Azure resource monitoring with Azure Functions v2

MonitorMetrics.cs

using Microsoft.ApplicationInsights;
using Microsoft.ApplicationInsights.Extensibility;
using Microsoft.Azure.WebJobs;
using Microsoft.Extensions.Logging;
using Microsoft.WindowsAzure.Storage;
using System;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace AzureMonitoring
{
    public class MonitorMetrics
    {
        private static string key = TelemetryConfiguration.Active.InstrumentationKey = Environment.GetEnvironmentVariable("APPINSIGHTS_INSTRUMENTATIONKEY", EnvironmentVariableTarget.Process);
        private static TelemetryClient telemetry = new TelemetryClient() { InstrumentationKey = key };

        [FunctionName("MonitorQueueLength")]
        public static async Task MonitorQueueLength([TimerTrigger("*/10 * * * * *")]TimerInfo myTimer,ILogger log)
        {
            log.LogInformation($"C# Timer trigger function executed at: {DateTime.Now}");

            // connect to Azure Storage
            var connectionString = Environment.GetEnvironmentVariable("queue_storage_connection_string");
            var account = CloudStorageAccount.Parse(connectionString);
            var queueClient = account.CreateCloudQueueClient();

            var queueNames = new [] {"myqueue", "myqueue-poison"};
            var tasks = queueNames.Select(async x =>
            {
                // get a reference to the queue and retrieve the queue length
                var queue = queueClient.GetQueueReference(x);
                await queue.FetchAttributesAsync();
                var length = queue.ApproximateMessageCount;

                // log the length
                log.LogInformation($"{x}: {length}");
                telemetry.GetMetric($"QueueLength.{x}").TrackValue(length);
            });
            await Task.WhenAll(tasks);
        }
    }
}