Flaneur2020

Recently while studying 3fs, I learned that it uses CRAQ (Chain Replication with Apportioned Queries) as its replication algorithm.

Recently, I’ve been delving into the architecture of production-grade inference engines.

Recently I followed this tutorial to implement a basic Q-Learning reinforcement learning algorithm for Flappy Bird, which surprisingly worked quite well, reaching over 10,000 points.

Diffusion Model is undoubtedly the SOTA in image generation right now.

In the last blog, I went over the intuition behind VAE, which was pretty straightforward.

Recently, I wanted to learn about Stable Diffusion, but it seemed like I needed to first understand what VAE (Variational Autoencoder) is all about.

I didn’t pay much attention to Spilling before because an article about Presto mentioned that Facebook didn’t enable it in production.

Recently, I wanted to learn about the postgres ecosystem.

We learned earlier that data in ClickHouse doesn’t support updates, only insertions.

First off, I thought MergeTree was just like leveldb’s LSM, but after digging into ClickHouse’s MergeTree, I couldn’t find any of the familiar stuff, and I was confused for a while.

My impression about Percolator was that it could enable transactional capabilities on a regular distributed KV store, but the overhead of the 2PC + Raft process was significant.

RocksDB supports two concurrency control modes: PessimisticTransactionDB and OptimisticTransactionDB.

Badger is an open-source LSM Tree KV engine developed by dgraph.

All write operations in LevelDB, including Put and Delete are unified and recorded in the WriteBatch structure, then passed through the Write function as the only entry point for write operations: Status DB::Put(const WriteOptions& opt, const Slice& key,…

ZGC is a new garbage collector introduced in jdk11, promising pause times of no more than 10ms, and these pauses are independent of heap size, supporting heaps up to terabytes.

Prometheus is the most popular monitoring solution today.

Kafka’s data reliability totally depends on replication instead of a single-machine fsync.

Graceful Shutdown is supposed to be a solved problem, especially for HTTP transports, where the details had already been handled properly by the application servers.

The term “version” in LevelDB is a bit weird.

Container networking has changed a bit compared to the past virtualization of virtual machine networks.

Recently, I went through the mruby GC and basically figured out the logic.