gwlm(5)gwlm(5)NAMEgwlm - Global Workload Manager: Overview
DESCRIPTION
Global Workload Manager (gWLM) allows you to centrally define resource-
sharing policies that you can use across multiple HP servers. Using
these policies can increase system utilization and facilitate con‐
trolled sharing of system resources. In addition, gWLM provides both
real-time and historical monitoring of the resource allocation.
gWLM consists of a VSE Central Management Server, or CMS. You configure
gWLM and monitor your workloads from the system where the CMS software
is installed. Also, you use agent software on the systems where you
have workloads you want gWLM to manage.
MANUALLY ADJUSTING CPU RESOURCES
When an SRD is created, it has a certain number of cores. gWLM manages
the SRD using the same number of cores. If the SRD--or a policy used in
the SRD--is configured to use Temporary Instant Capacity (TiCAP), gWLM
can automatically activate that additional capacity to meet policies.
If neither the SRD nor its policies are configured to use TiCAP, you
may be able to temporarily provide additional resources to a deployed
SRD by:
+ Using an available core from the vpar monitor free pool.
+ Activating an iCAP core.
+ Deleting a core from an unmanaged vpar and then adding it to a
vpar in the SRD.
+ Deactivating a core in an npar and then activating one in an
npar in the SRD.
NOTE: If gWLM detects activated cores for which there is no request, it
deactivates them to avoid spending money on the unneeded capacity.
NOTE: After you manually change system resources (by modifying unman‐
aged partitions or changing bindings, for example), you might see
resize errors on one or more of the managed nodes. However, gWLM should
recover (and stop issuing errors) by the next resource allocation
interval--unless gWLM can no longer access the required resources.
NOTE: Deployed SRDs do not accept manual decreases in the available
resources. gWLM will attempt to reclaim any removed resources.
NOTE: Although a deployed SRD might recognize added resources, policy
maximum values are still in effect and can clip resource requests. Con‐
sider adjusting policy settings to use the added resources.
As already mentioned, gWLM can take advantage of the additional CPU
resources only temporarily. To take full, persistent advantage of the
extra resources using the gWLM command-line interface:
1. Undeploy the SRD containing the systems that were adjusted.
2. Re-create and re-deploy the SRD.
3. Ensure policies used in the SRD do not unintentionally limit
their associated workloads' resource requests.
To take full, persistent advantage of the extra resources using the
gWLM interface in HP SIM:
1. Modify the size of the SRD.
a. Select the SRD affected by the additional resources in the
Shared Resource Domain View.
b. Select the menu item Modify -> Shared Resource Domain.
c. Select the tab Workload and Policies.
d. Adjust the size of the SRD by editing the value, beneath
the table, labeled "Total Size."
e. Select the OK button.
2. Edit policies used in the SRD to ensure they do not uninten‐
tionally limit their associated workloads' resource requests.
gWLM cannot take advantage--even temporarily--of resources added by:
+ Adjustments to entitlements for virtual machines.
+ Changes to a virtual machine's number of virtual CPUs while
gWLM is managing the virtual machine.
+ Creation or deletion of a pset using psrset on a system where
gWLM is managing pset compartments.
+ Performing online cell operations using parolrad.
+ Enabling/disabling Hyper-Threading.
To make use of these additional resources using the gWLM command-line
interface:
1. Undeploy the SRD containing the systems that you want to
adjust.
2. Make your adjustments.
3. Re-create and re-deploy the SRD.
4. Ensure policies used in the SRD do not unintentionally limit
their associated workloads' resource requests.
To make use of these additional resources using the gWLM interface in
HP SIM, follow the procedure given for that interface above.
NOTE: After manually adjusting the number of cores in an SRD, always
confirm the changes after two gWLM resource allocation intervals have
passed. Changes may not be as expected due to gWLM behaviors such as
the ones described below.
* In an SRD with nested partitions, gWLM samples the inner par‐
titions for their sizes before sampling the outer partitions.
Adjusting resources between these samplings can cause gWLM to
report incorrect sizes. If you encounter this issue, try mak‐
ing your adjustment again.
* In an SRD with nested partitions that includes vpars, assume
you manually add cores from an unmanaged vpar. If you later
remove those cores--without returning them to an unmanaged
vpar before gWLM samples compartment sizes--those cores are
deactivated.
