DEV Community: vik-codes

Here are the 6 best Kubernetes newsletters to follow in 2023.

vik-codes — Wed, 08 Feb 2023 10:06:07 +0000

Kubernetes is getting ever so popular with each passing day. It is one of the world's top 3 most loved platforms.

With its popularity, it also becomes essential for developers to stay in line with its updates, getting access to a community which supports it and being exposed to content that takes them one step closer to mastering it.

Newsletters offer a comprehensive bundle of resources for any such technology; thus, we have shortlisted six newsletters that will help you get a grip on the latest and greatest from the world of Kubernetes.

1. KubeWeekly

KubeWeekly is a Kubernetes focussed weekly newsletter handpicked by the Cloud Native Computing Foundation (CNCF) team, which took over management of the Kubernetes technology from Google.

The newsletter is dense with multiple sections, including headlines, an ICYMI section that shows proximal CNCF programs, and a technical segment which includes tutorials, tools, and much more.

Their latest newsletter revealed End of year deals on Linux certifications, Rancher 2.7 deep dive, and much more. You can check their previous issues here

2. Last Week in Kubernetes Development

Curated by the Kubernetes Contributor SIG, Last Week in Kubernetes Development (LWKD) is a weekly newsletter that aims to provide an update on the code activity in the Kubernetes project: merges, PRs, deprecations, version updates, release schedules, and community meetings.

LWKD is a sister publication to KubeWeekly and hence doesn't cover events or news, which the latter does a good job of.

In their latest issue, LWKD discusses Kubernetes version 1.26 and much more. You can subscribe to the newsletter here.

3. Learn Kubernetes weekly

Learnk8s offers Kubernetes training with self-paced online classes, as well as consulting services. Their newsletter includes access to handpicked Kubernetes guides, articles and even introduces its subscribers to the best Kubernetes jobs and events.

The newsletter aims to provide a comprehensive bundle of resources: right from technical guides to recent job listings and does an excellent job of it.

The latest issue includes articles such as a set of modern Grafana dashboards for Kubernetes and much more. You can subscribe to Learn Kubernetes weekly here

4. Upcoming Kubernetes Events

Upcoming Kubernetes Events is a weekly newsletter curated by the team at Kube Events, which is the place to find all the information regarding Kubernetes events, including meetups, conferences, training and webinars.

The newsletter also offers subscribers exclusive discount codes for events, call-for-papers announcements, and much more.

You can subscribe to the Upcoming Kubernetes Events newsletter here

5. Kubelist

Kubelist is a newsletter curated by Replicated, Shipyard, and snyk. It also has a podcast with the same name.

This newsletter, not strictly weekly, but consistent, contains information on the latest Kubelist podcast episode, curated articles around Kubernetes, and features tweets (often sarcastic) from the Kubernetes realm.

The latest issue of this newsletter talks about their latest projects: Kubecost and Opencost, and you can check out the previous issues here

6. Learn Cloud Native

The Learn Cloud Native, similar to the Kubelist newsletter, is not a weekly newsletter. However, it covers a lot of information once it is sent to subscribers.

The newsletter contains a curated list of podcasts, guides, articles, and news in the cloud native space.

This newsletter's latest issue discussed Deploying Traefik Proxy using Flux and GitOps principles. You can check out the previous issues here

Conclusion

Yes, tackling the challenges of a reasonably new technology such as Kubernetes can be difficult, but adopting tools such as Newsletters can be a good start.

Did you like our list of the Best Kubernetes Newsletters? Do you know of a newsletter that could have been on this list? Let me know in the comments section below.

Here are the 6 best Kubernetes newsletters to follow in 2023.

vik-codes — Wed, 11 Jan 2023 12:02:32 +0000

Kubernetes is getting ever so popular with each passing day. It stands as one of the world's top 3 most loved platforms.

1. KubeWeekly

KubeWeekly is a Kubernetes focussed weekly newsletter handpicked by the Cloud Native Computing Foundation (CNCF) team, which took over management of the Kubernetes technology from Google.

The newsletter is dense with multiple sections, including headlines, an ICYMI section that shows proximal CNCF programs, and a technical segment which includes tutorials, tools, and much more.

Their latest newsletter revealed End of year deals on Linux certifications, Rancher 2.7 deep dive, and much more. You can check their previous issues here

2. Last Week in Kubernetes Development

LWKD is a sister publication to KubeWeekly and hence doesn't cover events or news, which the latter does a good job of.

