Keeping the lights on

Having spent years running 24×7 internet-facing production systems, I find that the monitoring element of an application delivery environment is often the last item to be addressed and built outside of the application delivery architecture. As we continue to build our application delivery infrastructure in the cloud, having a good monitoring strategy will allow us to arm ourselves with the information we need to make intelligent decisions.

So exactly what should be monitored?

Availability

The first element in a monitoring strategy is to determine whether the application is accessible. The most simplistic form of determining availability is ping. However, as most applications are obscured behind a load balancer, a ping response doesn’t necessarily mean that the application is responding to requests. Use a monitoring system that can speak application-layer protocols to ensure that the application is indeed healthy and responding to user requests. It’s best to leverage a 3rd party solutions that can assess availability from multiple networks and provide an unbiased view on the availability of the application.

Resource Utilization / Load

Next element in a good monitoring strategy is to determine how healthy a system is. Tracking the load of various system components will enable us to uncover bottlenecks within the application delivery environment. Leverage SNMP to capture and record utilization statistics on CPU, memory, disk IO, network IO, threads, and so on. Graph these stats to establish baseline and find correlations between each monitored element. (more…)

Technology as a service

Cloud computing concept is transforming the IT industry and shaping the IT service delivery into a pay-as-you-grow model. Here’s a whitepaper from Cisco on Cisco-powered “network clouds”. Thought I’d share some keypoints / highlights…

Abstraction of physical hardware (virtualization) & the ability to share common resources among users (multi-tenancy) are at the heart of cloud computing. It is with virtualization & multi-tenancy that various utility-based approach can be realized and built onto one another:

Infrastructure as a service (IaaS): the abilityy to buy servers, data center resources, network equipment as an outsourced service delivered through the network cloud. Amazon, Joyent, GoGrid and FlexiScale are some examples of providers in this arena.

Platform as a service (PaaS): provides developers access to development tools for various software platforms that the developer needs to develop on. Some examples of development platforms currently out there:

• AppEngine from Google: based on Python and Django
• Force.com from SalesForce: based on the SalesForce SaaS infrastructure and Apex language
• Bungee Connect: visual development studio based on Java
• LongJump: based on Java/Eclipse
• WaveMaker: visual development studio based on Java and hosted on Amazon EC2

Software as a service (SaaS): enables service subscribers to access a software application from a software vendor through the web. Many traditional off-the-shelf application providers are transitioning to a SaaS model. The most well known SaaS provider is probably salesforce.com. WebEX is another example of SaaS.

IT as a service (ITaaS) encompasses IaaS, PaaS, and SaaS. It is a service model where an organization or individual contracts with a service provider to provide individual or bundled services. (more…)

State of the Cloud: Use of Infrastructure-As-A-Service

InfiBase researched top 500,000 websites (based on Quantcast metrics) and their usage of cloud services. While EC2 showed a 9% growth from July to August, less than 1% of all the sites use cloud for infrastructure services. (more…)

Making the case for a virtualized hardware appliance

As Data Center infrastructures become more virtualized, the desire for virtualized network services increases. We see 2 types of offerings:

1. virtual appliances delivered in a VM image, such as the Netscaler VPX from Citrix
2. hardware appliances that can be virtualized, such as Cisco ACE or ASA

(more…)

Another Amazon EC2 story

Looks like HotPads.com has abandoned traditional hosting and moved into Amazon’s elastic compute cloud (EC2). This is a trend that I’ve been following in the web space. (more…)

Painting the Cisco Unified Computing vision and the steps to go there…

Wanted to share my thoughts around the launch of Cisco Unified Computing System (UCS) and my thoughts around what Unified Computing means to me (more…)

Back to Mainframes… well, sort of

This particular topic has been on my mind for some time now. If we looked at the evolution of business computing, it looks something like:

’60s & ’70s – Users accessing applications that run on Mainframes through dumb terminals. No need for the management of end-user computing. (more…)

DNS design 101

A little dated but has a good background on DNS design. This is a must-know for anyone that deals with delivery of applications.

Domain Name System Design Considerations