使用 memcached 运行服务器 rails 2.3.5 时出错

Question

我使用 ruby​​ 版本 1.8.7、gem 版本 1.3.5、rails 版本 2.3.5 和 memcache。运行服务器时出现此错误

phuongnm-lap:~/trunk/hurricane$ ruby script/server
=> Booting Mongrel
=> Rails 2.3.5 application starting on http://0.0.0.0:3000
/home/asiantech/.rvm/gems/ruby-1.8.7-p374/gems/bundler-1.11.2/lib/bundler/runtime.rb:77:in `require': /home/asiantech/trunk/hurricane/vendor/bundle/ruby/1.8/gems/get_process_mem-0.2.0/lib/get_process_mem.rb:60: undefined (?...) sequence: /(?<value>(\d*\.{0,1}\d+))\s+(?<unit>\w\w)/ (SyntaxError)
    from /home/asiantech/.rvm/gems/ruby-1.8.7-p374/gems/bundler-1.11.2/lib/bundler/runtime.rb:77:in `require'
    from /home/asiantech/.rvm/gems/ruby-1.8.7-p374/gems/bundler-1.11.2/lib/bundler/runtime.rb:72:in `each'
    from /home/asiantech/.rvm/gems/ruby-1.8.7-p374/gems/bundler-1.11.2/lib/bundler/runtime.rb:72:in `require'
    from /home/asiantech/.rvm/gems/ruby-1.8.7-p374/gems/bundler-1.11.2/lib/bundler/runtime.rb:61:in `each'
    from /home/asiantech/.rvm/gems/ruby-1.8.7-p374/gems/bundler-1.11.2/lib/bundler/runtime.rb:61:in `require'
    from /home/asiantech/.rvm/gems/ruby-1.8.7-p374/gems/bundler-1.11.2/lib/bundler.rb:99:in `require'
    from ./script/../config/boot.rb:41:in `load_gems'
    from /home/asiantech/trunk/hurricane/vendor/bundle/ruby/1.8/gems/rails-2.3.5/lib/initializer.rb:164:in `process'
    from /home/asiantech/trunk/hurricane/vendor/bundle/ruby/1.8/gems/rails-2.3.5/lib/initializer.rb:113:in `send'
    from /home/asiantech/trunk/hurricane/vendor/bundle/ruby/1.8/gems/rails-2.3.5/lib/initializer.rb:113:in `run'
    from /home/asiantech/trunk/hurricane/config/environment.rb:34
    from /home/asiantech/trunk/hurricane/vendor/bundle/ruby/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:156:in `require'
    from /home/asiantech/trunk/hurricane/vendor/bundle/ruby/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:156:in `require'
    from /home/asiantech/trunk/hurricane/vendor/bundle/ruby/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:521:in `new_constants_in'
    from /home/asiantech/trunk/hurricane/vendor/bundle/ruby/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:156:in `require'
    from /home/asiantech/trunk/hurricane/vendor/bundle/ruby/1.8/gems/rails-2.3.5/lib/commands/server.rb:84
    from script/server:3:in `require'
    from script/server:3

请帮帮我！

Answer 1

您的 ruby​​ 版本太旧，get_process_mem gem 无法运行。 gem 使用 complex regular expression 来解析来自您的 linux 服务器上的 /proc 文件的信息。但是，ruby 1.8.7 还不支持这种复杂的正则表达式。

您可以在 irb 中亲自查看。在 ruby​​ 1.8.7 中匹配失败：

"aaa" =~ /(?<value>(\d*\.{0,1}\d+))\s+(?<unit>\w\w)/
# => SyntaxError: compile error
# => (irb):1: undefined (?...) sequence: /(?<value>(\d*\.{0,1}\d+))\s+(?<unit>\w\w)/

而在 ruby​​ 2.2 下它工作正常（在此测试用例中不返回任何内容，但更重要的是，不会因错误而失败）：

"aaa" =~ /(?<value>(\d*\.{0,1}\d+))\s+(?<unit>\w\w)/
# => nil

你现在有几个选择：

• 如果可以的话，升级到较新的 ruby​​（和 rails），您将不必解决这些与代码相关的老问题，也不会再使用不受支持的 ruby​​/rails 版本，但这仍然是一个繁琐的过程。
• 摆脱get_process_mem gem。您可以使用命令行实用程序查看相同的信息，即进程消耗的内存，而无需安装任何 gem。 例如尝试top 或htop 命令。