Delayed Code Execution?

[Jim in Arizona]

I realize that by design, web client/server interaction is disconnected.
I'm wondering if there is a way that when a client/server interaction
occurs, if there is a way to start a time on the web server which will
run some code after a specific amount of time (or variable amount of
time), such as send an e-mail.

We have a page that is a ticket page (computer support ticket page) that
employees use to submit a help/trouble ticket to IS. I want to be able
to have an e-mail sent back to their email account after a variable
amount of time, say, between 2 and 5 minutes. I already have a message
sent back when they submit their ticket, but I need to delay the
response email to them somehow. Any pointers?

TIA,
Jim

 

[KJ]

Hello Jim,

I can think of a few ways to do this, for example:

1) Use message queues (MSMQ ala System.Messaging) and only read
messages that are of a certain age
2) Use SQL Server Service Broker queueing (if you have SQL 2005) and do
the same
3) Create a system.threading.timer, and set it to go off after a
certain amount of time elapses and execute your code
4) Create a simple work queue table in your DB, and mark the age of the
entries. Use a service program running on the server to retrieve the
messages and do the work.

Personally, I would consider 1 and 2 first, because they are by the
most reliable, but they can be heavy to implement. 3 and 4 are easy to
implement. But 3 might not be the most reliable choice. Let me know
what you choose to do. In a jam, I'd do number 4.

-KJ

 

[Jim in Arizona]

Hello Jim,

I can think of a few ways to do this, for example:

1) Use message queues (MSMQ ala System.Messaging) and only read
messages that are of a certain age
2) Use SQL Server Service Broker queueing (if you have SQL 2005) and do
the same
3) Create a system.threading.timer, and set it to go off after a
certain amount of time elapses and execute your code
4) Create a simple work queue table in your DB, and mark the age of the
entries. Use a service program running on the server to retrieve the
messages and do the work.

Personally, I would consider 1 and 2 first, because they are by the
most reliable, but they can be heavy to implement. 3 and 4 are easy to
implement. But 3 might not be the most reliable choice. Let me know
what you choose to do. In a jam, I'd do number 4.

-KJ

I'm not very advanced when it comes to dev (VB/ASPNET OR SQL), so most
of what you said went over my head pretty high. Option 3 sounds like
something I may be able to implement with much help and guidance.

When creating a system.threading.timer object, I'm guessing I do it
something like:

Dim objTimer As System.Threading.Timer
objTimer.

And that's as far as I get. There's a few options but I don't know which
one to use or how to implement it.

I also noticed in the object browser that there's System.Timers
namespace. I can't imagine that would work on a page since client/server
interaction is disconnected. I guess that's where threading comes in
instead?

 

[KJ]

Hi Jim,

Glad to hear back from you. I've been thinking a bit more about using a
threaded timer, and I am now feeling that this is not the best
solution, especially for a newer developer.

I think there is an easy way to do this, but it will require some
design work. A few questions first: are you using a database platform
such as SQL Server for your application? If so, do you have much
experience on that platform?

-KJ

 

[Jim in Arizona]

Hi Jim,

Glad to hear back from you. I've been thinking a bit more about using a
threaded timer, and I am now feeling that this is not the best
solution, especially for a newer developer.

I think there is an easy way to do this, but it will require some
design work. A few questions first: are you using a database platform
such as SQL Server for your application? If so, do you have much
experience on that platform?

-KJ

I'm running a 2003 server (IIS6) with SQL2000 Standard (also on same web
server). I have a little knowledge of it, such as basic SQL commands and
basic server administration. I've considered upgrading it to 2005 but
always a little nervous about upgrading a production server. Since my
databases are very small and I've no large or imperative stored
procedures, views or triggers, I'm sure upgrading wouldn't be a problem.
I am planning on doing so soon, if I can get over the potential upgrade
disaster fear.

The internal website that i've mostly built has about 6 simple databases
.. Each database has no more than, say, 6 tables, with maybe two of them
related and the others just lookup tables. I've never used stored
procedures until recently when I decided to make a few to give them a
try, since I heard its the more secure way to go and better performance.

This whole delayed code execution thing isn't completely necessary. It
was a side thing I was going to do to make things look a bit less, um,
computer controlled.

 

[KJ]

Instead of coding this, have you considered changing the mail-sending
frequency setting on your email server?