Career Day Resources

A few resources for Northland High School's Career Day...

I can be reached by email at jroller@espacecommunications.com.

High Availability Servers

Keeping a web server up 24x7 takes a bit of work. There are security patches that need applied, hackers that you need to keep out and random operating system bugs that can make the system unresponsive. As a someone who has maintained servers for a decade-and-a-half, this is all just part of the job.

But what happens when the facility that hosts the server has issues? Power failures, network backbone connectivity issues and scheduled downtime are events that are out of my control. How do we deal with these problems?

At E Space Communications,  we use pairs of servers in different geographic area with separate backbone connections to both distribute the workload and also offer automatic failover when hosting provider outages occur. When a server on the east coast becomes unavailable, it automatically drops out of the rotation and the server in the other part of the country takes over. Most users don't even notice anything happened.

We don't put all our eggs in one basket. Neither should you.

Interested? Let us know!

Optimizing Database Access

Be careful going down the query optimization path. Knowing that query takes "n.nn" seconds to execute only gives you part of the picture. A query that takes 2 seconds to run but that only gets executed twice a day is probably not worth examining. Bigger gains can usually be found by finding that query that gets executed 20 times on the same page. Or by identifying the function call that runs a query for each child rows instead of pulling in the all of the child rows by referencing the parent element in one query. Or taking it to the next level, caching the data on one page for use in other pages later in that user session.