Category Archives: Liferay

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Liferay: In A Serverless and Microservices Era

In the era of microservices and serverless architecture, it is essential to evaluate if you need to build or buy a software. A decade ago, there was still a lot of push back against virtual machines (VMs) for production servers as they were considered the cause of performance issues. One easy solution at that time was to scale vertically by adding more vCPU and memory. That is not the case anymore. Organizations have not only adopted virtual machines, they are also moving towards containers and serverless. Applications don’t have to be built and deployed as a massive piece of software anymore.

Modular Monolith

As tech giants were sharpening their skills related to microservices, containers and serverless, most businesses were still struggling with modular monolithic applications. The reason they are called modular monolith is because the applications are written as modules but deployed as a monolith.

How can you tell if you are running a modular monolith? In order to figure that out, you should evaluate a few points. The first is that if you are upgrading the application, all the services will be down during that process. The second is that if you need to scale parts of your application, you have to scale the whole application server. One more indicator that you should pay attention to is that your application demands that you use certain programming languages and constructs.


As of now, many businesses have adopted or are considering their options with microservices and serverless architecture. They do have their own challenges when it comes to orchestration, monitoring and management. It is a different problem to deal with than with the traditional modular monolithic applications. Many tools make it easy to deal with microservices and serverless architecture. Several of them support a single CLI command to deploy the changes to any environment. In the serverless area, Amazon has its own AWS SAM CLI while Serverless, Inc has a serverless framework.

Cloud technologies adoption is becoming common in sectors such as government, healthcare and payment card industries.

What Are We Solving? Is There A Business Driver?

The goal is not to adopt technology for technology’s sake. The goal should be to solve the business need in a cost-effective and timely manner while meeting the demands of ever-changing requirements. We need agility and speed while simultaneously running a highly available application. It is important to keep our eyes on the goal. If a modular monolith solves your need really well, you may want to keep it. But let’s not allow the love for our legacy applications keep us away from innovating in business and technology.

How Do We Adopt?

Adoption takes time. It does not have to be an all or nothing approach. The best way to start is to explore the options for some parts of your application. If you have to parse documents, scan documents, analyze text or video etc., it may be better to externalize those to use the serverless offerings than to deploy and manage those services yourself. Traditionally applications will run command-line tools in the same application server to perform a whole bunch of tasks. The issue with this approach is that you are forced to scale the whole application layer when you have to scale these other processes that are competing for the same resources. A piecemeal approach may be a good starting point.

Is Liferay a Modular Monolith?

The above prelude is important for the following discussion. It is very likely that some of the readers may not even have heard about Liferay. Liferay is a Java based digital experience product that is primarily used to build intranets, customer portals, dashboards and public facing sites. As a product, Liferay has been around for more than 15 years. I have spent more than a decade with Liferay since I was introduced to it in early 2007.

Liferay has evolved over the past decade, yet it may fundamentally look the same when it comes to the deployment architecture. Let’s quickly go over a few points:

  • Search. A decade ago Liferay was using Lucene by default and supported Solr and other engines for search and index of documents. Now it uses elastic search by default while providing support for Solr.
  • Database. Liferay runs on a relational database, but you could develop applications (portlets) that use their own datasources. This remains the same since founding. Liferay did remove some of the supports for database sharding at application level.
  • Deployment Architecture.  In a high availability environment, Liferay instances are deployed as clusters with all the instances sharing the same database and data storage. Plugins that are developed can share the same database or connect to external services and databases. The major change for enterprise customers is that Liferay has recently started supporting the elastic licensing model where you could increase and decrease the number of instances while paying only for the additional time. In earlier versions the request for license was through a ticketing system. This has changed since the introduction and evolution of the Liferay Connected Services plugin.
  • Vertical Scaling. It is very common for Liferay installation to demand a more powerful application server configuration as a lot of heavy lifting happens at this layer. As an example, all the document parsing, conversion etc. happens in the application server and only the indexed document is pushed to the search engine. Also, all the content images that are being stored are rendered and cached at the application server layer. It is technically possible to externalize the cache with external caches.
  • Plugin Portlet Development. Portlets are generally written in Java or a few Java frameworks such as Spring MVC, JSF etc. In the latest version of Liferay, you can write portlets using Javascript frameworks such as React, Angular etc. Liferay supports bundling the JS application and deploying it to the server or running it as standalone JS application using Liferay remote services. It may be very convenient to bundle all the Javascript and deploy it to the application server. Deploying in such a manner means your application server is also the web server serving a lot of Javascript and CSS.
  • Services.  Liferay has supported exposing the remote services via SOAP, JSON APIs for a long time now.

