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brettwooldridge/hikaricp

Analysis updated 2026-06-21

★ 21,106JavaAudience · developerComplexity · 2/5Setup · easy

TLDR

A fast, lightweight JDBC connection pool for Java applications, it manages a pool of pre-opened database connections so your app doesn't pay the cost of creating a fresh connection on every database query.

Mindmap

mindmap
  root((hikaricp))
    What it does
      JDBC connection pool
      Reuses DB connections
      Fast and lightweight
    Tech Stack
      Java Maven
      JDBC
    Use Cases
      Spring Boot DB pooling
      Replace legacy pools
      High-traffic APIs
    Audience
      Java developers
      Backend engineers
    Configuration
      Pool size
      Timeout settings
      Auto-commit
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What do people build with it?

USE CASE 1

Add HikariCP as a Maven dependency to a Spring Boot backend to efficiently manage connections to PostgreSQL or MySQL.

USE CASE 2

Replace a slower connection pool like commons-dbcp2 or Tomcat's pool in a Java web service to reduce database connection overhead.

USE CASE 3

Configure HikariCP's pool size, connection timeout, and idle timeout for a high-traffic API to prevent connection exhaustion under load.

USE CASE 4

Use HikariCP's legacy Java 6 artifact to add fast connection pooling to an existing Java application without upgrading the runtime.

What is it built with?

JavaMavenJDBC

How does it compare?

brettwooldridge/hikaricpcarguo/gsyvideoplayerapache/shardingsphere
Stars21,10621,43220,715
LanguageJavaJavaJava
Setup difficultyeasymoderatehard
Complexity2/53/55/5
Audiencedeveloperdeveloperops devops

Figures from each repo's GitHub metadata at analysis time.

How do you get it running?

Difficulty · easy Time to first run · 5min

In plain English

HikariCP is a JDBC connection pool for Java applications. A connection pool is a behind-the-scenes pool of pre-opened database connections that an application can borrow from and return to, so it does not pay the cost of opening a fresh connection every time it talks to the database. HikariCP's pitch is that it is fast, small, and reliable, the README calls it a zero-overhead, production-ready pool weighing in at roughly 90 kilobytes, and quotes Edsger Dijkstra's line that simplicity is a prerequisite for reliability. In practice you add HikariCP as a Maven dependency in your Java project, point it at your database, and let it manage connections for you. The library exposes a fairly small set of configuration knobs: an essential property to identify the JDBC DataSource class or a JDBC URL, plus username and password, and then optional settings like autoCommit, connectionTimeout (how long a caller will wait for a free connection), idleTimeout (how long an unused connection can sit before being closed), maximum pool size, and so on. HikariCP ships with sensible defaults, so for many applications you barely need to configure it. The author has also done extensive performance work using the OpenJDK JMH microbenchmark framework, and the README includes JMH benchmark results comparing HikariCP against other pools such as commons-dbcp2, Tomcat's pool, Vibur, and c3p0 on Java 8. There is also a separate Java 6 artifact for legacy applications, which is in maintenance mode. Someone would use HikariCP as the connection pool inside a Java service that talks to a relational database, web backends, batch jobs, or any application where the cost and reliability of database connections matter.

Copy-paste prompts

Prompt 1
I want to replace my current JDBC setup in a Spring Boot app with HikariCP. Show me the Maven dependency to add, the minimal configuration for PostgreSQL, and how to tune the maximum pool size and connection timeout.
Prompt 2
My Java service is getting connection timeout errors under load. Using HikariCP, walk me through how to set connectionTimeout, maximumPoolSize, and idleTimeout to handle traffic spikes without exhausting the pool.
Prompt 3
Show me how to configure HikariCP programmatically in Java using HikariConfig and HikariDataSource, pointing it at a MySQL database, without using Spring.
Prompt 4
How does HikariCP compare to commons-dbcp2 in terms of performance and configuration, and what are the main settings I need to tune to go production-ready?

Frequently asked questions

What is hikaricp?

A fast, lightweight JDBC connection pool for Java applications, it manages a pool of pre-opened database connections so your app doesn't pay the cost of creating a fresh connection on every database query.

What language is hikaricp written in?

Mainly Java. The stack also includes Java, Maven, JDBC.

How hard is hikaricp to set up?

Setup difficulty is rated easy, with roughly 5min to a first successful run.

Who is hikaricp for?

Mainly developer.

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