yuanbiao
/
emqx
1
0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

docs(ds): Move Raft-related parts to emqx_ds_builtin_raft README

This commit is contained in:
ieQu1 2024-06-28 15:55:10 +02:00
parent afe1c5617d
commit 71dad0242e
No known key found for this signature in database
GPG Key ID: 488654DF3FED6FDE
2 changed files with 39 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
apps/emqx_ds_builtin_raft/README.md
View File

@ -1,3 +1,36 @@
# `emqx_ds_builtin_raft`
Replication layer for the builtin EMQX durable storage backend that uses Raft algorithm.
Raft backend introduces the concept of **site** to alleviate the problem of changing node names.
Site IDs are persistent, and they are randomly generated at the first startup of the node.
Each node in the cluster has a unique site ID, that is independent from the Erlang node name (`emqx@...`).
## Configurations
OTP application environment variables:
- `emqx_durable_storage.reads`: `leader_preferred` | `local_preferred`.
# CLI
Runtime settings for the durable storages can be modified via CLI as well as the REST API.
The following CLI commands are available:
- `emqx ctl ds info` — get a quick overview of the durable storage state
- `emqx ctl ds set_replicas <DS> <Site1> <Site2> ...` — update the list of replicas for a durable storage.
- `emqx ctl ds join <DS> <Site>` — add a replica of durable storage on the site
- `emqx ctl ds leave <DS> <Site>` — remove a replica of a durable storage from the site
# HTTP APIs
The following REST APIs are available for managing the builtin durable storages:
- `/ds/sites` — list known sites.
- `/ds/sites/:site` — get information about the site (its status, current EMQX node name managing the site, etc.)
- `/ds/storages` — list durable storages
- `/ds/storages/:ds` — get information about the durable storage and its shards
- `/ds/storages/:ds/replicas` — list or update sites that contain replicas of a durable storage
- `/ds/storages/:ds/replicas/:site` — add or remove replica of the durable storage on the site

30
apps/emqx_durable_storage/README.md
View File

@ -13,11 +13,10 @@ This makes the storage disk requirements very predictable: only the number of _p
DS _backend_ is a callback module that implements `emqx_ds` behavior.
EMQX repository contains the "builtin" backend, implemented in `emqx_ds_replication_layer` module, that uses Raft algorithm for data replication, and RocksDB as the main storage.
EMQX repository contains two builtin backends based on RocksDB:
Note that builtin backend introduces the concept of **site** to alleviate the problem of changing node names.
Site IDs are persistent, and they are randomly generated at the first startup of the node.
Each node in the cluster has a unique site ID, that is independent from the Erlang node name (`emqx@...`).
- `emqx_ds_builtin_local`
- `emqx_ds_builtin_raft`
### Layout
@ -113,8 +112,8 @@ In the future it can serve as a storage for retained messages or as a generic me
# Configurations
Global options for `emqx_durable_storage` application are configured via OTP application environment.
Database-specific settings are stored in the schema table.
Common global options for builtin backends are configured via OTP application environment.
Database-specific settings are stored in EMQX config.
The following application environment variables are available:
@ -124,26 +123,9 @@ The following application environment variables are available:
- `emqx_durable_storage.egress_flush_interval`: period at which the batches of messages are committed to the durable storage.
- `emqx_durable_storage.reads`: `leader_preferred` | `local_preferred`.
Runtime settings for the durable storages can be modified via CLI as well as the REST API.
The following CLI commands are available:
- `emqx ctl ds info` — get a quick overview of the durable storage state
- `emqx ctl ds set_replicas <DS> <Site1> <Site2> ...` — update the list of replicas for a durable storage.
- `emqx ctl ds join <DS> <Site>` — add a replica of durable storage on the site
- `emqx ctl ds leave <DS> <Site>` — remove a replica of a durable storage from the site
# HTTP APIs
The following REST APIs are available for managing the builtin durable storages:
- `/ds/sites` — list known sites.
- `/ds/sites/:site` — get information about the site (its status, current EMQX node name managing the site, etc.)
- `/ds/storages` — list durable storages
- `/ds/storages/:ds` — get information about the durable storage and its shards
- `/ds/storages/:ds/replicas` — list or update sites that contain replicas of a durable storage
- `/ds/storages/:ds/replicas/:site` — add or remove replica of the durable storage on the site
None
# Other