Various aspects of Liferay have evolved over the past decade, yet it may fundamentally look the same at a high level. Liferay deployments resemble more of a modular monolithic application when it comes to scaling and upgrade. Is there a way to address some of the concerns?

Microsites As An Option

One way Liferay solves some of the scalability and availability needs is via microsite architecture. As an example, we can see how Liferay addresses their own needs. probably started as a single application server which later evolved into a cluster. Various needs for separation of content and access were provided through communities and memberships in a single application cluster. One disadvantage with this approach is that you have to scale the whole system vertically and horizontally to support the growing user base. Another major challenge with a single application cluster is that an upgrade will affect all types of users, sites, and communities.

One way to solve the scalability and upgradability challenge is to run separate clusters of various microsites such as,,,, etc. They all are tied together via SSO, but exist independent of each other. Typically, if your departments are big, they may want to manage and upgrade their own microsites. This would result in multiple versions of Liferay running within the same organization. This could result in the creation of the very silos that organizations are wanting to prevent.  As we all know, the organization’s culture will reflect in the way the teams talk to each other.

Build Or Buy

If you have the capability to develop greenfield applications, you should definitely look into your options that are not constrained by a platform. Do you need a blog or are you trying to build a site like Is your need for service easily fulfilled by an existing platform or do you have to customize the platform heavily?

It all depends on your business needs. If you are going to spend a significant amount of time and money to customize a product, it may be worth looking into building greenfield applications. Also you could take a hybrid approach where your application leverages functions as a service and other serverless features as needed. If your application has a need to export a lot of files as part of the regular use, it would be wise to run this zip process in an AWS Lambda function or as a separate microservice in an asynchronous way. Running such processes in an asynchronous way within the same application server may not be suitable for your use case. It is better to free up your application server resources so that it can better serve other requests.

What’s Next?

I wish I could cover everything in a single article. But that would become a modular monolithic article. I hope to cover more on this topic in future articles. If there is something that interests you specifically, please comment.

Published: May 22, 2019

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OSGi Adoption and Liferay

Category : Development , Liferay , OSGi

Where Do We Start ?

The goal of this article is to provide a perspective of how relevant the adoption of OSGi in Liferay is to a business executive. Is it really worth the effort to learn OSGi? There are many ways to develop an application. The are numerous frameworks in various languages such as Java, JavaScript, Ruby, PHP, Python etc. If you are a firm that does not deal with Java technologies, OSGi is not for you. If you have a Liferay implementation or are considering one, continue reading.

A Little Bit of History

OSGi has been around since 1999. Liferay has invested more than 5 years in the OSGi technology. The last two years probably were the most intense of all when Liferay started migrating most of the core portlets and services. Until recently most of the Liferay developer community could have easily ignored OSGi and continued to develop plugins the old way. The recommended approach going forward is to use the OSGi bundle, though a legacy deployment may still be supported.

Why OSGi in Liferay?

This is what Ray Augé had to say over the years. Ray has been leading this effort and is the key player behind this implementation.

“Liferay is a large, complex application which implements its own proprietary plugin mechanisms. While Liferay has managed well enough dealing with those characteristics over its history, it’s reached a point on several fronts where these are becoming a burden which seem to bleed into every aspect of Liferay: development, support, sales, marketing, etc.” – Ray Augé October 11, 2012

“Liferay is a complex beast with an intricate network of features, so many features in fact that they occasionally have such indistinct lines such as finding the where one feature ends and another begins can be difficult…The number of benefits is almost too great to list. However, one of the greatest advantages can’t be discussed enough: Modularity.” – Ray Augé Feb 4, 2013

The primary reason Liferay adopted OSGi is to easily manage Liferay as a platform. It is to make things easier for core Liferay developers. The key benefit is the modularity of the OSGi platform. OSGi allows the end user to easily add/remove/enhance services and offerings dynamically. The hardware industry has been following a very modular approach that allows us to add and remove components easily. There is a software piece to it as well which recognizes those dynamic components. Not all software is developed in such a way. Also it should not be the responsibility of the software but rather the platform which should enable such modularity. A capable platform ensures that we don’t have to reinvent the wheel on every piece of code. This is one of the promises of the OSGi platform. If you can tell what your piece of code does and someone can tell what their piece of code needs, the platform can match that up for you while you are still up and running. The OSGi platform does offer various other benefits that you can read up on.