In their latest issue, LWKD discusses Kubernetes version 1.26 and much more. You can subscribe to the newsletter here.

3. Learn Kubernetes weekly

The newsletter aims to provide a comprehensive bundle of resources: right from technical guides to recent job listings and does an excellent job of it.

The latest issue includes articles such as a set of modern Grafana dashboards for Kubernetes and much more. You can subscribe to Learn Kubernetes weekly here

4. Upcoming Kubernetes Events

The newsletter also offers subscribers exclusive discount codes for events, call-for-papers announcements, and much more.

You can subscribe to the Upcoming Kubernetes Events newsletter here

5. Kubelist

Kubelist is a newsletter curated by Replicated, Shipyard, and snyk. It also has a podcast with the same name.

The latest issue of this newsletter talks about their latest projects: Kubecost and Opencost, and you can check out the previous issues here

6. Learn Cloud Native

The Learn Cloud Native, similar to the Kubelist newsletter, is not a weekly newsletter. However, it covers a lot of information once it is sent to subscribers.

The newsletter contains a curated list of podcasts, guides, articles, and news in the cloud native space.

This newsletter's latest issue discussed Deploying Traefik Proxy using Flux and GitOps principles. You can check out the previous issues here

Conclusion

Yes, tackling the challenges of a reasonably new technology such as Kubernetes can be difficult, but adopting tools such as Newsletters can be a good start.

Did you like our list of the Best Kubernetes Newsletters? Do you know of a newsletter that could have been on this list? Let me know in the comments section below.

How much salary does a Kubernetes engineer get?

vik-codes — Mon, 02 Jan 2023 11:28:28 +0000

$250,000 is the maximum salary offered for a Kubernetes job in our dataset!

Then, what is the average salary for a Kubernetes Engineer? Are the metrics vastly different between the US and Europe?

Let's try to find the answers to the above questions (and perhaps more) with Kube Careers job listings data for Q3 2022 (July to September).

Before you read further, know that:

At Kube Careers, we only include job listings with a clear salary range, and which have Kubernetes as a requirement and not a nice to have/plus.
Our dataset is small, with 86 job listings from July to September 2022.
We have divided the salary ranges into two categories: North American Kubernetes jobs (normalised to be in USD), and European Kubernetes jobs (normalised to be in EUR).

Salary ranges for American jobs in USD

The minimum salary offered in America, on average, stands at $139,269, while the maximum salary (on average) offered stands at $174,246.

The minimum average salary has increased by 13%, while the maximum average salary has increased by 12% over Q3 of 2021, which is a definite positive sign.

The highest salary range for Q3 2022 is between $200,000-250,000, which is also a whopping 25% increase over the highest salary range for Q3 2021.

Overall, it's good to see that the average minimum salaries are increasing at a reasonable rate so that not only the positions at the top but the entry-level positions also seem desirable.

Salary ranges for European jobs in Euros

The minimum salary offered in Europe, on average, stands at €89,729, while the maximum salary (on average) is at €114,337.

We have recently started analysing the salary ranges for Europe and America differently, so we can't compare these numbers with Q3 2021.

However, the minimum salary range has increased more than 7% over the last quarter, i.e., Q2 2022, which is encouraging.

Note: Europe is a vast, diverse continent with varied living costs, economies, and technological status. Thus, we can't be conclusive with these numbers, but we can get a decent representation of the state of salaries in Europe.

Like what you read?

Click here if you'd like to read our detailed job trends report for Q3 2022, which includes salary ranges, popular technologies, popular skills listed in job descriptions, and much more.

Which programming language(s) are important for a Kubernetes job?

vik-codes — Mon, 02 Jan 2023 11:28:07 +0000

74% of the job descriptions mentioned at least one programming language as their requirement!

Sounds logical, but what about specifics? Which language is the most popular among the mentions? And which aren't so popular?

Let's try to answer some of the above questions (and perhaps more) with Kube Careers job listings data for Q3 2022 (July to September).

Before you read further, know that:

At Kube Careers, we only include job listings with a clear salary range, which have Kubernetes as a requirement and not a nice to have/plus.
Our dataset is small, with 86 job listings from July to September 2022.

