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====== WPAR: using Worload Manager to contol ressource between WPAR ======

===== Concept =====

On WPAR, it's possible to limit many parmeters, but it can be dangerous! The best practice is to only limit the CPU utilization. If you limit the memory on a WPAR, this WPAR can die.

**Important:** Keep in mind that when you specify the minimum, soft maximum, and hard maximum percentages, the following rules apply:
  * The sum of minimum percentage for all running WPARs must not exceed 100.
  * For each WPAR, the minimum percentage must not exceed the soft maximum percentage.
  * For each WPAR, the soft maximum percentage must not exceed the hard maximum percentage.

Parameters to change in case of CPU limitation:
<code>
  - shares_CPU=<n> 
    Specifies the number of processor shares available for the WPAR. Shares value can be from 1 to 65535.
</code>
<code>
  - CPU=<min>%-<sMax>%,<hMax>% 
    Specifies <min> as the minimum CPU percentage, <sMax> as the soft maximum CPU percentage and <hMax> as the hard maximum CPU percentage for the WPAR.
</code>

==== Using share-based resource control ====

The share-based approach implies allocating available CPU resources to WPARs based on their importance. The total amount of processing power is conceptually divided in shares.

Example:
<code>
Assume there are two WPARs: WPAR A is assigned 5 shares and WPAR B is assigned 10 shares.
– The total number of shares is 5+10=15.
– The WPAR A percentage is 5/15=33%.
– The WPAR B percentage is 10/15=66%.
Therefore, WLM assigns 33% of the existing CPU resources to WPAR A, and 66% of existing CPU resources to WPAR B.

A new WPAR named WPAR C is added to the system and assigned 15 shares.
– The total number of shares is now 5+10+15=30.
– The WPAR A new percentage is 5/30=17%.
– The WPAR B new percentage is 10/30=33%.
– The WPAR C new percentage is=15/30=50%.
</code>

==== Using percentage-based resource control ====

Consider using percentage-based controls in these cases:
  * When you want to guarantee at all times that a minimum amount of CPU resources is available for a WPAR
  * When you want to limit the maximum amount of CPU resources a WPAR can use

- The minimum percentage value reflects the amount of CPU resource capacity allocated to a WPAR. If the WPAR uses less than this amount, depending on the WLM setup, one of the following conditions will occur:
  * The amount of CPU resources will be reserved for the WPAR’s exclusive usage and will not be redistributed to the global environment.
  * WLM will raise the priority of WPAR processes and redistribute the unused amount to the global environment. If at any time later the WPAR needs the unused  resource it can reclaim it, and because it has the highest priority, it will get it.

- The soft maximum percentage reflects the maximum amount of CPU resources a WPAR may ever get when contention conditions for CPU resources occur. If the system has enough CPU power and contention does not occur, then the WPAR may go over this limit.

- The hard maximum percentage is the absolute amount of CPU resources that a WPAR may ever have. This limit can never be exceeded.

===== Setup Worload Manager =====

Change the settings shares_CPU and CPU (dynamic):
<code>
# chwpar -R shares_CPU=100 CPU=6%-30%,45% wpar01
</code>

List the settings on the WPAR:
<code>
# lswpar -R wpar01
=================================================================
wpar01 - Active
Tip: We recommend that you start with the share-based approach to control
the resources. In almost all cases, your requirements will be met.
=================================================================
Active: yes
RSet:
CPU Shares: 100
CPU Limits: 6%-30%,45%
</code>

====== WPAR: preview ressources used for a WPAR ======

List WPAR ressources:
<code>
[root@lpartest]/root# lswpar -R
=================================================================
wpar01 - Active
=================================================================
Active:                             yes
Resource Set:
CPU Shares:                         unlimited
CPU Limits:                         0%-100%,100%
Memory Shares:                      unlimited
Memory Limits:                      0%-100%,100%
Per-Process Virtual Memory Limit:   unlimited
Total Virtual Memory Limit:         unlimited
Total Processes:                    unlimited
Total Threads:                      unlimited
Total PTYs:                         unlimited
Total Large Pages:                  unlimited
Max Message Queue IDs:              100%
Max Semaphore IDs:                  100%
Max Shared Memory IDs:              100%
Max Pinned Memory:                  100%

=================================================================
wpar02 - Active
=================================================================
Active:                             yes
Resource Set:
CPU Shares:                         unlimited
CPU Limits:                         0%-100%,100%
Memory Shares:                      unlimited
Memory Limits:                      0%-100%,100%
Per-Process Virtual Memory Limit:   unlimited
Total Virtual Memory Limit:         unlimited
Total Processes:                    unlimited
Total Threads:                      unlimited
Total PTYs:                         unlimited
Total Large Pages:                  unlimited
Max Message Queue IDs:              100%
Max Semaphore IDs:                  100%
Max Shared Memory IDs:              100%
Max Pinned Memory:                  100%
</code>

Worload Manager command:
<code>
# wlmstat -@
   CLASS    CPU    MEM   DKIO 
  wpar01   5.79   6.49   0.00 
  wpar02   0.07   1.90   0.00 
  wpar03  40.06   6.48   0.00 
  wpar04   0.06   0.55   0.00 
  wpar05   0.14   4.85   0.00 
  wpar06  16.96   9.87   0.00 
  wpar07   0.16   4.90   0.00 
  wpar08  32.94  10.98  13.61 
  wpar09   0.07   5.38   0.00 
  wpar10   0.07   0.42   0.00 
   TOTAL  96.32  51.82  13.61 
</code>
<code>
# wlmstat -@ 2
</code>

Topas command, real time:
<code>
# topas -@
then press: W
Topas Monitor for host:    lpartest    Interval:   2    Thu Apr 28 11:53:21 2011
WPAR                            CPU%      Mem%     Blk-I/O%
wpar08                          45        11            0
wpar06                          27        10            0
wpar01                           8         7            0
wpar03                           6         6            0
wpar07                           5         6            0
wpar05                           0         5            0
wpar09                           0         5            0
wpar02                           0         2            0 
wpar04                           0         1            0
==============================================================================
                                DATA  TEXT  PAGE               PGFAULTS
USER        PID    PPID PRI NI   RES   RES SPACE    TIME CPU%  I/O  OTH COMMAND
oracle  11534960 6094944  79 20  4153 22182  4153    5:12  2.0    0    1 oracle
oracle  18022546 5832948  80 20  7442 22182  7442    4:38  2.0    0    2 oracle
oracle  40960816 11141160  89 20 19903 22182 19903    3:07  2.0    0    2 oracle
oracle  6619350 11141160  70 20  9650 22182  9650    1:50  2.0    0    2 oracle
oracle  6750896 5046504  74 20  6646 22182  6646    0:40  2.0    0    0 oracle
oracle  62849486 11141160  69 20  7397 22182  7397  111:36  2.0    0    1 oracle
</code>

//Reference:// sg247656 Workload Partition Management in IBM AIX Version 6.1 (Redbook IBM http://www.redbooks.ibm.com/)
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