backtrace

/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/util/pool.rb:119:in `ping_time'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/util/read_preference.rb:119:in `block in select_near_pool'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/util/read_preference.rb:119:in `each'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/util/read_preference.rb:119:in `min_by'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/util/read_preference.rb:119:in `select_near_pool'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/util/read_preference.rb:114:in `select_secondary_pool'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/util/read_preference.rb:92:in `select_pool'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/util/read_preference.rb:67:in `read_pool'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/mongo_replica_set_client.rb:360:in `block in checkout_reader'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/mongo_replica_set_client.rb:344:in `checkout'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/mongo_replica_set_client.rb:359:in `checkout_reader'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/cursor.rb:568:in `checkout_socket_from_connection'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/cursor.rb:496:in `block in send_initial_query'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/util/logging.rb:55:in `block in instrument'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/util/logging.rb:20:in `instrument'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/util/logging.rb:54:in `instrument'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/cursor.rb:493:in `send_initial_query'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/cursor.rb:478:in `refresh'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/cursor.rb:124:in `next'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo-1.9.2/lib/mongo/collection.rb:317:in `find_one'
/usr/local/lib/ruby/gems/1.9.1/gems/plucky-0.5.2/lib/plucky/query.rb:69:in `find_one'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo_mapper-0.12.0/lib/mongo_mapper/plugins/identity_map.rb:74:in `find_one'
/usr/local/lib/ruby/gems/1.9.1/gems/plucky-0.5.2/lib/plucky/query.rb:86:in `first'
/usr/local/lib/ruby/gems/1.9.1/gems/plucky-0.5.2/lib/plucky/query.rb:75:in `find'
/usr/local/lib/ruby/gems/1.9.1/gems/mongo_mapper-0.12.0/lib/mongo_mapper/plugins/querying/decorator.rb:19:in `find!'