MANUALLY ADJUSTING MEMORY RESOURCES
The vparmodify command enables you to move memory from one vpar to
another. However, gWLM cannot move CPU resources while a vparmodify
operation is in progress. If a memory move takes longer than gWLM's
resource allocation interval, gWLM will not be able to satisfy CPU
resource requests for the missed intervals. gWLM resumes allocating
resources once the memory move is complete.
HYPER-THREADING
Hyper-Threading, available starting with HP-UX 11i v3 (B.11.31),
enables you to use multiple execution threads per core. (Cores were
formerly known as CPUs.) Each execution thread is a logical CPU.
Utilization is based on the usage of a core--not a logical CPU. For
example, assume a four-core system has Hyper-Threading enabled so that
it has eight logical CPUs. If the system has four processes, each con‐
suming an entire logical CPU, the reported utilization depends on where
those processes are. If the processes are on only two cores, the uti‐
lization is 50% (2/4). With the processes distributed across all four
cores though, each process can consume an entire core, resulting in a
utilization of 100%.
When fss groups are being used, gWLM disables Hyper-Threading for the
default pset, where fss groups are created, to optimize workload per‐
formance.
When an SRD is undeployed, gwlmagent restores the lcpu_attr tunable to
the value it had when the system booted. This value can be different
from the value in effect before deployment if kctune was used without a
reboot.
FOR MORE INFORMATION
The list below indicates where you can find additional information.
+ To view the structure (npars, vpars, ...) of your systems
VSE Management Page in HP Systems Insight Manager
(Tools -> VSE Management)
+ To learn about configuring, backing up, and maintaining your CMS
vseinitconfig(1M) manpage
+ To use gWLM immediately, reading as little as possible, see
gWLM Home Page in HP Systems Insight Manager
(Tools -> VSE Management, then select the Shared Resource Domain tab,
then Tools -> Global Workload Manager ->
Getting Started - gWLM Home)
or
"Global Workload Manager" topic in online help*
or
HP Global Workload Manager User's Guide
(http://docs.hp.com/en/vse.html**)
+ To learn about gWLM concepts, see
"Global Workload Manager" topic in online help*
or
HP Global Workload Manager User's Guide
(http://docs.hp.com/en/vse.html**)
+ To learn gWLM terms, see
glossary in online help*
+ To learn gWLM best practices, see
"Getting the Most Out of gWLM" topic in online help*
+ To learn about other gWLM features, see
HP Global Workload Manager User's Guide
(http://docs.hp.com/en/vse.html**)
+ To learn about the gWLM interface in HP Systems Insight Manager, see
Online help*
+ To learn about the gWLM command-line interface, see
gwlm(1M) manpage on HP-UX
+ To learn about gWLM daemons, see
gwlmcmsd(1M) manpage
+ To learn about securing gWLM's communications, see
"Securing gWLM Communications" topic in online help*
or
gwlmsslconfig(1M) manpage
+ To learn how to update metrics when using custom policies, see
gwlmsend(1M) manpage
+ To learn how to manually place processes in workloads based on psets
or fss groups, see
gwlmplace(1M) manpage
+ To learn about using gWLM with Serviceguard
The "Technical Documentation web site for HP Virtual Server Environ‐
ment (VSE)":
http://docs.hp.com/en/vse.html
+ Learn more about npars, vpars, virtual machines, and psets
HP Virtual Server Environment web site:
http://www.hp.com/go/vse
or
The "Technical Documentation web site for HP Virtual Server Environ‐
ment (VSE)":
http://docs.hp.com/en/vse.html
* Access online help in SIM by selecting Tools -> VSE Management, fol‐
lowed by the tab Shared Resource Domain, and then the question mark [?]
in the top right corner.
** Referenced documentation is in English. For documentation in other
languages, see http://docs.hp.com.
AUTHOR
gWLM was developed by HP.
FEEDBACK
If you would like to comment on the current HP gWLM functionality or
make suggestions for future releases, please send email to:
gwlmfeedback@rsn.hp.com
SEE ALSOgwlm(1M), vseinitconfig(1M), gwlmcmsd(1M), gwlmagent(1M), gwlmre‐
port(1M), gwlmstatus(1M), gwlmplace(1M), gwlmsend(1M), gwlmsslcon‐
fig(1M), gwlmexportkey(1M), gwlmimportkey(1M), gwlmlistkeys(1M),
gwlmdeletekey(1M), gwlmxml(4)gwlm(5)
