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New Developer
christian1234
Posts: 10
Registered: ‎02-12-2009
My Device: Not Specified

MIDP and DNSException

[ Edited ]

Hello community, Hello RIM Support,

 

we are currently developing a MIDP application that connects to a server using HTTP POST, which works fine on most of the devices...

 

Anyway, we have a customer who is starting to use Blackberrys along with our application, who is running into troubles on a regular basis. We spent the last week to investigate the problem and we identified the following behaviour:

- If the first connection to our server fails due to a DNSException: "Bad DNS address", then every further attempt will also fail. We then need to remove the devices battery in order to be able to connect again.

- Not using deviceside=true seems to make things even worse.

- If server is being addressed by its IP Address and not the hostname, then things are ok. Unfortunetaly, this is not acceptable, since we then are not able to use https.

 

My questions now are:

1. Is a fix for the DNSException issue planned? (We are currently using BB ROM Version 4.5.055) This issue is at least known since 2005, and still there is no fix!

2. Are there any workarounds to this?

3. Why does the device lock up its DNS resolution once the BAD DNS address error occurs? Is there a official Blackberry FAQ or anything that explains why this happens? At least I would like to know what happens.

 

Currently the only we can do is to recommend our customer not to use Blackberry devices...

 

regards,

Christian S.

 

Message Edited by christian1234 on 02-12-2009 10:00 AM
BlackBerry Development Advisor
MSohm
Posts: 14,753
Registered: ‎07-09-2008
My Device: BlackBerry Passport

Re: MIDP and DNSException

What route is your connection being made over?  You can see the available routes here:

 

What Is - Different ways to make an HTTP or socket connection
Article Number: DB-00396

http://www.blackberry.com/knowledgecenterpublic/livelink.exe/fetch/2000/348583/800451/800563/What_Is...

 

Are you able to browse to the same server?  If so what browser are you testing with (you can see the default browser under Options, Advanced Options, Browser).  The carrier you are connecting over may not be able to resolve your server name.  I also recommend contacting them regarding this issue to ensure it is not an issue with their DNS server.

Mark Sohm
BlackBerry Development Advisor

Please refrain from posting new questions in solved threads.
Problem solved? Click the Accept As Solution button.
Found a bug? Report it using Issue Tracker
Developer
marchywka
Posts: 1,415
Registered: ‎07-30-2008
My Device: Not Specified

Re: MIDP and DNSException

feel free to read any of my prior posts on this topic and consider providing your own dns look ups,

routing everything through your own  ( or RIM's LOL ) proxy, or paying ransom to carriers.

IF you can find a reasonable technical solution, please let me know. I have seen this

come up on several phones and I included in-app diagnostics etc. You get variants of DNS

messages in a variety of setting and probably the "remove the battery" strategy is

more superstitous than causal ( although I would be happy to find out this is a problem

specific to RIM phones, I have seen it on everything from 7130 to various 8xxx series phones ).

 

New Developer
christian1234
Posts: 10
Registered: ‎02-12-2009
My Device: Not Specified

Re: MIDP and DNSException

Hello Mark, glad to hear from you!

 

We are using standard HTTP (no https), and we were trying both deviceside true and false. I assume that the problem is a issue on the device itself, not a server issue

We are still able to connect to the host via the WebBrowser. I assume that the problem is within the JVM that runs the MIDP applications. how many JVMs are there on a BB?

Our carrier (vodafone germany) was referring to the RIM developer zone, so here I am :-) For me it seems that vodafone has some load issues where our customer is located, so I guess they are dropping requests from time to time - which should not be the problem. The problem is that the device hangs everytime a DNS request is being dropped. Is it possible that the Blackberry's JVM caches bad DNS requests?

 

Thank you,

Christian

 

 

 

Developer
marchywka
Posts: 1,415
Registered: ‎07-30-2008
My Device: Not Specified

Re: MIDP and DNSException

If the device hangs, and you are removing the battery to get your phone back, I would imagine

your app is dying with the event lock ( not a phone specific problem). I thought you meant

that removing the battery would fix the DNS problem. On US carriers, I see this usually as a persisent,

nominally reproducible ( probably not load related ) most frequent on some domains or host names.

It should not be fatal to the phone and, yes, AFAIK, making request by IP should work ok.

 

New Developer
christian1234
Posts: 10
Registered: ‎02-12-2009
My Device: Not Specified

Re: MIDP and DNSException

Hello marchywka,

 

this issue persists for quite some time now, does it? I think I've seen forum posts discussing this issue 2005 already... :-(

 

For me it really seems like a one line fix in the JVM's coding. I'm hoping that Mark is able to forward this issue to the BB dev Team.

 

Unplugging the devices battery is definetaly no solution.

 

regards,

Christian

New Developer
christian1234
Posts: 10
Registered: ‎02-12-2009
My Device: Not Specified

Re: MIDP and DNSException

[ Edited ]

@marchywka:

I hope my last post was not misleading ... If we unplug the battery, then the DNS works again, that is correct!

 

What I meant with my last post was:The trigger, which causes the device to lock up any further DNS requests from the JVM,might be a failed DNS Request (I guess they are caching a DNS request failure within their JVM) - maybe due to dropped IP packets or whatever.

 

 

Message Edited by christian1234 on 02-16-2009 10:13 AM
Developer
marchywka
Posts: 1,415
Registered: ‎07-30-2008
My Device: Not Specified

Re: MIDP and DNSException

As far as that goes, good luck finding anyone who is even willing to talk about this issue.

LOL.

The partnered apps don't seem to have as much problem using public frequency spectrum to get

the money's worth from YOUR digital service monthlty fees. In the US, we are having some

arguments over equal/fair access to various web sites from things like cable ISP's. I don't

imagine the wireless carriers would be any more open as ISP's.

 

 

BlackBerry Development Advisor
MSohm
Posts: 14,753
Registered: ‎07-09-2008
My Device: BlackBerry Passport

Re: MIDP and DNSException

After the application hangs, are you able to task switch out of it (Alt+Escape)?  What line of code is the application blocking on?

Mark Sohm
BlackBerry Development Advisor

Please refrain from posting new questions in solved threads.
Problem solved? Click the Accept As Solution button.
Found a bug? Report it using Issue Tracker
New Developer
christian1234
Posts: 10
Registered: ‎02-12-2009
My Device: Not Specified

Re: MIDP and DNSException

Sorry, my post was a bit confusing. It is not the application that hangs, its the OS quitting all further DNS requests with DNSExceptions. The problem is that, once a DNSException occurs any further DNS request will fail too.