Workload Manager for AIX 4.3.3.0 Standards
This document describes the Workload Manager implementation
standards on AIX 4.3.3.0 machines only. For WLM implementation on
AIX version 5 systems, see the AIX 5 WLM
standards document.
The workload manager (WLM) shall be implemented on all AIX systems.
On most systems WLM will be running in "passive" mode, which does not
limit resources. In CGE's environment, only a few selected systems will
have WLM implemented in "active" mode to control and regulate resources.
If there is any question as to whether WLM should be implemented in
"active" or "passive" mode, default to "passive".
The WLM provides a mechanism to classify and segment resources by
process, user, group, etc. The classification scheme must be
constructed by the AIX system administrator. This WLM classification
scheme in the CGE environment is based on the concept of the Resource
Group. Each Resource Group will be represented in WLM as a class.
Multiple instances of an application within a single resource group
shall be represented in WLM as subclasses.
In order to configure WLM, the system administrator must first
define the resource groups names. Once
the resource group names have been defined, then a WLM class must be
defined using the resource group name as the WLM class name.
To define a new WLM class using smitty, start smitty using the "wlm"
fastpath.
smitty wlm
Select "Add a class" to define a new WLM class.
Workload Management
Move cursor to desired item and press Enter.
List all Classes
Add a Class
Change / Show Characteristics of a Class
Remove a Class
Class Assignment Rules
Start/Stop/Update WLM
Enter the resource group name as the WLM class name, and provide a
description of this WLM class. The Tier level will normally be 0 (zero)
unless there is a specific reason to change this. The CPU and Memory
values will be defaulted to a minumum of 0% and a maximum value of
100%.
Add a Class
Type or select values in entry fields.
Press Enter AFTER making all desired changes.
[Entry Fields]
Class name [atladtu1]
Description [Atlas pre-prod Database for TXU, instance 1]
Tier [0]
Minimum CPU time (%) [0]
Maximum CPU time (%) [100]
Shares of CPU [1]
Minimum Memory (%) [0]
Maximum Memory (%) [100]
Shares of Memory [1]
Class rules are used to determine which processes are assigned to
which WLM classes and the order of the rules is significant. The first
rule that matches is used to determine the WLM class assignment, so the
class rules should be ordered from highly specific to less specific.
To define WLM class rules using smitty, start smitty using the "wlm"
fastpath.
smitty wlm
Select "Class assignment rules" to define a new WLM class.
Workload Management
Move cursor to desired item and press Enter.
List all Classes
Add a Class
Change / Show Characteristics of a Class
Remove a Class
Class Assignment Rules
Start/Stop/Update WLM
Select "Class assignment rules" to define a new WLM class rule.
Class Assignment Rules
Move cursor to desired item and press Enter.
List all Rules
Create a new Rule
Change / Show Characteristics of a Rule
Delete a Rule
In the following example, a rule is defined to assign all processes
owned by oracl817 to the the WLM class "atladtu1". Again the order of
the rules is important. The rules should be ranked in order of highly
specific, starting at 1, to less specific.
Create a new Rule
Type or select values in entry fields.
Press Enter AFTER making all desired changes.
[Entry Fields]
* Order of the Rule [1]
* Class [atladtu1]
User [oracl817]
Group [-]
Application [-]
Under AIX 4.3.3.0, to start WLM in passive mode, it
must be done from the command line. If WLM is started from "smitty", it
will be started in "active" mode. So to be safe and exact, always
start/stop WLM from the command line using the appropriate flags.
To start WLM from the command line in "passive" mode:
wlmcntrl -p
To start WLM from the command line in "active" mode:
wlmcntrl -a
To stop WLM from the command:
wlmcntrl -o
Any changes to the WLM configuration will require that WLM be stopped
and restarted in order for the changes to take effect.
An example WLM configuration of the Atlas pre-production Database
server for TXU follows. The "standard" WLM configuration for this
machine contains five WLM classes. It is important to recognize that
the "standard" WLM configuration will be different for every machine.
The term "standard" is used in reference to the local machine, this is
not enterprise wide terminology used here.
The AIX 4.3.3.0 WLM does not support the concept of subclasses,
therefore multiple instances of an application will likely be configured
as multiple WLM classes, requiring multiple resource groups. Since the
AIX 4.3.3.0 WLM does not support subclasses, the WLM configuration will
be different between AIX 4.3.3.0 and AIX 5.X systems.
- ddcadatl01:/etc/wlm/standard/classes
-
System:
Default:
atladtu1:
description = "Atlas pre-prod Database for TXU, AMST instance"
atladtu2:
description = "Atlas pre-prod Database for TXU, C2KR instance"
atladtu3:
description = "Atlas pre-prod Database for TXU, ATLP instance"
The class rules associated with this "standard" configuration assign
processes to multiple classes depending upon the user id. Rules are
defined to segment the processes owned by the three oracle instances
into separate WLM classes. All processes owned by "root" are assigned
to the class "System", and all other processes are assigned to the class
"Default".
- ddcadatl01:/etc/wlm/standard/rules
-
* class resvd user group application
atladtu1 - oracl817 - -
atladtu2 - oracle8i - -
atladtu3 - oracle - -
System - root - -
Default - - - -
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