Are programming languages mentioned regularly in job descriptions?

Yes. It's almost a usual affair.

Of the 86 jobs we listed in Q3 2022, 71 mentioned at least one programming language in the job descriptions.

How often does a single job description mention more than one programming language?

Quite often.

In fact, of the 71 job descriptions (that cite programming languages), there were 206 instances of programming language mentions.

Meaning most of the job descriptions cite more than one programming language.

That's an average of almost 3 programming language mentions per job description!

Which are the popular programming languages mentioned in job descriptions?

Here are the takeaways from our Programming languages analysis:

Python is the undisputed programming language King. It has topped all of the quarterly charts we have published.
Go is a close second in demand, and it has also been reflected in the last four quarters that we analysed.
Other important programming languages are: Java, Shell, Javascript, Rust, and Ruby.

Did you like what you read?

Click here if you'd like to read our detailed job trends report for Q3 2022, which includes salary ranges, popular technologies, popular skills listed in job descriptions, and much more.

How much experience do you need for a Kubernetes job?

vik-codes — Mon, 19 Dec 2022 08:11:13 +0000

78% of the jobs that mention experience specified a senior-level experience!

How many years of experience equates to senior-level experience? What about junior roles? Do most of the companies mention experience requirements?

Let's try to answer some of the above questions (and perhaps more) with Kube Careers job listings data for Q3 2022 (July to September).

Before you read further, know that:

At Kube Careers, we only include job listings with a clear salary range and which have Kubernetes as a requirement and not a nice to have/plus.
Our dataset is small, with 86 job listings from July to September 2022.

How much experience do companies seek?

In this quarter, only 27% of the jobs mentioned an experience requirement such as senior, mid-level or junior.

Was this metric any different in Q3 2021?

Slightly.

In the same quarter last year, almost 40% of the job listings mentioned an explicit experience requirement.

Of the ones that mention experience, what is the polarity?

From the numbers, it's undeniable what the companies are looking for: Senior-level experience.

This quarter, of the job listings that mention experience, 78% mentioned senior-level (4-6 years) experience.

The mid-level (2-3 years) experience came in at 17%, and a distant third was the veteran level (7+ years) experience at 4%.

And sadly, there wasn't a single mention of a junior-level (0-1 years) experience in our listings for this quarter.

What was the trend in Q3 2021?

Wasn't very different.

Commonalities between the two quarters and takeaways for us:

Senior-level (4-6 years) experience is the most sought-after.
Junior-level roles are very scarce!
Veteran-level (7+ years) experience is scarce too! (I guess we all knew that)

Did you like what you read?

Click here if you'd like to read our detailed job trends report for Q3 2022, which includes salary ranges, popular technologies, popular skills listed in job descriptions, and much more.

Are certifications necessary for a Kubernetes job? If so, which ones are popular?

vik-codes — Wed, 14 Dec 2022 09:57:45 +0000

Only 9% of the jobs we listed in Q3 of 2022 mentioned a requirement for a Certification!

Was this the case for all quarters? Of the jobs that mentioned a certification requirement, which ones were popular?

Let's try to answer some of the above questions (and perhaps more) with Kube Careers job listings data for Q3 2022 (July to September).

Before you read further, know that:

At Kube Careers, we only include job listings with a clear salary range and which have Kubernetes as a requirement and not a nice to have/plus.
Our dataset is small, with 86 job listings from July to September 2022.

How many Job descriptions mentioned a need for a certification in Q3 2022?

Not many.

In Q3 2022, only a handful of 8 job descriptions (9% of the total jobs listed) mentioned a requirement for certification.

If this seems less, in Q3 2021, more than 94% of the jobs didn't convey a requirement for certification.

For better context, let's look at the stats for certification requirements over the last four quarters. Mind you; these numbers are normalised.

It can be seen that certifications aren't mentioned in most of the job descriptions.

Of the job descriptions that mention certifications, which ones are popular?

What's interesting to see is that 50% of the jobs that mention certifications didn't mention specifics but just the word certification.

These were primarily mentioned in the Nice to have / Plus category.

And when it comes to the specifics, AWS Certifications were mentioned in almost 38% (of the jobs that mention certification requirements) of the times, CKA at 25%, Linux foundation certifications at 25%, and CCNA at 12.5 % share.

