Manage Load Profiles

Load profiles let you define the operating criteria for a logical cluster.

Load profile criteria are typically called “load score metrics,” with the value associated for each criteria rolled into a “score” for each instance in the logical cluster that uses the load profile. You can periodically compare load scores for different instances within a logical cluster to detect when the workload is undesirably skewed to one or more instances, or to determine if an instance is underutilized.

Instances included in multiple logical clusters can be impacted by multiple load profiles, so take care when associating instances with multiple logical clusters and when defining and applying load profiles.

The Cluster Edition includes two system load profiles: sybase_profile_oltp for OLTP environments and sybase_profile_dss for DSS environments. You cannot modify or delete system load profiles. However, you can duplicate them and modify the duplicates to create your own load profiles.

The load profile status reports the:

• Name – name of load profile configuration.
• Type – system or user.
• Metric weights – relative weight assigned to each metric in the load profile, including:
  • User connections
  • CPU busy
  • Run queue length
  • IO load
  • Engine deficit
  • Users
• Thresholds – configured difference, as a percentage, in the load between two instances in a logical cluster at which point the following can occur:
  • Login redirection – used for connection-time load balancing, and routing connections to a logical cluster. If necessary, an instance directs a client to stop the current login attempt and try connecting to instances it supplies as a list of available network addresses.
  • Dynamic migration – (also known as the hysteresis value) the dynamic migration configuration.
• Minimum load score – load score necessary to trigger login redirection and dynamic migration.

• Adding a Load Profile
  Use a load profile to consolidate all configurable aspects of the workload scoring system into a single named entity.
• Deleting a Load Profile
  Delete a user-created load profile.
• Generating a DDL Script for a Load Profile
  Generate DDL to create a load profile.
• Load Profile Properties
  Use the Properties window to view load profile information.