2065be569e
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. |
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| etc | ||
| i18n | ||
| include | ||
| src | ||
| test | ||
| .gitignore | ||
| README.md | ||
| rebar.config | ||
emqx_connector
This application is a collection of connectors.
A connector is a callback module of emqx_resource that maintains the data related to
external resources. Put all resource related callback modules in a single application is good as
we can put some util functions/modules here for reusing purpose.
For example, a MySQL connector is an emqx resource that maintains all the MySQL connection related parameters (configs) and the TCP connections to the MySQL server.
An MySQL connector can be used as following:
(emqx@127.0.0.1)5> emqx_resource:list_instances_verbose().
[#{config =>
#{auto_reconnect => true,cacertfile => [],certfile => [],
database => "mqtt",keyfile => [],password => "public",
pool_size => 1,
server => {{127,0,0,1},3306},
ssl => false,user => "root",verify => false},
id => <<"mysql-abc">>,mod => emqx_connector_mysql,
state => #{poolname => 'mysql-abc'},
status => connected}]
(emqx@127.0.0.1)6> emqx_resource:query(<<"mysql-abc">>, {sql, <<"SELECT count(1)">>}).
{ok,[<<"count(1)">>],[[1]]}