In Q3 2021, AWS certifications were at the top of the certifications list with a 60% representation and were followed by GCP and Azure certifications, which weren't mentioned in this quarter.

What's the trend for Kubernetes certifications for Q3 2022?

Kubernetes certifications are still seen as a plus to have and not a requirement.

Only 4% of the jobs that we published this quarter mentioned a need for a Kubernetes certification.

Although this is too low to be meaningful, the number has grown almost twice, as it was at a measly 2% in Q3 of 2021.

Of the jobs that require Kubernetes certifications, half mentioned the Certified Kubernetes Administrator (CKA), while the other half mentioned the generic Linux Foundation certification (that could either be the KCNA, CKAD, CKA or CKS).

Note: Do remember that only 2 job listings each, published in the entire quarter, mentioned the CKA and Linux foundation certifications.

Since the sample size is small, we shouldn't derive any conclusions about the popularity of the Kubernetes certifications.

What about the Cloud provider certifications?

Of the 86 job listings published this quarter, there were only 3 mentions of a cloud provider certification.

All of these 3 mentions were for AWS certifications!

AWS certifications also lead the mentions in Q3 of 2021.

Did you like what you read?

Click here if you'd like to read our detailed job trends report for Q3 2022, which includes salary ranges, popular technologies, popular skills listed in job descriptions, and much more.

Remote Kubernetes jobs: How many are there? What do the trends suggest?

vik-codes — Wed, 07 Dec 2022 10:45:35 +0000

Remote jobs are the talk of the town, and why shouldn't they be? Everyone is looking for some sort of remoteness in their current or next job.

So what about remote Kubernetes jobs? Where is the trend headed?

To seek answers to the above questions (and perhaps more), we at Kube Careers took our job listing data for Q3 2022 (July to September) and analysed it to derive a few patterns.

Before you read further, know that:

At Kube Careers, we only include job listings with a clear salary range, and which have Kubernetes as a requirement and not a nice to have/plus.
Our dataset is small, with 86 job listings from July to September 2022.

Here are some of the interesting things we found.

For Q3 2022, only 7% of the jobs mentioned a Remote only working nature. Of the others, Europe had the most Kubernetes jobs at 40%, APAC (Asia Pacific) at 33%, and North America at 16%.

What about remote jobs? What's the current scenario like?

It's complicated, and how!

Remote work mentions stand at 34% of the total jobs published this quarter. This metric is down by almost half when compared to the Q3 2021 quarter.

It also must be noted that there exist different tiers of remote work.

There are remote-only jobs that allow employees to work from anywhere in the world without needing to visit any of the company offices. Then there are remote-hybrid jobs that require the employee to be present in the same country/state as the company office and occasional office visits.

This quarter, a total of 23 job descriptions mentioned a remote-hybrid working setup, while only 6 job descriptions asked for a remote-only setup.

Has the scenario changed over the quarters?

It has.

If we normalise and then compare the numbers for Q3 of 2021 vs 2022, we find interesting things.

What is apparent is the fall of remote work and the rise of office-only jobs between the two quarters.

What is the reason for the fall? There could be numerous reasons contributing to the tilt. Still, one of the reasons could be the lifting of the COVID restrictions and the industry inviting its employees to the offices (at least partially).

Like what you read?

Click here if you'd like to read our detailed job trends report for Q3 2022, which includes salary ranges, popular technologies and skills listed in job descriptions, and much more.

How much salary does a Kubernetes engineer get?

vik-codes — Wed, 30 Nov 2022 11:44:49 +0000

$250,000 is the maximum salary offered for a Kubernetes job in our dataset!

Then, what is the average salary for a Kubernetes Engineer? Are the metrics vastly different between the US and Europe?

Let's try to answer some of the above questions (and perhaps more) with Kube Careers job listings data for Q3 2022 (July to September).

Before you read further, know that:

At Kube Careers, we only include job listings with a clear salary range, and which have Kubernetes as a requirement and not a nice to have/plus.
Our dataset is small, with 86 job listings from July to September 2022.
We have divided the salary ranges into two categories: North American Kubernetes jobs (normalised to be in USD), and European Kubernetes jobs (normalised to be in EUR).

Salary ranges for American jobs in USD

The minimum salary offered in America, on average, stands at $139,269, while the maximum salary (on average) offered stands at $174,246.

