2 Killer Features of Apache 2.2

By On September 1, 2009 · Leave a Comment

This morning I read an article on Linux Magazine (Ten Things You Didn’t Know Apache 2.2 Could Do | Linux Magazine). Two features really jumped out at me.

Server Name Indication (SNI): Allows a single IP address to support multiple SSL certificates. This is great because not only does it usually cost more for [...]

This morning I read an article on Linux Magazine (Ten Things You Didn’t Know Apache 2.2 Could Do | Linux Magazine). Two features really jumped out at me.

Server Name Indication (SNI): Allows a single IP address to support multiple SSL certificates. This is great because not only does it usually cost more for more IPs, but it starts to get harder to manage. Documentation for this functionality is in the docs wiki, at http://wiki.apache.org/httpd/NameBasedSSLVHostsWithSNI.

mod_proxy_balancer: Allows apache to function as a front-end load balancer. More docs are here http://httpd.apache.org/docs/2.2/mod/mod_proxy_balancer.html. I’m imagining using this to boost performance and reliability LAMP apps, in particular Moodle. Imagine this configuration:

Load Balancer: Dual OpenBSD with CARP shared IP addresses, running Apache 2.2 and mod_proxy_balancer. This way the proxy is always fail-safe.

Application Servers: VMware installation, perhaps ESXi and multiple CentOS running Apache and PHP, etc.

SAN: Dedicated file storage to share application files, configurations, all date but not database.

Database Servers: WMware or straight installation on hardware running CentOS and MySQL or PostgreSQL. Two servers running with database replication should work.

Summary: Fault tolerant, high availability configuration using standard apps with little to no “cleverness” or kernel. I really want to try this!

Question for readers:

Can anyone experienced with mod_proxy_balancer tell me if it would support geographic load balancing?

 

SSH with Keys HOWTO: SSH with Keys in a console window

By On August 20, 2009 · Leave a Comment

When setting up passwordless logins I always seem to miss a step. The following link is a useful resource.

SSH with Keys HOWTO: SSH with Keys in a console window.

When setting up passwordless logins I always seem to miss a step. The following link is a useful resource.

SSH with Keys HOWTO: SSH with Keys in a console window.

 

Amazon S3 downtime

By On August 11, 2009 · Leave a Comment

According to Pingdom, Amazon S3 uptime for 8/9/2009 was 32.84%! Downtime today is already at 12h 44m. That’s pretty disturbing. I ran a google news search and found nothing related to this outage: http://news.google.com/news?q=amazon%20s3%20downtime&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&sa=N&hl=en&tab=wn

Here are some links that were forwarded from my colleague, Len.

Regarding a PayPal outage: http://www.businessinsider.com/outage-costs-paypal-users-at-least-7-million-2009-8

Regarding an Amazon [...]

According to Pingdom, Amazon S3 uptime for 8/9/2009 was 32.84%! Downtime today is already at 12h 44m. That’s pretty disturbing. I ran a google news search and found nothing related to this outage: http://news.google.com/news?q=amazon%20s3%20downtime&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&sa=N&hl=en&tab=wn

Here are some links that were forwarded from my colleague, Len.

Regarding a PayPal outage: http://www.businessinsider.com/outage-costs-paypal-users-at-least-7-million-2009-8

Regarding an Amazon bug with international shipping: http://news.cnet.com/8301-17939_109-10304824-2.html

Regarding previous outages: http://www.datacenterknowledge.com/archives/2009/07/19/outage-for-amazon-web-services/

You can see the diagnostics for yourself here: Pingdom – Web site monitoring for 100% uptime. Measure your downtime..

Why do I care?

As a web developer and a web host, uptime challenges are an ongoing concern. People bandy about terms like 5-nines uptime like it’s an industry standard. The reality, as demonstrated by those with the deepest pockets, is that despite our best efforts Internet fabric is more brittle that we would like to tolerate. For example, when I read about Amazon’s S3 and related AWS services I was pretty sure that geographical load balancing was one of the perks. However, if that were true, how could  lightning strike cause any meaningful downtime.

What Is A Cloud, Anyway?

A physical server is tied to hardware. CPU fails, and the OS is toast: all the services running on the machine fail. As the services move to virtual machines, what is changing? Certainly there’s a decoupling of the OS from the physical hardware. Virtualization does this and we’ve been happily running VMWare for years. But at what point does the VM become a cloud? I had imagined that a cloud was always distributed from any single VM. I suppose that I’m wrong about that. Does anyone else have ideas on what makes a cloud a cloud and not just a virtual environment?

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Google down – Computerworld Blogs

By On May 18, 2009 · Leave a Comment

Monopolies are never a good thing:

Google down – Computerworld Blogs.

And another blog.

it was estimated that 5% of the Internet was unavailable or slow. While still relatively small, it does make Google’s growing significance in the Internet an issue

Monopolies are never a good thing:

Google down – Computerworld Blogs.

And another blog.

it was estimated that 5% of the Internet was unavailable or slow. While still relatively small, it does make Google’s growing significance in the Internet an issue

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Google Docs: Service Unavailable

By On February 6, 2009 · Leave a Comment

Ack! I can’t get to my google docs!

Just when I was starting to really feel the love for Google Docs, I get this:Service Unavailable.

Ugh. Well, we’ll see how long they’re off for.

Update

Looks like they are back online. So that was less than 10 minutes from noticing the error, to apparent fix. Food for thought.

 

PHP-GD on RHEL / CentOS

By On February 4, 2009 · Leave a Comment

While getting this site setup today I realized that I was missing the php-gd module. The theme is using timthumb.php and I needed to run

yum install php-gd

in order to get it to work.

While getting this site setup today I realized that I was missing the php-gd module. The theme is using timthumb.php and I needed to run

yum install php-gd

in order to get it to work.

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Why ASP.NET annoys me, aka studip IIS defaults

By On February 4, 2009 · Leave a Comment

I know Microsoft has huge marketshare when it comes to technology and programming languages. .NET (a ridiculous name, if you ask me) is popular and smart developers like it.

But is that any excuse for activating it by default on every IIS site? It would be one thing if it was a hardened language that [...]

I know Microsoft has huge marketshare when it comes to technology and programming languages. .NET (a ridiculous name, if you ask me) is popular and smart developers like it.

But is that any excuse for activating it by default on every IIS site? It would be one thing if it was a hardened language that simply gave you leverage toward functionality. Instead, I find event log errors indicating that users are hitting “…/trace.axd” trying to find trace data from my web apps. Ack! I scratch my head thinking, Who enabled axd files on my site? Microsoft, that’s who.

Now I have the irritating responsibility of going through all the IIS sites I host, and removing all the ASP extensions. Here’s the MS link describing how to “fix” the problem: http://support.microsoft.com/kb/815175

Am I missing something here? It just doesn’t seem like a feature to me.

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