It’s important to know your limits. In this case study we find a situation stemming from SMTP being throttled. This is part of the packet capture I received: The top lines show the previous conversation ending. SMTP successfully sent 3 messages. After the 3rd message the mail server stopped responding and retransmits began. This pattern was repeatable. More than that it was repeatable from other EC2 instances. The only thing between the EC2 instances and the mail server was a router and a firewall.
If you refer to this post, you’ll see that one of my objectives for this year was to develop an Alexa app for my kids. Well, I am happy to report this objective as completed. The cover art and the image below show the high level architecture. The app idea actually started based on something I was doing for my kids that they really took a liking to. Unfortunately, for this post it might be an idea that I could actually publish and potentially monetize.
Being that I recently took the plunge to a static site hosted on AWS S3 I thought I would create a post outlining the high-level process for future reference. There are quite a few blogs in the interwebs outining this process, but if this helps someone else too then it’s a win-win. If you are curious as to WHY I migrated, you can find a short bit about that in this post.
This is old news, but I recently found out that Jeff Bezos considered “Relentless” as a possible name for his company instead of Amazon. If this is news to you as well, you can read a short article about it from Business Insider here. Webster Dictionary defines “relentless” this way: showing or promising no abatement of severity, intensity, strength, or pace For some reason this word has stuck with me the past couple of weeks.
Moving to S3 I’m currently in the process of moving my blog to Amazon S3. I’m not the first to do this and I won’t be the last. My reasons for this are similar to everyone else. Wordpress is an excellent blogging and site platform. I have really enjoyed working with it and getting to know its innards. As I continuously evaluate the purpose of my site though, I have to keep the technology behind it in sync.
Yesterday I sat for the AWS Solutions Architect Associate exam and passed! Thanks to the teams at A Cloud Guru and WhizLabs for the training.
So, all credit goes to Colm MacCárthaigh for this one. I think his recent post on Shuffle Sharding is so go it deserves a share and a place on my blog to serve as a reminder for me from time-to-time. This is one way AWS achieves the level of reliability and stability it has for its customers. Some of the methodology can easily be applied to traditional and on-prem infrastructure though as well.
Symptoms Website randomly goes down a few times a week Server stopped responding Network and CPU logs show a small spike, but not enough to lock up a server Stopping and starting the server resolves the problem Details This pattern repeated several weeks until the customer grew tired of rebooting the server. The evidence did not seem to lead to a system issue or network or security security problem such as a denial of service.
Other than the main character being a manager, it is amazing how close this book mirrors my career path so far. This is fiction, but does a good job introducing business and cloud concepts. I would definitely recommend this for anyone in IT. The Phoenix Project: A Novel About IT, DevOps, and Helping Your Business Win by Gene Kim My rating: 3 of 5 stars A story that anyone from an IT operations background can relate to.
As I transition to working in “the cloud” more I am embracing the new technologies and methodologies. However, I’m also trying to replicate what I do in on-prem environments when it makes sense. One way I like to collect and analyze data is using NetFlow. NetFlow provides network conversation details at a higher and summarized level. This has led to quicker recovery time on numerous occasions, or avoided issues entirely.
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