Logging protocol error on Mobilink client

[former_member329524]

Hello, all

I have an urgent issue with one of my sites.

From time to time Mobilink client stops synchronizing because of some network error.

The only thing logged in the text log file is "Protocol error".

How can I get more information on it without using -v+ and causing the hard drive to fill up?

Also, how can I issue report on the server side that a specific DB did not connect for X minutes?

Thank you

Arcady

[Former Member]

Protocol Error is returned when the Mobilink server doesn't understand the request being sent by the client, for example, if the client version is newer than the Mobilink server version.

Protocol Error

This normally means the client connected successfully to Mobilink but didn't understand some of all of the communication. Another possible cause is a corrupt client database. Can you successfully validate the client database?

ulvalid - Ultralite client (not ULj)

dbvalid - SQLA client

Thanks

Mark

[former_member329524]

Does not look like it in this case.

There is no code in the line of "Protocol Error". It looks like the communication error lacks verbosity.

BTW, meanwhile we have found the reason for the problem on the client side - it was an incorrect setting of internet options.

It would be good if SAP expanded the verbosity of communication errors, could have saved us some time. Simple "Protocol error" is very confusing, it does not even state if the client managed to connect to the server. Even addition of HTTP/TCPIP/HTTPS error code would be very helpful.

[jeff_albion]

Hi Arcady,

For this issue, can you clarify which Internet options you needed to adjust to resolve this issue?

As Mark suggested, a -10001 Protocol Error suggests that we received only part of an internal MobiLink Protocol command during a synchronization session - this could indicate a general problem with either the remote database, the MobiLink client/server code, or an intermediate network issue, so it's difficult for the MobiLink server to determine where the fault is exactly when printing out the error message.

Simple "Protocol error" is very confusing, it does not even state if the client managed to connect to the server. Even addition of HTTP/TCPIP/HTTPS error code would be very helpful.

To clarify, this isn't an error at the network protocol level - the client is connected to the MobiLink server successfully from a network perspective.

For network-level errors, we will log error -1305 "MobiLink communication error -- code: %1, parameter: %2, system code: %3", typically with the MobiLink communication code set as 8 "Unable to read %1 bytes" or 9 "Unable to write %1 bytes". The system code is usually the Winsock (Windows) or errno.h (Linux/UNIX) codes.

What happens during a generic "Protocol Error" is happening at the MobiLink level though - this is why I am surprised that adjusting your Internet options worked around the problem.

Regards,

Jeff Albion

SAP Active Global Support

[former_member329524]

Hi, Jeff

I never said that Mobilink showed code '-10001' in the log. There was no code, only the message 'Protocol error'

The mobilink client machine had a user profile, which alternated it's internet options for some obscure reason. Some of the time it went through firewalled proxy and on other times it went directly to the server. So, part of the time he could reach the server and part of the time he could not.

When it went out through the proxy, I tried to simply open the relay server URL in the browser and got a FW error. So, basically, the mobilink client should have returned 'NOT FOUND' or something like that.

[jeff_albion]

Hi Arcady,

I think we would need to take a closer look at the environment and log file from dbmlsync, but I can see that dbmlsync will also note a 'Protocol Error' as a MobiLink communication error code - see: DocCommentXchange.

As mentioned previously, a 'Protocol Error' communication error still indicates that the issue should be with the MobiLink protocol commands themselves and we would expect that some connectivity has happened. Not finding the server at all should result in:

=====================

I. 2015-02-19 14:19:40. Connecting to MobiLink server at 'host=missinghost' using 'TCPIP'

E. 2015-02-19 14:19:46. The host name 'missinghost' could not be found. The system-specific error code is 11001 (hex 00002af9).

E. 2015-02-19 14:19:46. Unable to connect to MobiLink server.

=====================

We know that some HTTP proxies will buffer HTTP requests before forwarding them on, so a misconfigured (buffering) proxy could also result in protocol errors if it is not flushing the HTTP requests immediately.

Regards,

Jeff Albion

SAP Active Global Support