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Table Of Contents
One Node Can Provide Adequate Resource Support, but the Other Cannot
If total resource requirements of applications exceed 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.
Problem
Applications operate normally when the Primary node is active but operate slowly when the Secondary node
is active (or the reverse).
Cause
A large discrepancy occurs in the processing power between the Primary and Secondary nodes. One node
can handle the operational load while the other cannot.The load on a node is greater while in the active role
when the protected application starts. Applications on the pair run successfully when the Primary is active, but
experience performance issues when the Secondary is active (or the reverse). Problems can arise even when
the more powerful node is active.
Solution
Both nodes must have approximately equivalent processing power, RAM and disk performance. Upgrade
the hardware or allocate additional resources on one node in the pair so that the two nodes have roughly
the same performance.
Scheduled Resource Intensive Tasks
Scheduling multiple resource intensive tasks at the same time can adversely impact node performance and
affect application performance.
Problem
Resource-intense scheduled tasks impact performance at certain times.
Cause
Two or more resource-intense processes run simultaneously or one process performs actions that increase
the load on vCenter Server Heartbeat by triggering additional and sometimes unnecessary replication traffic.
Examples: processes such as backups, database maintenance tasks, disk defragmentation, or scheduled
anti-malware scans.
Solution
Schedule operations so that they do not overlap and schedule them outside regular working hours, when
fewer users are accessing the protected application and consequently less load on the node.
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Chapter 5 vCenter Server Heartbeat Diagnostics