Describes the name, location, and contents of the First Failure Support Technology ( FFST ) files that are generated by the IBM MQ classes for JMS.
When using the IBM MQ classes for JMS, FFST information is recorded in a file in a
directory that is called FFDC, which by default is a subdirectory
of the current working directory for the IBM MQ classes for JMS application that was running when the
FFST was generated. If the property
com.ibm.msg.client.commonservices.trace.outputName has been set in the IBM MQ classes for JMS configuration file, the FFDC directory
is a subdirectory of the directory that the property points to. For information about
the IBM MQ classes for JMS, see The IBM MQ classes for JMS configuration file.
An FFST file contains one FFST record. Each FFST record contains information about an error that is normally severe, and possibly unrecoverable. These records typically indicate either a configuration problem with the system or an internal error within the IBM MQ classes for JMS .
FFST files are named JMSC nnnn.FDC, where nnnn starts at 1. If the full file name already exists, this value is incremented by one until a unique FFST file name is found.
An instance of an IBM MQ classes for JMS application writes FFST information to multiple FFST files. If multiple errors occur during a single execution of the application, each FFST record is written to a different FFST file.
Sections of an FFST record
An FFST record that is generated by the IBM MQ classes for JMS contains the following sections:
The header
A header, indicating the time when the FFST record was created, the platform that the IBM MQ classes for JMS application is running on, and the internal method that was being called. The header also contains a probe identifier, which uniquely identifies the place within the IBM MQ classes for JMS that generated the FFST record.
Data
Some internal data that is associated with the FFST record.
Version information
Information about the version of the IBM MQ classes for JMS being used by the application that generated the FFST record.
Stack Trace
The Java stack trace for the thread that generated the FFST record.
Property Store Contents
A list of all of the Java system properties that have been set on the Java Runtime Environment that the IBM MQ classes for JMS application is running in.
WorkQueueMananger Contents
Information about the internal thread pool that is used by the IBM MQ classes for JMS .
Runtime properties
Details about the amount of memory and the number of processors available on the system where the IBM MQ classes for JMS application is running.
Component Manager Contents
Some information about the internal components that are loaded by the IBM MQ classes for JMS .
Provider Specific information
Information about all of the active JMS Connections, JMS Sessions, MessageProducer, and MessageConsumer objects currently being used by the IBM MQ classes for JMS application that was running when the FFST was generated. This information includes the name of the queue manager that JMS Connections and JMS Sessions are connected to, and the name of the IBM MQ queue or topic objects that are being used by MessageProducers and MessageConsumers.
All Thread information
Details about the state of all of the active threads in the Java Runtime Environment that the IBM MQ classes for JMS application was running in when the FFST record was generated. The name of each thread is shown, together with a Java stack trace for every thread.
The information in the header, Data, and Stack Trace sections of the FFST record are used by IBM to assist in problem determination. In many cases, there is little that the system administrator can do when an FFST record is generated, apart from raising problems through the IBM Support Center.
Suppressing FFST records
An FFST file that is generated by the IBM MQ classes for JMS contain one FFST record. If a problem occurs multiple times during the execution of an IBM MQ classes for JMS application, multiple FFST files with the same probe identifier are generated. This might not be desirable. The property com.ibm.msg.client.commonservices.ffst.suppress can be used to suppress the production of FFST files. This property must be set in the IBM MQ classes for JMS configuration file used by the application, and can take the following values:
0: Output all FFDC files (default).
-1: Output only the first FFST file for a probe identifier.
integer: Suppress all FFST files for a probe identifier except those files that are a multiple of this number.