Configure HikariCP with Spring Boot JPA Hibernate and PostgreSQL as a database

README.md

I came across HikariCP and I was amazed by the benchmarks and I wanted to try it instead of my default choice C3P0 and to my surprise I struggled to get the configurations right probably because the configurations differ based on what combination of tech stack you are using.

I have setup Spring Boot project with JPA, Web, Security starters (Using [Spring Initializer][1]) to use PostgreSQL as a database with HikariCP as connection pooling.
I have used Gradle as build tool and I would like to share what worked for me for the following assumptions:

1. Spring Boot Starter JPA (Web & Security - optional)
2. Gradle build tool
3. PostgreSQL running and setup with a database (i.e. schema, user, db)

This gist is related to SO post https://stackoverflow.com/questions/26490967/how-do-i-configure-hikaricp-in-my-spring-boot-app-in-my-application-properties-f

application.properties

server.contextPath=/
debug=true

# Spring data source needed for Spring boot to behave
# Pre Spring Boot v2.0.0.M6 without below Spring Boot defaults to tomcat-jdbc connection pool included 
# in spring-boot-starter-jdbc and as compiled dependency under spring-boot-starter-data-jpa
spring.datasource.type=com.zaxxer.hikari.HikariDataSource
spring.datasource.url=jdbc:postgresql://localhost:5432/somedb
spring.datasource.username=dbuser
spring.datasource.password=dbpassword

# Hikari will use the above plus the following to setup connection pooling
spring.datasource.hikari.minimumIdle=5
spring.datasource.hikari.maximumPoolSize=20
spring.datasource.hikari.idleTimeout=30000
spring.datasource.hikari.poolName=SpringBootJPAHikariCP
spring.datasource.hikari.maxLifetime=2000000
spring.datasource.hikari.connectionTimeout=30000

# Without below HikariCP uses deprecated com.zaxxer.hikari.hibernate.HikariConnectionProvider
# Surprisingly enough below ConnectionProvider is in hibernate-hikaricp dependency and not hibernate-core
# So you need to pull that dependency but, make sure to exclude it's transitive dependencies or you will end up 
# with different versions of hibernate-core 
spring.jpa.hibernate.connection.provider_class=org.hibernate.hikaricp.internal.HikariCPConnectionProvider

# JPA specific configs
spring.jpa.properties.hibernate.show_sql=true
spring.jpa.properties.hibernate.format_sql=true
spring.jpa.properties.hibernate.use_sql=true
spring.jpa.properties.hibernate.id.new_generator_mappings=false
spring.jpa.properties.hibernate.default_schema=littracker
spring.jpa.properties.hibernate.search.autoregister_listeners=false
spring.jpa.properties.hibernate.bytecode.use_reflection_optimizer=false

# Enable logging
logging.level.org.hibernate.SQL=DEBUG
# Enable logging for HikariCP to verify that it is used
logging.level.com.zaxxer.hikari.HikariConfig=DEBUG
logging.level.org.hibernate.type.descriptor.sql.BasicBinder=TRACE 

build.gradle

buildscript {
	ext {
		springBootVersion = '1.5.8.RELEASE'
	}
	repositories {
		mavenCentral()
	}
	dependencies {
		classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
	}
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
apply plugin: 'war'

group = 'com'
version = '1.0'
sourceCompatibility = 1.8

repositories {
	mavenCentral()
}


dependencies {
	compile('org.springframework.boot:spring-boot-starter-aop')
	
	// Exclude the tomcat-jdbc since it's used as default for connection pooling
  // This can also be achieved by setting the spring.datasource.type to HikariCP 
  // datasource see application.properties below
	compile('org.springframework.boot:spring-boot-starter-data-jpa') {
		exclude group: 'org.apache.tomcat', module: 'tomcat-jdbc'
	}
  
	compile('org.springframework.boot:spring-boot-starter-security')
	
  compile('org.springframework.boot:spring-boot-starter-web')
	
  runtime('org.postgresql:postgresql')
  
  testCompile('org.springframework.boot:spring-boot-starter-test')
	testCompile('org.springframework.security:spring-security-test')
	
	// Download HikariCP but, exclude hibernate-core to avoid version conflicts
	compile('com.zaxxer:HikariCP:2.5.1') {
		exclude group: 'org.hibernate', module: 'hibernate-core'
	}
	
  // Need this in order to get the HikariCPConnectionProvider
	compile('org.hibernate:hibernate-hikaricp:5.2.11.Final') {
		exclude group: 'com.zaxxer', module: 'HikariCP'
		exclude group: 'org.hibernate', module: 'hibernate-core'
	}
}