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- A life ordinary by Amit Sarkar - Issue #20
A life ordinary by Amit Sarkar - Issue #20
Hello friends,
Welcome to another edition of my newsletter.
Last week we went to play Garba in North London and met a lot of friends, we normally wouldn't meet since they are all north of the Thames river.
We also hosted a party at home for our son's 1st birthday (coming soon) and Diwali (coming soon as well). It was a wonderful gathering of friends with food, drinks and banter.
Ever since my wife returned from India, we and a few of our friends have been playing Catan every week. We were introduced to this game by some other friends and have been literally obsessed with this game.
Our son also started his settling-in session at a nursery and he was really happy during the session. Another new phase begins in our and our son's lives. This week he would be officially starting at his nursery.
And UK's current PM, Liz Truss, sacked her Chancellor, Kwasi Kwarteng. She appointed Jeremy Hunt as her new Chancellor. Currently, the UK has high inflation, high energy prices (partially offset by Energy Bills Support Scheme and Energy Price Guarantee), and high-interest rates. The gilts market is also facing a huge sell-off. All this has put a lot of pressure on the government and the economy which seems to be spiralling out of control. Let's see what happens this week in UK politics and with the UK economy.
📶 Wi-Fi
Each Wi-Fi network standard has two parameters -
Speed
This is the data transfer rate of the network measured in Mbps (1 megabit per second).
Frequency
On what radio frequency, the network is carried on. Two bands of frequency for the Wi-Fi are 2.4 GHz and 5 GHz. In short, it is the frequency of radio wave that carries data.
Two Frequencies of Wi-Fi signal
Wi-Fi routers that come with 2.4 GHz or5 GHz are called the single-band routers but a lot of new routers support both 2.4 GHz and 5 GHz frequency they are called dual-band routers.
The 2.4 GHz transmits data at a slower speed than 5 GHz but does have a longer range than 5 GHz. The 5 GHz transmits data at a faster rate, but it has a shorter range because it has a higher frequency.
Wi-Fi standards
New naming scheme for Wi-Fi standards
There is also Wi-Fi 6E operating at 6 GHz frequency.
And some additional Wi-Fi standards are as follows -
IEEE 802.11ah - Sub-1 GHz Wi-Fi standard prioritizing range over speed
IEEE 802.11ad - 60 GHz frequency with a very low range. Useful for AR/VR headsets and laptop docks. Max. speed 8 Gbps
IEEE 802.11ay - 60 GHz frequency with improved range over 802.11ad. Useful for AR/VR headsets and laptop docks. Max. speed 40 Gbps
IEEE 802.11be or Wi-Fi 7 - 6 GHz frequency
🌐 Site Reliability Engineering
I have been reading a lot about Site Reliability Engineering (SRE) lately and there are a few principles that struck me.
In a world where connectivity and the need to be ‘always on’ has never been more important, the reliability and availability of our communications is a critical factor for most organisations and industry sectors. The most meaningful measure of this is the Service Level Agreement - or SLA - which most enterprise communications providers state as a percentage for the guaranteed uptime of their service.
"Five nines” refers to 99.999% availability, which equates to just over 26 seconds of downtime a month for that cloud application or service. This is the gold standard for uptime SLAs.
Source - RingCentral
⏱️ Latency
The time it takes to service a request. It’s important to distinguish between the latency of successful requests and the latency of failed requests.
🚦 Traffic
A measure of how much demand is being placed on your system, measured in a high-level system-specific metric.
❌ Errors
The rate of requests that fail, either explicitly (e.g., HTTP 500s), implicitly (for example, an HTTP 200 success response, but coupled with the wrong content), or by policy (for example, "If you committed to one-second response times, any request over one second is an error"). Where protocol response codes are insufficient to express all failure conditions, secondary (internal) protocols may be necessary to track partial failure modes.
🥛 Saturation
How "full" your service is. A measure of your system fraction, emphasizing the resources that are most constrained (e.g., in a memory-constrained system, show memory; in an I/O-constrained system, show I/O). Note that many systems degrade in performance before they achieve 100% utilization, so having a utilization target is essential.
❓ The 5 Whys
While reading some articles about testing I stumbled upon this principle of the 5 Whys and went on exploring it. I have tried to summarize the article, mentioned below.
An in-depth look at the 5 Whys, a simple problem-solving exercise designed to unearth the root of any problem or unexpected situation.
What is it?
A discussion of the unexpected event or challenge that follows one train of thought to its logical conclusion by asking “Why?” five times to get to the root of what happened.
Who created it?
The 5 Whys technique was developed and fine-tuned within the Toyota Motor Corporation as a critical component of its problem-solving training.
Taiichi Ohno, the architect of the Toyota Production System in the 1950s, describes the method in his book, Toyota Production System: Beyond Large-Scale Production, as “the basis of Toyota’s scientific approach by repeating why five times, the nature of the problem, as well as its solution, becomes clear.”
What is its purpose?
The purpose of the 5 whys isn't to place blame, but rather to uncover the root cause of why something unexpected occurred.
Example
How to run a 5 Whys session?
🍕 Pizza as a Service 2.0
When it comes to technology, we often find that there are many amazing things around us that we simply don't understand.
One such thing is SaaS or Software as a Service. It's overly used but people don't understand what it actually means.
Paul Kerrison in the image below tries to help us understand what the different services in the software world are.
On-Premises – like a homemade pizza, made from scratch, you do everything yourself (no change so far). Example: Datacentre
Infrastructure as a Service – You share a kitchen with others. The utilities and oven are provided, but you make and cook the pizza yourself. Example: EC2
Containers as a Service – You bring the pizzas but someone else uses their facilities and cooks the pizza for you. Example: ECS
Platform as a Service – You order a pizza for collection, the pizzeria make and cook the pizza using their facilities. Example: App Engine
Function as a Service – You go to a pizzeria with some friends. You order and then eat pizza made by the restaurant. You order drinks from the bar and they’re made for you. Example: AWS Lambda
Software as a Service – You go to someone’s house for a party, they provide the pizza and invite others round for you to meet. Conversation with the guests is still your responsibility! Example: Gmail
Such a simple yet elegant way of understanding complex terminologies.
Thank you so much once again for reading my newsletter this week. Please feel free to Buy me a coffee if you are enjoying what I am sharing.
Until we meet again next week, please stay alert, follow the news, count your blessings, and save more.
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