The minimum average salary has increased by 13%, while the maximum average salary has increased by 12% over Q3 of 2021, which is a definite positive sign.

The highest salary range for Q3 2022 is between $200,000-250,000, which is also a whopping 25% increase over the highest salary range for Q3 2021.

Overall, it's good to see that the average minimum salaries are increasing at a reasonable rate so that not only the positions at the top but the entry-level positions also seem desirable.

Salary ranges for European jobs in Euros

The minimum salary offered in Europe, on average, stands at €89,729, while the maximum salary (on average) is at €114,337.

We have recently started analysing the salary ranges for Europe and America differently, so we can't compare these numbers with Q3 2021.

However, the minimum salary range has increased more than 7% over the last quarter, i.e., Q2 2022, which is encouraging.

Note: Europe is a vast, diverse continent with varied living costs, economies, and technological status. Thus, we can't be conclusive with these numbers, but we can get a decent representation of the state of salaries in Europe.

Like what you read?

Click here if you'd like to read our detailed job trends report for Q3 2022, which includes salary ranges, popular technologies, popular skills listed in job descriptions, and much more.

Where are most Kubernetes job offers located? Let's try to find out.

vik-codes — Tue, 29 Nov 2022 07:38:36 +0000

We at Kube Careers took our job listings data for Q3 2022 (July to September) and analysed it to derive a few patterns.

Before you read further, know that:

At Kube Careers, we only include job listings with a clear salary range that have Kubernetes as a requirement and not a nice to have/plus.
Our dataset is small, with 86 job listings from July to September 2022.

Here are some of the interesting things we found.

Europe had the most Kubernetes job offers for Q3 2022.

Out of the 86 job descriptions we published this quarter, 35 (more than 40%) were from Europe. Followed by 29 job descriptions from the Asia-Pacific region, 16 from North America, and only 6 job listings were Remote only.

What about the details? Which part of Europe was the most popular?

Western Europe.

If we normalise the numbers for all the jobs from Europe, Western Europe leads the way with 57% of the job listings, Central Europe is at 33%, and Southwestern Europe comes third with only 3% of the listings.

Did Europe lead the charts year-on-year? Or all four quarters?

Not really.

In fact, in Q3 of 2021, the North American region represented the most jobs with a 32% stake, while Europe was close with a 29% representation.

It also must be noted that the COVID-19 situation in 2021 differed in all countries; some lifted restrictions earlier, while some took longer. Thus we can't compare the Q3 numbers of 2021 with those of 2022 at face value.

Like what you read?

Click here if you'd like to read our detailed job trends report for Q3 2022, which includes salary ranges, popular technologies and skills listed in job descriptions, and much more.

Remote Kubernetes jobs: How many are there? What do the trends suggest?

vik-codes — Mon, 21 Nov 2022 10:45:56 +0000

We at Kube Careers took our job listing data for Q3 2022 (July to September) and analysed it to derive a few patterns.

Before you read further, know that:

At Kube Careers, we only include job listings with a clear salary range, and which have Kubernetes as a requirement and not a nice to have/plus.
Our dataset is small, with 86 job listings from July to September 2022.

Here are some of the interesting things we found.

For Q3 2022, only 7% of the jobs mentioned a Remote only working nature. Of the others, Europe had the most Kubernetes jobs at 40%, APAC (Asia Pacific) at 33%, and North America at 16%.

What about remote jobs? What's the current scenario like?

It's complicated, and how!

Remote work mentions stand at 34% of the total jobs published this quarter. This metric is down by almost half when compared to the Q3 2021 quarter.

It also must be noted that there exist different tiers of remote work.

This quarter, a total of 23 job descriptions mentioned a remote-hybrid working setup, while only 6 job descriptions asked for a remote-only setup.

Has the scenario changed over the quarters?

It has.

If we normalise and then compare the numbers for Q3 of 2021 vs 2022, we find interesting things.

What is apparent is the fall of remote work and the rise of office-only jobs between the two quarters.

Like what you read?

Click here if you'd like to read our detailed job trends report for Q3 2022, which includes salary ranges, popular technologies and skills listed in job descriptions, and much more.

Where are most Kubernetes job offers located? Let's try to find out.

vik-codes — Mon, 14 Nov 2022 10:52:26 +0000

We at Kube Careers took our job listings data for Q3 2022 (July to September) and analysed it to derive a few patterns.

