Re: Blocking excessive JDBC connections -- MIDRANGE-L

Hi,

one idea might be to setup Query Supervisor, and e. g. set limits to CPU usage:

- https://www.ibm.com/docs/en/i/7.5.0?topic=services-add-query-threshold-procedure

The other idea might be to write an exit program:

- https://www.ibm.com/docs/en/i/7.5.0?topic=performance-exit-programs

The QIBM_QZDA_SQL2 exit point should be the one that is called when a statement is executed. If you can break it down to a single user id it should never easy - if not, you might have to look for a client ip address to sort out clients with multiple connections - you might have to do some research on that.

HTH
Daniel

Am 28.12.2025 um 23:12 schrieb Jason Olson <josys36@xxxxxxxxx>:

There is an exit point, that I have used in the past, to control which accounts can make ODBC/JDBC connections. You have to create a custom program and then register that to the exit point.

I'm positive that you could create something that would look at the incoming connection, see how many are already running under that same user, and then deny the connection if over the limit. I do not remember the name of the exit point off the top of my head, but I could look for it tomorrow if someone else does not chime in.

Jason

On 12/28/25 3:59 PM, smith5646midrange@xxxxxxxxx wrote:
My client has a problem where non-IBMi applications (Windows servers) are
creating MANY JDBC connections to pull data.one file is 98G and is pulled in
full every day. Their app needs to finish faster so they create additional
threads to bust up the file but they never talk to us about it first. Our
system currently sits at over 100% CPU for hours at a time while these JDBC
connections are active. Last night it was 4+ hours at 150+%. This is
impacting other IBMi programs.

There is a whole lot wrong with that previous paragraph and we are actively
working on the root of the problem but it is a long process getting it
changed. I don't need help fixing that part of the problem so please don't
offer solutions for it.

The problem that I am trying to solve is how to limit the number of JDBC
connections from a single IP address. They are connecting through a job
named QRWTSVR (or something close to that). When I look at the joblog, I
can see what IP address did the connection. I have gotten permission to
limit an IP address to 5 threads and if they try to open a sixth, it will
fail. This sixth connection's failure assumes all of the first five jobs
are still active. If one has ended / disconnected, the sixth connection
should be allowed. My problem is how can I do it? Is there a way through
an exit point? I've been looking but not finding anything. The exit points
that I have found do not show me the job information.

Does anybody have any thoughts that I can research to find a way do to this?

--
Jason E. Olson
IBM i / Python Engineer/Developer
josys36@xxxxxxxxx
480.223.2952

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