Hi everyone, I have been trying to solve this problem for quite some time now and I really don''t have any further clue to investigate. I am running a mongrel_cluster 1.0.5-2 (mongrel verison : 1.1.5-5) on a ubuntu box with apache2 2.2.12-1ubuntu2.1 I have 4 different apps on the same box and each app has two mongrel instances. After a short period of time ( < 2 hours ) some of the 8 mongrel instances just stop responding. I read the mongrel FAQ and tried to set ActiveRecord::Base.verification_timeout = 14400 (the mysql parameter is set to the default 28800) in myapp/config/environments/production.rb The problem kept happening. I decided to lower that number, making it 60. No more success. I installed gdb and the ruby macros to make sure i was in the mysql driver while hanging and sure enough, here is the top of the BT from GDB : /var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/mysql_adapter.rb:264:in `active?''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract_adapter.rb:136:in `verify!''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:256:in `checkout_and_verify''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:252:in `checkout_existing_connection''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:186:in `checkout''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:184:in `loop''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:184:in `checkout''", "/usr/lib/ruby/1.8/monitor.rb:242:in `synchronize''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:183:in `checkout''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:98:in `connection''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:326:in `retrieve_connection''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:121:in `retrieve_connection''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:113:in `connection''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/base.rb:2934:in `quoted_table_name''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/base.rb:1626:in `construct_finder_sql''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/base.rb:1490:in `find_every''", "/var/lib/gems/1.8/gems/activerecord-2.2.2/lib/active_record/base.rb:589:in `find''", I figured that since I was running a packaged version of mongrel_cluster (not the gem installed one), I should use the package version of mysql driver for ruby. So i did gem uninstall mysql and installed : apt-get install libmysql-ruby1.8 I then restarted the mongrels and sure enough after 1h25 one of them was hanging in the mysql_adapter.rb, showing the same backtrace as before. I really am out of clue here and any advice / help would be much appreciated. I have to note that I am far from being an ROR guru and maybe the solution to my problem is simpler than what I have been looking for, but I just don''t know where to look anymore. Thanks for any advice / answer Damien -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://rubyforge.org/pipermail/mongrel-users/attachments/20100126/c809cb37/attachment.html>