Shows Workload Manager (WLM) per class resource utilization statistics.
wlmstat [-l Class | -t Tier] [-S | -s] [-@] [-c ] [-m] [-b] [-B Device] [-T] [-a] [-w] [-v] [Interval] [Count]
wlmstat [-l Class | -t Tier] [-@] [-c] [-m] [-b] [-u] [Interval] [Count]
wlmstat [-l Class | -t Tier] [-@] [-M] [-S | -s] [-w] [-v] [Interval] [Count]
The wlmstat command symbolically displays the contents of WLM data structures retrieved from the kernel. If a Count is specified, wlmstat loops Count times and sleeps Interval seconds after each block is displayed. If Interval and Count are not specified, one output report is produced. If Interval is specified but no Count is given, wlmstat outputs results continuously at the given interval until stopped by a signal (SIGINTR, SIGQUIT, and SIGKILL). By default, wlmstat displays the statistics for all the resources for every superclass and subclass. You can specify flags to narrow the focus of the statistics to a type of resource, tier, superclass, or subclass and alter the output format.
It is possible for a process with a hard limit of 50 percent to use more than 50 percent of the processor between two consecutive WLM usage updates. Each tenth of a second, every process is assigned a priority, and the scheduler then schedules all processes based on their assigned priorities. A process might receive more of the processor resources than the process hard limit between WLM updates.
By default, each instantaneous value of processor usage from each update is kept for the following 15 readings and is averaged with the other 14 readings before being displayed by wlmstat. This can potentially result in a value of greater than 50 percent due to a single instance of more than 50 percent usage between WLM updates.
The priority of a process will be greatly reduced and the process will be unable to run if the process consistently reaches or exceeds its hard limit. Over the long term, the resource utilization of the process must be at or under the process hard maximum. Over a short time interval, wlmstat may show the process using more than the process hard limit. The /usr/samples/kernel/wlmtune command that is available in the bos.adt.samples PTF can be used to modify the behavior of WLM in such an instance. The related tunables are:
To make WLM more responsive so that classes do not exceed their maximums over long periods, it is recommended that you first try modifying schedhz until the wlmstat output displays the desired results. You may want to also modify cpuhist so that wlmstat averages over the same time interval. For example, if schedhz is 20 and cpuhist is 15, wlmstat will average over a period of 0.75 seconds (15/20), so you may want to change cpuhist to 30 so that wlmstat still averages over 1.5 seconds.
On systems with no contention for processor, an Interval of 5 for wlmstat is recommended in order to adhere to WLM limits.
Item | Description |
---|---|
-@ | Displays workload partition resource information. |
-a | Displays subclass consumption in absolute terms. By default, the subclass consumption percentages are shown relative to the superclass consumption. With this option, subclass consumption is displayed relative to the total amount of resource available on the system (as is done for superclasses). All values are displayed with 1% precision. For instance, if a superclass has a processor target of 20% and the processor percentage shown by wlmstat without -a for a subclass is 10%, wlmstat with -a shows the processor percentage for the subclass as 2%. |
-b | Displays only disk I/O statistics. |
-B Device | Displays disk I/O device statistics. Passing an empty string (-B "") displays the statistics for all the disks accessed by the class. |
-c | Shows only processor statistics. |
-l Class | Displays statistics for Class name. If not specified, all classes display along with a summary for appropriate fields. |
-m | Shows only physical memory statistics. |
-M | Displays the Real/Virtual Memory statistics. Use of the -M option
adds the following columns in the output:
Note: A - will be displayed for the RMLIM, VMLIM,
and LGPGLIM fields if the limit is undefined.
When the -M and -w options
are used together, RMSIZ and VMSIZ fields
contain the high watermarks for these attributes instead of the actual
utilized values. In addition, the LGPGSIZ and LGPGLIM fields
is turned off.
|
-s | Displays only subclass statistics. |
-S | Displays only superclasses statistics. |
-t Tier | Displays statistics only for the specified Tier. |
-T | Displays the total numbers for resource utilization since WLM
was started or the class was created, whichever is the latter. The
units are:
|
-v | Specifies verbose mode. This flag, intended for trouble shooting,
also displays some class attributes, resource shares and limits and
other WLM parameters, including internal parameter values intended
for AIX support personnel.
The following information can be of interest for users:
The other columns are for internal use only and bear no meaning for administrators and end users. This format is better used with a resource selector (-c, -m, or -b), otherwise the lines might be too long to fit into a line of a display terminal. |
-w | Displays the memory high water mark, that is the maximum number of pages that a class had in memory at any given time since WLM was started or the class was created (whichever happened last). |
-u | Displays per-tier and total unused resources. |
Results are tabulated, with the following fields:
Name | Class name |
---|---|
CPU | Percentage of total processor time consumed by the class. |
MEM | Percentage of physical memory consumed by the class. |
DKIO | Percentage of the disk IO bandwidth consumed by the class. This number is the average of the disk bandwidth on all the disk devices accessed by the class, and is usually not significant. For instance if a class consumes 80% of the bandwidth of one disk and 5% of the bandwidth of two other disks, the DKIO column shows 30%. For details on the per device utilization, use the -B device option. |
wlmstat
This produces the following output:
CLASS CPU MEM DKIO
Unclassified 0 0 0
Unmanaged 0 0 0
Default 0 0 0
Shared 0 0 0
System 0 0 0
class1 12 0 0
class1.Default 4 0 0
class1.Shared 0 0 0
class1.subclass1 4 0 0
class1.subclass2 4 0 0
class2 12 0 0
class2.Default 4 0 0
class2.Shared 0 0 0
class2.subclass1 4 0 0
class2.subclass2 4 0 0
wlmstat -l class1
CLASS CPU MEM DKIO
class1 12 0 0
class1.Default 4 0 0
class1.Shared 0 0 0
class1.subclass1 4 0 0
class1.subclass2 4 0 0
wlmstat -l class1.subclass2 10 6
CLASS CPU MEM DKIO
class1.subclass2 4 0 0
class1.subclass2 4 0 0
class1.subclass2 4 0 0
class1.subclass2 4 0 0
class1.subclass2 4 0 0
class1.subclass2 4 0 0
wlmstat -M
CLASS RMSIZ RMLIM VMSIZ VMLIM LGPGSIZ LGPGLIM
Unmanaged 1024 4096 4096 8192 0 -
Default 0 - 0 - 0 -
Shared 0 - 0 - 0 -
System 23567 50000 819234 1000000 0 -
wlmstat -M -w
CLASS RMSIZ RMLIM VMSIZ VMLIM
Unmanaged 1024 4096 4096 8192
Default 0 - 0 -
Shared 0 - 0 -
System 23567 50000 819234 1000000
A warning message is issued by wlmstat if WLM is not started.