[rules-users] Strange intermittent problem with Drools Flow

Wed Apr 20 12:26:32 EDT 2011

Bump

Regards,

Dan Nathanson


On Mon, Apr 11, 2011 at 4:37 PM, Dan Nathanson <dan at ddnconsulting.com> wrote:
> Hi Mauricio,
>
> This is now happening intermittently for another user and a couple of
> times on our build machine.  I have never seen it happen on my
> machine.  This will be a show-stopper for us if we cannot figure out
> the cause.  Our business processes will stall after one user completes
> their task and the next user is never notified that they have a task,
> and no errors will be reported.
>
> Regards,
>
> Dan Nathanson
>
>
>
>
> On Mon, Apr 4, 2011 at 9:27 PM, Dan Nathanson <dan at ddnconsulting.com> wrote:
>> Hi Mauricio,
>>
>> Were you able to make determine anything from the info I sent you?
>>
>> Regards,
>>
>> Dan Nathanson
>>
>> On Fri, Apr 1, 2011 at 11:03 AM, Dan Nathanson <dan at ddnconsulting.com> wrote:
>>> Hi Mauricio,
>>>
>>> Thanks for looking into this. These are the types of errors that scare
>>> me.  They only happen in one environment and I cannot reproduce them.
>>> How will I know if it happens in production?
>>>
>>> We generate our rule flow's dynamically from our own concept of a
>>> process flow.  I don't have a custom work item implementation, but I
>>> do have a custom WorkItemHandler registered against work items of type
>>> "Step" called StepWorkItemHandler. StepWorkItemHandler has uses and
>>> injected CallbackHandler to do actual processing.  In test code, the
>>> injected callback handler just records what steps (work items) have
>>> been activated.  In production code, the injected handler sends JMS
>>> messages to notify assigned users that work needs to be completed.
>>>
>>> Below is an example of a simple generated flow that fails
>>> intermittently for one developer here.  I captured it using the
>>> XmlRuleFlowProcessDumper.
>>>
>>> <?xml version="1.0" encoding="UTF-8"?>
>>> <process xmlns="http://drools.org/drools-5.0/process"
>>>         xmlns:xs="http://www.w3.org/2001/XMLSchema-instance"
>>>         xs:schemaLocation="http://drools.org/drools-5.0/process
>>> drools-processes-5.0.xsd"
>>>         type="RuleFlow" name="flow-1"
>>> id="bd5556f7_581d_422f_a382_3bb3ac041c4f"
>>> package-name="com.xxx.process.manager" >
>>>
>>>  <header>
>>>    <imports>
>>>      <import name="org.drools.ruleflow.instance.RuleFlowProcessInstance" />
>>>    </imports>
>>>  </header>
>>>
>>>  <nodes>
>>>    <start id="1" name="flow-1 Start" />
>>>    <join id="2" name="step-1 Reject Join" type="2" />
>>>    <workItem id="3" name="step-1 Step" >
>>>      <work name="Step" >
>>>      </work>
>>>    </workItem>
>>>    <workItem id="4" name="step-1 Approval" >
>>>      <work name="Step" >
>>>      </work>
>>>    </workItem>
>>>    <split id="5" name="step-1 Approval Split" type="2" >
>>>      <constraints>
>>>        <constraint toNodeId="2" toType="DROOLS_DEFAULT"
>>> name="rejected" priority="110" type="code" dialect="java" >return
>>> true;</constraint>
>>>        <constraint toNodeId="6" toType="DROOLS_DEFAULT"
>>> name="approved" priority="100" type="rule" dialect="mvel"
>>>>StepApproval( approved == true, sliceValue == "NO_SLICE",
>>> approvalStepNodeId == "1a8a5a64-1e32-46a9-8b04-806c1706a97a"
>>> )</constraint>
>>>      </constraints>
>>>    </split>
>>>    <state id="6" name="null Wait" >
>>>      <onEntry>
>>>        <action type="expression" dialect="java"
>>>>Terminator.terminateFlow(context);</action>
>>>      </onEntry>
>>>      <constraints>
>>>        <constraint toNodeId="7" >Terminator()</constraint>
>>>      </constraints>
>>>    </state>
>>>    <end id="7" name="null End" />
>>>  </nodes>
>>>
>>>  <connections>
>>>    <connection from="1" to="2" />
>>>    <connection from="5" to="2" />
>>>    <connection from="2" to="3" />
>>>    <connection from="3" to="4" />
>>>    <connection from="4" to="5" />
