Fred Feng
A passionate Java programmer. Notes on the open-source projects I build: distributed schedulers, crawlers, time series databases, and the Java libraries around them.
Projects
Latest writing
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SqlJam: Move Tables Across Databases with Schema, Data and All
Tables, indexes, constraints, sequences, partitions and rows, in one go. 1. Overview SqlJam: Move tables across databases. Schema, data and all. A Java 17 + JavaFX desktop tool that copies tables between MySQL, Postgr...
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Vortex TSDB: Live Metrics in One Command — HTTP Writes, Minute Aggregates, Sliding Windows, Replicated in Memory
1. Overview Lightweight. Replicated. Real-time. Vortex TSDB is a distributed time series database for live metrics. Push numbers over HTTP; read per-minute aggregates, instant values and tumbling or sliding windows. E...
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Cronflower: Turn a Spring Boot app into a distributed cron cluster easily
cronflower is an open-source, distributed cron scheduler for the JVM with a web console. It forms its own cluster and needs no external database, broker, or coordinator. This post is the usage tour of its distributed ...
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cronflower: run a DAG workflow across your cluster
cronflower is an open-source, distributed scheduler for the JVM with a web console. cronflow is its optional DAG add-on: declare the steps and how they depend on each other as a graph, and the same cluster runs the gr...
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Greenfinger 2.0: one url in, a searchable archive out
Crawl the whole site. Keep every page, every picture, every version. Search it by words, by meaning, or by describing a picture you remember. Add a node and it goes faster. Kill one and it keeps going. Nothing to inst...
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EasyJPA: Criteria API Power in Three Lines, Not Thirty
1. Overview EasyJPA — Criteria API power. Three lines, not thirty. EasyJPA is a Spring Boot starter that puts a fluent, lambda-driven API over the JPA Criteria API. Every condition is a method reference, every join ha...
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Stop hand-writing cron: build and parse it in Java
Cronsmith is a Java library that builds, parses and runs cron through a fluent, object-oriented API instead of hand-typed strings. You describe when in plain method calls and get back a cron expression, the exact date...
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Chaconne Framework
a lightweight distributed task scheduling framework Chaconne is a lightweight distributed task scheduling framework based on SpringBoot framework. It not only has high availability and scalability but also is easy to ...
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Doodler
Doodler is a comprehensive scaffolding framework built on Spring Boot and Spring Cloud, designed to streamline the development of Spring-based projects. With its modular architecture, Doodler provides 37 highly focuse...
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Devtools Series
A Java basic tool library, which provides a large amounts of useful and cool utility methods and APIs to optimize your code, making your code more efficient and elegant. Install <dependency> <groupId>com.g...
devtools