Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.
Grafana Pyroscope
Configure the client to send profiles
Grafana Alloy and Grafana Agent
Profiling Java using Alloy or AgentProfiling Java using Grafana Alloy or Agent
Grafana Alloy and Grafana Agent in Flow mode support Java profiling.
The collector configuration file is composed of components that are used to collect, transform, and send data. Alloy configuration files use the Alloy configuration syntax. Agent Flow files use the River language.
Caution
Grafana Alloy is the new name for our distribution of the OTel collector. Grafana Agent has been deprecated and is in Long-Term Support (LTS) through October 31, 2025. Grafana Agent will reach an End-of-Life (EOL) on November 1, 2025. Read more about why we recommend migrating to Grafana Alloy.
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 dicovery.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, see Components.
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, either Grafana Alloy (recommended) or Agent (legacy), 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: Replace configuration.alloy with your configuration file name:
alloy run configuration.alloyTo start Grafana Alloy v1.0/1.1: Replace configuration.alloy with your configuration file name:
alloy run --stability.level=public-preview configuration.alloyThe 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.
To start Grafana Agent, replace configuration.river with your configuration filename:
grafana-agent-flow run configuration.river
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
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$"
}
// Filter processes. For example: only processes with command line containing "FastSlow"
rule {
source_labels = ["__meta_process_commandline"]
regex = "java FastSlow"
action = "keep"
}
// Provide a service name for the process, otherwise it will be unspecified.
rule {
action = "replace"
target_label = "service_name"
replacement = "java-fast-slow"
}
}
pyroscope.java "java" {
forward_to = [pyroscope.write.example.receiver]
targets = discovery.relabel.java.output
}
pyroscope.write "example" {
endpoint {
url = "http://pyroscope:4040"
}
}Profiling docker containers
discovery.docker "local_containers" {
host = "unix:///var/run/docker.sock"
}
discovery.process "all" {
join = discovery.docker.local_containers.targets
}
discovery.relabel "java" {
targets = discovery.process.all.targets
// Filter only java processes
rule {
source_labels = ["__meta_process_exe"]
action = "keep"
regex = ".*/java$"
}
// 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
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:
