Logback VS JDK

Java -> Logback, Log4j2, JDK (Java Util Logging), Slf4j, e.t.c.

This is a GitHub link to my demo app. It’s simple Spring Boot web app used to debugging various stuff. There are many ways to configure JSON logging in Spring Boot. I decided to use Logback because it is easy to configure and one of the most widely used logging library in the Java Community. To enable JSON logging we need to add below dependencies.

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

> Then apache decides to put new people on log4j, do a backward incompatible v2 design that nevertheless is worse than slf4j. Why?

slf4j itself isn't a logging framework. It's a facade to logging frameworks.

Simple Logging Facade for Java ( https://www.slf4j.org )

It needs a logging framework behind it - log4j, log4j2, logback, commons, JUL.

The question is "why do log4j2?"

Logback went from the log4j1.x path ( https://logback.qos.ch )

Log4j2 has a lot of features that weren't present when the project started ( https://en.wikipedia.org/wiki/Log4j#Apache_Log4j_2 ).

There is a licensing difference between Logback (LGPL) and Log4jx (Apache Commons).

Also, I'd like you to pay attention to the log consumer. You see, when the E2E scenario fails, it's not always obvious why. Sometimes to understand the source of the problem you have to dig into containers' logs. Thankfully the log consumer allows us to forward a container's logs to any SLF4J logger instance. In this project, containers' logs are forwarded to regular text files (you can find the Logback configuration in the repository). Though it's much better to transfer logs to external logging facility (e.g. Kibana).

This shows that the MariaDB JDBC driver uses Logback as a logging framework. Although Logback is not affected by Log4Shell, it has a related vulnerability (of much lesser severity, no need to panic) fixed in version 1.2.8 and 1.3.0-alpha11. I checked the version used by the connector and found that it used 1.3.0-alpha10. Even though Logback is included as a test dependency in the MariaDB driver, I sent a pull request on GitHub to update it. I encourage you to do the same in any open-source project you find and that includes a vulnerable dependency.

Dependencing on the project, changing the logger might range from easy peasy to a multi-week task. I'm ready to bet that in many (most?) cases, it'd actually be quite easy, so let's explore how to do it, using Logback as the target (there aren't that many alternatives actually).

behold logback doing a bunch of JNDI fixes: https://github.com/qos-ch/logback/commit/c43bd30e1092b89bb91f5fb6a28310956b3bac61

Completely gutted from the OpenJDK, last I checked. See here for the culprit PR: https://github.com/openjdk/jdk/pull/18688

> Yes, they're changing one aspect of signal handler use to work around this problem. They're not stopping the use of signal handlers in general. Hotspot continues to use signals for efficiency in general. See https://github.com/openjdk/jdk/blob/9059727df135dc90311bd476...

This whole thread is about SIGSEGV, and specifically their SIGSEGV handling. However, catching normal signals is not about efficiency.

Some of their exception handling is still odd: There is no reason for a program that receives SIGILL to ever attempt continuing. But others is fine, like catching SIGFPE to just forward an exception to the calling code.

(Sure, you could construct an argument to say that this is for efficiency if you considered the alternative to be implementing floating point in software so that all exceptions exist in user-space, but hardware floating point is the norm and such alternative would be wholly unreasonable.)

> The wonderful thing about choosing not to care about facts is having whatever opinions you want.

I appreciate the irony of you making such statement, proudly thinking that your opinion equals fact, and therefore any other opinion is not.

This discussion is nothing but subjective opinion vs. subjective opinion. Facts are (hopefully, as I can only speak for myself) inputs to both our opinions, but no opinion about "good" or "bad", "nasty" or not can ever be objective. Objective code quality does not exist.

I remember talking to Brendan about the PreserveFramePointer patch during my first months at Netflix in 2015. As of JDK 21, unfortunately it is no longer a general purpose solution for the JVM, because it prevents a fast path being taken for stack thawing for virtual threads: https://github.com/openjdk/jdk/blob/d32ce65781c1d7815a69ceac...

Map doesn't implement the Collection interface.

https://github.com/openjdk/jdk/blob/master/src/java.base/sha...

C++ lets you write anything you can imagine, and the language features and standard library often facilitate that. The committee espouses the view that they want to provide many "zero [runtime] cost," abstractions. Anybody can contribute to the language, although the committee process is often slow and can be political, each release the surface area and capability of the language gets larger.

I believe Hazard Pointers are slated for C++26, and these will add a form "free later, but not quite garbage collection" to the language. There was a talk this year about using hazard pointers to implement a much faster std::shared_ptr.

It's a language with incredible depth because so many different paradigms have been implemented in it, but also has many pitfalls for new and old users because there are many different ways of solving the same problem.

I feel that in C++, more than any other language, you need to know the actual implementation under the hood to use it effectively. This means knowing not just what the language specifies, but can occaissionally require knowing what GCC or Clang generate on your particular hardware.

Many garbage collected languages are written in or have parts of their implementations in C++. See JS (https://github.com/v8/v8)and Java GC (https://github.com/openjdk/jdk/tree/36de19d4622e38b6c00644b0...)

I am not an expert on Java (or C++), so if someone knows better or can add more please correct me.