FMW "ONS configuration failed" or "oracle.ons.NoServersAvailable: Subscription time out"

(Doc ID 2308193.1)

Last updated on APRIL 15, 2018

Applies to:

JDBC - Version and later
Oracle Fusion Middleware - Version to [Release 12c]
Oracle WebLogic Server - Version to [Release 12c]
Information in this document applies to any platform.


After installing Weblogic Server (WLS) or Fusion Middleware (FMW) or upgrading from 12.2.1.x to, JDBC fails with the error "ONS configuration failed" or "Subscription time out".

While this is JDBC issue, in the FMW/WLS context, this issue can bee seen during Upgrade, Installation/Configuration or starting Admin/Managed Servers. 

Exception stack

- Exact same configuration works fine in SQL Developer (
- This issue is consistent.
- Issue is seen for all datasources.
- Issue is seen while creating a new datasource as well as while testing an existing datasource.
- This is a single instance database, not RAC, so no ONS service running.


Install or upgrade to using JDBC


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