Spring boot project with Oracle DB sometime get IO Connection timeout - oracle

Question

I deploy an app with Spring Boot + JPA and use Oracle DB for store data.
Sometimes I got this error in log after using the app for a while.
SQL Error: 17002, SQLState: 08006 - IO Error: Connection timed out
Config properties
server.port = 8095
# ===============================
# = DATA SOURCE
# ===============================
# Set here configurations for the database connection
spring.datasource.url=jdbc:oracle:thin:#//localhost:1521/xe
spring.datasource.username=root
spring.datasource.password=root
# Keep the connection alive if idle for a long time (needed in production)
spring.datasource.testWhileIdle=true
spring.datasource.validationQuery=SELECT 1
spring.datasource.driver-class-name=oracle.jdbc.OracleDriver
If I add autoReconnect=true to datasource url I got error when start app.
SQL Error: 12514, SQLState: 08006
oracle.net.ns.NetException: Listener refused the connection with the following error:
ORA-12514, TNS:listener does not currently know of service requested in connect descriptor
at oracle.net.ns.NSProtocolStream.negotiateConnection(NSProtocolStream.java:272)
at oracle.net.ns.NSProtocol.connect(NSProtocol.java:263)
at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1360)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:486)
... 46 common frames omitted
Does anyone know the issue root cause and how to fix it? Thanks.

Answer 1

Test the Oracle DB connection from SQLPlus.
Also, check if your Oracle service_name is valid in tnsnames.ora file.
For example, if you have a user entry in tnsnames.ora is as follows:
SAMPLEUSER =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = <fqdnHostNameOrAddress>)(PORT = <validPORT>))
)
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = <OracleDBServiceName>)
)
)
Then test with SQLPlus as below:
sqlplus user#SAMPLEUSER