Server Performance, Scaling, Reliability and Configuration Norman White

Scaling UP Run on faster computer Upgrade disk, memory etc. Out Replicate server across multiple machines Distribute “strategic” locations on the internet Host on services like AKAMAI

Scaling Up Can keep adding processors, memory etc. Advantages Single environment, easy to administer Disadvantages Processor limitations Network Bandwidth problems Reliability

Scaling out Add more computers Distribute workload across multiple systems Have application server(s), video server(s), DB servers etc. But watch out for reliability problems, decreases quickly with more servers Supported by UNIX, LINUX and W2K Cluster machines together so they can automatically take over in case of failure Distribute load across multiple machines. Still may have single failure points Power Network access

But there is a little Problem! How do your users get to your machine? Is it over the internet? How much bandwidth can you get to your site? What if you are Victoria Secret and have a huge event once or twice a year?

Need to go to edge hosting services Step 1 – Move your web site to your ISP’s location. ISP has backbone access to internet Step 2 – If that is not enough, go to a provider like AKAMAI They distribute your content all over the world at the “edge” points to the internet

Demo… Traceroute to several providers Visit Akamai Play akamai flash tutorial

Security Issues As we scale up, still only have one machine to guard.. As we scale out, more potential for problems. For internal servers, how do we control access to content?.htaccess Ldap etc. Edge hosting may “contain” problem to certain nodes…

Conclusion Need to understand management objectives before we can make a decision. Many tradeoffs. Often may do all of the above…

Configuring a WEB Server.

So what does a web administrator need to know? UNIX - Apache WINDOWS - IIS

Apache Apache uses industry standard configuration file Httpd.conf Can set many things like: File Locations Scripting capabilities (PHP, JSP etc.) Performance How many threads etc. Virtual Hosts (more than 1 server on same machine) Same IP ADDRESS, port, different name Same IP, name, different port

Windows IIS Configuration done through management control panel Easy to add new features, change configuration etc.

Conclusion Both Apache and IIS offer easy to use configuration tools. IIS very user friendly, Apache finer control.