title: How to configure hikari pool for eager initialization?
body: <p>I want to configure the Hikari pool to eagerly initialize on application startup and not when first query is issued.</p>
  
  <p>As of now spring initializr project shows that hikari pool is provisioned on first query.</p>
  
  <p>To reproduce issue - Create spring initializr project with web, jdbc and mysql dependency. Hikari pool is only created after GET request to controller</p>
  
  <p>application.properties</p>
  
  <pre><code>spring.datasource.url=
  spring.datasource.driver-class-name=
  spring.datasource.username=
  spring.datasource.password=
  logging.level.com.zaxxer.hikari.HikariConfig=DEBUG
  spring.datasource.hikari.maximum-pool-size=100
  spring.datasource.hikari.minimum-idle=10
  spring.datasource.hikari.connection-init-sql=SELECT 1
  </code></pre>
  
  <p>Controller</p>
  
  <pre><code>@RestController
  public class DemoController {
  
      @Autowired
      private JdbcTemplate template;
  
      @GetMapping(value="/request")
      public String testHikariEagerInitialization() {
  
          template.execute("SELECT COUNT(1) FROM trade");
  
          return "Hikari Pool created now!";
      }
  
  }
  </code></pre>
  
  <p>logs at application startup</p>
  
  <pre><code> :: Spring Boot ::        (v2.1.6.RELEASE)
  
  2019-07-09 08:36:02.074  INFO 37884 --- [           main] com.example.demo.DemoApplication         : Starting DemoApplication on  with PID 37884 ()
  2019-07-09 08:36:02.078  INFO 37884 --- [           main] com.example.demo.DemoApplication         : No active profile set, falling back to default profiles: default
  2019-07-09 08:36:03.132  INFO 37884 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
  2019-07-09 08:36:03.180  INFO 37884 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
  2019-07-09 08:36:03.197  INFO 37884 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.21]
  2019-07-09 08:36:03.330  INFO 37884 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
  2019-07-09 08:36:03.330  INFO 37884 --- [           main] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 1187 ms
  2019-07-09 08:36:03.416 DEBUG 37884 --- [           main] com.zaxxer.hikari.HikariConfig           : Driver class com.mysql.jdbc.Driver found in Thread context class loader sun.misc.Launcher$AppClassLoader@764c12b6
  2019-07-09 08:36:03.598  INFO 37884 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
  2019-07-09 08:36:03.832  INFO 37884 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
  2019-07-09 08:36:03.836  INFO 37884 --- [           main] com.example.demo.DemoApplication         : Started DemoApplication in 2.168 seconds (JVM running for 2.99)
  </code></pre>
  
  <p>new logs once GET request is made to controller </p>
  
  <pre><code>2019-07-09 08:39:20.039  INFO 37884 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
  2019-07-09 08:39:20.039  INFO 37884 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
  2019-07-09 08:39:20.046  INFO 37884 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 7 ms
  2019-07-09 08:39:20.071 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : demo-memsql-connection-pool - configuration:
  2019-07-09 08:39:20.073 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : allowPoolSuspension.............false
  2019-07-09 08:39:20.073 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : autoCommit......................true
  2019-07-09 08:39:20.073 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : catalog.........................none
  2019-07-09 08:39:20.073 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : connectionInitSql..............."SELECT 1"
  2019-07-09 08:39:20.073 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : connectionTestQuery.............none
  2019-07-09 08:39:20.073 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : connectionTimeout...............30000
  2019-07-09 08:39:20.074 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : dataSource......................none
  2019-07-09 08:39:20.074 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : dataSourceClassName.............none
  2019-07-09 08:39:20.074 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : dataSourceJNDI..................none
  2019-07-09 08:39:20.074 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : dataSourceProperties............{password=&lt;masked&gt;}
  2019-07-09 08:39:20.075 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : driverClassName................."com.mysql.jdbc.Driver"
  2019-07-09 08:39:20.075 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : healthCheckProperties...........{}
  2019-07-09 08:39:20.075 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : healthCheckRegistry.............none
  2019-07-09 08:39:20.075 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : idleTimeout.....................600000
  2019-07-09 08:39:20.075 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : initializationFailTimeout.......1
  2019-07-09 08:39:20.075 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : isolateInternalQueries..........false
  2019-07-09 08:39:20.076 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : jdbcUrl.........................jdbc:mysql://
  2019-07-09 08:39:20.076 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : leakDetectionThreshold..........0
  2019-07-09 08:39:20.076 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : maxLifetime.....................1800000
  2019-07-09 08:39:20.076 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : maximumPoolSize.................100
  2019-07-09 08:39:20.076 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : metricRegistry..................none
  2019-07-09 08:39:20.076 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : metricsTrackerFactory...........none
  2019-07-09 08:39:20.076 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : minimumIdle.....................10
  2019-07-09 08:39:20.076 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : password........................&lt;masked&gt;
  2019-07-09 08:39:20.076 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : poolName........................"demo-memsql-connection-pool"
  2019-07-09 08:39:20.077 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : readOnly........................false
  2019-07-09 08:39:20.077 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : registerMbeans..................true
  2019-07-09 08:39:20.077 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : scheduledExecutor...............none
  2019-07-09 08:39:20.077 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : schema..........................none
  2019-07-09 08:39:20.077 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : threadFactory...................internal
  2019-07-09 08:39:20.077 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : transactionIsolation............default
  2019-07-09 08:39:20.077 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : username........................""
  2019-07-09 08:39:20.077 DEBUG 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariConfig           : validationTimeout...............5000
  2019-07-09 08:39:20.077  INFO 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariDataSource       : demo-memsql-connection-pool - Starting...
  2019-07-09 08:39:20.466  INFO 37884 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariDataSource       : demo-memsql-connection-pool - Start completed.
  </code></pre>