Package ClusterShell :: Module Propagation :: Class PropagationChannel

Class PropagationChannel

Admin node propagation logic. Instances are able to handle incoming messages from a directly connected gateway, process them and reply.

In order to take decisions, the instance acts as a finite states machine, whose current state evolves according to received data.

-- INTERNALS -- Instance can be in one of the 4 different states:

init (implicit) This is the very first state. The instance enters the init state at start() method, and will then send the configuration to the remote node. Once the configuration is sent away, the state changes to cfg.
cfg During this second state, the instance will wait for a valid acknowledgement from the gateway to the previously sent configuration message. If such a message is delivered, the control message (the one that contains the actions to perform) is sent, and the state is set to ctl.
ctl Third state, the instance is waiting for a valid ack for from the gateway to the ctl packet. Then, the state switch to gtr (gather).
gtr Final state: wait for results from the subtree and store them.

Instance Methods

[hide private]

__init__(self, task, gateway)
x.__init__(...) initializes x; see help(type(x)) for signature

source code

send_queued(self, ctl)
helper used to send a message, using msg queue if needed

source code

send_dequeue(self)
helper used to send one queued message (if any)

source code

start(self)
start propagation channel

source code

recv(self, msg)
process incoming messages

source code

shell(self, nodes, command, worker, timeout, stderr, gw_invoke_cmd, remote)
command execution through channel

source code

write(self, nodes, buf, worker)
write buffer through channel to nodes on standard input

source code

set_write_eof(self, nodes, worker)
send EOF through channel to specified nodes

source code

recv_cfg(self, msg)
handle incoming messages for state 'propagate configuration'

source code

recv_ctl(self, msg)
handle incoming messages for state 'control'

source code

ev_hup(self, worker)
Channel command is closing

source code

ev_close(self, worker)
Channel is closing

source code

Inherited from Communication.Channel: ev_read, ev_start, send

Inherited from Communication.Channel (private): _close, _init, _open

Inherited from Event.EventHandler: ev_error, ev_msg, ev_pickup, ev_timeout, ev_timer, ev_written

Inherited from Event.EventHandler (private): _ev_routing

Inherited from object: __delattr__, __format__, __getattribute__, __hash__, __new__, __reduce__, __reduce_ex__, __repr__, __setattr__, __sizeof__, __str__, __subclasshook__