How to start spring-boot app without depending on Database?
Solution 1:
It was indeed a tough nut to crack.
After lot and lot of research and actually debugging the spring-boot, spring, hibernate, tomcat pool, etc to get it done.
I do think that it will save lot of time for people trying to achieve this type of requirement.
Below are the settings required to achieve the following requirement
- Spring boot apps will start fine even if DB is down or there is no DB.
- Apps will pick up the connections on the fly as DB comes up which means there is no need to restart the web server or redeploy the apps.
- There is no need to start the tomcat or redeploy the apps, if DB goes down from running state and comes up again.
application.yml :
spring:
datasource:
driverClassName: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/schema
username: root
password: root
continueOnError: true
initialize: false
initialSize: 0
timeBetweenEvictionRunsMillis: 5000
minEvictableIdleTimeMillis: 5000
minIdle: 0
jpa:
show-sql: true
hibernate:
ddl-auto: none
naming_strategy: org.hibernate.cfg.DefaultNamingStrategy
properties:
hibernate:
dialect: org.hibernate.dialect.MySQL5Dialect
hbm2ddl:
auto: none
temp:
use_jdbc_metadata_defaults: false
Solution 2:
I am answering here and will close the issue that you have cross-posted
Any "native" property of the JPA implementation (Hibernate) can be set using the spring.jpa.properties
prefix as explained here
I haven't looked much further in the actual issue here but to answer this particular question, you can set that hibernate key as follows
spring.jpa.properties.hibernate.temp.use_jdbc_metadata_defaults