DWR remote calls and callbacks intermittently not executed

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DWR remote calls and callbacks intermittently not executed

msm0813
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Re: DWR remote calls and callbacks intermittently not executed

david@butterdev.com
The fact that all of your calls are synchronous leads me to believe you
aren't doing things incorrectly.  Synchronous calls are highly discouraged.

You need to perform some basic troubleshooting and investigate these
problems further and provide more detail.  Regarding the first problem,
if the issue is on DWR's end you will almost certainly be seeing
something in the logs.  Do you have a proxy server?  Have you tried
placing some breakpoints in your server code?  Have you verified the DWR
Servlet is being called?  Have you verified the call is leaving the
browser?  You can do similar tests for the second problem.  Have you
checked the browser for errors?  Have you tried placing some breakpoints
in DWR's engine JS?  If your Java code is performing an insert instead
of an update, that is your issue and your code is obviously incorrect.
You should be able to figure out why this is happening by debugging your
code.

On 10/09/2013 03:31 AM, [hidden email] wrote:

> Dear all,
>
> We are experiencing a problem with DWR 3.0. Calling Java methods from
> JavaScript by DWR works just fine almost all of the time, but rarely
> the Java method doesn't get called at all. We wrote a workaround that
> detects this "missed" DWR call and retries it. Most of the time this
> second call is successful, i.e. there are cases where the second call
> fails as well. Nevertheless we have permanently implemented this
> workaround.
> However, even then there is an additional problem. The Java method gets
> called and completes successfully, but following completion, neither
> the DWR callback, nor the error handler get executed. We retry the call
> in this case as well and this time we've noticed that Hibernate (v.
> 3.3.2) misbehaves and erroneously does an INSERT instead of UPDATE. We
> tend to think that this may be related to the DWR not invoking the
> callback or error handler.
>
> Errors cannot be found anywhere in the logs, except for an error
> related to the above Hibernate problem.
>
> The DWR calls involved are all synchronous and there is a timeout of 10
> minutes (600000 ms).
>
> Thank you in advance for any advice.
>

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Re: DWR remote calls and callbacks intermittently not executed

david@butterdev.com
Correction:
The fact that all of your calls are synchronous leads me to believe you
are doing things incorrectly.


On 10/09/2013 06:26 AM, David Marginian wrote:

> The fact that all of your calls are synchronous leads me to believe
> you aren't doing things incorrectly.  Synchronous calls are highly
> discouraged.
>
> You need to perform some basic troubleshooting and investigate these
> problems further and provide more detail.  Regarding the first
> problem, if the issue is on DWR's end you will almost certainly be
> seeing something in the logs.  Do you have a proxy server?  Have you
> tried placing some breakpoints in your server code?  Have you verified
> the DWR Servlet is being called?  Have you verified the call is
> leaving the browser?  You can do similar tests for the second
> problem.  Have you checked the browser for errors?  Have you tried
> placing some breakpoints in DWR's engine JS?  If your Java code is
> performing an insert instead of an update, that is your issue and your
> code is obviously incorrect. You should be able to figure out why this
> is happening by debugging your code.
>
> On 10/09/2013 03:31 AM, [hidden email] wrote:
>> Dear all,
>>
>> We are experiencing a problem with DWR 3.0. Calling Java methods from
>> JavaScript by DWR works just fine almost all of the time, but rarely
>> the Java method doesn't get called at all. We wrote a workaround that
>> detects this "missed" DWR call and retries it. Most of the time this
>> second call is successful, i.e. there are cases where the second call
>> fails as well. Nevertheless we have permanently implemented this
>> workaround.
>> However, even then there is an additional problem. The Java method gets
>> called and completes successfully, but following completion, neither
>> the DWR callback, nor the error handler get executed. We retry the call
>> in this case as well and this time we've noticed that Hibernate (v.
>> 3.3.2) misbehaves and erroneously does an INSERT instead of UPDATE. We
>> tend to think that this may be related to the DWR not invoking the
>> callback or error handler.
>>
>> Errors cannot be found anywhere in the logs, except for an error
>> related to the above Hibernate problem.
>>
>> The DWR calls involved are all synchronous and there is a timeout of 10
>> minutes (600000 ms).
>>
>> Thank you in advance for any advice.
>>
>
>