Problem with eZ and GPRS/UMTS

Author Message

Massimiliano Bariola

Monday 02 October 2006 2:07:52 am

Hi,

some users accessing to the admin interface or to some login-protected section of the user site report that occasionally they get a kernel(20) error while navigating the site, adding content, etc.

Since the amount of people which will be browsing / using the site via GPRS/UMTS is increasing by the day, I need to understand what might be the cause or how could I troubleshoot the problem. it seems that the issue happens with both UMTS and GPRS, and both with handheld devices and with laptops which use connect cards or modem mobilephones.

Anyone can help?
thank you,

Massimiliano

Xavier Dutoit

Monday 02 October 2006 3:08:23 am

And they never have this problem with regular internet connections ?

X+

http://www.sydesy.com

Massimiliano Bariola

Monday 02 October 2006 3:22:37 am

Hi,

no, they haven't

Claudia Kosny

Monday 02 October 2006 12:19:21 pm

Hi Massimiliano

This looks like you need to gather more information form your users.
- Does this happen when they are moving(e.g. in a train) or also when stationary?
- Does that concern only some pages or all?
- Do your users use a special browser (especially on the handhelds)?
- Do they only get the kernel 20 or also other error messages (eg. kernel 1)?
- Does that happen only on your server or also on other websites (with or without EZ)?

If this is a major problem for you I would also suggest writing your own error handler which logs IP numbers, browser strings, times, sent headers, the requested url and whatever else might be interesting.

Greetings from Luxembourg

Claudia

André R.

Monday 02 October 2006 2:23:45 pm

You might also want to log post / get values.
Since this might be a proxy issue..

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Łukasz Serwatka

Tuesday 03 October 2006 12:04:34 am

In upcoming eZ publish 3.9 audit trailing is implemented. It gives possibility to audit some things like user name, time or IP address etc. So tracking errors will be much easier. And you can extend it of course.

http://pubsvn.ez.no/nextgen/trunk/doc/features/3.9/audit_trailing.txt

Personal website -> http://serwatka.net
Blog (about eZ Publish) -> http://serwatka.net/blog

Massimiliano Bariola

Wednesday 04 October 2006 1:45:15 am

Hi all, and thank you for your answers

@ Claudia: it is site - wide and intermittent, by an user who is stationary, and it's usually a kernel(20) and a very minor occurring of kernel (1). It happens only on eZ, while other sites o not present this problem. the kernel(1) happened once on a web-enabled phone, while in all other cases , on a laptop with a UMTS/GPRS connect card. I am beginning to debug this issue with the client, but so far it seems to me that the problem is due to a fluctuant quality of the carrier. Now, what this exactly means when translated to the technicalities of UMTS/GPRS, connected to how eZ handles authentication, I do not know yet.
I would not know where to start writing an error handler, though :-) have you any pointers for me?

@André : yes, I think it's connected, on the client part, to a proxy issue. on eZ part, it is clearly sensitive to some info which lacks or is corrupted thus it cannot correctly guess the client's state. if I were able to write a GPC logger for eZ, maybe I could troubleshoot it better. can you tell me how / where to start? is there any documentation for it?

@ Lukasz: the audit feature is very cool, can't wait to see it working and maybe backported to 3.8 / 3.7.

again, thanks to everyone, and if you have any pointers on how to proceed, they are highly appreciated.

Massimiliano

Petr Mifek

Wednesday 04 October 2006 6:28:40 am

I've very strong and lenghty experience using multiple user and admin eZ publish based sites through an GPRS, UMTS and even CDMA EVDO connections. This said, i've never encountered such problems you describe nor any of our clients did.

What I think, the issue might really be some strange PROXY/transparent PROXY/"accelerator" like thing on the side of the provider of your GPRS/UMTS connectivity. I've seen that many times, yet the worst cases were related, but not limited, to the crippling of SMTP (aka port 25) connections.

You should really check if the client or the provider (i think especcially t-mobile has such "accelerator" solution) is using such a thing.

By an "accident", I've been developing such accelerator solution for the VSAT connections and the methods we've used included pre-handling of page forwardings and cookies management, so this might be the issue. (Ok, through our accelerator solution the eZ publish works well, but I've seen others not-so-very-well behaving).

Good luck!

Claudia Kosny

Thursday 05 October 2006 4:18:31 am

Hi Massimiliano

In regards to creating an error handler: A real error handler is not strictly necessary as you only want to log some data right now. Handling of the errors might come later depending on what you find out.
As I never seem to have the time to work my way into what EZ already provides I just would write a custom template operator which fetches all the data I want from EZ, headers, post, get and all other interesting sources and writes them to a file or db. Then just use this template operator in the error templates. Unfortunately I don't know how to log the internal redirects made by EZ but for your problem this should not matter much.

In case you need it, here some documentation on how to write a custom template operator:
http://ez.no/products/ez_publish/documentation/development/extensions/template_operator

If you need help fetching interesting data have a look at the php manual:
http://lu.php.net/manual/en/reserved.variables.php
http://lu.php.net/manual/en/function.get-browser.php
http://lu.php.net/manual/en/function.apache-request-headers.php

Greetings from Luxembourg

Claudia

Massimiliano Bariola

Wednesday 11 October 2006 1:22:44 am

Hi all,

Petr: Yes, I have come to the same conclusion, it must be some connection mangling that episodically occurs. maybe the connection is served through different machines with different configurations, and sometimes we get a proxy which does not play nice.

Claudia: thank you for the links and the tips! I never had thought to add the special logging functionality to the error templates. My main problem was "where should I put the error functionality so that it will intercept the error" - I didn't think of the most sensible place :-)

Petr and Claudia have earned a dinner whenever any of you visit Rome :-)

thank you,

Massimiliano

Claudia Kosny

Wednesday 11 October 2006 1:32:12 am

Hi Massimiliano

The only problem might be that the interesting bits could already be over when the error template is called. So if the logging there does not bring any useful data it might be better to gather the data already in the index.php, keep it in memory and use the operator in the error template only to write the data into the logfile/logtable. Unfortunately this might impact the performance a bit so I would not do it unless there are no other options.

Greetings from Luxembourg

Claudia

Thanks for the invite by the way :-)

vish bhatt

Wednesday 29 November 2006 10:22:10 pm

Hi everyone,

I have an equipment which collects some data like temperature, pressure, etc. I want to send that collected data using GPRS communication to a server located in distant site.

Therefore, i have my equipment connected to a GPRS modem. Does any one know what will be the AT commands to connect to my server ip address. And also, how will i know at the server side as to when the data arrives?

Please advice.

Michael Katongo

Thursday 21 December 2006 5:25:45 am

Hi there, i need your help

am trying to connect my laptop to the internet using my Gprs enabled phone. am using a cable to connect my phone to the laptop and its detected as a modem then i did the dail up internet settings in control panel and its connected with a speed which is ok. but the problem is Internet Explorer (IE) can't browse while all the settings seem to be ok.

This is my first time am doing this, is there anybody who knows the solution? i will be very grateful.

email: katongom@hotmail.com

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