The debug/pprof
paths provided by the Go profiling tool (pprof
) expose several types of profiling data, which are essential for diagnosing performance issues in applications, particularly those written in Go (including many Kubernetes components). Here’s a rundown of what each of the primary pprof
profiles represents and who typically uses and understands them:
Types of Profiles
-
CPU Profile (/debug/pprof/profile
):
- What it measures: Records where the application spends its time in the CPU.
- Use case: Identify functions or areas in the code consuming excessive CPU time.
- Common users: Developers and performance engineers interested in CPU optimization.
-
Heap Profile (/debug/pprof/heap
):
- What it measures: Captures the memory allocation of live objects (those still reachable by the application).
- Use case: Identify memory leaks, frequent allocations, and memory bloat.
- Common users: Developers debugging memory issues like leaks or high memory usage.
-
Goroutine Profile (/debug/pprof/goroutine
):
- What it measures: Lists all current goroutines, showing stack traces.
- Use case: Used to analyze concurrency issues such as deadlocks or heavy use of goroutines.
- Common users: Developers working on highly concurrent systems and needing to understand threading and concurrency behaviors.
-
Block Profile (/debug/pprof/block
):
- What it measures: Measures where goroutines block on synchronization primitives (e.g., mutexes, channel operations).
- Use case: Diagnose contention issues where goroutines are delayed by blocking on shared resources.
- Common users: Developers optimizing performance-critical sections where synchronization is important.
-
Threadcreate Profile (/debug/pprof/threadcreate
):
- What it measures: Shows stack traces that led to the creation of new OS threads by the Go runtime.
- Use case: Understand thread usage and potential issues with excessive thread creation.
- Common users: System architects and developers interested in the low-level behavior of threading in applications.
apiVersion: v1
kind: Pod
metadata:
annotations:
kubeadm.kubernetes.io/kube-apiserver.advertise-address.endpoint: x.x.x.x:6443
creationTimestamp: null
labels:
component: kube-apiserver
tier: control-plane
name: kube-apiserver
namespace: kube-system
spec:
containers:
- command:
- kube-apiserver
- --advertise-address=x.x.x.x
- --allow-privileged=true
#- --profiling=false
- --authorization-mode=Node,RBAC
- --client-ca-file=/etc/kubernetes/pki/ca.crt
$ kubectl proxy &
$ go tool pprof http://localhost:8001/api/v1/nodes/{NODE-NAME}/proxy/debug/pprof/profile