4.3.5 Output Format and Contents

The records of resource depletion monitoring information are output in CSV format files.

The following figure shows the output format:

Figure 4‒1: Output format of resource depletion monitoring information

The output format is described below:

The title line is output after every 100 lines so that contents of each column are understood clearly.
The following items are output in the title as common information of resources. These items are output in the place of "Title1", "Title2", "Title3"... in the figure.
- Rate: Rate (usage)
- Current: Current value
- Max: Maximum value
- Threshold: Threshold value
Apart from this, required information is output for each resource. For details, see the output contents of each resource.
Result of determining the threshold value is output in the order of current value followed by the set threshold value. If multiple threshold values are determined multiple values are output.
If threshold value is set in %, the calculation result of threshold value is also output in %. For example, if the calculation result is 0.752, and you have specified the threshold value in %, the calculation result is output as 75.2.
If threshold value is an absolute value, the calculation result of the threshold value is not output.
If an upper limit is not set for the threshold value, the calculation result of threshold value is output as -.
If the value is in decimals, the second place after the decimal is rounded off and the value with one place after the decimal point is output. Even when determining a threshold value, the second place after the decimal is rounded off and the threshold value with one place after the decimal is used.

The file output contents depend on the values set in usrconf.properties, application attributes, or resource adapter attributes.

The output information for each is described in the following sections.

Organization of this subsection

(1) Monitoring information of memory depletion
(2) Monitoring information of depletion of file descriptors
(3) Monitoring information of thread depletion
(4) Monitoring information of depletion of thread dump
(5) Monitoring information of depletion of queue of HTTP requests pending execution
(6) Monitoring information of the number of depleted sessions
(7) Monitoring information of the depletion of connection pool

(1) Monitoring information of memory depletion

The following table describes the information output in monitoring information of memory depletion:

Table 4‒6: Contents output in monitoring information for memory depletion
Character string of output title	Output contents
Rate1	If serial GC is enabled: Memory usage of the Old area is output. The unit is %. The memory usage of the Old area is calculated using the following formula: Memory usage of the Old area = Size of occupied Old area / Total size of Old area × 100 (Rate1 = (Total [Old] - Free [Old]) / Total [Old] × 100) If G1 GC is enabled: The Java heap space usage is output. The unit is %. The memory usage in the Java heap space is calculated using the following formula: Memory usage in the Java heap space [%] = Size of the Java heap space that is used / size of the entire Java heap space × 100
Rate2	If serial GC is enabled: Total memory usage of the New area is output for maximum free memory in the Old area. The unit is %. Total memory usage of the New area for the maximum free memory in the Old area is calculated using the following formula: Total memory usage of the New area for the maximum free memory in the Old area = Total size of New area / Maximum free size in the Old area × 100 (Rate2 = Total [New] / (Max [Old] - (Total [Old] - Free [Old])) × 100) Note that this value may exceed 100. If G1 GC is enabled: No information is output for this item. The value `-1` is always output.
Rate3	Memory usage of the Metaspace area is output. The unit is %. The memory usage of the Metaspace area is calculated using the following formula: Memory usage of the Metaspace area = Occupied size of Metaspace area / Total size of Metaspace area × 100 (Rate3 = (Total [Permanent] - Free [Permanent]) / Total [Permanent] × 100)
Free [New]	The free memory size of the New area is output. The unit is bytes.
Total [New]	The total memory size of the New area is output. The unit is bytes.
Max [New]	If serial GC is enabled: The maximum memory size of the New area is output. The unit is bytes. If G1 GC is enabled: No information is output for this item. The value `-1` is always output.
Free [Old]	The free memory size of the Old area is output. The unit is bytes.
Total [Old]	The total memory size of the Old area is output. The unit is bytes.
Max [Old]	If serial GC is enabled: The maximum memory size of the Old area is output. The unit is bytes. If G1 GC is enabled: The maximum size of memory available in the Java heap space is output.
Free [Permanent]	The free memory size of the Metaspace area is output. The unit is bytes.
Total [Permanent]	The total memory size of the Metaspace area is output. The unit is bytes.
Max [Permanent]	The maximum memory size of the Metaspace area is output. The unit is bytes.
Threshold	Threshold value is output. The unit is %.

Important note

The memory depletion monitoring functionality assumes that it is used in a system in which memory requirements have been estimated properly and the settings are tuned so that Full GC is unlikely to occur. This functionality is aimed at detecting symptoms that trigger Full GC, resulting in a temporary stop of the application. Note that if the memory tuning is insufficient, unnecessary alerts may be output.

To monitor memory depletion, you must set the same value for the maximum size and initial size of the Metaspace area. To be more precise, set the same value for the -XX:MaxMetaspaceSize and -XX:MetaspaceSize of usrconf.cfg. If different values are specified, alerts might be issued even during the expansion of the Metaspace area. For details on other tuning parameters, see the information on the Oracle website.

Although this functionality monitors memory usage, Full GC does not always occur when the percentage of memory usage has become close to 100%. The monitoring results are used to detect symptoms that are highly likely to trigger Full GC.
From Application Server 09-00 onwards, the Java heap is efficiently utilized so that Full GC is unlikely to occur. For this reason, an unnecessary alert might be generated if the system continues to operate at high usage of Java heap space. To stop alert generation for Rate1, adjust the threshold. To stop alert generation for Rate2, set ejbserver.watch.memory.rate2alert.enabled=false in the usrconf.properties file.

Reference note

The heap and memory of JavaVM contain the following three types of areas:

New area

This area is applicable to Eden and Survivor. This area stores new objects.
Old area

This area is applicable to Tenured. This area stores objects existing for a long time.
Metaspace area

This area stores classes loaded in JavaVM.

