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