WLS Replay Statistics

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’t
useful in WLS. WLS 12.2.1 provides another mechanism to get the statistics at the datasource level.

The following code sample shows how to print out the available statistics for an individual connection using the oracle.jdbc.replay.ReplayableConnection interface, which exposes the method to get a oracle.jdbc.replay.ReplayStatistics object. See https://docs.oracle.com/database/121/JAJDB/oracle/jdbc/replay/ReplayStatistics.html for a description of the statistics values.

if (conn instanceof ReplayableConnection) {
  ReplayableConnection rc = ((ReplayableConnection)conn);
  ReplayStatistics rs = rc.getReplayStatistics(ReplayableConnection.StatisticsReportType.FOR_CURRENT_CONNECTION);
  System.out.println("Individual Statistics");
  System.out.println("TotalCalls="+rs.getTotalCalls());
  System.out.println("TotalCompletedRequests="+rs.getTotalCompletedRequests());
  System.out.println("FailedReplayCount="+rs.getFailedReplayCount());
  System.out.println("TotalRequests="+rs.getTotalRequests());
  System.out.println("TotalCallsTriggeringReplay="+rs.getTotalCallsTriggeringReplay());
  System.out.println("TotalReplayAttempts="+rs.getTotalReplayAttempts());
  System.out.println("TotalProtectedCalls="+rs.getTotalProtectedCalls());
  System.out.println("SuccessfulReplayCount="+rs.getSuccessfulReplayCount());
  System.out.println("TotalCallsAffectedByOutages="+rs.getTotalCallsAffectedByOutages());
  System.out.println("TotalCallsAffectedByOutagesDuringReplay="+rs.getTotalCallsAffectedByOutagesDuringReplay());
  System.out.println("ReplayDisablingCount="+rs.getReplayDisablingCount());
}

Besides a getReplayStatistics() method, there is also a clearReplayStatistics() method.

To provide for a consolidated view of all of the connections associated with a WLS datasource, the information is available via a new operation on the associated runtime MBean. You need to look-up the WLS MBean server, get the JDBC service, then search for the datasource name in the list of JDBC datasource runtime MBeans, and get the JDBCReplayStatisticsRuntimeMBean. This value will be null if the datasource is not using a replay driver, if the driver is earlier than 12.1.0.2, or if it’s not a Generic or AGL datasource. To use the replay information, you need to first call the refreshStatistics() operation that sets the MBean values, aggregating the values for all connections on the datasource. Then you can call the operations on the MBean to get the statistics values, as in the following sample code. Note that there is also a clearStatistics() operation to clear the statistics on all connections on the datasource. The following code shows an example of how to print the aggregated statistics from the data source.

public void printReplayStats(String dsName) throws Exception {
  MBeanServer server = getMBeanServer();
  ObjectName[] dsRTs = getJdbcDataSourceRuntimeMBeans(server);
  for (ObjectName dsRT : dsRTs) {
   String name = (String)server.getAttribute(dsRT, "Name");
   if (name.equals(dsName)) {
     ObjectName mb =(ObjectName)server.getAttribute(dsRT,
       "JDBCReplayStatisticsRuntimeMBean");
     server.invoke(mb,"refreshStatistics", null, null);
     MBeanAttributeInfo[] attributes = server.getMBeanInfo(mb).getAttributes();
     System.out.println("Roll-up");
     for (int i = 0; i <attributes.length; i++) {
       if(attributes[i].getType().equals("java.lang.Long")) {
         System.out.println(attributes[i].getName()+"="+
          (Long)server.getAttribute(mb, attributes[i].getName()));
       }
     }
    }
  }
}
MBeanServer getMBeanServer() throws Exception {
 InitialContext ctx = new InitialContext();
 MBeanServer server = (MBeanServer)ctx.lookup("java:comp/env/jmx/runtime");
 return server;
}

ObjectName[] getJdbcDataSourceRuntimeMBeans(MBeanServer server)  throws Exception {
 ObjectName service = new ObjectName( "com.bea:Name=RuntimeService,Type=\
 weblogic.management.mbeanservers.runtime.RuntimeServiceMBean");
 ObjectName serverRT = (ObjectName)server.getAttribute(service,  "ServerRuntime");
 ObjectName jdbcRT = (ObjectName)server.getAttribute(serverRT,  "JDBCServiceRuntime");
 ObjectName[] dsRTs = (ObjectName[])server.getAttribute(jdbcRT, "JDBCDataSourceRuntimeMBeans");
 return dsRTs;
}

Now run an application that gets a connection, does some work, kills the session, replays, then gets a second connection and does the same thing. Each connection successfully replays once. That means that the individual statistics show a single replay and the aggregated statistics will show two replays. Here is what the output might look like.

Individual Statistics
TotalCalls=35
TotalCompletedRequests=0
FailedReplayCount=0
TotalRequests=1
TotalCallsTriggeringReplay=1
TotalReplayAttempts=1
TotalProtectedCalls=19
SuccessfulReplayCount=1
TotalCallsAffectedByOutages=1
TotalCallsAffectedByOutagesDuringReplay=0
ReplayDisablingCount=0
Roll-up
TotalCalls=83
TotalCompletedRequests=2
FailedReplayCount=0
TotalRequests=4
TotalCallsTriggeringReplay=2
TotalReplayAttempts=2
TotalProtectedCalls=45
SuccessfulReplayCount=2
TotalCallsAffectedByOutages=2
TotalCallsAffectedByOutagesDuringReplay=0
ReplayDisablingCount=0

Looking carefully at the numbers, you can see that the individual count was done before the connections were closed (TotalCompletedRequests=0) and the roll-up was done after both connections were closed. 

You can also use WLST to get the statistics values for the datasource. The statistics are not visible in the administration console or FMWC in WLS 12.2.1.