Before you read further, know that:

At Kube Careers, we only include job listings with a clear salary range, and which have Kubernetes as a requirement and not a nice to have/plus.
Our dataset is small, with 86 job listings from July to September 2022.

Here are some of the interesting things we found.

Europe had the most Kubernetes job offers for Q3 2022.

What about the details? Which part of Europe was the most popular?

Western Europe.

Did Europe lead the charts year-on-year? Or all four quarters?

Not really.

In fact, in Q3 of 2021, the North American region represented the most jobs with a 32% stake, while Europe was close with a 29% representation.

It also must be noted that the COVID-19 situation in 2021 was different in all countries; some lifted restrictions earlier, while some took longer. Thus we can't compare the Q3 numbers of 2021 with those of 2022 at face value.

Like what you read?

Click here if you'd like to read our detailed job trends report for Q3 2022, which includes salary ranges, popular technologies and skills listed in job descriptions, and much more.

Should you use a few Large or many Small Kubernetes clusters for your application?

vik-codes — Wed, 25 Nov 2020 09:29:54 +0000

When you are designing your Kubernetes clusters, there are a few important decisions you need to make. One such decision that can have significant implications on your application is deciding the size of the cluster.

You can either use a few clusters that are larger in size or you can choose to use multiple clusters that are smaller in size.
So,

Which one should you choose?
What are the advantages of using one strategy over the other?
And are there other more efficient ways to architect your clusters?

Let’s find out.

In this article, we’ll look at:

What are the Pros and Cons of choosing a large cluster size, which inevitably means fewer clusters.
What are the Pros and Cons of choosing a smaller cluster size, and thus increasing the number of clusters required.
Two other cluster configurations that you must know of.

1. Using One Large Shared cluster

The first option is to run all your workloads in the same cluster:

With this approach, the cluster is used like a general-purpose infrastructure platform — whatever you need to run, you deploy it to your existing Kubernetes cluster.

Kubernetes provides namespaces to logically separate portions of a cluster from each other, and in the above case, you could use a separate namespace for each application instance.

Let's look at the pros and cons of this approach.

👍 Efficient resource usage

If you have only one Kubernetes cluster, you need to have only one copy of all the resources that are needed to run and manage a Kubernetes cluster.

This includes, for example, the master nodes — a Kubernetes cluster typically has 3 master nodes, and if you have only a single cluster, you need only 3 master nodes in total (compared to 30 master nodes if you have 10 Kubernetes clusters).

But this also includes other cluster-wide services, such as load balancers, Ingress controllers, authentication, logging, and monitoring.

If you have only a single cluster, you can reuse these services for all your workloads, and you don't need to have multiple copies of them for multiple clusters.

👍 Cheap

As a consequence of the above point, fewer clusters are usually cheaper, because the resource overhead with larger numbers of clusters costs money.

This is particularly true for the master nodes, which may cost you substantial amounts — be it on-premises or in the cloud.

Some managed Kubernetes services provide the Kubernetes control plane for free, such as Google Kubernetes Engine (GKE) or Azure Kubernetes Service (AKS) — in this cases, cost-efficiency is less of an issue.

However, there are also managed Kubernetes services that charge a fixed amount for running a Kubernetes cluster, such as Amazon Elastic Kubernetes Service (EKS).

👍 Efficient administration

Administrating a single cluster is easier than administrating many clusters.

This may include tasks like:

Upgrading the Kubernetes version
Setting up a CI/CD pipeline
Installing a CNI plugin
Setting up the user authentication system
Installing an admission controller

And many more...

If you have only a single cluster, you need to do all of this only once.

If you have many clusters, then you need to apply everything multiple times, which probably requires you to develop some automated processes and tools for being able to do this consistently.

Now, to the cons.

👎 Single point of failure

If you have only one cluster and if that cluster breaks, then all your workloads are down!

There are many ways that something can go wrong:

A Kubernetes upgrade produces unexpected side effects
An cluster-wide component (such as a CNI plugin) doesn't work as expected
An erroneous configuration is made to one of the cluster components
An outage occurs in the underlying infrastructure

A single incident like this can produce major damage across all your workloads if you have only a single shared cluster.

👎 No hard security isolation

If multiple apps run in the same Kubernetes cluster, this means that these apps share the hardware, network, and operating system on the nodes of the cluster.

