HikariCP Connection Pooling for Spring Boot for 1.x version

Introduction

In this article, we will learn the steps to configure Hikari with Spring Boot. We will cover steps to configure Hikari for both Spring Boot 1 and Spring Boot 2 application.

Hikari is a JDBC DataSource implementation that provides a connection pooling mechanism. Compared to other implementations, it promises to be lightweight, reliable, high-performance JDBC connection pool and better performing.

It is much faster, lightweight and have better performance as compare to other connection pool API. Because of all these compelling reasons, HikariCP is now the default pool implementation in Spring Boot 2. In this article, we will have a closer look to configure Hikari with Spring Boot.

Database Connection Pooling

Spring Boot uses Tomcat pooling tomcat-jdbc by default, and follow this sequence to find the connection pool in general:

Tomcat pool -->> HikariCP -->>  Commons DBCP -->>  Commons DBCP2

Step 1 : Configuring Hikari with Spring Boot 1

Spring Boot 1 use the tomcat JDBC connection pool. Spring Boot automatically add dependency to tomcat-jdbc if you use the spring-boot-starter-jdbc or spring-boot-starter-data-jpa ‘starters’ in your application. To configure Hikari in our application, we have the following two options

Add the HikariCP maven dependency.
Remove the Tomcat JDBC connection pool and let Spring Boot look for HikariCP in the classpath.

Step 2: Adding Maven Dependency

The first step for Hikari and Spring Boot configuration is to add Hikari dependency in the pom.xml file:

<dependency>
        <groupId>com.zaxxer</groupId>
        <artifactId>HikariCP</artifactId>
        <version>3.3.1</version>
 </dependency>

Note: In Spring Boot 2, Hikari is the default DataSource implementation. However, to use the latest version, we need to add the Hikari dependency in the pom.xml explicitly. The dependency to Hikari is now automatically included in spring-boot-starter-data-jpa and spring-boot-starter-jdbc. The discovery algorithm that automatically determines a DataSource implementation now prefers Hikari over TomcatJDBC (see the reference manual). So, we have nothing to do if we want to use Hikari in an application based on Spring Boot 2.x, unless we want to use its latest version.

Step 3: Remove Tomcat JDBC Dependency

Once we have the Hikari dependency in the class path, the next step is to remove the Tomcat JDBC dependency. This step will force Spring Boot to look for the Hikari data source in the class path. We can use the Maven standard tag for this.

<!-- exclude tomcat jdbc connection pool, use HikariCP -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
    <exclusions>
        <exclusion>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-jdbc</artifactId>
        </exclusion>
    </exclusions>
</dependency>

Step 4: HikariCP Configurations

One of Hikari’s advantages over other DataSource implementations is the fact that it offers a lot of configuration parameters. Below are the basic Hikari Data Source properties to include for fine tuning the spring boot application and some explanation in detail can be found h er e

#maximum number of milliseconds that a client will wait for a connection
spring.datasource.hikari.connection-timeout = 20000 

#minimum number of idle connections maintained by HikariCP in a connection pool
spring.datasource.hikari.minimum-idle= 10 

#maximum pool size
spring.datasource.hikari.maximum-pool-size= 10 

#maximum idle time for connection
spring.datasource.hikari.idle-timeout=10000 

# maximum lifetime in milliseconds of a connection in the pool after it is closed.
spring.datasource.hikari.max-lifetime= 1000

#default auto-commit behavior. 
spring.datasource.hikari.auto-commit =true

Step 5: Hikari Log Output

Once we start our application, monitor the console log, you may notice an identical output:

2020-11-08 13:39:57.896  INFO 10136 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Bean with name 'dataSource' has been autodetected for JMX exposure
2020-11-08 13:39:57.900  INFO 10136 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Located MBean 'dataSource': registering with JMX server as MBean [com.zaxxer.hikari:name=dataSource,type=HikariDataSource]
2020-11-08 13:39:57.946  INFO 10136 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)

Connection Polling datasource : HikariDataSource (HikariPool-1)
2020-11-08 13:39:57.949  INFO 10136 --- [           main] com.santhosh.hikari.SpringBootConfig     : Started SpringBootConfig in 2.581 seconds (JVM running for 2.904)
2020-10-08 13:40:10.925  INFO 10136 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring FrameworkServlet 'dispatcherServlet'
2020-11-08 13:40:10.925  INFO 10136 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization started
2020-11-08 13:40:10.940  INFO 10136 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization completed in 14 ms
2020-11-08 13:40:10.960  WARN 10136 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : HikariPool-1 - maxLifetime is less than 30000ms, setting to default 1800000ms.
2020-11-08 13:40:10.961  INFO 10136 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Starting...
2020-11-08 13:40:11.070  INFO 10136 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Start completed.

Conclusion

In this article, We learned how to configure Hiraki Connection pool with spring boot application version1.x. I would like to repeat “HirakiCP” is preferable for the concurrent database application. Sample Code can be found here