58 lines
1.9 KiB
Markdown
58 lines
1.9 KiB
Markdown
---
|
|
layout: "docs"
|
|
page_title: "Consul Protocol Compatibility Promise"
|
|
sidebar_current: "docs-upgrading-compatibility"
|
|
description: |-
|
|
We expect Consul to run in large clusters of long-running agents. Because safely upgrading agents in this sort of environment relies heavily on backwards compatibility, we have a strong commitment to keeping different Consul versions protocol-compatible with each other.
|
|
---
|
|
|
|
# Protocol Compatibility Promise
|
|
|
|
We expect Consul to run in large clusters of long-running agents. Because
|
|
safely upgrading agents in this sort of environment relies heavily on backwards
|
|
compatibility, we have a strong commitment to keeping different Consul
|
|
versions protocol-compatible with each other.
|
|
|
|
We promise that every subsequent release of Consul will remain backwards
|
|
compatible with _at least_ one prior version. Concretely: version 0.5 can
|
|
speak to 0.4 (and vice versa) but may not be able to speak to 0.1.
|
|
|
|
Backwards compatibility is automatic unless otherwise noted. Consul agents by
|
|
default will speak the latest protocol but can understand earlier ones. Note:
|
|
if speaking an earlier protocol, _new features may not be available_.
|
|
|
|
The ability for an agent to speak an earlier protocol is to ensure that any agent
|
|
can be upgraded without cluster disruption. Consul agents can be updated one
|
|
at a time, one version at a time.
|
|
|
|
For more details on the specifics of upgrading, see the [upgrading page](/docs/upgrading.html).
|
|
|
|
## Protocol Compatibility Table
|
|
|
|
<table class="table table-bordered table-striped">
|
|
<tr>
|
|
<th>Version</th>
|
|
<th>Protocol Compatibility</th>
|
|
</tr>
|
|
<tr>
|
|
<td>0.1</td>
|
|
<td>1</td>
|
|
</tr>
|
|
<tr>
|
|
<td>0.2</td>
|
|
<td>1</td>
|
|
</tr>
|
|
<tr>
|
|
<td>0.3</td>
|
|
<td>1, 2</td>
|
|
</tr>
|
|
<tr>
|
|
<td>0.4</td>
|
|
<td>1, 2</td>
|
|
</tr>
|
|
<tr>
|
|
<td>0.5</td>
|
|
<td>1, 2. 0.5.X servers cannot be mixed with older servers.</td>
|
|
</tr>
|
|
</table>
|