Ensar Basri Kahveci | The Blog Pros

June 18, 2019

Distributed Locks Are Dead, Long Live Distributed Locks

"Distributed locks aren't real," "Anyone who's trying to sell you a distributed lock is selling you sawdust and lies." This may sound rather bleak, but it doesn't say that locking, itself, is impossible in a distributed system: It's just that some like to remind us that all of the system's components must participate in the protocol. This blog post is the story of how we implemented a distributed locking protocol that gives your components a straightforward way of joining in.

The coordinating component of the protocol is an object that extends the semantics of java.util.concurrent.locks.Lock. We call it FencedLock, following the naming used in Martin Kleppmann's 2016 post "How to Do Distributed Locking."

June 12, 2019

Testing the CP Subsystem with Jepsen

At Hazelcast we take reliability very seriously. With the new CP Subsystem module, Hazelcast has become the first and only IMDG that offers a linearizable distributed implementation of the Java concurrency primitives backed by the Raft consensus algorithm. In addition to well-grounded designs and proven algorithms, reliability also requires a substantial amount of testing. We have been working hard to ensure the validity of our consistency claims.

In this blog post, I'll try to demystify the linearizability semantics of the CP Subsystem and explore our Jepsen test suite. This blog post is the fourth installment of my CP Subsystem blog post series.

Packages for Store Routines in MariaDB 11.4
No categories
MariaDB 11.4 introduced many advanced features. One that grabbed my attention is the general support of packages for stored routines. Although this was previously available by activating the Oracle compatibility mode, now the feature is available gener... […]
Maintain Chat History in Generative AI Apps With Valkey
No categories
A while back I wrote up a blog post on how to use Redis as a chat history component with LangChain. Since LangChain already had Redis chat history available as a component, it was quite convenient to write a client application. But, that's not the same... […]
Knowledge Graph Enlightenment, AI, and RAG
No categories
In the previous edition of the YotG newsletter, the wave of Generative AI hype was probably at its all-time high. Today, while Generative AI is still talked about and trialed, the hype is subsiding. Skepticism is settling in, and for good reason. Repor... […]
Building an Effective Zero Trust Security Strategy for End-To-End Cyber Risk Management
No categories
You've probably heard a lot about zero-trust security lately, and for good reason. As we move more of our applications and data to the cloud, the traditional castle-and-moat approach to security just doesn't cut it anymore. This makes me come... […]
Phased Approach to Data Warehouse Modernization
No categories
A modernized database will help you focus on building innovative solutions rather than investing your time and effort in managing these legacy systems. Based on the scale of your existing data warehouse processes or jobs, it can be an enormous task to ... […]