What is Logging in Java

Logging is the process of recording the application insights as a readable log file. It is an important requirement for any application since it helps identify issues and fix bugs in applications while improving performance.

Logging frameworks are similar to the daily diary of a web application. They keep track of activities, errors, and sensitive details of internal processes. Therefore, picking the most secure and reliable option is crucial when selecting a logging framework.

In this article, I will discuss the best logging frameworks optimized for Java, focusing on their characteristics to help you choose the best.

1. Log4J and Log4J 2 - A well-known logging solution for Java

Log4J(https://logging.apache.org/log4j/2.x/) is a Java-based logging framework. It is a part of Apache Logging Services. It was also the most popular and widely used Java logging solution until the exposure of its Log4Shell vulnerability last year.

Log4J 2 is the actively maintained version of Log4J, and it has some amazing features for developers.

• API separation for forward compatibility - The isolated Log4J API from the implementation is a significant feature. It guarantees the forward compatibility of web applications' code. And also, it creates loosely coupled logging framework integration.
• Automatic reloading of configuration - During the application runtime, Log4J2 supports reloading the framework if there are any configuration changes without affecting the application and its previous logs.
• Asynchronous logging for better performance - Many developers unintentionally make their web applications slow by not focusing on the performance of the logging framework. However, Log4J2 has asynchronous logging, which has significantly large throughput. especially when the program executes in a multi-threaded environment.

However, async logging is not enabled by default. Hence, it is better to check all the pros and cons beforehand through the official Apache documentation if you wish to enable async logging.

As a free and open-source Java logging framework, Log4J 2 is good for web applications that do not deal with sensitive data. On the other hand, there can be security and reliability loopholes due to the openness and majority of users of the framework. So you must constantly check for security updates and patches.

2. Logback - A free and open source modularized logging framework

Logback(https://logback.qos.ch/) is another non-commercial Java logging framework. It labels itself as a successor to the previously discussed Log4j framework.

Logback has three main modules:

• logback-core - The base module which is essential for operating the other two modules.
• logback-classic - This module implements SLF4J API allowing developers to easily integrate with other logging frameworks if required.
• logback-access - This allows communication with Java Servlet containers (e.g., Tomcat and Jetty) so that its framework can provide HTTP access logs.

In addition, Logback has a simple architectural design with some exciting features:

• Automatic log archive cleanup: You can configure Logback to delete the archives using the maxHistoryproperty of TimeBasedRollingPolicy or SizeAndTimeBasedFNATP.
• Automatic log archive compression: Logback can automatically compress archived logs in an asynchronous manner. So there will be no significant performance impact on your application during the compression process as well.
• Easy to implement: This library has a well-modularized design and a more familiar implementation of the famous Log4J framework. It is developer-friendly and quick to set up.

Suppose you are a Java developer looking for a free logging framework but do not want to risk using Log4J or Log4J2. In that case, I recommend you to have a look at Logback.

3. Tinylog - A lightweight logging framework

Tinylog(https://tinylog.org/v2/) is a lightweight logging framework for Java and Andriod applications. It is an open-source framework and can be used with any JVM language like Kotlin and Scala.

Although it is relatively new and lightweight, it brings some unique features:

• Static logger class: This implementation allows you to use the logger directly instead of creating logger instances everywhere you need to create logs.
• Fast output of log records: The benchmarks prove that the tinylog is well optimized for writing log outputs to files.
• Lightweight: Most significant feature of tinylog is the small library size of approx. 178KB only.

If you are looking for a small-size free and open-source logging framework, Tinylog is one of the best options you have.

4. Solarwinds Loggly - A commercial logging toolkit with HTTP/HTTPS log management

Using text-based logging frameworks comes in for practical difficulties like analyzing logs, time-consuming log search, and third-party integrations.

Loggly by Solarwinds(https://www.solarwinds.com/loggly) resolves these issues by providing a log management toolkit and a Java extension that can record logs. It is a commercial product and offers 4 different packages, including a free trial.

• Lite - Free version
• Standard - Starting at 79 USD per month. This package is annually billed and suitable for small-scale businesses.
• Pro - This package, starting at 159 USD per month, is annually billed and suitable for growing businesses.
• Enterprise -This package, which starts at 279 USD per month, is annually billed. It includes all the features.

Loggly has user-friendly log management options like:

• Centralized Log Monitoring Tool
• Automated Log Summaries
• Smart Querying of Logs with Filters

However if you are running on a tight budget, using Loggly can be tricky due to its expensive pricing model.

5. Sidekick - An alternative to all logging solutions

As has been discussed, there are many Java logging frameworks with different features. But, there is a major limitation with all of them. They do not allow you to add logs into the built-in dependencies of your web application.

Sidekick(https://www.runsidekick.com) resolves this issue by allowing developers to put logpoints in dependencies. Apart from the simplicity, the below items explain why Sidekick is an alternative to the other logging solutions:

• Dynamic logging - This feature allows developers to add and remove logs on demand. You can add logs to your running applications without stopping or redeploying it. This feature not only solves the issues of traditional logging but also does not bring any overhead or security issues.
• Ingest collected logs anywhere - Sidekick makes it easier to add new logs to multiple services without rebooting & redeploying and then you can start sending your logs to anywhere you wish. Here are some recipes telling about how you can send your logs to your Loki or Elastic instances.
• Integrations with IDEs - This feature is one of my favorites. It allows developers to debug applications within the IDE itself with the Sidekick plugin. At the moment, this integration works well with IntelliJ IDEA, VSCode, and PyCharm.

The below process shows how Sidekick works in a nutshell.

If you are looking for a secure and reliable Java logging framework, Sidekick is the go-to option. As you can use this for free, I highly recommend trying it out by yourself. You can get started from the official documentation below.

Official Sidekick Documentation:

https://docs.runsidekick.com/

Final Thoughts

Selecting a reliable and secure logging framework for Java applications is more complicated than it sounds. Especially with the identified Log4J vulnerability last year, many developers and product owners are highly picky about logging frameworks.

However, in this article, I have presented 5 latest Java logging solutions with their features, including my thoughts about each of them. Based on my hands-on experiences, the following comparison summarizes each of the above-discussed logging solutions.

I hope this article will help you explore the aforementioned frameworks further and pick the best one for your needs. Thank you for reading!