emqx/apps/emqx_resource
Zaiming (Stone) Shi 2065be569e fix(emqx_cluster_rpc): fail fast on stale state
Due to:

* Cluster RPC MFA is not idempotent!
* There is a lack of rollback for callback's side-effects

For instance, when two nodes try to add a cluster-singleton
concurrently, one of them will have to wait for the table lock
then try to catch-up, then try to apply MFA.
The catch-up will have the singleton created, but the initiated
initiated multicall apply will fail causing the commit to rollback,
but not to 'undo' the singleton creation.
Later, the retries will fail indefinitely.
2022-06-12 20:18:48 +02:00
..
include fix: also alarm resource down when start resource failed 2022-06-01 15:41:55 +08:00
src fix(emqx_cluster_rpc): fail fast on stale state 2022-06-12 20:18:48 +02:00
test fix(resource): fast return when starting a unavailable resource 2022-06-01 08:24:53 +08:00
README.md refactor(authn resources): add `emqx_resource` and `emqx_authn` tests 2021-11-22 21:08:04 +03:00
rebar.config style: reformat all remaining apps 2022-04-27 15:51:18 +02:00

README.md

emqx_resource

The emqx_resource is a behavior that manages configuration specs and runtime states for resources like mysql or redis backends.

It is intended to be used by the emqx_bridges and all other resources that need CRUD operations to their configs, and need to initialize the states when creating.

There can be foreign references between resource instances via resource-id. So they may find each other via this Id.

The main idea of the emqx resource is to put all the general code in a common lib, including the config operations (like config validation, config dump back to files), and the state management. And we put all the specific codes to the callback modules.

See

  • test/emqx_test_resource.erl for a minimal emqx_resource implementation;
  • test/emqx_resource_SUITE.erl for examples of emqx_resource usage.