Author: Prasanna Raghavendra

  • DevOps Debates: Monoliths or Microservices

    DevOps Debates: Monoliths or Microservices

    From the time software came into existence, application software has been booming to leverage the benefit of the computing paradigm. During this cycle, it has transformed decades of design and architectural thinking, and has crossed all aspects of application development and management needs, be it configurability, reusability, maintainability, scalability or security (a good list is of these “ilities” is here).

    While many have been addressed, one “ility” that has turned a lot of eyes and attention in the last few years is deployability. More than that, it is the ability to do so continuously. This requirement has changed the thinking of building software for two main reasons: (a) Businesses have started asking to release software faster than ever, even in verticals unheard of before; and (b) Cloud and infrastructure as code has made faster deployment a easier possibility. When you look at application design with deployability in mind, given the need to be agile, what you end up getting is a microservice.

    Most applications of old style addressed most “ilities” in an architecture but did not consider “continuous deployability” as a core need as well. I call these monolith from a deployment perspective. They are tightly coupled, and for any small change a complete build of the application was necessary.

    Now the question is, Should you really look at microservice as a silver bullet to deploy all software? Should you consider that as the de facto standard to deliver any application functionality? Will applications cease to exist the way we know? Here are my thoughts. As usual, feel free to add yours or write to me personally, as some of you do as well.

    Applications as monoliths will stay as they are

    1. Monoliths have evolved over generations of design and architecture tests and stood the test of time. The focus on modular development is, in fact, a way of creating modules, which are built with separation of concerns in mind.
    2. Monoliths were built to run for a long time. It had addressed some of the “ilities” well before they became considerations.
    3. Applications will remain easier to debug, as most of the debuggable areas are in developer’s hand, instead of having to work with a team.
    4. Applications will perform better, as they can share data in memory; they don’t have to do out-of-process calls to get one task executed.
    5. Applications will be more secure, as they will be a black box from an end user perspective or even a hacker perspective, with little coming out from the system.

    Microservices will be a monolith-killer all the way

    1. Deploy, deploy and deploy to correct your problems away. Fail fast and fix faster is the mantra that you can practice.
    2. It helps bundle two-pizza teams owning microservices and hence embrace better ownership and faster response.
    3. The overall architecture to deliver an end-to-end use-case may become complex, but each piece of the jigsaw puzzle can be handled faster.
    4. In the faster-moving world, business wants to try a concept rather thinking through all the “ilities” ahead of time, and progressively make everything better. Microservices helps abstract all complexities much better.
    5. Microservices will help developers think out of box from day one, while helping business deliver smaller chunks, without having to make the system a “big ball of mud.”

    At the end of the day, irrespective of the approaches, the key is to ensure the applications are managed well, changes are refactored well, the code that is written is readable and maintainable, and significant test assets are created to regress the entire system quickly. So whether it is a large system or microservices, you are able to make any necessary changes quickly and can deploy fast.

    While microservices surely will help this new faster-deployment thinking, I—and I am sure you all—have also seen large monolithic systems that are making delivery at an astounding pace.

    Thoughts?

  • DevOps Debates: Image-Driven or Build-Driven Delivery

    DevOps Debates: Image-Driven or Build-Driven Delivery

    In the last 12 months, Docker and the containerization paradigm has challenged the foundation of some of the software delivery principles. People are resorting to things that were unheard of 18 months back and are now using them to successfully deliver software faster and cheaper. One such thing is the debate around build-driven delivery vs image-driven delivery.

    Over the last few decades, software has been packaged and built by a build system and tagged with a number; testers aligned their testing to the tag as the entity being tested and promoted them until it reached production. The build number was one of the most important tag for anyone to communicate about the status of the software in the delivery pipeline.

    For some time now—primarily due to Docker—several teams are moved to a methodology in which the image defines the version of a software. Every change in application program and deployment program will together create a new image, which is tagged and used as the version of the software to be launched for downstream use and finally into production.

    The debate then is, which option is better?

    Let me take a shot at this, and will invite your thoughts on this as well.

