Blog posts by Arjan/Blog2023-08-18T02:54:17.0000000Zhttps://world.optimizely.com/blogs/arjanblog/Optimizely WorldFinetuning Azure Application Insights in CMS12<p><strong>The problem</strong></p>
<p>If you have ever managed a DXP environment, you might have found the Azure Application Insights log to look like this:</p>
<p><img src="/link/700792bbeae34e909ff55e2af2139221.aspx" width="1094" height="274" /></p>
<p>The Dependency logging is dominant, representing most of the data. Also note the warning that sampling is active: not every message comes through.<br />On closer inspection, the Dependency logging mostly consists of uninformative SQL messages:</p>
<p><img src="/link/f1e9203a9b744c309d783ab5c5b7ed5d.aspx" width="409" height="398" /></p>
<p>The main goal to achieve was:</p>
<p><strong>Create high fidelity application logging for our custom codebase</strong></p>
<p>This was hindered by the <a href="https://learn.microsoft.com/en-us/azure/azure-monitor/app/sampling">telemetry sampling</a> as not every message was guaranteed to come through.<br />To reach this goal, the following subtasks are implemented:</p>
<ul>
<li>Configure custom application logging to allow Informational messages</li>
<li>Reduce Dependency logging to the level where sampling can be turned off</li>
<li>Retain SQL logging for longer-duration queries</li>
</ul>
<h2>Application Insights provider setting</h2>
<p>Configure the provider for ApplicationInsights in appsettings.json. See <a href="https://learn.microsoft.com/en-us/aspnet/core/fundamentals/logging/?view=aspnetcore-7.0#configure-logging">documentation</a>.<img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" /></p>
<pre class="language-javascript"><code> "Logging": {
"LogLevel": {
"Default": "Warning",
"Microsoft": "Warning",
"EPiServer": "Warning",
"Microsoft.Hosting.Lifetime": "Warning"
},
"ApplicationInsights": {
"LogLevel": {
"Default": "Warning",
"MyNamespace": "Information",
"Microsoft": "Warning",
"EPiServer": "Warning"
}
}
},</code></pre>
<p>This will cause everything to emit Warnings only, except for our projects' messages which are <strong>Information</strong> and up. </p>
<h2>Custom Application Insights options</h2>
<p>To make these changes, the following IServiceCollection extension method is introduced:</p>
<pre class="language-csharp"><code>public static class ServiceConfigurationContextExtensions
{
public static void AddCustomApplicationInsights(this IServiceCollection services)
{
ApplicationInsightsServiceOptions aiOptions = new ApplicationInsightsServiceOptions();
// Disables adaptive sampling.
aiOptions.EnableAdaptiveSampling = false;
// Disables QuickPulse (Live Metrics stream).
aiOptions.EnableQuickPulseMetricStream = true;
aiOptions.EnableDependencyTrackingTelemetryModule = true;
services.AddApplicationInsightsTelemetry(aiOptions);
services.AddApplicationInsightsTelemetryProcessor<SqlDependencyFilter>();
services.ConfigureTelemetryModule<DependencyTrackingTelemetryModule>((module, o) =>
{
module.EnableSqlCommandTextInstrumentation = true; // Injects SQL cmd text into telemetry
});
}
}</code></pre>
<p>Notably, this will:</p>
<ul>
<li>turn off adaptive sampling</li>
<li>add a custom telemetry processor</li>
<li>turn on SQL command text logging</li>
</ul>
<p>It is loaded in startup.cs, and must be before <strong>AddCmsCloudPlatformSupport</strong>. </p>
<pre class="language-csharp"><code>public void ConfigureServices(IServiceCollection services)
{
if (!_webHostingEnvironment.IsDevelopment())
{
services.AddCustomApplicationInsights();
services.AddCmsCloudPlatformSupport(_configuration);
services.AddCommerceCloudPlatformSupport(_configuration);
}
....
}</code></pre>
<p>The custom telemetry processor SqlDependencyFilter introduces a filter to all messages "SQL" to only process if the duration is greater than 100ms: </p>
<pre class="language-csharp"><code>public class SqlDependencyFilter : ITelemetryProcessor
{
private ITelemetryProcessor Next { get; set; }
// next will point to the next TelemetryProcessor in the chain.
public SqlDependencyFilter(ITelemetryProcessor next)
{
this.Next = next;
}
public void Process(ITelemetry item)
{
// To filter out an item, return without calling the next processor.
if (!OKtoSend(item)) { return; }
this.Next.Process(item);
}
private bool OKtoSend(ITelemetry item)
{
var dependency = item as DependencyTelemetry;
if (dependency == null || dependency.Type != "SQL") return true; // only filter for Dependency & SQL
if (dependency.Duration.TotalMilliseconds < 100) return false; // we don't want shorties
return true; // this is a long SQL query
}
}</code></pre>
<h2>Results</h2>
<p>Typically, Application Insights for a site with these changes applied looks like this:</p>
<p><img src="/link/beea0ba136a0444881d18e176d8fce6a.aspx" /></p>
<p>With a notably smaller Dependency component. Its SQL logging will be for queries with a minimum of 100ms duration, and the actual SQL command will be included.<br />Also note the sampling warning message has disappeared.</p>
<p><img src="/link/57b3137d342948b196bc42ca38c89688.aspx" width="409" height="411" /></p>
<p>Our application's Information messages are unfiltered, appearing as Trace messages:</p>
<p><img src="/link/09989be6c22246a382bea64d6fdca243.aspx" width="523" height="215" /></p>
<p>Any thoughts or concerns, please let me know!</p>2023-08-18T02:54:17.0000000ZBlog post