Spring 多个打开的连接

Question

I set up a new Spring Boot Application including only the spring-boot-starter-data-mongodb dependency and added basic mongodb configs (host, port, username, password, ..) in the application.properties.
When I execute the application the following appears in the console:

2020-12-27 23:30:21.306  INFO 25230 --- [localhost:27017] org.mongodb.driver.connection            : Opened connection [connectionId{localValue:1, serverValue:86}] to localhost:27017
2020-12-27 23:30:21.306  INFO 25230 --- [localhost:27017] org.mongodb.driver.connection            : Opened connection [connectionId{localValue:2, serverValue:87}] to localhost:27017

I am curios why the connection was opened twice by spring. Isn't one opened connection enough?

Answer 1

Please add the below line into your properties file.

spring.data.mongodb.min-connections-per-host=1

The default size is 2 for the MongoDB java driver.

Hope this will work for you!