Applications insights in an azure function app - metrics and custom dimensions missing

Question

I have some trouble adding logs from an azure function app to application insigths. I am using this code:

import azure.functions as func
import datetime
import logging
import requests
from settings import settings
from services.exchangerate_service import ExchangeRateService

from azure.identity import DefaultAzureCredential
from azure.monitor.opentelemetry import configure_azure_monitor
from opentelemetry import metrics

credential = DefaultAzureCredential()

configure_azure_monitor(
    connection_string="InstrumentationKey=xx-xx-xx-xx-xx;IngestionEndpoint=https://westeurope-5.in.applicationinsights.azure.com/;LiveEndpoint=https://westeurope.livediagnostics.monitor.azure.com/;ApplicationId=xx-xx-xx-xx-xx",
    credential=credential
)

logger = logging.getLogger(__name__) 
logger.setLevel(logging.INFO)

app = func.FunctionApp()
@app.timer_trigger(schedule=settings.IBAN_CRON, arg_name="myTimer", run_on_startup=True,
              use_monitor=False) 
def timer_trigger(myTimer: func.TimerRequest) -> None:
    
    if myTimer.past_due:
        logging.info('The timer is past du3e!')

    logger.info("Segato5", extra={"custom_dimension": "Kam_value","test1": "val1"})

    meter = metrics.get_meter_provider().get_meter(__name__)
    counter = meter.create_counter("segato2")   
    counter.add(8)

I get traces but not custom dimesions and no metrics:

Answer 1

I modified your code by moving the meter and counter outside the function and configuring the MeterProvider globally instead of creating a new meter inside the function on each invocation. This ensures that metrics persist across function executions and correctly send custom dimensions.

Code :

import azure.functions as func
import logging
from settings import settings
from azure.monitor.opentelemetry import configure_azure_monitor
from opentelemetry import metrics
from opentelemetry.sdk.metrics import MeterProvider
from opentelemetry.sdk.metrics.export import PeriodicExportingMetricReader
from azure.monitor.opentelemetry.exporter import AzureMonitorMetricExporter
from opentelemetry.instrumentation.logging import LoggingInstrumentor

configure_azure_monitor(
    connection_string=settings.APPLICATION_INSIGHTS_CONNECTION_STRING
)

LoggingInstrumentor().instrument(set_logging_format=True)
logger = logging.getLogger(__name__) 
logger.setLevel(logging.INFO)

reader = PeriodicExportingMetricReader(AzureMonitorMetricExporter(
    connection_string=settings.APPLICATION_INSIGHTS_CONNECTION_STRING
))
provider = MeterProvider(metric_readers=[reader])
metrics.set_meter_provider(provider)

meter = metrics.get_meter_provider().get_meter("my_function_metrics")
counter = meter.create_counter("segato2")

app = func.FunctionApp()
@app.timer_trigger(schedule=settings.IBAN_CRON, arg_name="myTimer", run_on_startup=True, use_monitor=False)
def timer_trigger(myTimer: func.TimerRequest) -> None:
    if myTimer.past_due:
        logger.warning("Timer is past due!")

    logger.info("Segato5", extra={"custom_dimension": "Kam_value", "test1": "val1"})
    counter.add(1, {"custom_dimension": "Kam_value"})

I successfully retrieved the traces, metrics, and custom dimensions by running the following queries in Azure Application Insights Logs.

traces :

traces
| where timestamp >= ago(30m) 
| where message contains "Segato5"
| extend customDimensions = todynamic(customDimensions)
| project timestamp, message, customDimensions
| order by timestamp desc

output :

metrics :

customMetrics
| where timestamp >= ago(30m)  
| where name == "segato2"
| extend customDimensions = todynamic(customDimensions)
| project timestamp, name, value, customDimensions
| order by timestamp desc

output :

customdeminsions :

customMetrics
| where timestamp >= ago(30m)  
| where name == "segato2"
| extend customDimensions = todynamic(customDimensions)
| where tostring(customDimensions.custom_dimension) == "Kam_value"
| project timestamp, name, value, customDimensions
| order by timestamp desc

output :

Traces in Transaction Search :