Module Nn_monitor
module Nn_monitor:sig..end
Management of datastores, i.e. which datastores are available on which
datanodes
This module is run inside the single nn_monitor process. Read access
from other processes is possible via the Nn_datastore_news module
(using a pub/sub scheme).
The module can also be notified to merge db changes into its in-core
set of datastores.
val list : unit -> Nn_datastores.datastore list
Returns the list of all datastores
val get : string -> Nn_datastores.datastore
Get the store record by identity string, or raise
Not_foundval add : Nn_datastores.datastore -> unit
Add the datastore record as-is (for initializing this module from db).
val update_from_db : ?when_done:(unit -> unit) -> int -> unit
Read the db version of this record, and trigger the update of the
module copy of it. The actual update will happen at some point in the
future.
val delete : string -> unitdelete identity: Remove this storeval enable : string -> unitenable identity: Sets enabled to trueval disable : string -> unitdisable identity: Sets enabled to falseval is_alive : string -> boolis_alive identity: Returns whether the datanode having this store
is good as seen by the monitor. Fails if the monitor is not started.val start_publishing : unit -> unit
Updates on the datastores are published and can be retrieved from
any other process using
Nn_datastore_newsStops feeding the news module
val post_add_hook : Netplex_types.socket_service -> Netplex_types.controller -> unit
Needs to be called from the
post_add_hookval receive_message : Pfs_auth.client_auth ->
Netplex_types.container -> string -> string array -> unit
Needs to be called from the
receive_message hook in order to
arrange notifications about db updatesval post_start_hook : Netplex_types.container ->
Nn_config.nn_node_config -> Pfs_auth.client_auth -> unit
Reads the datastore table from the database, and starts discovering
datanodes.
It is required that Nn_db.init was called before.
val shutdown : unit -> unit
To be called at shutdown time
