Monitoring MessageQ

 

The Monitor utility is a MessageQ application that allows you to monitor and control the performance of your MessageQ for Windows NT message queuing system.

Using the Monitor utility requires that you be connected to a bus and group. If you set the DMQ_BUS_ID and DMQ_GROUP_ID environment variables prior to invoking the Monitor utility, you will connect to that bus and a group when you invoke the Monitor utility. If you do not set the environment variables before invoking the Monitor utility, you must connect to the bus and group from the command line or from the Monitor utility.

Using the Monitor utility, you can:

• Open a Monitor view and attach it to a MessageQ group.

• Enable, disable, and reset statistics collection.

• Enable and disable quotas.

• View cumulative counts of the messages sent and received for all links and queues of a selected group.

• Shut down groups.

Invoking the Monitor Utility

To start the Monitor utility:

1. Open the MessageQ Version 5.0 group in the Program Manager.

2. Double click the Monitor icon.

Enabling Statistics

To monitor your application's messaging capabilities, you need to collect statistics on the queue and link activities of the groups. Because statistic collection is not automatically started when you open the Monitor utility, you must enable statistics gathering using the Enable Statistics option in the Manage menu. To disable statistics gathering, click again on the Enable Statistics option in the Manage menu to remove the check mark. Statistics stop being collected when you exit the Monitor utility.

At any time while statistics are enabled, they can be reset for a selected group's links and queues using the Statistics and Reset items under the Manage menu. Link and queue statistics can be reset either individually or as a whole. Reset zeroes out the statistics collection counters. Using Reset allows you to view your application's messaging traffic over short-term periods, which can be useful for detecting messaging bottlenecks.

Enabling Quotas

The Monitor utility allows you to enable or disable quotas on permanent queues that you have defined in the %QCT section of the group initialization file. You can enforce quotas on the maximum number of uncollected messages and bytes that can reside in a given queue. For more information on setting these quotas, see the Defining Queues in the Queue Configuration Section topic in Chapter 2.

To enable quota enforcement, use the Quotas and Enable items from the Manage menu. You can disable quota enforcement by using the Disable item. If you are not concerned whether your application exceeds quotas, you should disable quotas to increase performance and reduce screen clutter.

Viewing Link and Queue Activity

To view link and queue statistics of MessageQ message queuing groups, use the Link Information and Queue Information items of the View menu to display the following dialogs:

• Link Information

  • Traffic Counts

  • Traffic Rates

  • Traffic Detail

  • Detail

• Queue Information

  • Queue Traffic Counts

  • Queue Traffic Rates

  • Queue Traffic Detail

  • Detail

Viewing Link Traffic Counts

Use the Link Information and Traffic Counts menu items to view the connection state and the cumulative messages and bytes for links between groups. Understand that the group for the node from which you are using the Monitor utility will not appear in this dialog; only the groups to which that group is currently connected or could be connected to will appear.

Table 4-1 describes the fields of the Link Traffic Counts dialog.

Table 4-1 Link Traffic Counts Dialog

Statistic	Definition
Group Number	Number of the group
State Receiver	State of the inbound connection; either connected or unconnected
State Sender	State of the outbound connection; either connected or unconnected
Messages Sent	Cumulative messages sent from the last time statistics were reset
Messages Received	Cumulative messages received from the last time statistics were reset
Bytes Sent	Cumulative bytes sent from the last time statistics were reset
Bytes Received	Cumulative bytes received from the last time statistics were reset
Disconnected In	Cumulative number of successful connections since the last disconnect
Disconnected Out	Cumulative number of failed connection attempts since the last disconnect

Use the Disconnected In/Out statistic to see if any link between groups is constantly going up and down (cycling). A cycling link could indicate a network timeout problem.

This dialog can be useful for diagnosing bad message puts. For example, if you sent a cross-group message and it does not show up, yet the Viewing Link Traffic Counts dialog shows that all the links are up, your application may be in error.

Viewing Link Traffic Rates

Use the Link Information and Traffic Rates menu items to view the connection state and the average byte and message counts per second for the links of all groups. Average bytes and message counts per second is referred to as "throughput rates". Table 4-2 describes the fields of the Link Traffic Rates dialog.

