reckon_db_store_coordinator (reckon_db v5.11.4)

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Store coordinator for reckon-db

Coordinates cluster join operations and prevents split-brain scenarios.

Responsibilities: - Detecting existing clusters via RPC - Coordinator election (lowest node name) - Coordinated cluster joining - Split-brain prevention

Summary

Types

index_decl/0
integrity_config/0
integrity_key_source/0
store_config/0

Functions

handle_call(Request, From, State)
handle_cast(Msg, State)
handle_info(Info, State)
init(Store_config)
is_leader(StoreId)

Check if this node is the leader

join_cluster(StoreId)

Join the Khepri cluster using coordinated approach.

join_cluster(StoreId, TargetNode)

Join a specific node's cluster.

leader(StoreId)

Get current leader node

members(StoreId)

Get cluster members

should_handle_nodeup(StoreId)

Check if this node should handle nodeup events.

start_link(Store_config)
terminate(Reason, State)

Types

index_decl/0

-type index_decl() ::
          tags | event_type |
          {meta, Key :: binary()} |
          {payload, Key :: binary()} |
          {payload_hash, Keys :: [binary()]}.

integrity_config/0

-type integrity_config() :: disabled | #{enabled := true, key_source := integrity_key_source()}.

integrity_key_source/0

-type integrity_key_source() :: {env_var, EnvName :: binary()} | {sealed_file, Path :: file:filename()}.

store_config/0

-type store_config() ::
          #store_config{store_id :: atom(),
                        data_dir :: string(),
                        mode :: single | cluster,
                        timeout :: pos_integer(),
                        writer_pool_size :: pos_integer(),
                        reader_pool_size :: pos_integer(),
                        gateway_pool_size :: pos_integer(),
                        options :: map(),
                        integrity :: integrity_config(),
                        indexes :: [index_decl()]}.

Functions

handle_call(Request, From, State)

handle_cast(Msg, State)

handle_info(Info, State)

init(Store_config)

is_leader(StoreId)

-spec is_leader(atom()) -> boolean().

Check if this node is the leader

join_cluster(StoreId)

-spec join_cluster(atom()) -> ok | coordinator | no_nodes | waiting | failed | {error, term()}.

Join the Khepri cluster using coordinated approach.

Returns {error, not_started} if the coordinator process isn't registered yet (startup race or after a store stop). gen_server:call/3 throws {exit, {noproc}} as an exception when the target process doesn't exist — the guard converts that to an error tuple.

join_cluster(StoreId, TargetNode)

-spec join_cluster(atom(), node()) -> ok | {error, term()}.

Join a specific node's cluster.

Returns {error, not_started} if the coordinator process isn't registered.

leader(StoreId)

-spec leader(atom()) -> {ok, node()} | {error, no_leader}.

Get current leader node

members(StoreId)

-spec members(atom()) -> {ok, [term()]} | {error, term()}.

Get cluster members

should_handle_nodeup(StoreId)

-spec should_handle_nodeup(atom()) -> boolean().

Check if this node should handle nodeup events.

Returns false if the coordinator isn't running — a store without a coordinator should not handle nodeup events.

start_link(Store_config)

-spec start_link(store_config()) -> {ok, pid()} | {error, term()}.

terminate(Reason, State)