stackimpact

StackImpact Go Agent

Overview

StackImpact is a performance profiling and monitoring service for production Go applications. It gives you continuous visibility with line-of-code precision into application performance, such as CPU, memory and IO hot spots as well execution bottlenecks, allowing to optimize applications and troubleshoot issues before they impact customers. Learn more at stackimpact.com.

Main features:

• Automatic hot spot profiling for CPU, memory allocations, network, system calls and lock contention.
• Automatic bottleneck tracing for HTTP handlers and HTTP clients.
• Error and panic monitoring.
• Health monitoring including CPU, memory, garbage collection and other runtime metrics.
• Alerts on hot spot anomalies.
• Multiple account users for team collaboration.

Learn more on features page (with screenshots).

StackImpact agent (this package) reports performance information to the Dashboard running as SaaS or On-Premise.

Requirements

Linux, OS X or Windows. Go version 1.5+.

Getting started

Create StackImpact account

Sign up for a free account at stackimpact.com.

Installing the agent

Install the Go agent by running

go get github.com/stackimpact/stackimpact-go

And import the package github.com/stackimpact/stackimpact-go in your application.

Configuring the agent

Start the agent by specifying agent key and application name. The agent key can be found in your account's Configuration section.

agent := stackimpact.NewAgent();
agent.Start(stackimpact.Options{
    AgentKey: "agent key here",
    AppName: "MyGoApp",
})

Other initialization options:

• AppVersion (Optional) Sets application version, which can be used to associate profiling information with the source code release.
• AppEnvironment (Optional) Used to differentiate applications in different environments.
• HostName (Optional) By default host name will be the OS hostname.
• Debug (Optional) Enables debug logging.
• DashboardAddress (Optional) Used by on-premises deployments only.

Example:

package main

import (
  	"fmt"
  	"net/http"

  	"github.com/stackimpact/stackimpact-go"
)

func handler(w http.ResponseWriter, r *http.Request) {
  	fmt.Fprintf(w, "Hello world!")
}

func main() {
  	agent := stackimpact.NewAgent()
    agent.Start(stackimpact.Options{
        AgentKey: "agent key here",
        AppName: "Basic Go Server",
        AppVersion: "1.0.0",
        AppEnvironment: "production",
    })

    http.HandleFunc("/", handler)
    http.ListenAndServe(":8080", nil)
}

Measuring code segments (OPTIONAL)

To measure performance and detect bottlenecks in arbitrary parts of application, the segment API can be used.

segment := agent.MeasureSegment("Segment1")
defer segment.Stop()

subsegment := agent.MeasureSubsegment("Segment1", "Subsegment1")
defer subsegment.Stop()

Monitoring errors (OPTIONAL)

To monitor exceptions and panics with stack traces, the error recording API can be used.

Recording handled errors:

agent.RecordError(someError)

Recording panics without recovering:

defer agent.RecordPanic()

Recording and recovering from panics:

defer agent.RecordAndRecoverPanic()

Analyzing performance data in the Dashboard

Once your application is restarted, start observing regular and anomaly-triggered CPU, memory, IO, and other hot spot profiles, execution bottlenecks as well as process metrics in the Dashboard.

Troubleshooting

To enable debug logging, add Debug: true to startup options. If debug log doesn't give you any hints on how to fix a problem, please report it to our support team in your account's Support section.

Overhead

Reporting CPU, network and system profiles requires regular and anomaly-triggered profiling and tracing activation for short periods of time. Unlike memory profiling and process-level metric reporting, they produce some overhead when active. The agent makes sure the overhead stays within 2% and has no effect on application in any way.