Home » 2021

Yearly Archives: 2021


The Yale Ledger is a student-led magazine showcasing content from around the Yale community.

If you are affiliated with the Yale student community and have an article you want to share, please email Layla Winston.

If you notice any spam or inappropriate content, please contact us so we can remove it.

AWS Pricing Models Explained

The Fundamentals of AWS Pricing

Amazon Web Services (AWS) is a top cloud provider, offering many services, including storage, artificial intelligence (AI) and machine learning (ML), networking, and more. Each service is priced differently, and there are many pricing models available.

The most flexible of the six AWS pricing models is the “pay as you go” model, which lets you pay only for the resources you use and quickly scale as needed. There is no need for long-term contracts. The basic option lets you pay for what you actually use. Other pricing models enable you to pay less when reserving resources in advance or get volume discounts when you use more resources.

6 AWS Pricing Models

Understanding AWS pricing models is critical for optimizing your Amazon costs

AWS Free Tier 

AWS offers a free tier that lets you sample a wide range of products for free. Here are the three types of free offerings:

  • Always free—this option lets you use a wide range of AWS resources for free. There is a limitation on the amount of resources you can use, and as long as you do not exceed it you can continue using the service without a time limitation. For example, you can get one million AWS Lambda requests per month.
  • 12 months free—the count starts after the initial sign-up date to AWS. This model provides you with free resources for each service for a limited time period. For example, you can get 5 GB of standard storage in Amazon Simple Storage Service (Amazon S3).
  • Short-term free trial—AWS provides a free trial, which you can use to try out certain services. For example, you can use Amazon Redshift for free for a duration of two months.

Note that additional features not included in the free tier may incur additional charges. You can learn more in the official free tier page


The on-demand pricing model lets you pay by the second or by the hour without any upfront payment. There is no need to commit in advance. You can start using the service and pay as needed. However, while on-demand pricing is usually the most flexible model it is also often the most expensive option. It is ideal for unpredictable workloads but not for long term use.

Spot Instances

AWS offers major discounts on their available and unused compute capacity. This model is called Spot Instances. You can get discounts of up to 90% for using spot instances—this is the largest possible discount available on AWS. 

To use spot instances, you need to set up a bid, and when an instance is available at that price you can get a discount on using spare capacity. You can also leverage the Hibernate option, which keeps your instance in the same state and launches it again when there is spare capacity.

While Spot Instances offers major discounts, it also has its limitations. The most concerning limitation is that once the instance is no longer available, it is terminated. You get a 2-minutes notice and then your instance is dropped. This is not ideal for demanding workloads. You can set up AWS monitoring to receive “rebalancing warnings” which are sometimes sent by Amazon in advance of the two minute notice period.

Reserved Instances

Reserved Instances (RIs) provide discounts in return for an upfront commitment to use these resources for a long duration of 1-3 years. This model lets you purchase instances in advance, and use them as needed. AWS provides several payment options, including No Upfront, Partial Upfront, and All Upfront. The more you pay in advance, the bigger the discount.

There are two main types of RIs—Standard RI and Convertible RI. Each comes with different options and several instance families. Convertible RIs let you commit only to a specific region for a certain period of time and change the instance family as needed. This level of flexibility makes Convertible RIs more expensive than the Standard RIs.

RIs are initially less difficult to use than Spot Instances and offer great discounts. However, as you accumulate more RIs, management becomes complex. Additionally, it can be difficult to choose the right instance family and you must pay for the capacity you committed to even if you later do not need it. 

Saving Plans

Saving Plans let you get a high discount rate in return for committing to use AWS resources for a duration of one to three years. You pay an hourly rate, and the discount is subtracted from the  on-demand pricing of your resources. 

AWS offers three main payment options for Saving Plans—Upfront, Partial Upfront, and All Upfront. You can choose one option or a combination of the three and leverage the discounts across your workloads. 

Saving Plans are applied in the account they are purchased from, and then can be applied across all connected accounts. This ensures you can get discounts for several different services, rather than just one. If you want more control over how discounts are applied, you can use an empty account to purchase all available Saving Plans.

Dedicated Hosts

A dedicated host is a physical server offered for rent. AWS lets you rent an entire server, which is reserved for your use only. You gain access to the server and AWS is responsible for administrative tasks, including hardware maintenance and cleaning. 

Dedicated Hosts offer a secure and reliable option for running workloads on AWS. However, this service can be highly expensive, which is why it is used primarily by enterprises. 


In this article I explained the fundamentals of pricing in Amazon’s cloud services, including the following pricing models:

  • Free tier – letting you experience some Amazon services free forever, and others free for a limited time and quantity
  • On-demand – paying per hour or second of usage for Amazon resources
  • Spot instances – deeply discounted instances from Amazon’s spare capacity, which can be interrupted on short notice
  • Reserved instances – letting you commit to computing capacity for a period of 1 or 3 years and receive substantial discounts
  • Savings plans – committing to a certain level of spend on Amazon across your organization in exchange for a discount
  • Dedicated hosts – a physical server provided for your use within the Amazon data center

I hope this will be of help as you plan your use of Amazon and other cloud services.

