This document details the deprecation policy for the following
Logging and Monitoring agents and related
client-side components:

- [Legacy Cloud Logging agent](https://docs.cloud.google.com/logging/docs/agent)
- [Legacy Cloud Monitoring agent](https://docs.cloud.google.com/monitoring/agent)
- [Stackdriver Metadata agent](https://github.com/Stackdriver/metadata-agent/blob/master/README.md)
- [Heapster](https://github.com/Stackdriver/heapster/blob/master/README.md) (for GKE version 1.15 and below)
- [Cloud Monitoring-Prometheus integration](https://docs.cloud.google.com/monitoring/kubernetes-engine/prometheus)

This document does not apply to the
[Ops Agent](https://docs.cloud.google.com/stackdriver/docs/solutions/agents/ops-agent) or
the [Google-Built OpenTelemetry Collector](https://docs.cloud.google.com/stackdriver/docs/instrumentation/google-built-otel).
For information about support for these agents, see
[Support time horizons for the Ops Agent and Google-Built OpenTelemetry Collector](https://docs.cloud.google.com/stackdriver/docs/support-info/telemetry-agents).

## Deprecating a release version

### Release version support

All agents and their client-side components follow
the \<MAJOR\>.\<MINOR\>.\<PATCH\> versioning convention. For example,
**stackdriver-agent 5.5.2**. A new release increments:

- The **MAJOR** version when making backwards-incompatible changes,
- The **MINOR** version when adding functionality in a backwards-compatible manner,
- The **PATCH** version when making backwards-compatible bug fixes.

Supporting a version of the agent means that bugs in the agents are debugged and
fixed on each of the supported platforms. Customers may need to upgrade their
agent to the latest minor release of the same major version to take advantage of
any bug fixes. However, they are not required to upgrade to a later major
version of the agent, which may contain backward incompatible changes.

If a security issue or critical bug found in one of the supported major versions
also exists in other supported major versions, the bug fix is backported to all
supported major versions unless the fix is not backwards compatible.
New features will not be backported.

Backwards-compatible changes, including new features or bug fixes, go to minor
releases of the most recent major version at any time. Backwards-incompatible
changes are incorporated into the next major release.

### Decommission

The lifespan of any major version of a Cloud Logging or Cloud Monitoring agent is at
least 12 months. A major version (e.g., version N) is decommissioned 12 months
after the release of the next major version (e.g., version N+1). Decommissioning
a major version means that it doesn't receive any further bug fixes or minor
releases. It also means that customer support is no longer available for that
version. Once a version is decommissioned, the agent's installer files for that
version are removed and not available to download.

Subsequent agent releases where only the minor version is updated don't reset
the clock. The lifespan of any minor version follows its major version's
deprecation and decommission schedule.

You will not receive a Mandatory Service Announcement (MSA) for each release.
Instead, you can find the **planned decommission date** on the agent README
pages.

When an environment, for example, Amazon Elastic Compute Cloud (EC2), or an
operating system reaches its end of life, agent support is deprecated as well.
The actual decommission happens when support for the environment or operating
system ends, unless a specific decommission date has already been set for an
agent. Refer to the
[Deprecating support for environments, operating systems, and features](https://docs.cloud.google.com/stackdriver/docs/agent-deprecation-policy#env)
section of this guide for more information.

### Transition plan for existing agents and components

Versions of the agents and client-side components that existed before this
deprecation policy will be available and supported at least until
February 28, 2020. However, bug fixes will not be backported for these releases.

#### Click the **+** sign to see which versions of the agents
and components are affected by the transition plan


| Legacy Logging agent ||
| Name | Version number |
|---|---|
| google-fluentd | 1.6.3 and all earlier versions |
| fluent-plugin-google-cloud | 0.7.4 and all earlier versions |
| fluentd-catch-all-config | 1.0 and all earlier versions |
| fluent-plugin-detect-exceptions | 0.0.11 and all earlier versions |
| gcr.io/stackdriver-agents/stackdriver-logging-agent | 0.8-1.6.2-1 and all earlier versions |

| Legacy Monitoring agent ||
| Name | Version number |
|---|---|
| stackdriver-agent | 5.5.2-383 and all earlier versions |

| Metadata agent ||
| Name | Version number |
|---|---|
| metadata | 0.0.21 and all earlier versions |

| Heapster ||
| Name | Version number |
|---|---|
| heapster | 1.6.0-beta.1 and all earlier versions |

| Prometheus Sidecar ||
| Name | Version number |
|---|---|
| stackdriver-prometheus-sidecar | 0.3.1 and all earlier versions |

<br />

To see the decommission dates for other versions of the agents and components,
refer to the README page for each component.

## Deprecating support for environments, operating systems, and features

### Environments and operating systems support

Logging and Monitoring agents are binaries that
are installed in client
environments. Each agent supports different environment and operating system
combinations. An example combination is Amazon Linux on EC2.

### Feature support

A feature refers to a unit of functionality of the agents that satisfies a
requirement, represents a design decision, and/or provides a potential
configuration option. An example feature would be support for ingesting metrics
for a monitored resource.

### Deprecation

When support for an environment, operating system, or feature is deprecated, you
will receive an MSA to announce the deprecation, including a link to this
deprecation policy. The MSA is bound to the major version of the agent and
component release.
The decommission date for the environment, operating system, or feature is the
same as the decommission date for that major version of the agent release. That
major version is the last major version that supports the environment, operating
system, or feature.

### Decommission

When support for an environment, operating system, or feature is
decommissioned, customer support is no longer provided for that environment,
operating system, or feature. An MSA will be sent out to announce the
decommissioning.