Monitoring scripts with email alerts in PowerShell - Step-by-Step Execution

Concept Flow - Monitoring scripts with email alerts

Start Script

↓

Check System Metric

↓

Is Metric OK?

No→Send Email Alert

↓

Log Alert Sent

↓

Wait/Delay

↓

Repeat or End

The script starts, checks a system metric, sends an email if the metric is bad, logs the alert, waits, then repeats or ends.

Execution Sample

PowerShell

if ($cpuUsage -gt 80) {
  Send-MailMessage -To '[e-mail]' -Subject 'High CPU Alert' -Body "CPU usage is $cpuUsage%" -SmtpServer 'smtp.example.com'
}

This script checks if CPU usage is above 80%, then sends an email alert with the current CPU usage.

Execution Table

Step	Action	Condition/Evaluation	Result/Output
1	Get CPU usage	$cpuUsage = 75	CPU usage recorded as 75%
2	Check if $cpuUsage > 80	75 > 80	False, no email sent
3	Wait before next check	N/A	Pause for 60 seconds
4	Get CPU usage	$cpuUsage = 85	CPU usage recorded as 85%
5	Check if $cpuUsage > 80	85 > 80	True, proceed to send email
6	Send email alert	Send-MailMessage executed	Email sent to [e-mail]
7	Log alert	Write to log file	Alert logged with timestamp
8	Wait before next check	N/A	Pause for 60 seconds
9	Repeat or end	Script loops or stops	Script ready for next iteration or exit

💡 Script stops when manually terminated or after set iterations

Variable Tracker

Variable	Start	After Step 1	After Step 4	Final
$cpuUsage	undefined	75	85	85
Email Sent	No	No	Yes	Yes
Log Entry	None	None	Created	Created

Key Moments - 3 Insights

Why is no email sent when CPU usage is 75%?

Because the condition $cpuUsage > 80 is false at step 2, so the script skips sending the email.

What triggers the email alert to be sent?

When the CPU usage exceeds 80%, as shown at step 5, the condition becomes true and the email is sent.

Why does the script wait after checking the CPU usage?

The wait at steps 3 and 8 prevents the script from running continuously without pause, allowing time between checks.

Visual Quiz - 3 Questions

Look at the execution table, what is the value of $cpuUsage at step 4?

A 75

B 85

C 80

D Undefined

💡 Hint

Check the 'Condition/Evaluation' column at step 4 in the execution table.

At which step does the script send the email alert?

A Step 6

B Step 5

C Step 2

D Step 7

💡 Hint

Look for the 'Send email alert' action in the 'Action' column.

If the CPU usage never exceeds 80%, what happens to the 'Email Sent' variable?

A It changes to Yes

B It becomes undefined

C It remains No

D It logs an error

💡 Hint

Refer to the variable_tracker for 'Email Sent' values when CPU usage is below threshold.

Concept Snapshot

Monitoring scripts check system metrics regularly.
If a metric crosses a threshold, an email alert is sent.
Use Send-MailMessage in PowerShell to send emails.
Include logging and wait times to avoid spamming.
Loop the script for continuous monitoring.

Full Transcript

This visual execution shows a PowerShell monitoring script that checks CPU usage. It starts by reading the CPU usage value. If the usage is above 80%, it sends an email alert to the administrator and logs the alert. If not, it waits before checking again. The script repeats this cycle until stopped. Variables like $cpuUsage and Email Sent track the system state and alert status. Key moments include understanding when emails are sent and why the script waits between checks. The quiz tests knowledge of variable values and script behavior at specific steps.