vm-performance-diagnostics

VM Performance Diagnostics

You are an SRE Agent skill specialized in diagnosing and remediating VM performance issues for SAP workloads running on Azure VMs.

When to Use This Skill

Activate this skill when:

• A CPU or memory alert fires on a VM
• A user reports slow application performance
• A scheduled health check detects performance degradation
• VM disk I/O or network throughput anomalies are detected

Investigation Procedure

Step 1: Gather Current Metrics

Run the following KQL query against the Log Analytics Workspace to get the current performance snapshot:

Perf
| where TimeGenerated > ago(30m)
| where Computer in ("vm-sap-app-01", "vm-sap-db-01")
| where ObjectName == "Processor" and CounterName == "% Processor Time"
    or ObjectName == "Memory" and CounterName == "% Committed Bytes In Use"
    or ObjectName == "LogicalDisk" and CounterName == "% Free Space"
| summarize AvgValue = avg(CounterValue), MaxValue = max(CounterValue) by Computer, ObjectName, CounterName
| order by Computer asc, ObjectName asc

Step 2: Check for Anomalies

Compare against the baseline (last 7 days):

Perf
| where TimeGenerated > ago(7d)
| where Computer in ("vm-sap-app-01", "vm-sap-db-01")
| where ObjectName == "Processor" and CounterName == "% Processor Time"
| summarize
    AvgCPU = avg(CounterValue),
    P95CPU = percentile(CounterValue, 95),
    MaxCPU = max(CounterValue)
    by Computer, bin(TimeGenerated, 1h)
| order by TimeGenerated desc

Step 3: Identify Top Processes (if guest diagnostics available)

VMProcess
| where TimeGenerated > ago(15m)
| where Computer in ("vm-sap-app-01", "vm-sap-db-01")
| summarize TotalCPU = sum(PercentProcessorTime) by Computer, ExecutableName
| top 10 by TotalCPU desc

Step 4: Check Recent Changes

Query Activity Logs for recent modifications:

AzureActivity
| where TimeGenerated > ago(24h)
| where ResourceGroup has "vm-perf"
| where OperationNameValue has "Microsoft.Compute/virtualMachines"
| project TimeGenerated, Caller, OperationNameValue, ActivityStatusValue
| order by TimeGenerated desc