#
# Binary Star client
#
package require zmq
set REQUEST_TIMEOUT 1000 ;# msecs
set SETTLE_DELAY 2000 ;# Before failing over, msecs
zmq context context
set server [list "tcp://localhost:5001" "tcp://localhost:5002"]
set server_nbr 0
puts "I: connecting to server at [lindex $server $server_nbr]…"
zmq socket client context REQ
client connect [lindex $server $server_nbr]
set sequence 0
while {1} {
# We send a request, then we work to get a reply
set request [incr sequence]
client send $request
set expect_reply 1
while {$expect_reply} {
# Poll socket for a reply, with timeout
set rpoll_set [zmq poll client {POLLIN} $REQUEST_TIMEOUT]
# If we got a reply, process it
if {[llength $rpoll_set] && "POLLIN" in [lindex $rpoll_set 0 1]} {
set reply [client recv]
if {$reply eq $request} {
puts "I: server replied OK ($reply)"
set expect_reply 0
after 1000 ;# One request per second
} else {
puts "E: malformed reply from server: $reply"
}
} else {
puts "W: no response from server, failing over"
# Old socket is confused; close it and open a new one
client close
set server_nbr [expr {($server_nbr + 1) % 2}]
after $SETTLE_DELAY
puts "I: connecting to server at [lindex $server $server_nbr]…"
zmq socket client context REQ
client connect [lindex $server $server_nbr]
# Send request again, on new socket
client send $request
}
}
}
client close
context term