Home > Articles

  • Print
  • + Share This
This chapter is from the book

This chapter is from the book

Creating a New Application with Microservices

Before we begin, let me say that I have not seen many real-world scenarios of building a microservices-based application from scratch. Typically, an application is already in place, and most applications I have worked on are more of a transition to a microservices architecture from a monolithic architecture. In these cases, the intention of architects and developers has always been to reuse some of the existing implementation. As skills become readily available in the market and some successful implementations are published, we will see more examples of building microservices-based applications from scratch, so it is certainly worthwhile to discuss this scenario.

Let’s say you have all the requirements figured out and ready to go into the architecture design of the application you are going to build. There are many common best practices you need to think about as you get started, which are covered in the following sections.

Organization Readiness

As we discussed in Chapter 2, “Switching to Microservices,” the first question you have to ask yourself is whether your organization is ready to transition to microservices. That means the various departments of your organization now need to think differently about building and releasing software in the following ways:

  • Team structure. The monolithic application team (if one exists) needs to be broken down into several small high-performance teams aware of or trained in microservices best practices. As you saw in Figure 4.3, the new system will consist of a set of independent services, each responsible for offering a specific service. This is one key advantage of the microservices paradigm—it reduces the communication overheads, including those multiple nonstop meetings. Teams should be organized by business problems or areas they are trying to address. The communication then becomes about the timing and set of standards/ protocols to follow so that these microservices can work with each other as one platform.

  • Agility. Each team must be prepared to function independently of others. They should be the size of a standard scrum team; otherwise, communication will become an issue again. Execution is the key, and each team should be able to address the changing business needs.

  • Tools and training. One of the key needs is the organization’s readiness to invest in new tools and people training. The existing tools and processes, in most cases, would need to be retired and new ones picked up. This will require a large capital investment as well as investment in hiring people with new skills and retraining existing staff members. In the long term, if the decision is right to get on microservices, organizations will see savings and recoup the investment.

Services-Based Approach

Unlike with monolithic applications, with microservices you need to take a self-sustained services-based approach. Think of your application as a bunch of loosely coupled services that communicate with each other to provide complete application functionality. Each service must be thought of as an independent, self-contained service with its own lifecycle that can be developed and maintained by independent teams. These teams may select from a variety of technologies, including languages or databases that best suit their services’ needs. For example, for an e-commerce site, the team would write a completely independent service, such as a shopping cart microservice, with an in-memory database, and another one, such as an ordering microservice, with a relational database. A real-world application may employ microservices for basic functions such as authentication, account, user registration, and notification with the business logic encapsulated in an API gateway that calls these microservices based on the client and external requests.

Just a reminder: a microservice may be a small service implemented by a single developer or a complex service requiring a few developers. With microservices, the size does not matter; it all depends on one function that a service has to provide.

Other aspects that must be considered at this point are scaling, performance, and security. Scaling needs can be different and provided on an as-needed basis at each microservice level. Security should be thought of at all levels, including data at rest, interprocess communication, data at motion, and so on.

Interprocess (Service-to-Service) Communication

We discussed the topic of interprocess communication in depth in Chapter 3, “Interprocess Communication.” Key aspects that must be thought of are security and communication protocol. Asynchronous communication is the way to go, as it keeps all requests on track and does not hold resources for extended periods of time.

Using a message bus such as RabbitMQ may prove to be beneficial for this kind of communication. It is simple and can scale to hundreds of thousands of messages per second. To prevent the messaging system from becoming a single point of failure if it goes down, the messaging bus must be properly designed for high availability. Other options include ActiveMQ, which is another lightweight messaging platform.

Security is key at this stage. In addition to selecting the right communication protocol, industry standard tools such as AppDynamics may be used to monitor and benchmark the interprocess communication. Any anomalies must be reported automatically to the security team.

When there are thousands of microservices, it does become complex to handle everything. We already discussed how to address such issues through discovery services and API gateways in Chapter 3.

Technology Selection

The biggest advantage of transitioning to microservices is that it enables choices. Each team can independently select the language, technology, database, and so on, that is the best fit for the given microservice. Usually in a monolithic approach, the team does not have this flexibility, so make sure you do not overlook and miss the opportunity.

Even if a team is handling multiple microservices, each microservice must be looked at as a self-contained service, and it needs be analyzed. Scalability, deployment, build time, integrations and plugins operability, and so on, must be kept in mind when choosing the technology for each microservice. For microservices with lighter data but faster access, an in-memory database may be most suitable, whereas others may share the same relational or NoSQL databases.


