Shuffle Sharding

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. Check it out here!...
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Case Study: Out of Memory

Case Study: Out of Memory

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. The application logs were clean as well. Also of importance is that this server was a Linux EC2 instance in AWS. Troubleshooting Being that rebooting the server resolved the problem every time, it was decided to duplicate the EC2 instance from its snapshot image. This was completed quickly, but the issue appeared again that night and several times the following day. Finally, an error was seen in the system logs which pointed directly to a memory issue. Solution After this, it was discovered that the server was a T2.micro instance with...
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Book Recomendation: “The Phoenix Project”

Book Recomendation: “The Phoenix Project”

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. The various character personalities keep it interesting and even relatable still! It helps provide motivation to use ITIL methodologies, Kanban process, cloud computing, and more. My only critique is that it's a slow start with an abrupt end. I'm interested to read "The DevOps Handbook" now to see the real world advice and stories. View all my reviews...
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Log AWS VPC Flows

Log AWS VPC Flows

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. It isn’t exactly the same, but I have figured out how to log AWS VPC flows to provide the data. Here’s a brief walk through of the setup.   Create Flow Logs The first step is to select the VPC and then the “Create Flow Log” menu item from the “Actions” drop down.   See them attached to VPC After confirming its creation I saw the log ID listed in the “Flow Logs” tab.   View Configured Flow Logs Hopping over to the CloudWatch logs I could see my newly created log group.   Log View After selecting the log, I could...
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Diagram Your Service

Diagram Your Service

 I love packets and tracing issues at a micro level. However, like I stated in Preparing for the Capture you need to know where to capture before you can dig into the bits an bytes. In order to know where to capture you must understand your service/app/network. The best way to do that is to diagram your service. The Diagram The featured image on the post and the same one included below is a high level example of an architecture diagram of this blog. I use CloudFlare and AWS services currently to host it. The diagram shows this flow along with the purpose of these services and a little more detail outlining the layout of AWS. In a more detailed and private diagram I could also include breakouts showing the actual services running such as Wordpress, Apache, and MariaDB. I could also include external services that provide MFA, email, monitoring, and notifications.   Created with draw.io The Purpose An architecture diagram does more than highlight good capture points....
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AWS Monitoring with IFTTT

AWS Monitoring with IFTTT

Performance monitoring is two-fold. There is proactive performance monitoring and reactive investigation. The majority of my posts and case studies reflect the latter. This post is more related to the former. Services on premise typically rely on SLAs, NetFlow, scripts, synthetic transactions and more to provide monitoring and alerting. While some of this is possible in the cloud to keep track of specific pieces, you first need a good foundation by knowing if the underlying technology by your cloud provider is operating as expected. In this example, I will walk through setting up an alert to monitor individual Amazon Web Services and send a notification using an IFTTT applet. Create the Applet Before creating an applet/recipe, you might want to see if one is already available with the functionality you need in IFTTT's discover section. If one isn't available, you can create one following their instructions here. I will skip the step by step that they provided, and demonstrate how you might...
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AWS Cloud Practitioner

AWS Cloud Practitioner

My career has recently shifted directions. While I still have a passion for network performance and the apps that run on the network, my focus will be directed towards the cloud and the future of application performance. More specifically, I will be specializing in AWS technologies. To start that journey, I achieved the AWS Cloud Practitioner certification. I felt this certification was another test that was well done. It was a good entry level test, but still reinforced the knowledge Amazon feels you need. It has a good blend of introductory content and challenging material. I was able to achieve it with two weeks of evening study. If you'd like to pursue it as well, here are the resources I recommend: Amazon's training Amazon Whitepapers A Cloud Guru ...
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