Hikari CP DB 连接未在异步块中释放

Question

I am using Spring Boot application which has API controller to generate reports. The actual service function is wrapped around @Async annotation and function makes DB calls and generates the csv reports. I am also using Hikari CP for connection pool management and JPA + QueryDSL for forming select queries.

I am seeing strange issue in that DB connections are not being released after the files are successfully generated. Every new call to the controller/service function creates new active connections and it remains active. Its not getting released because of which I am getting Connection is not available error from Hikari once my max pool size limit is reached.

Any suggestions why connection is not being released. The service function issues only select queries, no updates or inserts.

Hikari CP configs:

spring.datasource.hikari.maximum-pool-size: "80"
spring.datasource.hikari.idle-timeout: "300000"
spring.datasource.hikari.connectionTimeout: "600000"
spring.datasource.hikari.minimum-idle: "15"

My service function

@Async
@Override
public void exportListing(String[] filter) {
        try {
}
catch(Exception e)
{
}

Answer 1

I fixed it by wrapping it within @Transactional block which ensures that DB connections are closed once the function completes.