https://github.com/pertsevds/dns_srv_cluster
Elixir clustering with DNS SRV records
https://github.com/pertsevds/dns_srv_cluster
elixir
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Elixir clustering with DNS SRV records
- Host: GitHub
- URL: https://github.com/pertsevds/dns_srv_cluster
- Owner: pertsevds
- License: mit
- Created: 2023-10-30T20:22:54.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2025-03-18T11:15:12.000Z (3 months ago)
- Last Synced: 2025-03-18T12:25:26.627Z (3 months ago)
- Topics: elixir
- Language: Elixir
- Homepage:
- Size: 78.1 KB
- Stars: 7
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE.md
Awesome Lists containing this project
README
# DNSSRVCluster
Elixir clustering with DNS SRV records.
---
[](https://github.com/pertsevds/dns_srv_cluster/actions/workflows/ci.yml)
[](https://coveralls.io/github/pertsevds/dns_srv_cluster?branch=main)
[](https://hex.pm/packages/dns_srv_cluster)
[](https://hex.pm/packages/dns_srv_cluster)
[](https://hexdocs.pm/nbpm)
[](https://hex.pm/packages/dns_srv_cluster)
## Installation
The package can be installed by adding `dns_srv_cluster` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[
{:dns_srv_cluster, "~> 0.3.0"}
]
end
```
Add to your DNS zone your SRV record (https://en.wikipedia.org/wiki/SRV_record):
```sh
_app._tcp.yourdomain.com. 60 IN SRV 0 10 1234 node1.yourdomain.com.
_app._tcp.yourdomain.com. 60 IN SRV 0 10 1234 node2.yourdomain.com.
_app._tcp.yourdomain.com. 60 IN SRV 0 10 1234 node3.yourdomain.com.
_app._tcp.yourdomain.com. 60 IN SRV 0 10 1234 node4.yourdomain.com.
```
Add to your config files (`config/prod.exs`, `config/dev.exs`):
```elixir
config :dns_srv_cluster,
query: "_app._tcp.yourdomain.com"
```
Add this to your `rel/env.sh.eex`:
```sh
export RELEASE_DISTRIBUTION="${RELEASE_DISTRIBUTION:-"name"}"
export RELEASE_NODE="${RELEASE_NODE:-"<%= @release.name %>"}"
```
By default, nodes from the same release will have the same cookie. If you want different
applications or releases to connect to each other, then you must set the `RELEASE_COOKIE`,
either in your deployment platform or inside `rel/env.sh.eex`:
```sh
export RELEASE_COOKIE="my-app-cookie"
```
## Configuration options
* `query` - your DNS SRV record, for example: "_app._tcp.yourdomain.com".
* `interval` - the millisec interval between DNS queries. Defaults to `5_000`.
* `connect_timeout` - the millisec timeout to allow discovered nodes to connect. Defaults to `10_000`.
## If you want it in your supervision tree
Do in `mix.exs`:
```elixir
def deps do
[
{:dns_srv_cluster, "~> 0.3.0", runtime: false}
]
end
```
`runtime: false` will block application from starting.
And use `DNSSRVCluster.Worker` as a child:
```elixir
children = [
{DNSSRVCluster.Worker, query: "_app._tcp.yourdomain.com"}
]
{:ok, pid} = Supervisor.start_link(children, strategy: :one_for_one)
```
## Support Matrix
Tests automatically run against a matrix of OTP and Elixir Versions, see the [ci.yml](https://github.com/pertsevds/dns_srv_cluster/tree/main/.github/workflows/ci.yml) for details.
| OTP \ Elixir | 1.15 | 1.16 | 1.17 | 1.18 |
|:------------:|:----:|:----:|:----:|:----:|
| 24 | ✅ | ✅ | N/A | N/A |
| 25 | ✅ | ✅ | ✅ | ✅ |
| 26 | ✅ | ✅ | ✅ | ✅ |
| 27 | N/A | N/A | ✅ | ✅ |
## Documentation
Documentation can be found at .