mysql - 续集数据库连接池超时错误

我无法确定我编写的Ruby脚本中以下Sequel::PoolTimeout错误的原因是什么：

Sequel::PoolTimeout: Sequel::PoolTimeout
             hold at /Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/connection_pool/threaded.rb:100
             hold at /Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/connection_pool/threaded.rb:93
      synchronize at /Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/database/connecting.rb:234
          execute at /Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/adapters/jdbc.rb:258
          execute at /Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/dataset/actions.rb:793
       fetch_rows at /Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/adapters/jdbc.rb:671
             each at /Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/dataset/actions.rb:143
    single_record at /Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/dataset/actions.rb:583
     single_value at /Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/dataset/actions.rb:591
              get at /Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/dataset/actions.rb:250
           empty? at /Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/dataset/actions.rb:153
            scrap at /Users/username/projectname/processers/get_category.rb:46
             each at org/jruby/RubyArray.java:1617
  each_with_index at org/jruby/RubyEnumerable.java:920
            scrap at /Users/username/projectname/processers/get_category.rb:44
            scrap at /Users/username/projectname/processers/get_category.rb:32

我已经使用MRI和JRuby尝试了完全相同的结果。

按照Sequel宝石here上的说明，我尝试如下提高pool_timeout限制：

DB = Sequel.connect("jdbc:mysql://localhost/project_db?user=USERNAME&password=PASSWD&max_connections=10&pool_timeout=120")

似乎max_connections和pool_timeout可能无法识别，但是我没有看到任何其他方法将这些args传递到连接中。

这里有问题的实际代码是：
if DB[:products].where(url: url.to_s).empty?

我已经看到代码可以正常工作了一点，但是没有失败，它立即失败了，或者几分钟后就失败了，就发生时间而言没有任何可重复性。我开始怀疑这是MySQL配置问题，还是导致localhost DBMS延迟较长的原因，尽管同样，我无法手动重现可见的超时，我可以通过手动查询等告知超时。

关于该问题为何会继续发生的任何想法，或更具体地说，如何通过提供Sequel正确的设置（也许我的arg列表格式错误）或针对这种情况修改MySQL的/etc/my.cnf来解决它？

最佳答案

Sequel jdbc适配器将连接字符串直接传递给JDBC，它不解析嵌入式选项。您需要做：

DB = Sequel.connect("jdbc:mysql://localhost/project_db?user=USERNAME&password=PASSWD", :max_connections=>10, :pool_timeout=>120)

关于mysql - 续集数据库连接池超时错误，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/18774259/