Should You Move to the Caribbean?

Every winter, we dream about going on holiday to a tropical island full of sunny days and sandy beaches. Some people have taken their relaxing escape further and made the decision to go on permanent vacation. If you have ever pondered the prospect of living close to the turquoise waters of the Caribbean coast, here are some popular islands for expatriates.

Ambergris Caye, Belize

Ambergris Caye is the biggest island in Belize and is lovingly known as Isla Bonita thanks to Madonna’s 80s hit song. The beautiful island is a mere 25 miles long and approximately a mile wide. Located only half a mile from the Belize Barrier Reef, the island is a popular destination for tourists who come for the scuba diving and snorkeling and stay for the incredible island vibe.

San Pedro is the only town on Ambergris Caye. Although it is the second-largest town in Belize, it only has a modest population of fewer than 20,000 people, many of whom belong to a close-knit community of expats. While the island has developed significantly and the sandy paths are now paved roads, it still retains its laidback charm with golf carts, bicycles, and walking being the preferred mode of transport.

With the increased development also comes reliable utility services, amenities, and a thriving dining and bar scene. Almost all of the locals speak English, and immigration policies are extremely foreigner-friendly. For those who need to be close to the big smoke, the island is a short skip to the bustling metropolitan Belize City and only a two-hour flight to Florida, USA.

St Maarten, Dutch Caribbean

Sint Maarten (St Maarten) is an island country of the Kingdom of the Netherlands in the Caribbean. The island of Saint Martin is divided into two separate countries. The northern side is French, encompasses 60 percent of the island, and is called Saint Martin; The southern side is Dutch, covers 40 percent of the island, and is called Sint Maarten. 

St Maarten attracts hordes of visitors every year who indulge in all varieties of water sports such as sailing, surfing, snorkeling, diving, and kitesurfing. Its secluded coves and 37 white-sand beaches are another big draw. Maho Beach, in particular, has become the trademark spot to capture exhilarating photographs of low-flying aircraft preparing to land at the nearby international airport.

Because of the interesting history of Saint Martin island, St Maarten has become a diverse and unique blend of cultures. Expats from all over the world call the island home and they revel in the modern supermarkets and reliable utility infrastructure. The dining scene is exceptionally vibrant, and St Maarten is often known as the gastronomic hub of the Caribbean.

For those who are interested in renting or buying their piece of paradise, there is a wide range of homes available from studio St Maarten condos with stunning views to six-room villas with swimming pools that sit right on the water. Best of all, property titles operate under the European system and there is no annual property tax for property owners or capital gains tax for residents.

Roatán, Honduras

Roatán is a long and thin island located about 35 miles off the northern coast of the Honduras mainland. This 50 square mile island boasts stretches of lush hills, untouched jungle, and the world’s second-largest barrier reef. Formerly a secret escape of scuba divers, this Caribbean island has now become a favorite of expats who seek a low-key lifestyle.

As Roatán was once a British colony, most of the residents on the island speak good English along with the national language of Spanish. There are approximately 80,000 residents spread out over little villages and communities that dot the island. Each district has its distinctively different feel and lifestyle with the larger towns and amenities such as hospitals and government offices located in the middle of the island.

Roatán’s expat community is very welcoming, especially to retirees. With tourist traffic and development mostly concentrated on the north-western side of the island, the majority of expats choose to live and socialize in villages there. However, others prefer to stay in the remote bays of the east side and use boats as their primary mode of transport into town.

These islands in the Caribbean sit at the sweet spot between rustic authenticity and developed comfort. There is just enough international influence to ensure that expats can maintain their standard of living and have their desired groceries from home, without taking away from the small island charm and slow-paced lifestyle.

Life is paradise is a possibility. Whether you want to purchase St Maarten real estate or a little shack on the beach, a reliable and knowledgeable real estate agent will help you to find your perfect new home. Lush, green jungles, azure blue waters bursting with life, pristine and secluded beaches, and the best dining options that global cultures can offer. This is the life that awaits you in the Caribbean.

The Importance of Maintaining Your Mental Health as a Student

One important — and often understated — part of your job as a student is looking after your mental health. Yes, college is work, it’s not meant to be a joy ride, you’re here to learn and prove yourself and there is often a certain level of struggle associated with both of those things. But getting through graduation and potentially even more learning after you’re done, requires that you be able to stay motivated and productive in the long term. And for that to happen, you need to be able to look after your mental health and well-being during the graduation process.

Mental health and dropping out

If you have never looked at the college dropout rates before, you should, because the statistics are eye-opening. According to data from Admissionsly.com, 57% of students enrolled in college take more than 6 years to graduate, and the overall college dropout rate for undergraduate students in the US is 40%. The number goes up to 50% for students who attend public universities.