Table 4-2 Link Traffic Rates Dialog

Statistic	Description
Group Number	Number of the group
State Receiver	State of the inbound connection; either connected or unconnected
State Sender	State of the outbound connection; either connected or unconnected
Messages Sent per Second	Average number of messages sent per second since the last time statistics were reset
Messages Received per Second	Average number of messages received per second since the last time statistics were reset
Bytes Sent per Second	Average number of bytes sent per second since the last time statistics were reset
Bytes Received per Second	Average number of bytes received per second since the last time statistics were reset

The Viewing Link Traffic Rates dialog is useful for checking the put/get rate of messages:

• If the throughput is lower than expected, the network may be busier than usual (hence slower) due to other traffic.

• If the throughput is lower than expected and you suspect that enqueuing is occurring at a normal rate, but dequeuing is not happening quickly enough, the remote group's system could be congested.

Viewing Link Traffic Detail

Use the Link Information and Traffic Detail menu items to view the connection state and the average byte and message counts of a single link.

Table 4-3 describes the fields of the Link Traffic Detail dialog.

Table 4-3 Link Traffic Detail Dialog

Statistic	Description
Group Name	Name of the group
Group Number	Number of the group
State Receiver	State of the inbound connection; either connected or unconnected
State Sender	State of the outbound connection; either connected or unconnected
Messages Sent per Second	Average number of messages sent per second since the last time statistics were reset
Messages Received per Second	Average number of messages received per second since the last time statistics were reset
Bytes Sent per Second	Average number of bytes sent per second since the last time statistics were reset
Bytes Received per Second	Average number of bytes received per second since the last time statistics were reset

Use the Link Information and Traffic Detail dialog if you suspect that a traffic problem is occurring between two particular groups. If you want to narrow down the problem further and suspect that the problem is due to one queue only, use the Queue Traffic Detail dialog.

Viewing Link Detail

Use the Link Information and Detail menu items to view the link attributes of a selected group.

Table 4-4 describes the fields of the Link Detail dialog.

Table 4-4 Link Detail Dialog

Statistic	Description
Group Name	Name of the group
Group Number	Number of the group
Time Connected	Time the current connection to a remote group was made
Time Disconnected	Time the last connection to a remote group was severed
Time Statistics Reset	Time statistics were last reset
PID	Process ID for the sender and receiver
State	State of the sender and receiver; either connected or unconnected
Window Timer	Number of seconds the sender must wait before using a new window. This value is set by the Window Delay parameter in the %XGROUP section of the group initialization file (see the Enabling Network Connections in the Cross-Group Section topic in Chapter 2).
Window Size	Number of messages the link driver can send before it has to ask permission to send more. Window size is initially set to 0 and changes dynamically, based on the message throughput needs and the minimum and maximum values of the Window Size parameter in the %XGROUP section of the group initialization file. For example, if a sender sends 10 messages per second, but the receiver can only dequeue 1 message per second, a congestion situation is created. The window size changes dynamically in a congestion situation in order to reach an equilibrium between the sender and receiver.
Window Max	Number of messages that can be sent before adjusting for congestion. This value is set by the Window Size parameter in the %XGROUP section of the group initialization file (see the Enabling Network Connections in the Cross-Group Section topic in Chapter 2).

Viewing Queue Traffic Counts

Use the Queue Information and Traffic Counts menu items to view the cumulative counts of the messages sent and received for all queues of the group. Note that statistics must be turned on for this screen to be useful.

Table 4-5 describes the fields of the Queue Traffic Counts dialog.

