Performance problem with RegEx

I have a performance issue related to regular expressions and
caching , hopefully someone can point me in the right direction?

I have a asp.net web service that is called several million times a
day. It does not have data caching enabled since the input variables
for the webmethods change every time its called. It's my understanding
that if the input paramters change frequently that the hash table
created by a caching option wont actually do any good.

Everytime the web service is called, among other things, the webmethod
gets a list of RegEx from a sql database and then loops through each
expression trying to find a match with a webmethod input paramter.

I have seen that as I add more regular expressions to test against, my
processor usage on the machine goes up accordinly. Right now I have
about 100 RegX in my db table and my proc usage is pretty consistantly
at 100%. In addition I see "random" out of memory exceptions from the
RegEx engine itself, the web server has 4 gigs of ram running on
server 2003.

I have two questions:

1. Is there a way for me to cache the list of regular expressions I am
getting from the sql db? If I was using a aspx page I would use the
datacache property on ado.net however how can I accomplish the same
thing the web service?

2. Can I "Pre-Compile" or otherwise improve the performance of the
regular expression testing itself?

thanks,
JeffStore a DataTable in the Application Cache. You will only need to create it
when the Application starts.

--
HTH,

Kevin Spencer
Microsoft MVP

Printing Components, Email Components,
FTP Client Classes, Enhanced Data Controls, much more.
DSI PrintManager, Miradyne Component Libraries:
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<jmacduff@.gmail.comwrote in message
news:1184799694.193160.125230@.j4g2000prf.googlegro ups.com...

Quote:

Originally Posted by

>I have a performance issue related to regular expressions and
caching , hopefully someone can point me in the right direction?
>
I have a asp.net web service that is called several million times a
day. It does not have data caching enabled since the input variables
for the webmethods change every time its called. It's my understanding
that if the input paramters change frequently that the hash table
created by a caching option wont actually do any good.
>
Everytime the web service is called, among other things, the webmethod
gets a list of RegEx from a sql database and then loops through each
expression trying to find a match with a webmethod input paramter.
>
I have seen that as I add more regular expressions to test against, my
processor usage on the machine goes up accordinly. Right now I have
about 100 RegX in my db table and my proc usage is pretty consistantly
at 100%. In addition I see "random" out of memory exceptions from the
RegEx engine itself, the web server has 4 gigs of ram running on
server 2003.
>
I have two questions:
>
1. Is there a way for me to cache the list of regular expressions I am
getting from the sql db? If I was using a aspx page I would use the
datacache property on ado.net however how can I accomplish the same
thing the web service?
>
2. Can I "Pre-Compile" or otherwise improve the performance of the
regular expression testing itself?
>
thanks,
Jeff
>