Instrumentation

This document enumerates the various instrumentation provided with the apm-agent-ios sdk. These instrumentations can be configured as described in instrumentation configuration.

The agent will automatically capture and upload crashes to the apm server. These crashes will be stored in the format as described in the mobile agent event spec.

URLSession instrumentation is provided by the Open Telemetry Swift sdk, and will automatically generate traces for all network requests generated with URLSessions. More details can be found in the URL Session instrumentation Open Telemetry documentation

The agent provides SwiftUI.View and UIViewController instrumentation, where the load time of a View is measured using spans. All Views simultaneously loaded will be grouped under the same starting span. The spans' names will be dictated by the following rules, from least to highest precedence:

The View’s class name will be a swift name-mangled string, and is the least desirable naming method. If it’s possible, set a navigation title on your views:

AllProductsList.swift

struct AllProductsList: View {
    @EnvironmentObject var modelData : ModelData

    var body: some View {
        VStack {
            List(modelData.products, id: \.id) { product in
                AdminProductRow(product: product)

            }
        }.onAppear  {
            modelData.loadProducts()
        }.navigationTitle("All Products")
    }
}

You’ll see "All Products - view appearing" in Kibana.

If it isn’t possible to set a navigation title, use reportName(_ name: String) -> View to set the name that will show in Kibana:

AllProductsList.swift

struct AllProductsList: View {
    @EnvironmentObject var modelData : ModelData

    var body: some View {
        VStack {
            List(modelData.products, id: \.id) { product in
                AdminProductRow(product: product)

            }
        }.onAppear  {
            modelData.loadProducts()
        }.reportName("All Products - view appearing")
    }
}

System-metric instrumentation records cpu and memory usage minutely as metrics. Cpu metrics are recorded as system.cpu.usage and memory usage is recorded as system.memory.usage.

Available for iOS 13 and greater, the agent provides instrumentation of key MetricKit data points:

Technical details on the metric generated can be found in the Mobile spec

This histogram metric provides launch duration broken down by first draw, first draw (optimized), and resumed. More details about the MetricKit data point can be found in the Apple documentation.

A histogram of the different durations of time in which the app is too busy to handle user interaction responsively. More details about the MetricKit data point can be found in the Apple documentation.

A count of application exits categorized by various attributes: foreground or background, and normal or abnormal, where abnormal exits are further subdivided. More details can be found in the Apple documentation.

In v0.5.0 the application lifecycle events are automatically instrumented. The technical details can be found in the Mobile spec.