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API-First Product Managers’ Popular API Tools and API Metrics

We interviewed the product managers at a number of the larger API-first companies that are based in San Francisco. The companies are all publicly traded, have TTM revenue of more than $100M and are in the fields of billing, security, communications and workflow automation.

The PMs were asked what were their favorite tools and what API metrics they cared most about. Where possible we identified tools and metrics that were common across all market segments, excluding the (many) edge cases that you’d expect when your customer base numbered in the 1,000s.

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The Best Way to Optimize Garbage Collection Is NOT By Tuning it

The best way to optimize garbage collection is NOT by tuning it.

When asked: "What would you do if your Java app experiences long GC pauses?" — most people would answer: "increase the heap size and/or tune the garbage collector." That works in many but not all situations. The heap may already be close to the total memory available. And GC tuning, beyond a few most obvious and efficient flags, often becomes a black art where each new change brings a smaller improvement. Worse, hyper-tuning GC makes it tightly coupled with your current heap size, number of CPUs, and workload patterns.

Need help choosing the right GC? Check out this post!

If any of these components changes in the future, the GC may suddenly perform much worse. And (what a surprise!) at that point, it may be really hard to remember why each of the flags in the combination like the one below is there, and what its effect was supposed to be: 

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Java: Chronicle Bytes, Kicking the Tires

I recently contributed to the open-source project “Chronicle Decentred” which is a high-performance decentralized ledger based on blockchain technology. For our binary access, we relied on a library called “Chronicle Bytes” which caught my attention. In this article, I will share some of the learnings I made while using the Bytes library.

What Is Bytes?

Bytes is a library that provides functionality similar to Java’s built-in ByteBuffer but obviously with some extensions. Both provide a basic abstraction of a buffer storing bytes with additional features over working with raw arrays of bytes. They are also both a VIEW of underlying bytes and can be backed by a raw array of bytes but also native memory (off-heap) or perhaps even a file.

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How to Tune Garbage Collection in Java

Garbage collection is the mechanism by which the JVM reclaims memory on behalf of the application when it's no longer needed. At a high level, it consists of finding objects that are no longer in use, freeing the memory associated with those objects, and occasionally compacting the heap to prevent memory fragmentation.

The garbage collector performs it's work using one or more threads. But in order to do the job of tracking down object references and moving objects around in memory, it needs to make sure that the application threads are not currently using those objects because if, for example, an application thread is using an object and then the memory location of the object changes due to GC, then bad and unpredictable things could happen. This is why garbage collectors must pause all application threads when performing certain tasks. These pauses are sometimes called Stop-The-World pauses, and the minimization of them is the primary concern of GC tuning, as they can have a huge impact on the performance of a Java application.