Under Monitoring, select Logs (Analytics), then copy the following telemetry query and paste it into the query window and select Run. This query returns the total memory usage at each sampled time.
performanceCounters
| where name == "Private Bytes"
| project timestamp, name, value
The results look like the following example:
| timestamp [UTC] | name | value |
|---|---|---|
| 9/12/2019, 1:05:14.947 AM | Private Bytes | 209,932,288 |
| 9/12/2019, 1:06:14.994 AM | Private Bytes | 212,189,184 |
| 9/12/2019, 1:06:30.010 AM | Private Bytes | 231,714,816 |
| 9/12/2019, 1:07:15.040 AM | Private Bytes | 210,591,744 |
| 9/12/2019, 1:12:16.285 AM | Private Bytes | 216,285,184 |
| 9/12/2019, 1:12:31.376 AM | Private Bytes | 235,806,720 |
Azure Monitor tracks metrics at the resource level, which for Functions is the function app. Application Insights integration emits metrics on a per-function basis. Here's an example analytics query to get the average duration of a function:
customMetrics
| where name contains "Duration"
| extend averageDuration = valueSum / valueCount
| summarize averageDurationMilliseconds=avg(averageDuration) by name
| name | averageDurationMilliseconds |
|---|---|
| QueueTrigger AvgDurationMs | 16.087 |
| QueueTrigger MaxDurationMs | 90.249 |
| QueueTrigger MinDurationMs | 8.522 |