[julia-users] Julia Zmq Server creates Memory Leaks

[Dan]

 

Hi, 


I am trying to create a Julia server instance by using ZMQ with the Req/Rep 
pattern. My Julia code for the Rep-server looks like this:

module JServer

# import zmq
using ZMQ
import Base.gc

# create context
ctx=Context();
# create socket
socket=Socket(ctx, REP);
# msg
msg = 0;
# repeatedly collect garbage every second
timer = Timer(gc, 1, 1);

function connect(host, port)

# connect
ZMQ.connect(socket, string("tcp://", host, ":", port));
println(string("Julia server connected to ", host, " on port ", port));
end

 

function startServer()
  # notify
  println("Waiting for request...")
  i = 1
  while i <= 2
     # invoke garbage collection
     # gc();
     # Poll For message
     msg = receive();
     println("Message received");
     # Reply
     send();
     println("Message acknowledged");
    end
end

 

function receive()
   msg = ZMQ.recv(socket);
end

 

function send()
    ZMQ.send(socket, Message("test request"));
end

 

function gc(event)
    gc();
end

end

I can successfully start the server by runnung this script (indicating host 
and port via ARGS):

# include server module
include(string(dirname(Base.source_path()), "\JServer.jl"));
# connect server
JServer.connect(ARGS[1], ARGS[2]);
# start server
JServer.startServer();

My tests seem to be odd, however: Whenever I send large messages from 
client, i.e. ~1MB per message, Julia seems to properly keep tracking about 
memory usage: The overall process memory remains constant. But when I am 
sending small messaged (i.e. 10k per message) Julia memory usage is growing 
permanenlty. In addition response time slows down over my requests. This 
does not happen if I explicitly invoke the garbage collector inside the 
while loop, but this would slow down the replies significantly. 


I am using Julia 0.4.6.


Is my code ok? Is there a callback solution in order to be able to avoid 
the while loop?