Receiver Not Found Error

[lanmicro]

Hi Guys,

Periodically I am getting a ReceiverNotFound Error when attempting to send data to another computer.  This doesn't make sense to me because I do a getServers call just before looping through the servers list to get the servers to send to.  What might I be doing wrong?

See attached errormessage.

[attachment deleted by admin]

[Bruce]

Perhaps the other computer closed the program in between? The TCP comms part especially will take some finite period of time.

Can you give any more information as to the nature of the error?

You might just want to suppress the error if the message is not that important, and the other machine has closed down.

cheers
Bruce

[lanmicro]

Hi Bruce,

That is really the problem.  I have to send some information to other computers and that information has to get there. 

So what I have is a known number of servers that have to be updated I do a getservers if the queue doesn't contain the same number as the known number of servers I send the information to everybody that I have a server address for but do not delete the information that I am attempting to send. 

Every 5 minutes I try again. Eventually the number of servers in the queue will equal the known number of servers, when that happens I delete the information that I am attempting to send after sending it to all the servers.

But this message is troubling.  Are you saying that the server that I am sending it to might be a valid server and that server is down temporarily?  Or that they may have network problems that prevent the server from being reached? 

If so, is there a way to continually attempt reaching the server until successful?

[Bruce]

Hi Greg,

I'm assuming of course that you're not making any mistakes when addressing the outgoing packets. You might want to check that carefully. It would be a bummer if that was the root of the problem.

>> But this message is troubling.  Are you saying that the server that I am sending it to might be a valid server and that server is down temporarily?  Or that they may have network problems that prevent the server from being reached? 

no, I was alluding to the transient nature of programs. So just because you have a machine in the list, there's no guarantee the user on that machine won't close the program. But sure, if there are network issues you're gonna see problems in this area as well.

It sounds like you're coping with the issue correctly though - you just keep retrying till the message goes through. All you need to do is suppress the error that pops up.

cheers
Bruce

[lanmicro]

Hi Bruce,

I don't see it mentioned in the documentation but is GetServers asyncronis?  Will all servers that are broadcasting be found by GetServers before the next line of Clarion code is processed.  Or should I be waiting for some period of time before continuing processing my clarion code after a GetServers is issued?

[Bruce]

It appears to be synchronous Greg.
Are you trapping changes to the list in the .ServersChanged method?

Cheers
Bruce

[lanmicro]

Hi Bruce,

What I thought GetServers did was refresh the internal queue of Servers so that that queue always had a record for each Sever that was broadcasting an "Im here". 

Is that correct? 

Maybe a better thing to do is maintain my own list of servers That I keep updated in the ServersChanged method.

My results seem to be a continually changing number of Servers in the queue after each GetServer command.

[lanmicro]

Hi Bruce,

Follow-up.  It turns out that the customers network is awfully flaky.  They won't admit that<G>.

I had them install hamachi on each of their servers and we use hamachi to communicate between the servers and it looks like we are not getting the sporadic dropping of servers from the server list anymore.

Hope this helps someone.