Hi Tim,

Just letting you know that this error is continuing to occur on my
application, and has occurred on a new server that I have just installed the
DBISam Server onto, totalling 4 different sites now - the only sites I
currently have running in client/server mode.
In addition:

3 of these sites are running Terminal Services where the client and server
application are on the same machine (ie - it's not running via a network
cable / switch / etc).
1 of these sites are running workstations that does run over a network cable
/ switch etc.

None of these sites are setup to compress data between the server and
client.

None of these sites are setup to encrypt data between the server and client.

The servers at the sites range from Windows 2000 to Windows 2003.

After this error, some users have reported a second error:

Access violation at address 004B4234 in module 'dbsrvr.exe'. Read of address
00000000'

I'm unable to replicate the error as it happens at various locations of the
application, however it does appear to happen when doing queries to retrieve
data (ie, such as running reports, etc and not when posting, editing, etc).

I was wondering if you have any other suggestions as to what might be
causing this problem (as it appears as though it's not a network fault), or
any suggestions as to how to combat this problem?

Thanks & Regards

Adam.

Adam H.

I have the same problem here sometimes. But I realized, in some machines the
error simply had disappeared when I changed the NIC.

Eduardo

Adam,

<< After this error, some users have reported a second error:

Access violation at address 004B4234 in module 'dbsrvr.exe'. Read of
address 00000000' >>

Could you send me the server log ?  It probably won't help much, but it
might have the SQL in it.  We added SQL statement logging in 4.26 for this
type of situation in order to try and glean more information.

--
Tim Young
Elevate Software
www.elevatesoft.com

Adam,

<< Just letting you know that this error is continuing to occur on my
application, and has occurred on a new server that I have just installed the
DBISam Server onto, totalling 4 different sites now - the only sites I
currently have running in client/server mode. >>

BTW, I forgot to ask:

1) Are you running something like EurekaLog, MadExcept, etc. with your
application or the server ?

2) Is the error showing up as an error from the server, or an error strictly
on the client ?  You can tell if it's the former because the error message
will be:

An unknown error (''%s'') occurred with the connection to the database
server at ''%s'', please check the server log

--
Tim Young
Elevate Software
www.elevatesoft.com

Good Morning Tim,

> << After this error, some users have reported a second error:
>
> Access violation at address 004B4234 in module 'dbsrvr.exe'. Read of
> address 00000000' >>
>
> Could you send me the server log ?  It probably won't help much, but it
> might have the SQL in it.  We added SQL statement logging in 4.26 for this
> type of situation in order to try and glean more information.

Sure - great idea in 4.26 too - I didn't realise that. Unfortuantly though
the server log does not have any error to do with 'uncompressing data' (only
the client get's that), although the server does have the access violation
message (but without any SQL script).

I have placed the server log in the binary newsgroups under 'Server log for
Tim'.

Cheers

Adam.

Good Morning Tim,

> BTW, I forgot to ask:
>
> 1) Are you running something like EurekaLog, MadExcept, etc. with your
> application or the server ?

No. We were running EurekaLog in our application, but have removed this as
it was not helping to resolve where this particular error was comming from,
and I wanted to eliminate EurekaLog as a possible cause.

The server isn't running EurekaLog either. (We did try a few months back,
but got no helpful information).

> 2) Is the error showing up as an error from the server, or an error
> strictly on the client ?  You can tell if it's the former because the
> error message will be:
>
> An unknown error (''%s'') occurred with the connection to the database
> server at ''%s'', please check the server log

We have received "unknown errors" such as this from the server in the past
(and believe that it is connected), but don't get this all the time. In the
most recent instance, I've been told that we received the uncompressing
error first, and then the access violation second.

Best Regards

Adam.

Hi Tim,

>> An unknown error (''%s'') occurred with the connection to the database
>> server at ''%s'', please check the server log
>
> We have received "unknown errors" such as this from the server in the past
> (and believe that it is connected), but don't get this all the time. In
> the most recent instance, I've been told that we received the
> uncompressing error first, and then the access violation second.

CORRECTION:

The error we received was:

DBISAM Engine Error #11279 An unknown error ('Access violation at address
004B4234 in module 'dbsrvr.exe'. Read of address 00000000')

So the unknown error was listed with the access violation.

Best Regards

Adam.

Hi Jose,

Thanks for your reply...

> I have the same problem here sometimes. But I realized, in some machines
> the error simply had disappeared when I changed the NIC.

Are you saying that you had the same problem at numerous sites, and
replacing the NIC in these has fixed the problem (ie, it was the NIC in all
cases), or just some.

Also, were you running the client on a seperate machine to the server with
these sites, or did some of them where you were having the problem have the
client and server running off the same machine, and if so - did changing the
NIC in these instances fix the issue?

Thanks & Regards

Adam.

Adam,

I might be way off base on this however when you are performing these
queries, do you query any BLOB or memo fields for data? The reason I am
asking is because in dealing with BLOB and Memo data types, I believe
the database engine will allocate memory buffers for these and if your
query will overrun those buffers, you might run into the situation
where you would get a 15002 error. Since you are not getting these
errors on normal database operations, there might be a slight chance of
a correlation between your problem and the uncompressing of the
buffers. All the research I have found with regard to problems
uncompressing buffers generally always lead to ZLib, which is also used
in DBISAM.

--
Regards,
Jan Ferguson [Team Elevate]


Adam H. wrote:

<<I'm unable to replicate the error as it happens at various locations
<<of the application, however it does appear to happen when doing
<<queries to retrieve data (ie, such as running reports, etc and not
<<when posting, editing, etc).

Hi Jan,

Thanks for your reply...

> I might be way off base on this however when you are performing these
> queries, do you query any BLOB or memo fields for data? The reason I am
> asking is because in dealing with BLOB and Memo data types, I believe
> the database engine will allocate memory buffers for these and if your
> query will overrun those buffers, you might run into the situation
> where you would get a 15002 error. Since you are not getting these
> errors on normal database operations, there might be a slight chance of
> a correlation between your problem and the uncompressing of the
> buffers. All the research I have found with regard to problems
> uncompressing buffers generally always lead to ZLib, which is also used
> in DBISAM.

Yes - the queries that I have have results that include memo fields! As
previously mentioned, these errors are not common (could run the same
reports multiple times before it falls over, etc) or reproducable on demand.
Would that fit into the scenario that you've mentioned here?

Thanks & Regards

Adam.