This is documentation for the next version of Pyroscope. For the latest stable release, go to the latest version.
Set up Java profiling using Grafana Alloy
Grafana Alloy supports Java profiling. The collector configuration file is composed of components that are used to collect, transform, and send data. The Alloy configuration files use the Alloy configuration syntax.
Configure the components
The pyroscope.java
component is used to continuously profile Java processes running on the local Linux OS
using async-profiler.
pyroscope.java "java" {
profiling_config {
interval = "15s"
alloc = "512k"
cpu = true
lock = "10ms"
sample_rate = 100
}
forward_to = [pyroscope.write.endpoint.receiver]
targets = discovery.relabel.java.output
}
Using the targets
argument, you can specify which processes and containers to profile on the machine.
The targets
can be from discovery.process
component.
You can use discovery.process
join argument to join process targets with extra discoveries such as discovery.kubernetes
, discovery.docker
, and discovery.dockerswarm
.
You can use the discovery.relabel
component to relabel discovered targets and set your own labels.
For more information, refer to the Components documentation.
The forward_to
parameter should point to a pyroscope.write
component to send the collected profiles to your
Pyroscope Server or Grafana Cloud.
Name | Type | Description | Default | Required |
---|---|---|---|---|
targets | list(map(string)) | List of java process targets to profile. | yes | |
forward_to | list(ProfilesReceiver) | List of receivers to send collected profiles to. | yes | |
tmp_dir | string | Temporary directory to store async-profiler. | /tmp | no |
The special label __process_pid__
must always be present in each target of targets
and corresponds to the PID
of
the process to profile.
The special label service_name
is required and must always be present.
If service_name
isn’t specified, pyroscope.java
attempts to infer it from discovery meta labels.
If service_name
isn’t specified and couldn’t be inferred, then it’s set to unspecified
.
The profiling_config
block describes how async-profiler is invoked.
It supports the following arguments:
Name | Type | Description | Default | Required |
---|---|---|---|---|
interval | duration | How frequently to collect profiles from the targets. | “60s” | no |
cpu | bool | A flag to enable CPU profiling, using itimer async-profiler event. | true | no |
sample_rate | int | CPU profiling sample rate. It’s converted from Hz to interval and passed as -i arg to async-profiler. | 100 | no |
alloc | string | Allocation profiling sampling configuration It’s passed as --alloc arg to async-profiler. | “512k” | no |
lock | string | Lock profiling sampling configuration. It’s passed as --lock arg to async-profiler. | “10ms” | no |
For more information on async-profiler configuration, see profiler-options.
Set privileges for the collector
You must run the collector, such Alloy, as root and inside host pid
namespace for the pyroscope.java
and discover.process
components to work.
Start the collector
To start Grafana Alloy v1.2 and later, replace configuration.alloy
with your configuration filename:
alloy run configuration.alloy
To start Grafana Alloy v1.0 or 1.1, replace configuration.alloy
with your configuration file name:
alloy run --stability.level=public-preview configuration.alloy
The stability.level
option is required for pyroscope.scrape
with Alloy v1.0 or v1.1. For more information about stability.level
, refer to the run command documentation.
Send data to Grafana Cloud Profiles
When sending to Grafana Cloud Profiles, you can use the following pyroscope.write
component configuration which uses environment variables.
Ensure that you have appropriately configured the GC_URL
, GC_USER
, and GC_PASSWORD
environment variables.
pyroscope.write "endpoint" {
endpoint {
basic_auth {
password = env("GC_PASSWORD")
username = env("GC_USER")
}
url = env("GC_URL")
}
}
Examples
For more robust examples, refer to the Grafana Alloy and Agent Auto-instrumentation examples in the Pyroscope repository.
Profiling local process
discovery.process "all" {
}
discovery.relabel "java" {
targets = discovery.process.all.targets
// Filter only java processes
rule {
source_labels = ["__meta_process_exe"]
action = "keep"
regex = ".*/java$"
}
// Filter processes. For example: only processes with command line containing "FastSlow"
rule {
source_labels = ["__meta_process_commandline"]
regex = "java FastSlow"
action = "keep"
}
// Provide a service name for the process, otherwise it will be unspecified.
rule {
action = "replace"
target_label = "service_name"
replacement = "java-fast-slow"
}
}
pyroscope.java "java" {
forward_to = [pyroscope.write.example.receiver]
targets = discovery.relabel.java.output
}
pyroscope.write "example" {
endpoint {
url = "http://pyroscope:4040"
}
}
Profiling Docker containers
For a working example, refer to Java profiling via auto-instrumentation example in Docker.
discovery.docker "local_containers" {
host = "unix:///var/run/docker.sock"
}
discovery.process "all" {
join = discovery.docker.local_containers.targets
}
discovery.relabel "java" {
targets = discovery.process.all.targets
// Filter only java processes
rule {
source_labels = ["__meta_process_exe"]
action = "keep"
regex = ".*/java$"
}
// Filter only needed containers
rule {
source_labels = ["__meta_docker_container_name"]
regex = ".*suspicious_pascal"
action = "keep"
}
// Provide a service name for the process, otherwise it will default to the value of __meta_docker_container_name label.
rule {
action = "replace"
target_label = "service_name"
replacement = "java-fast-slow"
}
}
pyroscope.java "java" {
forward_to = [pyroscope.write.example.receiver]
targets = discovery.relabel.java.output
}
pyroscope.write "example" {
endpoint {
url = "http://pyroscope:4040"
}
}
Profiling Kubernetes pods
For a working example, refer to Grafana Alloy Java profiling via auto-instrumentation with Kubernetes.
discovery.kubernetes "local_pods" {
selectors {
field = "spec.nodeName=" + env("HOSTNAME")
role = "pod"
}
role = "pod"
}
discovery.process "all" {
join = discovery.kubernetes.local_pods.targets
}
discovery.relabel "java_pods" {
targets = discovery.process.all.targets
// Filter only java processes
rule {
source_labels = ["__meta_process_exe"]
action = "keep"
regex = ".*/java$"
}
rule {
action = "drop"
regex = "Succeeded|Failed|Completed"
source_labels = ["__meta_kubernetes_pod_phase"]
}
rule {
action = "replace"
source_labels = ["__meta_kubernetes_namespace"]
target_label = "namespace"
}
rule {
action = "replace"
source_labels = ["__meta_kubernetes_pod_name"]
target_label = "pod"
}
rule {
action = "replace"
source_labels = ["__meta_kubernetes_pod_node_name"]
target_label = "node"
}
rule {
action = "replace"
source_labels = ["__meta_kubernetes_pod_container_name"]
target_label = "container"
}
// Provide arbitrary service_name label, otherwise it will be inferred from discovery labels automatically
rule {
action = "replace"
regex = "(.*)@(.*)"
replacement = "java/${1}/${2}"
separator = "@"
source_labels = ["__meta_kubernetes_namespace", "__meta_kubernetes_pod_container_name"]
target_label = "service_name"
}
// Filter only needed services
rule {
action = "keep"
regex = "(java/ns1/.*)|(java/ns2/container-.*0)"
source_labels = ["service_name"]
}
}
pyroscope.java "java" {
forward_to = [pyroscope.write.example.receiver]
targets = discovery.relabel.java.output
}
pyroscope.write "example" {
endpoint {
url = "http://pyroscope:4040"
}
}
References
For more information: