Control.Distributed.Process.Extras.Monitoring

This module provides a primitive node monitoring capability, implemented as a distributed-process Management Agent. Once the nodeMonitor agent is started, calling monitorNodes will ensure that whenever the local node detects a new network-transport connection (from another cloud haskell node), the caller will receive a NodeUp message in its mailbox. If a node disconnects, a corollary NodeDown message will be delivered as well.

Documentation

data NodeUp

Sent to subscribing processes when a connection (from a remote node) is detected.

Constructors

NodeUp !NodeId

Instances

Show NodeUp

Methods

showsPrec :: Int -> NodeUp -> ShowS

show :: NodeUp -> String

showList :: [NodeUp] -> ShowS

Generic NodeUp

Associated Types

type Rep NodeUp :: * -> *

Methods

from :: NodeUp -> Rep NodeUp x

to :: Rep NodeUp x -> NodeUp

Binary NodeUp

Methods

put :: NodeUp -> Put

get :: Get NodeUp

putList :: [NodeUp] -> Put

NFData NodeUp

Methods

rnf :: NodeUp -> ()

type Rep NodeUp

type Rep NodeUp = D1 * (MetaData "NodeUp" "Control.Distributed.Process.Extras.Monitoring" "distributed-process-extras-0.3.5-7qzKH0dWmcLBNm6JMkdrjz" False) (C1 * (MetaCons "NodeUp" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 * NodeId)))

data NodeDown

Sent to subscribing processes when a dis-connection (from a remote node) is detected.

Constructors

NodeDown !NodeId

Instances

Show NodeDown

Methods

showsPrec :: Int -> NodeDown -> ShowS

show :: NodeDown -> String

showList :: [NodeDown] -> ShowS

Generic NodeDown

Associated Types

type Rep NodeDown :: * -> *

Methods

from :: NodeDown -> Rep NodeDown x

to :: Rep NodeDown x -> NodeDown

Binary NodeDown

Methods

put :: NodeDown -> Put

get :: Get NodeDown

putList :: [NodeDown] -> Put

NFData NodeDown

Methods

rnf :: NodeDown -> ()

type Rep NodeDown

type Rep NodeDown = D1 * (MetaData "NodeDown" "Control.Distributed.Process.Extras.Monitoring" "distributed-process-extras-0.3.5-7qzKH0dWmcLBNm6JMkdrjz" False) (C1 * (MetaCons "NodeDown" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 * NodeId)))

nodeMonitorAgentId :: MxAgentId

The MxAgentId for the node monitoring agent.

nodeMonitor :: Process ProcessId

Starts the node monitoring agent. No call to monitorNodes and unmonitorNodes will have any effect unless the agent is already running. Note that we make no guarantees what-so-ever about the timeliness or ordering semantics of node monitoring notifications.

monitorNodes :: Process ()

Start monitoring node connection/disconnection events. When a connection event occurs, the calling process will receive a message NodeUp NodeId in its mailbox. When a disconnect occurs, the corollary NodeDown NodeId message will be delivered instead.

No guaranatee is made about the timeliness of the delivery, nor can the receiver expect that the node (for which it is being notified) is still upconnected or downdisconnected at the point when it receives a message from the node monitoring agent.

unmonitorNodes :: Process ()

Stop monitoring node connection/disconnection events. This does not flush the caller's mailbox, nor does it guarantee that any/all node up/down notifications will have been delivered before it is evaluated.