search cancel

Could not get JDBC Connection; nested exception - Communications link failure


Article ID: 198062


Updated On:


CA API Gateway API SECURITY CA API Gateway Precision API Monitoring Module for API Gateway (Layer 7) CA API Gateway Enterprise Service Manager (Layer 7) STARTER PACK-7 CA Microgateway


We are trying to connect to oracle database server and seeing this error as below when trying to do perform JDBC query.

Oracle version is exadata

failed due to Could not get JDBC Connection Could not get JDBC Connection nested exception is java sql SQLException An SQLException was provoked by the following failure java lang InterruptedException java lang InterruptedException


Release : 9.4

Component : API GATEWAY


From Data Collector tool, DCT files reviewed : 

netstat-tnap.txt  shows :

SYN_SENT , means a problem (firewall,something blocking that connection):
tcp        0      1          SYN_SENT    3658/java

ssg.2020-08-20.log shows :
2020-08-20T09:41:47.683-0500 WARNING 85 com.l7tech.server.cluster.DatabaseReplicationMonitor: 2380: Error accessing host/database localhost/ssg: 
Could not get JDBC Connection; nested exception is com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

confirmed a Network Issue , Server blocked by firewall