The term Metaspace area has been adopted in Application Server 09-70 onwards.

In earlier versions of Application Server than 09-70, this area was called Permanent area. Therefore, the string Permanent is used, for compatibility with old versions, in the header strings for the output information items that indicate Metaspace area sizes.

The Information of free area, occupied area, and maximum area size for each of these areas at that point of time is output in memory monitoring result.

If memory monitoring is set, messages are output in the following cases:

If the occupied size of the Old area corresponding to the total size of the Old area exceeds the threshold value (when serial GC is enabled)

The message is output if "Occupied size of Old area / Total size of Old area × 100 ≥threshold value(%)".
If the total size of the New area corresponding to the maximum free size of the Old area exceeds the threshold value (when serial GC is enabled)

The message is output if "Total size of New area / Maximum free size of Old area × 100 ≥threshold value(%)".
If the percentage of the used Java heap area size in the entire Java heap area size reaches or exceeds the threshold value (when G1 GC is enabled)

A message is output if "Used Java heap area size / Total size of Java heap area × 100 ≥ Threshold value (%)".
If the percentage of the used Metaspace area size in the entire Metaspace area size reaches or exceeds the threshold value

A message is output if "Used Metaspace area size / Maximum Metaspace area size × 100 ≥ Threshold value (%)".

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(2) Monitoring information of depletion of file descriptors

The following table describes the information output in the result of monitoring file descriptors information. You cannot monitor the number of file descriptors in Windows or AIX.

Table 4‒7: Contents output in the monitoring information for depletion of file descriptors
Character string of output title	Output contents
Current	The number of file descriptors used by J2EE server processes is output.
Max	The number of file descriptors that can be allocated to a process is output.
Threshold	Threshold value is output.

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(3) Monitoring information of thread depletion

The following table describes the information output in monitoring information of thread depletion:

Table 4‒8: Contents output in the monitoring information for thread depletion
Character string of output title	Output contents
Current	The number of threads using self-process is output.
Max	In Windows Normally "-" is output In UNIX Number of threads that can be generated by a process is output.
Threshold	Threshold value is output.

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(4) Monitoring information of depletion of thread dump

The following table describes the information output in the monitoring information of depletion of thread dump:

Table 4‒9: Contents output in the monitoring information for thread dump depletion
Character string of output title	Output contents
Rate	The percentage of number of files of the current thread dump corresponding to its maximum value is output. The unit is %.
Current	The current value of the number of thread dump files is output.
Max	The upper limit of the number of thread dump files is output.
Threshold	Threshold value is output. The unit is %.

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(5) Monitoring information of depletion of queue of HTTP requests pending execution

The queue of HTTP requests pending execution is the pending queue for Web applications and the default pending queue corresponding to the concurrently executing threads of the Web application.

The following table describes the information output in the monitoring information depletion of queue of HTTP request pending execution. This depletion monitoring information includes the following two types of information:

Result of monitoring the number of default stored requests of the pending queues for each J2EE server.

Result of monitoring the number of stored queues of requests pending execution for each Web application.

Table 4‒10: Contents output in the monitoring information for depletion of HTTP requests pending queue
Character string of output title	Output contents
J2eeApplicationName	The J2EE application name is output. For monitoring results of default queue of requests pending execution, "-" is output.
ContextRootName	Context root name is output. For monitoring results of default queue of requests pending execution, "-" is output.
Rate	The percentage of the number of currently stored queues corresponding to its maximum value is output. The unit is %.
Current	The current value of the number of stored queues is output.
Max	The maximum value of the number of requests stored in the pending queue for Web applications and the default pending queue is output.
Threshold	Threshold value is output. The unit is %.

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(6) Monitoring information of the number of depleted sessions

The following table describes the information output in monitoring information of the number of depleted sessions:

Table 4‒11: Contents output in the monitoring information for depletion of the number of sessions
Character string of output title	Output contents
J2eeApplicationName	The J2EE application name is output.
ContextRootName	Context root name is output.
Rate	The percentage of the number of current sessions created corresponding to its maximum value is output. The unit is %. If the maximum value is not set, "-" is output.
Current	The current value of the number of sessions is output.
Max	The maximum value of the number of sessions is output. If the maximum value is not set, "-" is output.
Threshold	Threshold value is output. The unit is %.

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(7) Monitoring information of the depletion of connection pool

The following table describes the information output in monitoring information of depletion of a connection pool:

Table 4‒12: Contents output in the monitoring information for connection pool depletion
Character string of output title	Output contents
ResourceName	The resource adapter name given by the user is output in the following format: When the resource adapter is directly deployed on a J2EE server `Resource-adapter-name` When the resource adapter is deployed by including in a J2EE application `J2EE-application-name:Resource-adapter-name` When the resource adapter is deployed by including in a J2EE application, and then starting in the test mode `TEST#J2EE-application-name:Resource-adapter-name`
Rate	The usage of a connection pool is output. The unit is %. If the maximum value of the number of connections is infinite, "-" is output.
Active	The number of connections in use is output.
Free	The number of unused connections is output.
Current	The current value of the number of connections is output. ^#
Min	The minimum value of the number of connections is output.
Max	The maximum value of the number of connections is output. If a connection pool is infinite, "-1" is output.
Threshold	Threshold value is output. The unit is %.
All	The total number of connections (total number of connections managed in connection pool and not managed in connection pool) is output.^#

#: Depending on the timing when the connection is established, a value greater than All might be output to Current temporarily.

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