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From "Piet Blok" <pbh...@wanadoo.nl>
Subject Re: DRDA_InvalidReplyTooShort.S:Invalid reply from network server: Insufficient data.
Date Sun, 02 Apr 2006 09:23:32 GMT
The mechanisme I described attempts to ensure that one and only one Network 
Server will become active, even if, in multiple JVM's (on the same machine) 
an attempt is made to start a server. The design goal is to enable any 
application to request that a Network Server is available. If there was no 
Network Server ready , a Server is launched in a separate JVM and the 
application waits until that Server, or any other server, is ready.

(About a half year ago there was a long running thread in this forum on how 
to start a server on the fly and wait for it to become ready, that intrigued 

Yes, all sorts of problems, like port in use, arise, but the mechanisme is 
designed to detect these situations and cope with them. There will be only 
one winner that will serve all others. The loosers just die.

The problem I described does not always occurr. In fact it only happended 
once when simultaneously trying to start 30 servers. Other stress attempts, 
including starting 100 servers, worked just fine.

I will try to implement a capture of the winning Server err and out streams 
in order to provide the requested information when the problem occurrs 

Thanks very much for your answer.

Kind regards,

Piet Blok

----- Original Message ----- 
From: "Bryan Pendleton" <bpendleton@amberpoint.com>
To: "Derby Discussion" <derby-user@db.apache.org>
Sent: Saturday, April 01, 2006 9:27 PM
Subject: Re: DRDA_InvalidReplyTooShort.S:Invalid reply from network server: 
Insufficient data.

>> When stress testing a mechanism to simultaneously start the Derby network 
>> server from different applications at the same time, I sometimes get the 
>> following exception:
>> DRDA_InvalidReplyTooShort.S:Invalid reply from network server: 
>> Insufficient data.
>> Is this possibly a bug?
> I'm not sure I understand the first paragraph above very well, but I can't
> think of any reason you should be getting the ReplyTooShort response other
> than a bug, so I would say yes, this sounds like a bug to me.
> When this happens, can you look on the server side, and find your 
> derby.log,
> and look there? Are there interesting messages there?
> Also, can you capture the actual console (System.out and System.err) from 
> the
> server side, and see if there are any interesting messages there?
> I suspect that the problem is happening on the server side, and the stack
> trace and error message on the client side aren't going to be all that 
> helpful.
> If you are trying to simultaneously start multiple instances of the 
> network
> server at the same time, aren't you going to get "port number in use" 
> conflicts,
> and the like?
> Perhaps, in addition to letting us know what you can learn from crawling 
> around
> in your server-side logs, you could also explain a bit more about what 
> behavior
> you are expecting to see from your server-starting mechanism that you are 
> testing.
> thanks,
> bryan

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