Specifications

Reference Guide
194 VMware, Inc.
Cause
The Primary server's resource usage in one or more areas reached close to the maximum before vCenter Server
Heartbeat was installed.
Resolution
Heartbeat Diagnostics can report these conditions and issues warnings if CPU usage or memory usage exceed
a certain percentage of the available resource. Information provided by Heartbeat Diagnostics can minimize
the risk of application slowdown by identifying needed hardware upgrades on the Primary server.
Both Servers Can Accommodate the Initial Load but the Load Has Increased
Any software installed on a server or workstation consumes a finite amount of system resources when it runs
and it must share the resources it uses with any other applications running at the same time. Increased demand
caused by additional user activity can have an impact on the server performance.
Symptom
Increased user activity slows application response time.
Causes
The server pair operates normally when vCenter Server Heartbeat is first installed, but performance decreases
due to increased user activity. For example, users on the SQL Server system increase or the typical usage
pattern becomes more intense. This can be a gradual and sustained increase over time, or transient if a specific
event triggers a temporary surge in user activity.
Resolution
If the situation is sporadic, it can correct itself when the load decreases. If the increase is sustained and
permanent, upgrade the server hardware.
One Server Can Provide Adequate Resource Support, but the Other Cannot
If the total resource requirements of the applications exceed the available physical resources, the operating
system attempts to provide resources, but leaves some applications under resourced. When this situation
occurs, an application cannot obtain enough memory to operate normally, or a process must wait before
accessing the hard disk
Symptom
Applications operate normally when the Primary server is active but operate slowly when the Secondary
server is active (or the reverse).
Cause
A large discrepancy occurs in the processing power between the Primary and Secondary servers. One server
can handle the operational load while the other cannot. The load on a server is greater while in the active role
when the protected application starts. Applications on the server pair run successfully when the Primary
server is active, but experience performance issues when the Secondary is active (or the reverse). Problems can
arise even when the more powerful server is active.
Resolution
Both servers must have approximately equivalent processing power, RAM and disk performance. Upgrade
the hardware on one server in the pair so that the two servers have roughly the same performance.