open-consul/website/content/docs/upgrading/compatibility.mdx

45 lines
2.3 KiB
Plaintext
Raw Normal View History

2014-02-08 00:41:03 +00:00
---
2020-04-07 18:55:19 +00:00
layout: docs
page_title: Consul Protocol Compatibility Promise
sidebar_title: Compatibility Promise
2020-04-07 18:55:19 +00:00
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.
2014-02-08 00:41:03 +00:00
---
# Protocol Compatibility Promise
2015-02-17 19:29:00 +00:00
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.
2014-02-08 00:41:03 +00:00
2014-02-19 01:37:23 +00:00
We promise that every subsequent release of Consul will remain backwards
2014-02-08 00:41:03 +00:00
compatible with _at least_ one prior version. Concretely: version 0.5 can
2015-02-17 19:29:00 +00:00
speak to 0.4 (and vice versa) but may not be able to speak to 0.1.
2014-02-08 00:41:03 +00:00
2015-02-17 19:29:00 +00:00
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_.
2014-02-08 00:41:03 +00:00
2015-02-17 19:29:00 +00:00
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.
2020-04-09 23:46:54 +00:00
For more details on the specifics of upgrading, see the [upgrading page](/docs/upgrading).
2014-02-08 00:41:03 +00:00
## Protocol Compatibility Table
2020-04-07 23:56:08 +00:00
| Consul Version | Protocol Compatibility |
| -------------- | ---------------------------------------------------------------------------- |
| 0.1 - 0.3 | 1 |
| 0.4 | 1, 2 |
| 0.5 | 1, 2. 0.5.X servers cannot be mixed with older servers. |
| 0.6 | 1, 2, 3 |
| >= 0.7 | 2, 3. Will automatically use protocol > 2 when speaking to compatible agents |
2020-04-09 23:46:54 +00:00
-> **Note:** Raft Protocol is versioned separately, but maintains compatibility with at least one prior version. See [here](/docs/upgrade-specific#raft-protocol-version-compatibility) for details.