

好奇，您使用的是什么Rails版本？

redis-store项目中的这个问题似乎与您遇到的问题有关：https://github.com/jodosha/redis-store/issues/56。该修复程序仅解决了Rails 3。

Rails 2的修复程序在这里：https://github.com/jodosha/redis-store/pull/83。查看redis-store 1.0.0.1的源代码，我没有看到包含该修复程序。