With my team, I am using the wonderful Ruote engine (recently upgraded
to 2.3.0) in a production environment, with an average of 20 new
processes created every day.

I recently fixed a bug in a workflow that caused some workitems to
move into an error condition.

I had the following information about the error:
message:
  #<NoMethodError: undefined method `size' for nil:NilClass>
trace:
  /home/rails/apps/arts/shared/bundle/ruby/1.8/gems/ruote-2.2.0/lib/
ruote/exp/fe_concurrence.rb:286:in `merge_all_workitems'
  .../ruby/1.8/gems/ruote-2.2.0/lib/ruote/exp/fe_concurrence.rb:258:in
`reply_to_parent'
  .../ruby/1.8/gems/ruote-2.2.0/lib/ruote/exp/flowexpression.rb:228:in
`do_apply'
  .../ruby/1.8/gems/ruote-2.2.0/lib/ruote/worker.rb:326:in `launch'
  .../ruby/1.8/gems/ruote-2.2.0/lib/ruote/worker.rb:243:in `process'
  .../ruby/1.8/gems/ruote-2.2.0/lib/ruote/worker.rb:173:in `step'
  .../ruby/1.8/gems/ruote-2.2.0/lib/ruote/worker.rb:75:in `run'
  ./script/ruote_worker:23
  ./script/service:107:in `instance_eval'
  ./script/service:107:in `boot!'
  ./script/service:38:in `initialize'
  ./script/ruote_worker:12:in `new'
  ./script/ruote_worker:12

The mistake was the use of a :unless clause in a :concurrence
expression, as highlighted by the following unit test:
https://gist.github.com/beaefdcc70a718c42ed5

Nesting the :concurrence expression into a :sequence expression and
moving the :unless clause up into the :sequence resolved the problem
(but there were other ways, such as an :if expression).
Probably the issue is documented, but I could not find it.

However, my current problem is with the errors that such situation
raised.
From my business point of view, I resolved with restarting a new
process for any process in error state.
Therefore the processes in error state had to be removed from the
engine.

I tried to kill those processes with
  @engine.kill_process(error.wfid)
but that seems to have no effect.

Am i making any mistake?
Can someone suggest me a way to remove definitely the processes?

excellent! I will dig into this issue report. Thanks a lot!

I guess you're using ruote-couch. It would mean removing all the documents
that have a "wfid" => your_wfid or a "fei" => { "wfid" => your_wfid } at
their top level (proceed with caution).

Tell me if you need help with that.

I can probably write a "vaporize" method that works with any storage, tell me
if you're interested. I should write it anyway, it seems a very necessary
tool.

Cheers,

Thank you
Claudio

I think I fixed the issue yesterday while working on different symptoms:

  https://github.com/jmettraux/ruote/commit/14e8a835a4ae39b9897641662bb...

I updated your gist and it seems to confirm it:

  https://gist.github.com/e229de6db40823053797

Please tell me if it's not fixed.

Thanks a ton!

I pushed Ruote::Dashboard#remove_process(wfid):

  https://github.com/jmettraux/ruote/commit/9be845973d9525256397e439c7f...
  https://github.com/jmettraux/ruote/commit/c8dfd3627fbaa69232fd21ed86a...
  https://github.com/jmettraux/ruote-couch/commit/c2d1192599d3eebc52053...

Make sure to remove the design document in the "schedules" database of
your couch system before calling this remove_process, else the
schedules registered for your processes won't get removed.

Please tell me if it doesn't work. Thanks and best regards,