Ben Chuanlong Du's Blog

It is never too late to learn.

Exception Error and Critical

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

https://stackoverflow.com/questions/2031163/when-to-use-the-different-log-levels

Java

An Error is a subclass of Throwable that indicates serious problems that a reasonable application should not try to catch. Most such errors are …

Tips on Graph Database

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

vesoft-inc/nebula

A high performance distributed Graph Database

[neo4j/neo4j]0https://github.com/neo4j/neo4j0

Neo4j is the world’s leading Graph Database. It is a high performance graph store with …

Use Scala With Picocli

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

It is easy to make mistakes due to type of parameters when use picocli in Scala. It is suggested that you

  1. Have all parameters prepared before using them.

  2. manually specify types …

Tips on Spark MLlib

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

  1. Spark MLlib RDD-based API supports stratified sampling but the DataFrame-based API hasn't implemented it yet as of Spark 2.4.3.

sample keys (not rows) with equal probability

References

https://spark …