107
balancing from generating "artificial" recommendations for this period by setting the Relocation interval
to more than an hour.
• If server loads and activity increase gradually in your environment, you may want to increase the number
of minutes for the optimization interval.
When Automation is configured, it is especially important to be careful when modifying the optimization
interval. If an issue occurs that leads to continuous, recurring spikes, increasing the frequency (setting a
lower number) can generate many recommendations and, consequently, relocations.
Note:
Setting an optimization interval does not affect how long Workload Balancing waits to factor recently
rebalanced servers into the servers it recommends for Start-On placement, Resume, and Maintenance
Mode.
Number of Times an Optimization Recommendation is Made
When you enable Automation, you can specify how many times you want Workload Balancing to wait
before it accepts (applies) its optimization recommendations. Accepting optimization recommendations uses
system resources and affects performance while Workload Balancing is relocating the virtual machines.
Setting this interval prevents Workload Balancing from applying optimization recommendations too soon
after the last optimization (for example, if there was a temporary utilization spike). The interval you choose
to set depends on factors such as the following:
• If server loads and activity increase extremely quickly in your environment, you may want to decrease
the optimization interval.
• If server loads and activity increase gradually in your environment, you may want to increase the
optimization interval.
Citrix does not recommend modifying this setting unless Citrix Technical Support directs you to do so.
Setting the Minimum Optimization Severity
All optimization recommendations include a severity rating (Critical, High, Medium, Low) that indicates
the importance of the recommendation. Workload Balancing bases this rating on a combination of factors
including configuration options you set, such as thresholds and metric tunings; resources available for
the workload; and resource-usage history. (The severity rating for a recommendation appears in the
Optimization Recommendations pane on the WLB tab.)
When you configure Workload Balancing to apply optimization recommendations automatically, you can set
the minimum severity level that should be associated with a recommendation before Workload Balancing
automatically applies it.
Modifying the Aggressiveness Setting
The Workload Balancing Aggressiveness setting controls how strictly Workload Balancing applies
optimization criteria when determining whether to apply recommendations automatically when Automation
is enabled.
The conditions under which Workload Balancing applies optimizations automatically vary according to the
settings you configure in the VM Recommendations Interval section of this dialog box.
Specifically, Workload Balancing looks at these settings in this dialog conjunction with the following
principles:
Before applying a recommendations, the exact same recommendation has to occur x number (where x is
specified by the user. Workload Balancing checks for recommendations every two minutes.
