As we all know, microservices is the new god in the tech industry. Yes, we always have old gods and new gods. Surely microservices have been accepted by the many of the companies, without even understanding how the business will be aligned with it.
Let’s not discuss what is microservices, but we should surely discuss what not to do if you don’t want fire on your ass.Today will try to discuss few of the shortcoming which I have felt after I have[NOT]proudly redesigned the system from monolith to microservices.
- Domain is Important, But not the same Domain For every one
We all know the domain is very important for every application.Let’s make our code closer to the real-world entity. But does the sharing of domain make sense?Often people debate about how come we can have a different domain for the same entity.For example, let’s have a Flight domain, Flight will be flight, no matter it is in search service or booking service. Flight can have different attributes in both the context.And you will never replicate these attributes.Never create a single jar of domains to share it among different services. If you have to just kill other your services.
- How services are talking to each other
Often developers create many microservices, they all the talking to each other in exactly the same way, it has been doing if they were a monolith.Direct interaction with microservice can be dangerous, can create a bottleneck for a process. Try to design a system in such a way that one service should not be waiting because of the action from another service. Utilize the power of asynchronous request using the messaging queue or any other design.Blocking request can be a hassle. Don’t just create distributed monolith
- Complete System Design is Important, Microservice alone cannot do anything
When you are designing the microservice, you are not designing it for fun. It will eventually be plugged in the system to complete the bigger task. So know your system design. All the constraints against which your service will be run should be known. Development of microservice can be done in the isolation, but the birth of any microservice should always be an outcome of whole system design.
- Be Ready before you start, DevOps if your key
You can ask yourself, why the concept of microservice in a boom these days. This is because now we have such a capability which can handle such a massive complexity. So DevOps is too important. If your DevOps is not ready to support the proper microservice architecture, never ever think to go towards microservices.You can never create a home if your basic structure is not setup first.
- Don’t try to clean the mess of other
Your service is not designed to clean the work of any other service. If any service is not doing its task completely, it’s not your duty to do it, ask that service to do it. There was a very simple example which I want to share, I was consuming one of the services whose owner was sitting beside me. Few of the attributes were missing from the result of that service, so I asked the owner to provide me the missing data, but the conversation finally went in a disappointed way. The owner asks me to fill the data by myself as getting those data points were very difficult for that service. And eventually, my service ends up doing a task which was not in the context of its boundary.
- Learn from others, but don’t ever replicate their mistakes
We often share code, when a business is trying to solve the same kind of problems they often end up using the same type of approach/code for the different problem statement. There may be a chance good chance you will solve a problem very quickly by just simple copy paste, but you never know the constraints under which that code was written. With the power of that code, your are also copying the weakness of it. Learn from others, but never accept its solution for granted.
- Let the services to micro, not the knowledge pool
In the last point, I have discussed how dangerous the code replication. But This point doesn’t say we should blindly learn from other services. What I want to point out here is share the knowledge of other services, either the technical findings or the business constraints. Because in the end every micro service a broken piece of a giant puzzle
- Let the code be agile, not just the process
Often people make the process agile but forget that if your code is not agile you cannot achieve agility. Make your services loosely coupled.Each service should be independent, and there should be minimum effort even if we have to rewrite the entire service.
- Monolith business with microservices is as bad as Monolith
“This is the way things are done here”. One of the very old statements from old timers or from the business guys. But this will never help a project. If your system is going toward microservice, itis very important your business should also reflect the same, or honor it.At the end business thinking will be reflected on your system.
- Common decision for every service is a hazard
Since every service is designed for its own purpose, a single and common solution can be dangerous for the lifecycle of services. It is very similar to the problem of selling shoes in the two very different geographic area.
- Frameworks as awesome, but maybe not awesome for every service
Frameworks are awesome, it will hide the complexity from the developers, and magically do a lot of the stuff. But in-house framework can be a risk to the ongoing project. If you add the in-house framework to each and every service of your, you are binding the bugs associated with the framework to every service. It even often delays the release cycles.
- Event Sourcing, I will be another Netflix
Don’t just use any of the modern design just for the sake of using it. Understand the business requirement first. Analyse the scope of your problem in terms of the traffic and availability of the system. What I have seen people often used event sourcing even to solve the simple problem stating the reason “We will be next Netflix”.
- Different shops, with the same warehouse
Lest assume we have 5 different shops, but all the shops using the resource from a common pool. We have 10 resources in the pool and 5 services.Ideally 2 resources for each service, but if one of the services goes greedy/faulty and consumed 8 resources.Certainly there is a resource crunch for other services. even though other services are related to service one, but it got affected because of it. Same conditions are very common whenever we are using the same Database for the different microservices.Even in normal conditions, we know that database will be the choking point in the high traffic situation. Should implement the seperate database for separate services.
- Pool of PolyGlot can be a pool of death
This point is more in the concern of the company.But not just company is affected, even the developers are affected, as it often increases the effort in maintenance. Choosing entirely different tech stack for each service can increase the project cost, as you need the tech specialist for each tech. Sharing of tech knowledge will be limited. And often the company cannot afford many tech specialists for tech, so eventually, it can let to the dependencies on few of the forks.
- Anonymous service is a ghost
One of the common design we can see these days is, if few of the task which is not a good fit any of the existing services, developer eventually put all these tasks in the anonymous service, where no one knows what is happing. Service with no boundary, no exact reason. I call these kinds of services as a ghost. Ghost services are dangerous, and they are often the result of poor design or to support existing business for the time being. But remember you can never get rid of the ghost, and they will haunt you from time to time.
All these are the points which are the concern for me, maybe true or not true for you. These can be avoided or can be tackled with different designs, but do consider them before it late for your service.