on 03-10-2015 9:21 PM
Hi experts,
We have the following set up in our production SMP landscape.
We have 2 application nodes(active-active), requests are routed to these nodes via a Cisco load balancer. We have 2 database nodes(active-standby), only one of the DB nodes is active at a given time. In case the primary DB node goes down, requests are routed to the other node(which was on standby earlier).
I have the following questions:
- In case the primary DB node fails, do we need to restart SMP to make it point/failover to the other DB node? Or is there a way this can be
automated?
- I want to try this on my local SMP installation. Is there a way for me to switch off the Derby database on my local machine(I went ahead with the
developer installation not the production installation)? I want to see how the application behaves when the DB is shut down.
Thank you for your help.
Cheers,
Abhinav
Tas edited by: Jitendra Kansal (Moderator)
Bill,
Thank you for your reply. One of the members from my client's BASIS team was awesome enough to try this and share the learning with me, I am posting it here so that all can benefit.
Following behavior was seen:
When a database failover happens, SMP stops and restarts itself. Then it keeps checking for successful database connection. When a successful connection is made, it initializes the bundles again.
Here are some logs:
SMPServerStatusManager: The SMP server has initialized and is ready.
Exception in thread "Thread-20" Local Exception Stack:
Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.4.1.v20121003-ad44345): org.eclipse.persistence.exceptions
.DatabaseException
Internal Exception: java.sql.SQLRecoverableException: IO Error: The Network Adapter could not establish the connection
Error Code: 17002
… …
… …
at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:370)
... 111 more
Persistence bundle stopping...
Persistence bundle stopped.
SMPServerStatusManager: The SMP server stopped.
SMPServerStatusManager: The SMP server is restarting...
RESTARTING
Checking DB...
Failed to verify database status on startup:java.sql.SQLRecoverableException: IO Error: The Network Adapter could not est
ablish the connection
Checking DB...
Failed to verify database status on startup:java.sql.SQLRecoverableException: IO Error: The Network Adapter could not est
ablish the connection
Checking DB...
… …
(SMP keeps checking for DB connection)
… …
Checking DB...
DB connection successful.
Succeeded Version Check.
Cheers,
Abhinav
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--Bill
Abhinav,
You will need to reinstall SMP in production mode on your local machine and point to the Oracle instance (along with the necessary DB setup). I think this will be more of a function of how Oracle handles the request than SMP. If the Oracle connection seamlessly switches normally I would expect the same behavior with SMP.
All that being said, your plan to test and confirm is the right path as you don't want to assume here without testing.
Let us know how it goes!
--Bill
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