I’m using vaadin in my application. I’m facing a difficulty in an issue fixing. I suppose you must had an idea about it. The issue description is as follows
In my application, we use to generate reports from BO server to GUI
When the report generation takes more than 30 mins, the “Communication Problem take note of any unsaved data, and click here to continue.
(SyntaxError): Syntax error number: -2146827286 description: Syntax error - Original JSON-text:”
I changed the session time out in web.xml in my application and in application server (Tomcat) as well. But still i couldn’t fix the issue.
Is this issue is coming because the session configured in vaadin server expired? If yes, how can i change the vaadin server session time out
I approached many Java forums but still i’m not able to figure this problem out. I seen few posts in vaadin forums also but that didn’t help me
I have seen few posts to use smartsession and session guard add-ons. Can anyone please tell me how to use these?
I will be awaiting for your response.
I’m completely blocked at this issue, i desperately need help from vaadin team
Thankyou very much in advance
Thanks & Regards,
Kiran C
There may be multiple reasons where you can get Communication Errors, please try the following
Open Developer tools and check if there is any request that is returning with a 404 error(in Vaadin 7.1.x I believe HeartBeat request would return so after some time). If so please let me know which is that request we shall together troubleshoot the same.
Secondly, check if there are any runtime exceptions in your logs if so fix those.
Also, check if session is getting expired. In order check, create a class that implements httpsessionlistener that logs session expired event. Please see
this to implement the same.
I have seen but i could not find any 404 errors and run time exceptions. Can you please tell me how to increase the vaadin server session and also tell me how to use smartsession and session guard add-ons?
First things first, can you please check if you are getting communication error due to Session expired? This can be done my creating a web listener - httpsessionlistener. Then if this is the cause, then we shall go ahead and extend the timeout.
Next, can you please tell me what is the value of closeIdleSession param? if it is set to true then reset it to false, this will not close Vaadin Session until HttpSession expires.
Also, it would be great if you can share your web.xml. If you are using servlet 3 please share the settings of your Custom servelt that is extening Vaadin Servlet
In web.xml, i increased the session time-out to 60 mins but still i’m getting the same problem.
How to create httpsessionlistener in web.xml? and where to check closeIdleSession?
I strongly believe somewhere else also we need to change the time-out time but i’m not able to figure it out.
Please help me in this issue i’m not able to do anything because of this and i’m using vaadin 6.8 version