Managing the BEA MessageQ Environment

 

After you develop your BEA MessageQ programs and deploy your distributed application into the production environment, you need to monitor and tune your system's performance and occasionally troubleshoot BEA MessageQ problems.

To successfully manage your distributed BEA MessageQ applications, you need to:

• Understand the BEA MessageQ Environment

• Monitor System Performance

• Troubleshoot Errors

Understanding the BEA MessageQ Environment

To efficiently manage and troubleshoot a distributed BEA MessageQ application, it is important to be able to visualize the components of the BEA MessageQ environment. Figure 4-1 shows how Application A running in Group 1 can be configured to exchange messages with Application B running in Group 2 on the same message queuing bus though the systems do not run the same operating system. Communication between the two groups is enabled using the network communications link between both systems and a BEA MessageQ cross-group link.

Figure 4-1 The BEA MessageQ Environment

This typical configuration of the BEA MessageQ environment consists of:

• a single message queuing bus to provide the communication backbone for applications to exchange information using message queuing

• one or more message queuing groups per system. A message queuing group enables multiple queues to efficiently share BEA MessageQ services such as message recovery and broadcast services

• one or more message queues to receive BEA MessageQ messages. Message queues can be temporarily assigned for use by BEA MessageQ or can be permanently defined in the group initialization file

• one or more cross-group connections to enable message exchange between message queuing groups on the message queuing bus. (If the message queuing groups reside on different computer systems, a network connection must be present to enable the cross-group connection.)

Anatomy of a Message Queuing Group

Message queuing groups are designed to provide centralized resources for a group of queues running on a host system. As shown in Figure 4-2, each message queuing group may run a number of BEA MessageQ servers to service the needs of the temporary and permanent queues to which applications are attached.

Figure 4-2 BEA MessageQ Servers

Depending upon the services enabled in the group initialization file, a message queuing group may run the following processes:

• SBS Server-distributes broadcast messages based on the selection criteria set by registered applications

• Client Library Server-provides full message queuing services for applications running on BEA MessageQ Clients

• JRN Server-writes successfully delivered recoverable messages to the post confirmation journal; also writes recoverable messages to disk-based message recovery journals and resends the messages in the event of delivery failure

• Link Drivers-enables cross-group communication for applications running on different computer systems in different BEA MessageQ message queuing groups

• NA-the naming agent accesses and manages the BEA MessageQ bus-wide name space

Starting and Stopping Groups, Queues, Links and the CLS

As options of both its character-cell and GUI-based Monitor utility, BEA MessageQ enables users to interactively:

• Stop a message queuing group slowly (allowing processes to exit and clean up)

• Stop a message queuing group fast (immediate shutdown without clean up)

• Start a message queue

• Stop a message queue slowly (allowing messages to be read until the queue is empty)

• Stop a message queue fast (queue stops immediately and existing messages are lost)

• Start a cross-group connection

• Stop a cross-group connection

• Start the Client Library Server

• Stop the Client Library Server

Monitoring System Performance

The BEA MessageQ Monitor utility helps developers observe the BEA MessageQ environment on local and remote nodes. Developers and system managers can use the summary and detailed display of information by the Monitor utility to tune the BEA MessageQ system configuration.

To monitor or control your BEA MessageQ groups or buses, you can invoke either the Motif-based Monitor Utility or the character-cell Monitor utility. Either interface can be used to perform the following sets of functions:

• Collecting and displaying statistics for each queue

• Collecting and displaying statistics for each cross-group link

Error Logging and Recovery

BEA MessageQ has an error logging mechanism to display and capture informational, warning, and error messages that can occur during processing. The messages display a description of the condition to help developers gather more information about failure conditions within a message queuing group.

On UNIX and Windows NT systems the BEA MessageQ an error log file is created when the group is started using the appropriate switch on the dmqstartup command line. Error logs can be created for each message queuing group. On OpenVMS systems, an error log can be created at group startup or the System Manager utility can be used to redirect output to several error log files.

Listing 4-1 shows the kind of information logged for each BEA MessageQ event on a UNIX or a Windows NT system:

• the name of the process that logged the error

• the date and time on which the message was logged

• a description of the successful event or error condition

  Listing 4-1 Sample BEA MessageQ Event Log File

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  ************ dmqgcp (4150) 10-DEC-1999 15:25:23 ************
  gcp, group control process for group 19 is running
  ************ dmqqe (4536) 10-DEC-1999 15:25:24 ************
  qe, queuing engine is running
  ************ dmqloader (3366) 10-DEC-1999 15:25:24 ************
  ldr, MessageQ System Loader starting
  ldr, Parsing PROFILE Section
  ldr, Parsing MRS Section
  ldr, Parsing GROUP Section
  ldr, Parsing ROUTE Section
  ldr, Parsing QCT Section
  ldr, Parsing GNT Section
  ldr, Bad parameter sent to the GCP at line 318
  ldr, Bad parameter sent to the GCP at line 330
  ldr, Bad parameter sent to the GCP at line 331
  ldr, Parsing CLS Section
  ldr, Parsing NAM Section
  ldr, Loader exiting normally
  ************ dmqjourn (2590) 10-DEC-1999 15:25:27 ************
  jrn, journal process for group 19 is running
  ************ dmqld (2579.0) 10-DEC-1999 15:25:27 ************
  ld, link listener for group 19 is running
  ************ dmqld (2591.0) 10-DEC-1999 15:25:27 ************
  ld, link sender for group 19 to group 18 is running
  ************ dmqld (2579.0) 10-DEC-1999 15:25:32 ************
  ld, link receiver for group 19 from group 18 is running
  ************ dmqgcp (4150) 10-DEC-1999 15:26:21 ************
  ipi, dequeue message failed
  ************ dmqgcp (4150) 10-DEC-1999 15:26:21 ************
  gcp, group control process for group 19 has exited
  ************ dmqqe (4536) 10-DEC-1999 15:26:21 ************
  qe, queuing engine has exited

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