Re: caching web-database connections. licensing & performance?

Basel Shishani wrote:
>
> I'm confused about this point, can someone help please:
>
> Many web-database interface tool vendors (eg : WebDBC, NetDynamics, Cold
> Fusion ...) list among the features of their products the ability to cache
> database connections . According to this feature, the web-database
> interface application caches and reuses open database-server connections
> between web-server hits, which is supposed to improve performance. The
> number of open connections is usually user controllable.
>
> First, are these "open connections" between the database-server and the
> web-server counted as multiple users or connected devices by the
> database-server software, which will be limited by database-server
> license?

Basically what happens is that the server will open a connection for each WWW server process that is spawned off. So if you set your server to have a max of 8 simultaneous connections, you would have a max of one connection per child for a total of eight. Keep in mind that new servers like Netscape's will start with a smaller number of children and spawn more if necessary, up to the max you set in the configs. For example, we set ours to start with eight, but it can go up to 32 depending on the use.

Some of the products like cold fusion are great and fast if you are doing simple connectivity, but if you need more complicated stuff, such as if I get this answer from a query put out a standard output, but if I get no matches, run a query on a different set of data, then you have to do the innards yourself (it isn't that hard, though). In order to get the persistant connections to work with Informix & Illustra, I had to write some code snippets into our WWW server using Netscape's NSAPI.

For the licensing issues, you have to talk to your Informix rep. I know that some of the db companies are making special pricing for web-based db connectivity. For example Illustra has an unlimited license for web-based apps and my Informix rep has said that they are workin on the same thing. From a technical standpoint, when you use the persistant connections, the user running the webserver, usually "www" is the user that owns the db process. The database thinks that it is one user logged into the system with many connections. This means that theoritically, you could use a one-user license. Also, I don't believe informix even checks the number of users using the system. I know Illustra does.  

> And second, how would increasing the number of cached connections actually
> affect performance? If first above is true, the problem would be deciding
> between extra license costs and other upgrade areas.

I don't know about this, we very rarely have to use more than 12 connections at a time. Our site handles about 10-15,000 hits per day. The performance increase of using persistant connections at our site is great! Sometimes it would take 1-3 seconds to just open the connection before, but now that wait is gone! It is almost instantaneous. I've got friends that use other DB's like Ingress, who don't use them and they are waiting sometimes up to 10 secs just to open the connections. I can't say where the break even point would be, though, as our site is not big enough to test it.

Hope this helps.

>
> -------------------
> Basel Shishani
> basel_at_plpk.uq.oz.au
  Received on Fri Jul 05 1996 - 00:00:00 CEST