Java Web Development (JSP/Servlets) Services

Migrating from a monolithic Java 8 system to a reactive microservice architecture on Kubernetes allowed us to dramatically improve performance and maintainability. In this article, I’ll share our journey, key Spring Cloud Kubernetes features we adopted, the challenges we faced during development, and the lessons we learned along the way.

Business Logic

We have a data processing logic that streams information into S3 storage using Kafka, Spark Streaming, and Iceberg. Initially, we encountered multiple challenges, such as file optimization issues and Spark’s unpredictable memory behavior. After addressing these issues, we achieved significant cost savings. Once the insert service was completed, we needed to select an appropriate search engine service. We chose Trino as it fulfilled the needs of our data science department. We also serve customers who perform operations on our S3 data, which can result in high system load. Before this modernization, our platform ran on an old monolithic architecture built with Java 8, which created several performance and maintenance challenges.

Kilo is an open-source project for creating and consuming RESTful and REST-like web services in Java. Among other things, it includes the Collections and Optionals classes, which are designed to help simplify code that depends on collection types and optional values, respectively. Both are discussed in more detail below.

Collections

Kilo’s Collections class provides a set of static utility methods for declaratively instantiating list, map, and set values:

Recently, I wrote the Introduction to Spring Data Elasticsearch 5.5 article about Spring Data Elasticsearch usage as a NoSQL database. The article covered just the setup of the unsecured Elasticsearch. However, we need to be able to connect to the secured Elasticsearch as well. Let's follow the previous article and see the needed changes to run and connect to the secured Elasticsearch.

In This Article, You Will Learn

• How to create a secure Elasticsearch
• How to connect to the secured Elasticsearch with Spring Data Elasticsearch
• How to change the password in Elasticsearch

Set Up Secured Elasticsearch

The setup for creating a secure Elasticsearch is pretty similar to the steps in the already-mentioned article. The technologies used in this article, compliant with the compatibility matrix, are:

While running a synthetic benchmark that pre-warmed the cache, we noticed an abnormal performance impact on Ampere CPUs. Digging deeper, we found that there were many more page faults happening with Ampere CPUs when compared to x86 CPUs. We isolated the issue to the use of certain atomic instructions like ldadd, which load a register, add a value to it, and store data in a register in a single instruction. This triggered two “page faults” under certain conditions, even though this is logically an all-or-nothing operation, which is guaranteed to be completed in one step.

In this article, we will summarize how to qualify this kind of problem, how memory management in Linux works in general, explain how an atomic Arm64 instruction can generate multiple page faults, and show how to avoid performance slowdowns related to this behavior.

In a previous article, we explored how to implement full-text search in PostgreSQL using Hibernate 6 and the posjsonhelper library. We built queries with to_tsvector, to_tsquery, and their simpler wrappers for the plainto_tsquery, phraseto_tsquery, and websearch_to_tsquery functions.

This time, we’ll extend that foundation and explore how to rank search results based on their relevance using PostgreSQL’s built-in ranking functions like ts_rank and ts_rank_cd.