Chen Riang's Blog

Live everyday like it's your last

Understanding Elasticsearch Read/Write Model

Yesterday, while googling about the es_rejected_execution_exception error, I learn about the how an index is being written into Elasticsearch(ES). Thus, I think is best to write an article about t...

Posted by ChenRiang on June 20, 2021

Elasticsearch Bulk Index Request Rejection

Yesterday, I obtained the es_rejected_execution_exception error response when trying to perform bulk indexing request. 1 2 3 4 5 6 7 8 9 10 11 12 13 { "error": { "root_cause": [ ...

Posted by ChenRiang on June 19, 2021

Elasticsearch Synonym + Ngram = Problem

I believe Synonym Token Filter and NGram Token Filter are the two frequent filters that most people normally used in Elasticsearch(ES). In this article, I’m going to talk about some of the annoying...

Posted by ChenRiang on June 18, 2021

JMeter 101

Performance testing is a test technique that focuses on how the system behaves and performs. In real life, many software development teams tense to ignore this and only carry it out when it is requ...

Posted by ChenRiang on June 13, 2021

Spring Data Redis

Redis is a famous in-memory data store that often used as database, cache, and message broker. Spring framework come out with Spring Data Redis that provide a very easy configuration and access to ...

Posted by ChenRiang on June 7, 2021

Remove multi-line line end whitespace

Today, I bump into a problem when fixing some failed unit test. Long story short, I need to compare returned multiline string from class A and for some reason it randomly added a whitespace in eac...

Posted by ChenRiang on June 4, 2021

Jackson Ignore Null and Empty value

Today, I bump into a problem when fixing a unit test when asserting Jackson XML deserialized string. Problem Jackson XML deserialize null and empty value. POJO 1 2 3 4 5 6 7 8 9 10 11 12 13 14 ...

Posted by ChenRiang on June 4, 2021

Spring Repository Transnationality

Recently, I met the following exception when trying to create my custom delete method on repository. org.springframework.dao.InvalidDataAccessApiUsageException: No EntityManager with actual tra...

Posted by ChenRiang on May 30, 2021

Tensorflow Data Validation

In Google’s whitepaper (“Hidden Technical Debt in Machine Learning Systems”) highlighted that in a real production system, machine learning(ML) actually is just the tips of iceberg. To create a eff...

Posted by ChenRiang on May 29, 2021

Jackson XML Parsing

Recently, I have a task to parse XML document and found this awesome library called Jackson. Although it is famous in handling JSON parsing, their XML parsing implementation is pretty good and cle...

Posted by ChenRiang on May 15, 2021