>>>    <connection from="5" to="6" />
>>>    <connection from="6" to="7" />
>>>  </connections>
>>>
>>> </process>
>>>
>>>
>>>
>>> I'm attaching the log at trace level (there are no WARN level messages
>>> at all) that shows this flow failing to complete.  Lines of interest:
>>> 631: Generating the flow from our internal model
>>> 634: starting the flow
>>> 785: Process event listener shows that flow has started and proceeded
>>> to work item 1 ("step-1 Step")
>>> 802: StepWorkItemHandler called for work item 1 "step-1 Step"
>>> 803: Process event listener shows "unwinding"of activations
>>> 904: Work item 1 "step-1 Step" completed
>>> 921: work item loaded
>>> 939: process instance loaded
>>> 956: Process event listener shows leaving "step-1 Step", activating
>>> work item 2 "step-1 Approval"
>>> 969: StepWorkItemHandler called forwork item 2 "step-1 Approval"
>>> 970: Process event listener shows "unwinding"of activations
>>> 1024: work item 1 deleted
>>> 1032: Work item 2 "step-1 Approval" completed
>>> 1049: work item loaded
>>> 1067: process instance loaded
>>> ---Should now see leaving "step-1 Approval" and completing flow, but
>>> don't see any further progress in the flow.---
>>> 1141: work item 2 deleted
>>>
>>> The execution thread is part of the log output and it seems that
>>> everything is done in one thread.
>>>
>>> I've also attached a log file (without verbose hibernate output) for a
>>> successful test run.
>>>
>>> Regards,
>>>
>>> Dan Nathanson
>>>
>>>
>>>
>>>
>>> On Fri, Apr 1, 2011 at 2:42 AM, Mauricio Salatino <salaboy at gmail.com> wrote:
>>>> Hi Dan,
>>>> That's strange, it could be related to a non updated version of the fluent
>>>> API.
>>>> Send us the logs with warn verbosity and we will definitely take a look on
>>>> it.
>>>> If the workflow don't continue after a work item completion could be related
>>>> with some kind of threading problem.
>>>> What kind of work item are you implementing? Can you share some test with us
>>>> that shows the desired behavior?
>>>> Greetings.
>>>>
>>>> On Thu, Mar 31, 2011 at 4:32 PM, Dan Nathanson <dan at ddnconsulting.com>
>>>> wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> I'm seeing some odd behavior in some of my test cases.  And it only
>>>>> seems to happen to one guy. And he's done fresh checkouts of the code,
>>>>> blown away his local M2 repository and verified installed software
>>>>> like OS and Java is same as everyone else's.
>>>>>
>>>>> I have some test cases that build up some simple flows programatically
>>>>> using fluent API.  Very simple (start --> work item --> work item -->
>>>>> state --> end).  I am using Drools Flow 5.1.1 with JPA (in-memory H2
>>>>> DB for unit tests).  Intermittently, after completing a work item, the
>>>>> flow doesn't continue.  Logging in a process event listener shows that
>>>>> the the work item node is never left, although I can see in the logs
>>>>> that the work item is deleted from DB.
>>>>>
>>>>> There are no errors, warning or info level messages coming out of
>>>>> Drools or Hibernate prior to the failure.
>>>>>
>>>>> It only happens to one guy, but he can reproduce the problem
>>>>> regularly, although it moves around in different test cases and
>>>>> different points in the flows.
>>>>>
>>>>> Anyone ever seen this behavior before?  Any possible explanations?
>>>>>
>>>>> I'd attach the log file, but it is huge since I've got hibernate
>>>>> logging set very verbose.
>>>>>
>>>>> Regards,
>>>>>
>>>>> Dan Nathanson
>>>>> _______________________________________________
>>>>> rules-users mailing list
>>>>> rules-users at lists.jboss.org
>>>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>>
>>>>
>>>>
>>>> --
>>>>  - CTO @ http://www.plugtree.com
>>>>  - MyJourney @ http://salaboy.wordpress.com
>>>>  - Co-Founder @ http://www.jbug.com.ar
>>>>
>>>>  - Salatino "Salaboy" Mauricio -
>>>>
>>>
>>
>