RestClient::ServiceUnavailable: 503 Service Unavailable

backtrace

.bundle/gems/ruby/1.9.1/gems/rest-client-1.6.1/lib/restclient/abstract_response.rb:48:in `return!'
.bundle/gems/ruby/1.9.1/gems/rest-client-1.6.1/lib/restclient/request.rb:220:in `process_result'
.bundle/gems/ruby/1.9.1/gems/rest-client-1.6.1/lib/restclient/request.rb:169:in `block in transmit'
/usr/ruby1.9.2/lib/ruby/1.9.1/net/http.rb:627:in `start'
.bundle/gems/ruby/1.9.1/gems/rest-client-1.6.1/lib/restclient/request.rb:166:in `transmit'
.bundle/gems/ruby/1.9.1/gems/rest-client-1.6.1/lib/restclient/request.rb:60:in `execute'
.bundle/gems/ruby/1.9.1/gems/rest-client-1.6.1/lib/restclient/request.rb:31:in `execute'
.bundle/gems/ruby/1.9.1/gems/rest-client-1.6.1/lib/restclient/resource.rb:51:in `get'
.bundle/gems/ruby/1.9.1/gems/heroku-1.20.1/lib/heroku/client.rb:540:in `process'
.bundle/gems/ruby/1.9.1/gems/heroku-1.20.1/lib/heroku/client.rb:522:in `get'
.bundle/gems/ruby/1.9.1/gems/heroku-1.20.1/lib/heroku/client.rb:53:in `info'
.bundle/gems/ruby/1.9.1/gems/hirefire-0.1.0/lib/hirefire/environment/heroku.rb:27:in `workers'
.bundle/gems/ruby/1.9.1/gems/hirefire-0.1.0/lib/hirefire/environment/base.rb:51:in `hire'
.bundle/gems/ruby/1.9.1/gems/activesupport-3.0.6/lib/active_support/callbacks.rb:416:in `_run_create_callbacks'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/callbacks.rb:277:in `create'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/persistence.rb:246:in `create_or_update'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/callbacks.rb:273:in `block in create_or_update'
.bundle/gems/ruby/1.9.1/gems/activesupport-3.0.6/lib/active_support/callbacks.rb:419:in `_run_save_callbacks'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/callbacks.rb:273:in `create_or_update'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/persistence.rb:39:in `save'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/validations.rb:43:in `save'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/attribute_methods/dirty.rb:21:in `save'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/transactions.rb:240:in `block (2 levels) in save'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/transactions.rb:292:in `block in with_transaction_returning_status'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/connection_adapters/abstract/database_statements.rb:139:in `transaction'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/transactions.rb:207:in `transaction'
.bundle/gems/ruby/1.9.1/gems/newrelic_rpm-2.13.4/lib/new_relic/agent/method_tracer.rb:319:in `block in transaction_with_trace_ActiveRecord_self_name_transaction'
.bundle/gems/ruby/1.9.1/gems/newrelic_rpm-2.13.4/lib/new_relic/agent/method_tracer.rb:141:in `trace_execution_scoped'
.bundle/gems/ruby/1.9.1/gems/newrelic_rpm-2.13.4/lib/new_relic/agent/method_tracer.rb:314:in `transaction_with_trace_ActiveRecord_self_name_transaction'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/transactions.rb:290:in `with_transaction_returning_status'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/transactions.rb:240:in `block in save'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/transactions.rb:251:in `rollback_active_record_state!'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/transactions.rb:239:in `save'
.bundle/gems/ruby/1.9.1/gems/activerecord-3.0.6/lib/active_record/base.rb:498:in `create'
.bundle/gems/ruby/1.9.1/gems/delayed_job-2.1.3/lib/delayed/backend/base.rb:28:in `enqueue'