Minhchau Dang

Over the last few months, we at Liferay Support have encountered multiple customers who were having trouble with MEMORY_CLUSTERED scheduled jobs disappearing in their clustered environments. In trying to figure out why their clustered jobs were disappearing, we learned that the problem lay in a misunderstanding of the (undocumented) API that the customer was calling during their...

Part of content targeting involves scheduled jobs that periodically sweep through several tables in order to remove older data. From a modeling perspective, this is as if content targeting were to make the assumption that all of those older events have a weight of zero, and therefore it does not need to store them or load them for modeling purposes. If we wanted to evaluate whether...

Liferay is a large project, and many developers who are attempting to get their customizations to work with Liferay will often end up asking the question, "What version of module W should I use at compile time when I'm running on Liferay X.Y.Z?" To answer that question, Liferay has some instructions on how to find versions in its document, Configuring Dependencies. This blog entry...

A few months ago, in the Community Chat, one of our community members raised the question, "Why does Liferay prefer public pages over private pages?" For example, if you select the "Go to Site" option, if there are both private pages and public pages, Liferay sends you to the public pages. Unfortunately, I don't have an answer to that question. However, through some experimentation,...

When you compare a CE release with an EE release, you'll find that there are a few additional modules that are only available in EE releases. In Liferay terms, these are called "private" modules. They are private in the sense that their source code doesn't exist in any public GitHub repositories (only private ones, and usually inside of a folder named "private"), and their binaries...

At Liferay Symposium North America 2017, I had a discussion with a few of our customers on the hidden dangers of rolling back Liferay changes. There are multiple ongoing efforts to improve how we will handle the issue for the upcoming 7.1 release, such as LPS-76923. However, the 7.0 release is already affected, and DE-40 is fast approaching with another round of hidden dangers...

Welcome to the fourth entry in a series about what to keep in mind when building Liferay from source. First, to recap the previous entries in this series from last year: Getting Started with Building Liferay from Source: How to get a clone of the Liferay central repository and how to build Liferay from source. Also some tools that can help you setup your IDE (whether it's...

About one month ago, Liferay posted an announcement which talked about how to deploy the New Clustering Code for Liferay Portal Community. One of the first steps documented in this announcement was to clone the liferay-portal repository. As mentioned in a previous blog post, Liferay from Source, while this sounds like it shouldn't be a big deal, the large size of the...

Many months later, it's time to continue the series on Liferay from Source. For this segment, we'll start with the following question: why would you have wanted to build from source in the first place? This particular series entry assumes that maybe you want to fix a bug that affects you. Or maybe you feel like there is a feature that is missing from an existing module, but...

When a new intern onboards in the LAX office, their first step is to build Liferay from source. As a side-effect of that, usually the person that handles the intern onboarding will see that the reported ant all time is in hours rather than in minutes, and then start asking people, "Is it normal for it take this long to build Liferay for the first time?" It happens frequently...

Many years ago, Liferay's build validation was only getting started and so JSP pre-compilation related slowness wasn't a big deal (I think it was really only used during the distribution process). However, I wanted to make it faster for a client-related project (where we couldn't really do a server warm-up after deployment) and the research culminated in a blog entry summarizing my...

Once upon a time, a long time Liferay user decided to upgrade from an old version of Liferay (Liferay 6.0 GA2) to a new version of Liferay (Liferay 6.1 GA2). They performed this upgrade by shutting down Liferay 6.0 running on an old VM, starting Liferay 6.1 on a new VM, and then doing some DNS magic and some load balancer magic to switch to using the new VM after the upgrade completed....

A common problem that comes up is the need to change how documents are stored in the Document Library. For example, you may start out storing documents using Jackrabbit hooked to a database. However, as time goes on and you find yourself using more Liferay deployments, the number of database connections reserved for Jackrabbit alone gets dangerously close to the maximum number of...

Assuming that indexes have already been created against the fields you're querying against, the Dynamic Query API is a great way to create custom queries against Liferay objects without having to create custom finders and services. However, there are some "gotchas" that I've bumped into when using them, and I'm hoping that sharing these experiences will help someone out there if...

A "Gotcha!" situation came up today when I attempted to add a portlet developed in the plugins environment to the Control Panel (which is a new feature being developed for 5.2.0 that you can read about in Jorge's blog entry). In a nutshell, the Control Panel provides a centralized administrative interface for the entire portal. Unlike a standard layout where you 'manage pages' and...

There are times when I don't want to deal with the start up time of an integrated development environment and opt to use a fast-loading text editor instead. By making this trade-off, I wind up losing many of the nifty productivity features that are built into IDEs. One feature that can be taken for granted is the ability to run build targets with a double-click. By leaving the...

A feature I recently discovered was the ability to precompile all the JSPs in Liferay. The motivation behind this discovery was the need for sanity checking after making a small change to nearly a hundred JSPs across many different portlets. After using it on this particular problem, I wanted to know if it was possible to apply pre-compilation to a current ongoing project. In...

After reading through Jorge's blog post on the guidelines for Liferay contributions, and after following the link to the style guidelines on the Liferay wiki, I put together a configuration file which works with Eclipse's built-in code formatter to adjust the whitespace in your code so that is compatible with the stated Liferay guidelines. To use this configuration file, go to...

In Eclipse, everything is a plugin, including the IDE itself. So, if there's something which bothers you, all you need to do is replace the plugin with something which works in a way more consistent with your personal preferences, or if the plugin is open source, tweak the existing plugin to suit your needs. In my case, what bothered me was this: I don't have any reason to look at...

The nice thing about Liferay's drag and drop layout is that you (usually) don't have to remember any of the portlet ids. At least, until you do. If you skim through portal.properties, there's a set of properties all prefixed with default.user.layout which let you control this. However, it wants portlet ids, which Liferay doesn't readily give to you unless you dig through...