How Relevant is OSGi in Current Architecture?

If you are a business that is using Liferay or looking to use Liferay, it is important that the team invest the time to learn the basic concepts of OSGi. OSGi has a very dedicated group of members who have given all that they have to keep it more relevant. It is very likely that Liferay will continue to use OSGi for at least another 5 years (estimate based on what it took to adopt the OSGi technology). So the time spent on learning OSGi while using Liferay is not a waste.

OSGi provides the concept of µservices within a single JVM. Liferay primarily relies on this feature. In order to stay relevant with the modern cloud architecture and distributed services, there are various OSGi initiatives such as Amdatu that embraces cloud computing.

You could entirely develop a full fledged application using OSGi. Just like you would with Spring Boot and Angular JS or any other JavaScript, PHP, Ruby, or Python frameworks. We could put it this way. Instead of saying, “How relevant is OSGi?,” we can say that OSGi is trying to be relevant by making use of all the new technologies. One thing that the community may lack is the funding and hype similar to the some of the platforms.

Is OSGi the Only Way to Build Modular Applications?

OSGi is probably the only best way to build modular and dynamic application using Java within a single Java Virtual Machine (JVM). The key thing to note here is the single JVM. The way software architecture is evolving indicates that the applications are built in a more tolerant way so that you could remove a server and add it back in a matter a few seconds to a minute or two.

The concept of changing class or implementation within a JVM is not relevant if you are already a shop that knows how to build and deploy your application to an elastic cloud. At that level you are elastically scaling virtual machines in a more tolerant way.

Spring Boot along with PaaS providers such as Pivotal Cloud Foundry and Heroku are an alternative for those developing using Java. OSGi Enroute is trying to provide similar capabilities where you can bundle up your app as a jar file and run it anywhere. Along with the pipelines offered by some of the PaaS providers, nowadays it is as simple as committing the code and the rest is taken care for you.

If you are familiar with some of the javascript frameworks, they do a whole lot of things without having to worry about the class loading issues. In fact, Liferay themselves are working on a similar PaaS called WeDeploy. As of now WeDeploy is in Alpha. Liferay’s interest in providing such as platform clearly indicates the effort to stay relevant and diversify the risks.

It all depends on what you are looking for. If you are a platform or a tool builder, it makes a lot of sense to use frameworks like OSGi. If you are a already running tolerant applications in the cloud, the modularity offered by OSGi is something that definitely does not concern you.

A look at OSGi Adoption

Eclipse IDE is one of the most successful adopters of OSGi that a Java developer comes in contact with on a regular basis. Spring tried to support OSGi but later dropped Spring DM due to the complexity. Glassfish abopted OSGi but later the project was discontinued by Oracle. Liferay has taken the major step of adoption and successfully launched the major version. There is still a lot of work to do within Liferay, but Liferay does provide good support for those developing against it. OSGi has moved further on with OSGi enroute and various cloud computing offerings. Liferay’s primary focus in OSGi adoption is the capabilities within a single JVM. In my opinion, by doing so Liferay has committed itself and has become a major player in OSGi for web applications. A continued success and user adoption within the Liferay community could very well provide the oxygen that OSGi needs in the web application platform.

Liferay has done the toughest part of OSGi adoption in its platform. For the end users Liferay provides various utilities to interact easily with the OSGi service trackers etc. It is sufficient to just understand the basics of OSGi to develop plugins for the Liferay platform. Developers could deep dive into OSGi as needed while working with Liferay. This is in a way similar to how developers using Liferay interact with services without having to master Spring or Hibernate.

Bndtools and various others OSGi frameworks such Apache Felix , Amdatu etc., help it make easy for the developers. There is still a lot of activity primarily supported by the OSGi Alliance members which keeps the community strong even after 17 years.


There are many ways to develop rich applications. If you are a shop that has invested in Liferay, then getting up to speed with OSGi will make your job easier. If you are not a shop that is invested in Liferay or Java, you could live without ever knowing what OSGi is. The one thing that OSGi lacks is the hype and support from the extended Java community. As Liferay is trying to be more than a portal, as a business you need to think beyond any programming language or a platform and evaluate what is best for you. Technology changes so fast. Instead of adopting technology for the sake of it, you need to adopt it to solve your and your customers’ need.