[#12048] Configure connection pool using hikari (#12978)

* Configure hikari

* Remove spacing

* Lint

Author: FergusMok

build.gradle

@@ -77,8 +77,7 @@ dependencies {
     implementation("org.jsoup:jsoup:1.15.2")
     implementation("org.hibernate.orm:hibernate-core:6.1.6.Final")
     implementation("org.postgresql:postgresql:42.7.2")
-    implementation("org.hibernate.orm:hibernate-agroal:6.1.6.Final")
-    implementation("io.agroal:agroal-pool:2.1")
+    implementation("org.hibernate:hibernate-hikaricp:6.1.6.Final")
 
     testAnnotationProcessor(testng)
 

src/main/java/teammates/common/util/HibernateUtil.java

@@ -111,15 +111,18 @@ public static void buildSessionFactory(String dbUrl, String username, String pas
         Configuration config = new Configuration()
                 .setProperty("hibernate.dialect", "org.hibernate.dialect.PostgreSQLDialect")
                 .setProperty("hibernate.connection.driver_class", "org.postgresql.Driver")
+                .setProperty("hibernate.connection.provider_class",
+                        "org.hibernate.hikaricp.internal.HikariCPConnectionProvider")
                 .setProperty("hibernate.connection.username", username)
                 .setProperty("hibernate.connection.password", password)
                 .setProperty("hibernate.connection.url", dbUrl)
                 .setProperty("hibernate.hbm2ddl.auto", "update")
                 .setProperty("show_sql", "true")
                 .setProperty("hibernate.current_session_context_class", "thread")
-                .setProperty("hibernate.agroal.minSize", "5")
-                .setProperty("hibernate.agroal.maxSize", "50")
-                .setProperty("hibernate.agroal.reapTimeout", "PT1M")
+                .setProperty("hibernate.hikari.minimumIdle", "10")
+                .setProperty("hibernate.hikari.maximumPoolSize", "30")
+                .setProperty("hibernate.hikari.idleTimeout", "300000")
+                .setProperty("hibernate.hikari.connectionTimeout", "30000")
                 // Uncomment only during migration for optimized batch-insertion, batch-update, and batch-fetch.
                 // .setProperty("hibernate.jdbc.batch_size", "50")
                 // .setProperty("hibernate.order_updates", "true")