Table 4-5 Queue Traffic Counts Dialog

Statistic	Description
Queue Number	Number of the queue
Messages Sent	Cumulative number of messages sent since statistics were last reset
Messages Received	Cumulative number of messages received since statistics were last reset
Messages Current	Current number of messages waiting to be read. If this value continuously increments, it could be an indication that the receiving process cannot keep up with traffic.
Bytes Sent	Cumulative size, in bytes, of messages sent since statistics were last reset
Bytes Received	Cumulative size, in bytes, of messages received since statistics were last reset
Bytes Current	Size, in bytes, of the current messages waiting to be read
Queue Attributes	The type of queue, permanent or temporary. Any queue defined in the Configure Queues dialog is by default a primary queue. Queue 100, a reserved queue, is labeled Reserved

Viewing Queue Traffic Rates

Use the Queue Information and Traffic Rates menu items to view the traffic rates of all queues of a particular group. Traffic rates are defined as the throughput of messages, either sent or received, per second. The Queue Traffic Rates dialog allows you to verify that suspected problems with message throughput exist.

Note that you must reset statistics each time you monitor traffic rates. Failing to do so will result in an inaccurate throughput assessment.

Table 4-6 describes the fields of the Queue Traffic Rates dialog.

Table 4-6 Queue Traffic Rates Dialog

Statistic	Description
Queue Number	Number of the queue
Messages Sent per Second	Average number of messages sent per second since statistics were last reset
Messages Received per Second	Average number of messages received per second since statistics were last reset
Bytes Sent per Second	Average number of bytes sent per second since statistics were last reset
Bytes Received per Second	Average number of bytes received per second since statistics were last reset
Peak Messages	Highest number of messages in the queue at any given time since statistics were last reset.
Peak Bytes	Highest number of bytes in the queue at any given time since statistics were last reset.
Queue Attributes	The type of queue, permanent or temporary. Any queue defined in the Configure Queue dialog is by default a primary queue. Queue 100, a reserved queue, is labeled Reserved.

If you expect to see activity in the messages sent and received per second fields, but see 0.00 instead, try resetting the statistics. If an attached queue is inactive for a significant amount of time, the messages sent/received per second values approach zero because the value is derived as an average since statistics were last reset. Unless statistics are reset, these fields will not give an accurate assessment of recent queue activity.

Viewing Queue Traffic Detail

Use the Queue Information and Traffic Detail menu items to view the message and byte traffic rates of a single queue. Table 4-7 describes the fields of the Queue Traffic Detail dialog.

Table 4-7 Queue Traffic Detail Dialog

Statistic	Description
Queue Number	Number of the queue
Queue Attributes	The type of queue, permanent or temporary. Any queue defined in the Configure Queue dialog is by default a primary queue. Queue 100, a reserved queue, is labeled Reserved.
Messages Sent per Second	Average number of messages sent per second since statistics were last reset
Messages Received per Second	Average number of messages received per second since statistics were last reset
Bytes Sent per Second	Average number of bytes sent per second since statistics were last reset
Bytes Received per Second	Average number of bytes received per second since statistics were last reset
Peak Messages	Highest number of messages in the queue at any given time since statistics were last reset
Peak Bytes	Highest number of bytes in the queue at any given time since statistics were last reset

Viewing Queue Detail

Use the Queue Information and Detail screen to view the attributes of a selected queue. If quotas have been enabled, they can be viewed from this dialog. Queue Information and Detail shows the last time a queue was attached and detached, which can be useful for determining whether or not your application is truly interacting with a queue.

Table 4-8 describes the fields of the Queue Detail dialog.

Table 4-8 Queue Detail Dialog

Statistic	Description
Queue Number	Number of the queue
Queue Name	Name of the queue
Primary Queue	If the queue is secondary, the queue number of the controlling queue
Queue Attributes	The type of queue, permanent or temporary. Any queue defined in the Configure Queue dialog is by default a primary queue. Queue 100, a reserved queue, is labeled Reserved.
Owner PID	Process ID of the attached queue
Total Messages	Cumulative messages sent and received from the time statistics were last reset
Total Bytes	Cumulative bytes sent and received from the time statistics were last reset
Message Quotas	The maximum limit of uncollected messages that can reside in this queue, and the current number. This value is set by the Messages Quota parameter in the %QCT section of the group initialization file.
Byte Quotas	The maximum limit of uncollected bytes that can reside in this queue, and the current number. This value is set by the Bytes Quota parameter of the %QCT section of the group initialization file.