Implementation is the critical phase; this is where all the training and best practices knowledge comes in handy. Some of the critical aspects to keep in mind include the following:

  • Independency. Each microservice should be highly autonomous with its own lifecycle and treated as such. It needs to be developed and maintained without any dependencies on other microservices.

  • Source control. A proper version control system must be put at place, and each microservice must follow the standards. Standardizing on a repository is also helpful, as it ensures all the teams use the same source control. It helps in various aspects, such as code review, providing easy access to all the code in one place. In the long term, it makes sense to have all the services on the same source control.

  • Environments. All different environments, such as dev, test, stage, and production, must be properly secured and automated. The automation here includes the build process—that way the code can be integrated as required, mostly on a daily basis. There are several tools available, and Jenkins is widely used. Jenkins is an open source tool that helps automate the software build and release process including continuous integration and continuous delivery.

  • Failsafe. Things can go wrong, and software failure is inevitable. Handling failures of downstream services must be addressed within the microservice development. Failure of other services must be graceful to the extent that the failure should be invisible to the end user. This includes managing service response times (timeouts), handling API changes for downstream services, and limiting the number of auto-retry.

  • Reuse. With microservices, don’t be shy about reusing the code by using copy and paste, but do it within limits. This may cause some code duplication, but it’s better than using shared code that may end up coupling services. In microservices, we want decoupling, not tight coupling. For example, you will write code to consume the output response from a service. You can copy this code every time you call the same service from any client. Another way to reuse code is by creating common libraries. Multiple clients can use the same library, but then each client should be responsible for maintaining its libraries. It can sometimes become challenging when you create too many libraries and each client is maintaining a different version. In that case, you may have to include multiple versions of same library, and the build process may become difficult due to backward compatibility and similar concerns. Depending on your needs, you can go either way as long as you can control the number of libraries and versions by clients and put a tight process around them. This will certainly save you from lot of code duplication.

  • Tagging. Given the sheer number of microservices, debugging a problem may become difficult, so you need to do some kind of instrumentation at this stage. One of the best practices is to tag each request with a unique request ID and log each one of them. This unique ID will identify the originating request and should be passed by each service to any downstream requests. When you see issues, you can clearly track back through logs and identify the problematic service. This solution will be most effective if you establish a centralized logging system. All the services should log in all the messages to this shared system in a standardized format so that teams can replay the events as required all from one place, from infrastructure to application. A shared library for centralized logging is worth looking into, as we previously discussed. There are several log management and aggregation tools out there in the market, such as ELK (Elasticsearch, Logstash, Kibana) and Splunk, that are ideal.


Automation is the key during deployment. Without it, success with a microservices paradigm would be almost impossible. As we discussed, there may be hundreds to thousands of microservices, and for the agile delivery, automation is a must.

Think of deploying thousands of microservices and maintaining them. What happens when one of the microservices goes down? How do you know which machine has enough resources to run your microservices? It becomes very complicated to manage this without automation in place. Various tools, such as Kubernetes and Docker Swarm, can be used to automate the deployment process. Given the importance of this topic, a whole chapter, Chapter 9, “Container Orchestration,” is dedicated to deployment.


The operations part of the process needs to be automated as well. Again, we are talking about hundreds to thousands of microservices—organizational capabilities need to mature enough to handle this level of complexity. You’ll need a support system, including the following:

  • Monitoring. From infrastructure to application APIs to last-mile performance, everything should be monitored, and automatic alerts with proper thresholds should be put in place. Consider building live dashboards with data and alerts that pop up during issues.

  • On-demand scalability. With microservices, scalability is the simplest task. Provision another instance of your microservice you want to scale and just put it behind the existing load balancer and you are all set. But in a scaled environment, this also needs to be automated. As we will discuss later, it is a matter of setting up an integer value to tell the number of instances you want to run for a particular microservice.

  • API exposure. In most cases, you will want to expose the APIs externally for external users to consume. This is best done by using an edge server, which can handle all the external requests. It can utilize the API gateway and discovery service to do its job, and you can use one edge server per device type (e.g., mobile, browser) or use case. An open source application created by Netflix, called Zuul, can be utilized for this function and beyond.

  • Circuit breaker. Sending a request to a failed service is pointless. Hence, a circuit breaker can be built that tracks the success and failure of every request made to every service. In the case of multiple failures, all the requests to that particular service should be blocked (break the circuit) for a set time. After the set time expires, another attempt should be made, and so on. Once the response is successful, reconnect the circuit. This should be done at the service instance level. Netflix’s Hystrix provides an open source circuit-breaker implementation.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020