OS5: Connecting timeout to ODB problem...

Stephen Miller stephenmiller1958 at gmail.com
Tue Dec 27 15:02:30 EST 2011


Hi

Yes well timeouts are an issue for all TCP type connections.

Generally speaking ... and these are general comments from Windows use
 only.....

Is the IP number available?  This is a pregnant question. Is the IP
address fixed? If it is then then you can avoid the DNS and use the IP
Number... this avoids one cause of failure/delay?

Can you ping the IP number.??  (Ping basically contacts a port on the
server that is reserved to respond. Ping doesn't always work depending
on the setup on the destination site. For example ping www.ibm.com
times out however I can ping www.omnis.net. So you need to check that
ping works to the server.

I would suggest that if you have a fixed ip address that you use this.
(Networking people get angry now).
You can usually speed up access if you are using DNS where there is a
fixed ip address by bypassing it by adding details to the hosts file
in Windows. I think, but this is a guess that the IP layer first looks
here and tries the mapped IP number and if that doesn't work it then
uses the DNS...

If you are using the Internet what is the default proxy? I once had
the experience where a co-worker and I were sharing a network point in
India with a small hub. Accessing the same site from her machine was
taking minutes and from mine was taking seconds. The Indian network
guys had 'no clue' as to what was going on. As usual they said 'Ok,
OK, OK with head toggle and then said now we go for lunch...'  This
interprets to 'I have no idea what the problem is ... maybe if I go
away the problem will disappear?'

Anyway as I knew from our network  topography and corporate machine
setup it must be a problem on her machine I had a snoop.... The
culprit was the order of the proxy servers. I, through ignorance, had
the standard work proxy server as the top one in my list. Her machine
had a proxy server to a client as the top entry. So her Internet
performance was actually fantastically fast in the circumstances as
she was accessing our work network by connecting to a client access
point in Brisbane and through there into our corporate network and
back to India!!!!

So from playing around from my current connection (3G mobile (cell)
wifi with high latency)  and pinging www.omnis.net I can see that the
average is 1/2 second. On this basis and from testing on your system
the timeout value that you set on the ping should be very low. The
retry timer though should be set to 30 seconds or a minute - again
depends on the environment. Some systems will have a stay alive script
that will check to see if a server process - which is what the ODP
server piece is - is alive and if it isn't it will restart it.

At least with the above approach there is less likely that the user
will not have a 'Your system freezes all the time type experience'.

Maybe you could build in a decent user experience where if the ping
fails you pop up some sort of diagnostics window that tries the ping
with a ever increasing timeouts or, if you have access to the file
system, attempts to open a file called 'Tst.txt' located in the same
directory as you native data files?

Anyway just some thoughts.

Regards

Stephen Miller


So maybe the IP number is available but the port isnt.







For example from the Run/cmd

On Wed, Dec 28, 2011 at 5:58 AM, ADJob <mats at adjob.se> wrote:
> Hi,
>
>>> TCPPing (127.0.0.1) Returns lv_OK
>>> If lv_OK<0
>>>   Do msg.$error('odb')
>>>   Quit method
>>> End If
>>
>>
>>Watch out for the ping - it can take just as long if it too gets hung up
>>!!
>
> Is there any better options you prefer?
>
> TIA,
>
> Mats Olsson, ADJob Nordic AB, Sweden
>
>
> _____________________________________________________________
> Manage your list subscriptions at http://lists.omnis-dev.com



-- 
Kind Regards

Stephen Miller

+61 (0)415 968048

Skype: Stephen.Miller.1958

Work Phone: 08 6213 5697

Work E-mail: Stephen.Miller at health.wa.gov.au;



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