Re: how to test GWT app through a proxy

Thanks Jens for your pointers. Here are a few developments.

On Tuesday, March 13, 2012 5:25:47 PM UTC-7, Jens wrote:

The exception you see is thrown in RemoteServiceProxy.doInvoke(...) and simply wraps a possible RequestException. These RequestExceptions can be thrown by RequestBuilder.doSend(..) and are wrappers for JavaScriptExceptions that can be thrown by the browser if it can not do an ajax request using XMLHttpRequest.

All these exceptions are chained together so you should log the whole stack trace to get some more information.

That is probably a good next step: I changed it so that now it shows a stack trace of nonsense -- I could
put the symbol table into the app (with SourceMaps?), and then ask users who experience
the problem to email me the stack trace.
 

I don't think its an issue in GWT-RPC. Its just that your customer's browser sometimes can't establish a connection to your server

I still have not been able to see the problem for myself. On the theory that it
is likely to happen in places with weak internet, I have carried my laptop around
to various cafes etc. and run a bunch of apps, but so far no problem.

I have tried a few adventuresome things, like
* in the RemoteServiceServlet I made doGetSerializationPolicy()
always return null, thereby forcing it to use a 1.3.3 compatible policy.
This seems to have helped, in the sense that users had earlier reported
errors related to getting a serialization policy, and since this change,
no one has reported those errors.

Then last Thursday, my associate was giving a training in Sacramento in
a situation with possibly weak internet, at the same time
that several other users were keeping our server engaged with
massive uploads (I am still not sure if server load has anything to do with this).
The trainees were supposed to use our GWT apps. Many of them
got a ...client.rpc.StatusCodeException: 0 whenever the app they were
using tried to read or write through RPC.

The apps seem to report StatusCodeException 0 when they are not able
to reach the server, because I was not able to see any evidence of these
failures in any server log.

My associate says he ended up apologizing to the trainees instead
of covering the material, He thinks we should be investigating something
beside GWT, or at least hiring someone who really knows GWT RPC to
audit our apps. (Is there such a person?)

Another thing I have tried after Thursday was to put some of the critical
RPC calls (logging in) inside an iteration with DeferredCommands and Timers,
so that if the first attempt doesn't work, it will try a few more times before
giving up. I am not yet sure if this makes any difference. These are
desperate (read silly) measures.

--
You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group.
To view this discussion on the web visit https://groups.google.com/d/msg/google-web-toolkit/-/cx8hTxO1XiUJ.
To post to this group, send email to google-web-toolkit@googlegroups.com.
To unsubscribe from this group, send email to google-web-toolkit+unsubscribe@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.