#<Mongo::Error::OperationFailure: Transaction numbers are only allowed on storage engines that support document-level locking (20)>
2019-06-26T10:17:23.795331+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongo-2.9.0/lib/mongo/operation/result.rb:272:in `raise_operation_failure'
2019-06-26T10:17:23.795334+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongo-2.9.0/lib/mongo/operation/result.rb:268:in `validate!'
2019-06-26T10:17:23.795336+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongo-2.9.0/lib/mongo/operation/shared/executable.rb:26:in `execute'
2019-06-26T10:17:23.795338+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongo-2.9.0/lib/mongo/operation/shared/op_msg_or_command.rb:27:in `execute'
2019-06-26T10:17:23.795342+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongo-2.9.0/lib/mongo/collection/view/writable.rb:129:in `block (2 levels) in find_one_and_update'
2019-06-26T10:17:23.795344+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongo-2.9.0/lib/mongo/retryable.rb:211:in `write_with_retry'
2019-06-26T10:17:23.795347+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongo-2.9.0/lib/mongo/collection/view/writable.rb:121:in `block in find_one_and_update'
2019-06-26T10:17:23.795349+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongo-2.9.0/lib/mongo/cluster.rb:662:in `with_session'
2019-06-26T10:17:23.795351+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongo-2.9.0/lib/mongo/client.rb:733:in `with_session'
2019-06-26T10:17:23.795353+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongo-2.9.0/lib/mongo/collection/view.rb:204:in `with_session'
2019-06-26T10:17:23.795355+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongo-2.9.0/lib/mongo/collection/view/writable.rb:120:in `find_one_and_update'
2019-06-26T10:17:23.795357+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongoid-5.4.0/lib/mongoid/query_cache.rb:182:in `find_one_and_update_with_clear_cache'
2019-06-26T10:17:23.795359+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongoid-autoinc-5.0.2/lib/autoinc/incrementor.rb:53:in `inc'
2019-06-26T10:17:23.795361+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongoid-autoinc-5.0.2/lib/autoinc.rb:112:in `increment!'
2019-06-26T10:17:23.795363+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongoid-autoinc-5.0.2/lib/autoinc.rb:94:in `block in update_auto_increments'
2019-06-26T10:17:23.795366+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongoid-autoinc-5.0.2/lib/autoinc.rb:93:in `each'
2019-06-26T10:17:23.795368+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongoid-autoinc-5.0.2/lib/autoinc.rb:93:in `update_auto_increments'
2019-06-26T10:17:23.795370+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/activesupport-4.1.9/lib/active_support/callbacks.rb:424:in `block in make_lambda'
2019-06-26T10:17:23.795372+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/activesupport-4.1.9/lib/active_support/callbacks.rb:160:in `block in halting'
2019-06-26T10:17:23.795374+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/activesupport-4.1.9/lib/active_support/callbacks.rb:166:in `block in halting'
2019-06-26T10:17:23.795377+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/activesupport-4.1.9/lib/active_support/callbacks.rb:166:in `block in halting'
2019-06-26T10:17:23.795380+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/activesupport-4.1.9/lib/active_support/callbacks.rb:215:in `block in halting_and_conditional'
2019-06-26T10:17:23.795382+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/activesupport-4.1.9/lib/active_support/callbacks.rb:86:in `run_callbacks'
2019-06-26T10:17:23.795384+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongoid-5.4.0/lib/mongoid/interceptable.rb:138:in `run_callbacks'
2019-06-26T10:17:23.795386+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongoid-5.4.0/lib/mongoid/persistable/creatable.rb:117:in `block in prepare_insert'
2019-06-26T10:17:23.795388+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/activesupport-4.1.9/lib/active_support/callbacks.rb:113:in `call'
2019-06-26T10:17:23.795390+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/activesupport-4.1.9/lib/active_support/callbacks.rb:166:in `block in halting'
2019-06-26T10:17:23.795392+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/activesupport-4.1.9/lib/active_support/callbacks.rb:86:in `run_callbacks'
2019-06-26T10:17:23.795394+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongoid-5.4.0/lib/mongoid/interceptable.rb:138:in `run_callbacks'
2019-06-26T10:17:23.795396+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongoid-5.4.0/lib/mongoid/persistable/creatable.rb:116:in `prepare_insert'
2019-06-26T10:17:23.795398+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongoid-5.4.0/lib/mongoid/persistable/creatable.rb:23:in `insert'
2019-06-26T10:17:23.795401+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/mongoid-5.4.0/lib/mongoid/persistable/savable.rb:23:in `save'
2019-06-26T10:17:23.795404+00:00 app[web.1]: /app/app/controllers/comps_controller.rb:159:in `block in create'
2019-06-26T10:17:23.795406+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/actionpack-4.1.9/lib/action_controller/metal/mime_responds.rb:433:in `retrieve_collector_from_mimes'
2019-06-26T10:17:23.795408+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/actionpack-4.1.9/lib/action_controller/metal/mime_responds.rb:256:in `respond_to'
2019-06-26T10:17:23.795410+00:00 app[web.1]: /app/app/controllers/comps_controller.rb:158:in `create'
2019-06-26T10:17:23.795413+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/actionpack-4.1.9/lib/action_controller/metal/implicit_render.rb:4:in `send_action'
2019-06-26T10:17:23.795415+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/actionpack-4.1.9/lib/abstract_controller/base.rb:189:in `process_action'
2019-06-26T10:17:23.795422+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/actionpack-4.1.9/lib/action_controller/metal/rendering.rb:10:in `process_action'
2019-06-26T10:17:23.795424+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/actionpack-4.1.9/lib/abstract_controller/callbacks.rb:20:in `block in process_action'
2019-06-26T10:17:23.795426+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/activesupport-4.1.9/lib/active_support/callbacks.rb:113:in `call'