Are these numbers acceptable? That’s a complicated question. There are a variety of factors that lead students to drop out, and they are not all bad. Some people drop out because they have found career opportunities elsewhere or have decided to take a different route with their professional lives (i.e. trade school, usually). But more often than not students drop due to personal and financial stress brought upon them by trying to balance the responsibilities of daily life alongside trying to get through a tough undergraduate program.

Remember: it will more likely than not take you around six years to finish college, and a lot can change in that time. You might find yourself having to look after elderly relatives at that time, find yourself about to become a parent or find yourself affected by a major economic downturn or a global pandemic. These are all issues that can have a very practical impact on your life. Having to look after a relative, for example, will leave you less time to study and rest.

That said, how well you can take care of your mental health will play a big role in how you will be able to adapt to these issues. Major life changes are much more likely to overwhelm you if you were already stressed and burned out, to begin with. This is why if you are determined to finish your graduation, you should place self-care at the top of your list of priorities. Don’t ignore stress, sleep issues, and bad habits like procrastination when things are going well in your life, because these issues will greatly limit your ability to adapt when your living situation takes a turn.

Dealing with stress

A big part of dealing with stress is making sure you’re dealing with pointless sources of toxicity. Bad friends, drama-driven relatives, and toxic employers can all drain your mental health and wear you out over time, which will make your college harder than it has to be. So be ready to distance yourself from these and other sources of toxicity, especially when exam season comes around.

If the source of problems is an authority figure you can’t get away with, sit down with an adult abuse lawyer to talk. Even if the person in question hasn’t crossed the line into illegal behavior yet, it’ll still be useful for you to know where the line is, and what resources you have available to protect yourself from that person.

Helping Students Take Better Care of Their Health

While the youth of today is probably more health-conscious than any generation before them, the pressure of university life can still push students to ignore their own health. Young people are also more likely to underestimate the long-term consequences of neglecting their health.

After all, health is one of those things people tend to value only when it’s gone, and young students are less likely to have dealt with a health issue in the past. And while there is a certain expectation that university students should be mature enough to take care of themselves, it will help for campus staff and administration to put together measures to help students take care of their health.

This help can take two primary forms, which are (1) encouraging students to maintain their own health and (2) helping students get regular checkups from healthcare professionals.

Encouraging students

Most students leave high school with a vague sense of what is right when it comes to self-care. They know they should brush and floss, they know they should get some exercise done, and they know they should “eat healthy”, although they are probably unsure of the details of how to achieve all of the above.

College is a good time for them to learn the details, both of what they are supposed to do and what the consequences are if they don’t. The latter is crucial because it’s hard to take something seriously when you aren’t aware of the consequences.

Take oral health as an example. Most students will know that if they fail to take proper care of their teeth and mouth they will probably need dental work done. What they probably do not know is that dental work leads to more dental work. Repairs made by dentists last somewhere between 5 and 20 years, after which you need more dental work to get the dental work fixed again. Dental work can also increase the wear and tear between the teeth, leading to more dental work down the line.

In other words, a student who takes terrible care of their oral health in their 20s might be dooming themselves to a lifetime of endless dental appointments, discomfort, health problems, and — of course — dealing with a ton of dental costs. And that’s without even mentioning the long-term consequences associated with gum diseases, which afflicts over 40% of adults over the age of 30, and makes people more prone to suffer from diabetes, heart attacks, strokes, and more because bacteria living in your gums often finds its way into your bloodstream.

And students don’t know any of that. People tend to skip these details when explaining things to children, and adults don’t often discuss these topics.

Exercise and dieting have similar details and realities worth delving into. Like how lack of exercise makes people more prone to hormonal problems, or how the longer you stay on a sugar-rich diet the harder it will be to deal with food cravings once a student does decide to change their eating habits.

These and other basic types of information can all be made available to students on a simple self-care manual or leaflet, or just be explained in one big lecture for each class for college freshmen. Information can be a great source of motivation when it comes to encouraging people to be healthier.

Healthcare professionals

People of all ages need regular checkups to take proper care of their health and catch health issues early. Getting a proper checkup and cleaning from a dentist can prevent long-term issues, and blood work can help doctors catch all sorts of diseases in their early stages. Therefore, it is important to encourage students to get these checkups at regular intervals.

Encouragement can be as simple as sending out an email every six months reminding students to set appointments for their checkups. As for getting students in touch with professionals, it’s a good idea to have the contact information of local professionals at hand, as students who are from out of town might not even know where to start looking.

It is also wise to have tools available to assist students in finding affordable dental care and healthcare in general. Money is another big barrier for students looking to get checkups, so if there are any government programs or NGO initiatives in place to help low-income students get tests and treatment, it’s a good idea to publicize them on campus and make them easy to find.

Of course, none of the ideas in this article will have a 100% success rate. But even if only a handful of students end up changing their behavior due to these efforts every year, that can still amount to a lot of people living healthier lives over the years.

And again, university students are adults. It is within their rights to choose not to care for themselves as well as they could. But it is important that they know they could do better and what will happen if they don’t. After all, choices made based on incomplete knowledge are barely choices at all. Health is our most important asset; everyone should be taught how to protect it.