@spec child_data_alter() :: atom()

Hook triggered right before the supervisor starts the child process.

This is an alter hook used to modify child process data before it is started.

Data: map() (the child data map, returned modified)

@spec child_pid_updated() :: atom()

Hook triggered right after process has been restarted by local supervisor and the pid has been updated.

Data: %{node: node(), pid: pid()}

@spec child_registered() :: atom()

Hook triggered when a new process is registered in the ProcessHub registry.

Data: %{child_id: child_id(), node_pids: [{node(), pid()}]}

@spec child_unregistered() :: atom()

Hook triggered when a process is unregistered from the ProcessHub registry.

Data: %{child_id: child_id()}

@spec children_forwarded() :: atom()

Hook triggered when children are forwarded to other nodes during migration or when stop requests are redirected to the actual node hosting the child.

Data: %{forwards: [{node(), [map()]}]}

@spec coordinator_shutdown() :: atom()

Hook triggered inside the coordinator terminate/2 function.

Data: %{reason: any()}

Consumed by: :ch_shutdown (ConsistentHashing), :mhs_shutdown (HotSwap), :mcs_shutdown (ColdSwap)

@spec handover_delivered() :: atom()

Hook dispatched when handover states have been delivered to migrated processes.

Data: %{child_ids: [child_id()], target_node: node()}

@spec migration_completed() :: atom()

Hook triggered when the migration handler has finished processing. This does not indicate whether the migration has completed.

Data: %{nodes: [node()], child_specs: [child_spec()]}

@spec post_children_start() :: atom()

Hook triggered right after the children of a process are started.

Data: %{children: [%{child_id: cid, pid: pid, result: result, nodes: [node()], child_spec: spec, metadata: map()}]}

Consumed by: :rr_post_start (Replication strategy), :mhs_process_startups (HotSwap), :mcs_process_startups (ColdSwap)

@spec post_node_join() :: atom()

Hook triggered when a new node has joined the hub cluster and after handling the node join event.

Data: %{node: node()}

@spec post_node_leave() :: atom()

Hook triggered when a node has left the hub cluster and after handling the node leave event.

Data: %{node: node()}

@spec post_redistribution() :: atom()

Hook triggered after processes are redistributed.

Data: %{event: :node_join | :node_leave, nodes: [node()]}

@spec pre_children_redistribution() :: atom()

Hook triggered before redistribution of children is called.

This is only called with node addition or removal from the cluster.

Data: %{children: list(), event: :node_leave, node: node()}

Consumed by: :rr_post_update (Replication strategy)

@spec pre_children_start() :: atom()

Hook triggered before the children of a process are started.

Data: %{request: request, hub: hub}

Consumed by: :dg_pre_start_handler (Guided distribution strategy)

@spec pre_node_join() :: atom()

Hook triggered when a new node has joined the hub cluster and before handling the node join event.

Data: %{node: node()}

@spec pre_node_leave() :: atom()

Hook triggered when a node has left the hub cluster and before handling the node leave event.

Data: %{node: node()}

@spec pre_redistribution() :: atom()

Hook triggered before processes are redistributed.

Data: %{event: :node_join | :node_leave, nodes: [node()]}

@spec scoreboard_updated() :: atom()

Hook dispatched when the centralized load balancer scoreboard is updated.

Data: %{scoreboard: term(), node: node()}