linux下fastcgi + mysql Broken Pipe Error

rails application 运行10~12小时（没有request给fastcgi），当10~12小时过后，再发request，系统报internal 500 错误，看了日志，记录如下：
/!\ FAILSAFE /!\ Wed Apr 15 08:16:01 +0800 2009
Status: 500 Internal Server Error
Broken pipe
/usr/local/lib/ruby/1.8/mysql.rb:1042:in flush'
/usr/local/lib/ruby/1.8/mysql.rb:1042:inwrite'
/usr/local/lib/ruby/1.8/mysql.rb:462:in write'
/usr/local/lib/ruby/1.8/mysql.rb:436:incommand'
/usr/local/lib/ruby/1.8/mysql.rb:307:in stat'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/mysql_adapter.rb:264:inactive?'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract_adapter.rb:136:in verify!'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:256:incheckout_and_verify'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:252:in checkout_existing_connection'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:186:incheckout'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:184:in loop'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:184:incheckout'
/usr/local/lib/ruby/1.8/monitor.rb:242:in `synchronize'
..........
好像是mysql的connection已经关闭了，而fastcgi进程还运行着，当再次request时，找不到对应connection 所以报错
各位还有遇到过这种问题，如何解决的？是否可以更改mysql的connection连接超时时间？

可以更改mysql的connection连接超时时间