588bca2207
* Adding check-legacy-links-format workflow * Adding test-link-rewrites workflow * Updating docs-content-check-legacy-links-format hash * Migrating links to new format Co-authored-by: Kendall Strautman <kendallstrautman@gmail.com>
44 lines
2.3 KiB
Plaintext
44 lines
2.3 KiB
Plaintext
---
|
|
layout: docs
|
|
page_title: Consul Protocol Compatibility Promise
|
|
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](/consul/docs/upgrading).
|
|
|
|
## Protocol Compatibility Table
|
|
|
|
| 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 |
|
|
|
|
-> **Note:** Raft Protocol is versioned separately, but maintains compatibility with at least one prior version. See [here](/consul/docs/upgrading/upgrade-specific#raft-protocol-version-compatibility) for details.
|