-
Notifications
You must be signed in to change notification settings - Fork 881
docs: add high availability #4583
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Merged
Changes from all commits
Commits
File filter
Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,63 @@ | ||
| # High Availability | ||
|
|
||
| High Availability (HA) mode solves for horizontal scalability and automatic failover | ||
| within a single region. When in HA mode, Coder continues using a single Postgres | ||
| endpoint. [GCP](https://cloud.google.com/sql/docs/postgres/high-availability), [AWS](https://docs.aws.amazon.com/prescriptive-guidance/latest/saas-multitenant-managed-postgresql/availability.html), | ||
| and other cloud vendors offer fully-managed HA Postgres services that pair | ||
| nicely with Coder. | ||
|
|
||
| For Coder to operate correctly, every node must be within 10ms of each other | ||
| and Postgres. We make a best-effort attempt to warn the user when inter-coder | ||
| latency is too high, but if requests start dropping, this is one metric to investigate. | ||
| Note that this latency requirement applies _only_ to coder services. Coder will | ||
| operate correctly even with few seconds of latency on | ||
| workspace <-> coder and user <-> coder connections. | ||
|
|
||
| ## Setup | ||
|
|
||
| Coder automatically enters HA mode when multiple instances simultaneously connect | ||
| to the same Postgres endpoint. | ||
|
|
||
| HA brings one configuration variable to set in each Coder | ||
| node: `CODER_DERP_SERVER_RELAY_URL`. The HA nodes use these URLs to communicate | ||
| with each other. Inter-node communication is only required while using the | ||
| embedded relay (default). If you're using [custom relays](../networking.md#custom-relays), Coder ignores `CODER_DERP_SERVER_RELAY_URL` since Postgres is the sole rendezvous for the Coder nodes. | ||
|
|
||
| `CODER_DERP_SERVER_RELAY_URL` will never be `CODER_ACCESS_URL` because | ||
| `CODER_ACCESS_URL` is a load balancer to all Coder nodes. | ||
|
|
||
| Here's an example 3-node network configuration setup: | ||
|
|
||
| | Name | `CODER_ADDRESS` | `CODER_DERP_SERVER_RELAY_URL` | `CODER_ACCESS_URL` | | ||
| | ------- | --------------- | ----------------------------- | ----------------------- | | ||
| | `coder-1` | `*:80` | `http://10.0.0.1:80` | `https://coder.big.corp` | | ||
| | `coder-2` | `*:80` | `http://10.0.0.2:80` | `https://coder.big.corp` | | ||
| | `coder-3` | `*:80` | `http://10.0.0.3:80` | `https://coder.big.corp` | | ||
|
|
||
|
|
||
| ## Kubernetes | ||
|
|
||
| If you installed Coder via | ||
| [our Helm Chart](../install/kubernetes.md#install-coder-with-helm), just | ||
| increase `coder.replicaCount` in `values.yaml`. | ||
|
|
||
|
|
||
| If you installed Coder into Kubernetes by some other means, insert the relay URL | ||
| via the environment like so: | ||
|
|
||
| ```yaml | ||
| env: | ||
| - name: POD_IP | ||
| valueFrom: | ||
| fieldRef: | ||
| fieldPath: status.podIP | ||
| - name: CODER_DERP_SERVER_RELAY_URL | ||
| value: http://$(POD_IP) | ||
| ``` | ||
| Then, increase the number of pods. | ||
|
|
||
| ## Up next | ||
|
|
||
| - [Networking](../networking.md) | ||
| - [Kubernetes](../install/kubernetes.md) | ||
| - [Enterprise](./enterprise.md) | ||
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Since we surface the database latency, should we document the endpoint/dashboard to check this?
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
We should do that once the Admin Settings page is in. cc @kylecarbs