Concretely, two containers of two different apps running on the same node are technically two processes running on the same hardware and operating system kernel.

Linux containers provide some form of isolation, but this isolation is not as strong as the one provided by, for example, virtual machines (VMs). Under the hood, a process in a container is still just a process running on the host's operating system.

This may be an issue from a security point of view — it theoretically allows unrelated apps to interact with each other in undesired ways (intentionally and unintentionally).

Furthermore, all the workloads in a Kubernetes cluster share certain cluster-wide services, such as DNS — this allows apps to discover the Services of other apps in the cluster.

All these may or may not be issues for you, depending on the security requirements for your applications.

Kubernetes provides various means to prevent security breaches, such as PodSecurityPolicies and NetworkPolicies — however, it requires experience to tweak these tools in exactly the right way, and they can't prevent every security breach either.

It's important to keep in mind that Kubernetes is designed for sharing, and not for isolation and security.

👎 No hard multi-tenancy

Given the many shared resources in a Kubernetes cluster, there are many ways that different apps can "step on each other's toes".

For example, an app may monopolise a certain shared resource, such as the CPU or memory, and thus starve other apps running on the same node.

Kubernetes provides various ways to control this behaviour, such as resource requests and limits, ResourceQuotas, and LimitRanges — however, again, it's not trivial to tweak these tools in exactly the right way, and they cannot prevent every unwanted side effect either.

👎 Many users

If you have only a single cluster, then many people in your organisation must have access to this cluster.

The more people have access to a system, the higher the risk that they break something.

Within the cluster, you can control who can do what with role-based access control (RBAC) — however, this still can't prevent that users break something within their area of authorisation.

👎 Clusters can't grow infinitely large

If you use a single cluster for all your workload, this cluster will probably be rather large (in terms of nodes and Pods).

However, Kubernetes clusters can't grow infinitely large.

There are some theoretical upper limits for how big a cluster can be, which are defined by Kubernetes at about 5000 nodes, 150,000 Pods, and 300,000 containers.

However, in practice, challenges may show up already with much smaller cluster sizes, such as 500 nodes.

The reason is that larger clusters put a higher strain on the Kubernetes control plane, which requires careful planning to keep the cluster functional and efficient.

This issue is also discussed in a related article of this blog named Architecting Kubernetes clusters — choosing a worker node size.

Let's look at the opposite approach — many small clusters.

2. Many Small Single-Use clusters

With this approach, you use a separate Kubernetes cluster for every deployment unit:

For this article, a deployment unit is an application instance — such as the dev version of a single app.

With this strategy, Kubernetes is used as a specialised application runtime for individual application instances.

Let's see what the pros and cons of this approach are.

👍 Reduced blast radius

If a cluster breaks, the damage is limited to only the workloads that run on this cluster — all the other workloads are unaffected.

👍 Isolation

The workloads running in the individual clusters don't share any resources, such as CPU, memory, the operating system, network, or other services.

This provides strong isolation between unrelated applications, which may be a big plus for the security of these applications.

👍 Few users

If every cluster runs only a small set of workloads, then fewer people need to have access to this cluster.

The fewer people have access to a cluster, the lower the risk that something breaks.

Let's look at the cons.

👎 Inefficient resource usage

As already mentioned, each Kubernetes cluster requires a set of management resources, such as the master nodes, control plane components, monitoring, and logging solutions.

If you have many small clusters, you have to sacrifice a higher percentage of the total resources for these management functions.

👎 Expensive

Inefficient resource usage automatically results in higher costs.

For example, if you have to run 30 master nodes instead of 3 for the same compute power, you will see this in your monthly bill.

👎 Complex administration

Administrating many Kubernetes clusters is more complex than administrating a single Kubernetes cluster.

For example, you need to set up authentication and authorisation for each cluster — if you want to upgrade the Kubernetes version, you need to do this many times too.

You probably need to develop some automated processes for being able to do this efficiently.

3. Other Ways to Architect your Clusters

Can you design your clusters based on factors other than size? Absolutely.

You can also architect your Kubernetes clusters

Based on the application i.e one cluster for each application instance.
Based on the environment i.e. one cluster for every environment viz prod, dev, and test.

To know about these configurations and to read a more detailed article (along with visual diagrams) on how to ideally architect your Kubernetes cluster, click here