    For builds-driven delivery:

    1. Builds helps software to be tagged irrespective of the target hardware and other deployment options. It bundles all dependencies to ensure the software works when deployed to the expectation. This provides the development team a good hand-off point to move on to the next set of work, or sprint.
    2. Builds are much smaller in size, as the build bundles only necessary software needed by the application; hence, keeping them aligned with every change will not be a costly storage proposition.
    3. Versioning of artifacts and bundling them at run time has given tools such as maven to build and link dynamically, collecting all dependencies from the cloud. This makes it easier to keep a thin build and further reduce the redundant data to be kept in each build.
    4. Build repositories have matured over the years to provide a very easy way to version and mark dependencies so deployment tools can find new versions and automatically upgrade environments as needed.

    For images-driven delivery:

    1. Images takes the concept of build to the next level and ensures the variability in target hardware and deployment options are removed completely. It bundles the application as given in the build or built as part of the image creation and pushes the image as a build.
    2. Docker registries have started to compare and contrast themselves into a build repository by providing similar options for end users.
    3. The images-driven option provides a much better benefit of standardizing all your environments, removing the question,”It works in my environment; does it in yours?” If it works in the container in a developer’s laptop, it should work in production as well—everything is same, except for the size and number of resources.
    4. Images are much larger than builds, given that it has to now carry the system software and the application base software within the image. This option was unheard of earlier, but with container images coming down to megabytes, this is not such a big issue today. With layering sizes can be reduced much further as you start peeling the onion of dependencies. Take a look at this nice article by Brian on this topic.

    I guess the choice depends on where your application is in its life cycle, the questions teams should really ask are:

    a) Do we need to change too much to pick an option for an incremental benefit?

    b) Do I have the issue of environmental differences?

    c) Can I merge these options to get a hybrid solution going?

    But for me the larger question is, Which option would you choose, if you were starting from scratch tomorrow? I would love to hear your thoughts.

    Finally, irrespective of which way you lean, image-driven solutions is one of the best way to bring DevOps culture to a team: If the image works, the team has won; it doesn’t matter whether it was ops code or dev code!

     

  • DevOps Debates: The Benefits of Tool Standardization

    DevOps Debates: The Benefits of Tool Standardization

    As my role demands, I work with various large enterprises looking at implementing DevOps to improve their software delivery cycle times. I have seen many strategies being adopted by them—some working, and some not working yet. I have pulled together some of the more common ones so we could debate them to see if these indeed are worth looking at. With that, I kick off my “DevOps Debates” series.

    The first one on the list is a popular one: If you want to create anything in large volumes, you need to standardize the manufacturing process. That makes it easier to understand what is going on, control the quality and later change processes if necessary. This is happening in a similar fashion for software delivery processes and in DevOps.

    Standardization techniques adopted in many large enterprises often include standardizing the toolset used by software developers. To do this, companies create a centralized tools group or software center of excellence (COE), which tries to find the best tool for the company and then implements and manages it for the teams. The intent is to streamline DevOps implementation across the board by having a common DevOps platform that hooks into these standardized tools, delivering common practices and reporting.

    I have seen and heard a lot of emotional discussion on this. Here is my go, for and against the topic. Your thoughts are most welcome!

    For Standardization:

    1. Centralized teams can take a global view of how things are being used across the organization. As such, they are better placed to push best practices where necessary and learn best practices when they need to. This helps in picking the right set of tools.
    2. Centralized teams can create a generic DevOps platform that can serve the needs of the organization across all groups. They then can help bring a DevOps focus and manage budget centrally.
    3. Standardization helps organizations streamline license cost to optimize software use.
    4. Small teams focusing on DevOps may not have the muscle power or the budget to create a momentum needed for adoption. Running a central body for such implementations helps.

    Against Standardization:

    1. DevOps is still evolving—standardizing may be detrimental to the innovation process that needs to happen within the tools and needs ecosystem.
    2. Developers from various teams driving a DevOps implementation will be more successful; they can solve the issues “on the ground” rather than a central team trying to understand and then implementing a solution.
    3. Some tools are good for a specific use and may not be used companywide. Standardization may reduce productivity.
    4. Developers are the users of the tools—they need the freedom to choose what they want to use. Standardizing won’t allow them that freedom, which may upset them and, in turn, lead to decreased productivity.

    Would that then mean,

    1. While it is a good idea in the long run to standardize, is now too early to do it?
    2. Would it be better to create a DevOps platform that can provide multiple tools support while standardizing the organization’s needs?

    Thoughts?