Multi-IP connection support for OBClient

OBClient supports configuring multiple IP addresses for connection in various ways. If one IP address fails to connect, it automatically switches to another.

Method 1: Single-IP connection (default)

obclient -h100.88.109.130 -P38884 -utest@oracle -Dtest -ptest

Method 2: Configure multiple IPs using TNS

By setting the TNS_ADMIN environment variable, you can define multiple IP addresses in a TNS configuration file.

1. Set the environment variable:

   export TNS_ADMIN=/data
   

2. Configure in the /data/tnsnames.ora file:

   MYTEST=
     (DESCRIPTION=
       (ADDRESS_LIST=
         (OBLB_STRATEGY=SERVERAFFINITY)
         (ADDRESS=(PROTOCOL=tcp)(HOST=100.88.109.1)(PORT=38884)(WEIGHT=1))
         (ADDRESS=(PROTOCOL=tcp)(HOST=100.88.109.130)(PORT=38884)(WEIGHT=2)))
         (CONNECT_DATA=(SERVICE_NAME=TEST))
     )
   

   OBLB_STRATEGY supports three strategies:

   Strategy value	Description
   SERVERAFFINITY	Weight-based strategy, selects based on the WEIGHT value
   RANDOM	Random selection
   ROTATION	Round-robin selection

3. Connect using the TNS service name:

   obclient -h100.88.109.130 -P38884 -utest@oracle -Dtest -ptest --ob-service-name=MYTEST
   

During the connection process, all IP:port combinations are traversed and connected to one by one. The connection ends either with a successful connection or after all attempts fail.

Method 3: Specify multiple IPs in the -h parameter

Multiple IPs can also be directly specified in the -h parameter (the parameter must contain commas):

obclient -h[fe80::42:acff:fe11:2%eth0]:38884,[fe80::42:acff:fe11:2%eth0]:38882,[100.88.109.130]:2222,100.88.109.130:38884 -P38884 -utest@oracle -Dtest -ptest

Format: -h[ip1]:port1,[ip2]:port2,ip3:port3...

View the currently used IP

After a successful connection, you can use the \s or status command to view the currently used IP:

obclient> \s

References

• Client IP forwarding and tenant allowlist (F5 scenario)
• Overview of OBClient