Recent Posts by Stephen Felts

Starting in the 12.1.0.2 Oracle thin driver, the replay driver has statistics related to replay. This is useful to understand how many connections are being replayed. It should be completely transparent to the application so you won’t know if connection replays are occurring unless you check. The statistics are available on a per connection basis or on a datasource basis. However, connections on a WLS datasource don’t share a driver-level datasource object so the latter isn’tus...

WebLogic Server (WLS) 12.2.1 introduces a new datasource type that uses the Oracle Universal Connection Pool (UCP) as an alternative connection pool.  The UCP datasource allows for configuration, deployment, and monitoring of the UCP connection pool as part of the WLS domain.  It is certified with the Oracle Thin driver (simple, XA, and replay drivers).    The product documentation is at http://docs.oracle.com/middleware/1221/wls/JDBCA/ucp_datasources.htm#JDBCA746.  The goal...

Fast Application Notification (FAN) is used to provide notification events about services and nodes as they are added and removed from Oracle Real Application Clusters (RAC) and Oracle Data Guard environments. The Oracle Notification System is used as the transport for FAN. You can find all of the details in the following link. http://www.oracle.com/technetwork/database/options/clustering/overview/fastapplicationnotification12c-2538999.pdf Configuring ONS has been availablefor...

This is the third of this series on profiling enhancements in WLS 12.2.1 (but maybe not the least since this appears to happen quite often).  This is a common application error that is difficult to diagnose when an application leaves a local transaction open on a connection and it is returned to the connection pool. This error can manifest as XAException/XAER_PROTO errors, or asunintentional local transaction commits or rollbacks of database updates. Current workarounds to...

Accessing a closed JDBC object is a common application error that can be difficult to debug. To help diagnose such conditions there is a new profiling option to generate a diagnostic log message when a JDBC object (Connection, Statement or ResultSet) is accessed after the close() method has been invoked. The log message will include the stack trace of the thread that invoked the close() method. To enable closed JDBC object profiling, the datasourceProfileType attribute bitmask...

This is the first of a series of three articles that describes enhancements to datasource profiling in WLS 12.2.1. These enhancements were requested by customers and Oracle support. I think they will be very useful in tracking down problems in the application. The pre-12.2.1 connection leak diagnostic profiling option requires that the connection pool “Inactive Connection Timeout Seconds” attribute be set to a positive value in order to determine how long before anidle...

The earlier blog at Setting V$SESSION for a WLS Datasource described using system properties to set driver connection properties, which in turn automatically set values on the Oracle database session. Some comments from readers indicated that there were some limitations to this mechanism. - There are some values that can’t be set on the command line because they aren’t available until the application server starts. The most obvious value is the process identifier. - Values set...

See the  Blog announcing Oracle WebLogic Server 12.2.1 for more details on Multenacy and other new features. The largest and most innovative feature in WebLogic Server (WLS) 12.2.1 is Multitenancy.  It is integrated with every component in the application server.  As part of the Multi-tenancy effort one of the key concepts being introduced is the notion of a slice of the domain which is referred to as a Partition or DomainPartition.  A Partition defines applications and...

As I described in the blog Part2 - 12c Database and WLS - Application continuity, Application Continuity (AC) is a great feature for avoiding errors to the user with minimal changes to the application and configuration. In the blog Using Orachk to Clean Up Concrete Classes for Application Continuity, I described the one of the many uses of the Oracle utility program, focusing on checking for Oracle concrete class usage that needs to be removed to run with AC. The download page...