The Codebelay Blog

Month: August 2009

  • Advice for Middle Management

    Your team will sabotage your career worse than any other nemesis at work, if you let them.

    Here’s what you need to know to protect yourself and your company from sabotage:

    Who’s popular? Yeah, I know. It sounds like highschool, but like then it’s still in important and socially real factor that’s now kept track of on social media sites.

    What is your team’s weakness as perceived by those outside? By the team itself? A good manager can appease the two.

    Whose skills are the most respected? Yup you have to get along with this douchebag, if she or he is one. Just create enough space between the two of you.

    Any others?

  • Amazon EC2 in the Enterprise

    This is just a quick summary of what it was like implementing Amazon’s EC2 in an enterprise environment.

    1. You’ll need to write your own LDAP plug-ins to interface with any access control lists. E.G. where I work WordPress is used for corporate communications so an LDAP plug-in had to be written to make sure the right people saw the right information.

    2. Migration can be expensive if you’re using EBS on the first go. On windows, and I’m not sure why, it can cost about $50 to migrate 2GB of data into EBS. In linux, it happens at a fraction of that cost and as advertised.

    3. Windows can be very expensive. Although they say it’s 12 cents per hour per small instance beware of hidden costs like authentication services and SQL server. With both, you are using a server at the cost of $1.35 / hour, which IMHO could be run cheaper with just a small linux instance and do the same thing at 10 cents per hour.

    I’m pretty sure that with the right Amazon EC2 set up you could run a cluster of servers for a Fortune 500 company for under $1000.00 (one thousand dollars) per month without the CapEX costs associated with new hardware.

    If you have any more questions about Amazon EC2 in the enterprise I’d be happy to answer them. Please ask them in the comments below.

  • How to Load Balance and Auto Scale with Amazon’s EC2

    This blog post is a quick introduction to load balancing and auto scaling on with Amazon’s EC2.

    I was kinda amazed about how easy it was.

    Prelims: Download the load balancer API software, auto scaling software, and cloud watch software. You can get all three at a download page on Amazon.

    Let’s load balancer two servers.

    elb-create-lb lb-example --headers \
--listener "lb-port=80,instance-port=80,protocol=http" \
--availability-zones us-east-1a

    The above creates a load balancer called “lb-example,” and will load balance traffic on port 80, i.e. the web pages that you serve.

    To attach specific servers to the load balancer you just type:

    elb-register-instances-with-lb lb-example --headers \
--instances i-example,i-example2

    where i-example and i-example2 are the instance id’s of the servers you want added to the load balancer.

    You’ll also want to monitor the health of the load balanced servers, so please add a health check:

    elb-configure-healthcheck lb-example --headers \
--target "HTTP:80/index.html" --interval 30 --timeout 3 \
--unhealthy-threshold 2 --healthy-threshold 2

    Now let’s set up autoscaling:

    as-create-launch-config example3autoscale --image-id ami-mydefaultami \
--instance-type m1.small
    as-create-auto-scaling-group example3autoscalegroup  \
--launch-configuration example3autoscale \
--availability-zones us-east-1a \
--min-size 2 --max-size 20 \
--load-balancers lb-example
    as-create-or-update-trigger example3trigger \
--auto-scaling-group example3autoscalegroup --namespace "AWS/EC2" \
--measure CPUUtlization --statistic Average \
--dimensions "AutoScalingGroupName=example3autoscalegroup" \
--period 60 --lower-threshold 20 --upper-threshold 40 \
--lower-breach-increment=-1 --upper-breach-increment 1 \
--breach-duration 120

    With the 3 commands above I’ve created an auto-scaling scenario where a new server is spawned and added to the load balancer every two minutes if the CPU Utilization is above 20% for more than 1 minute.

    Ideally you want to set –lower-threshold to something high like 70 and –upper-threshold to 90, but I set both to 20 and 40 respectively just to be able to test.

    I tested using siege.

    Caveats: the auto-termination part is buggy, or simply didn’t work. As the load went down, the number of the server on-line remained the same. Anybody have thoughts on this?

    What does auto-scaling and load balancing in the cloud mean? Well, the total cost of ownership for scalable, enterprise infrastructure just went down by lots. It also means that IT departments can just hire a cloud expert and deploy solutions from a single laptop instead of having to figure out the cost for hardware load balancers and physical servers.

    The age of Just-In-Time IT just got ushered in with auto-scaling and load balancing in the cloud.