you can either use diag_log or download my debug_console extension http://killzonekid.com/arma-console-extension-debug_console-dll-v3-0/
create a mission with 1 playable unit
open mission.sqm and add this to your unit
init="'debug_console' callExtension str [isDedicated, time, this]";
Start dedicated server and join it.
Joining for the first time:
Server:
[true,0,B Alpha 1-1:1 (KK)]
Client:
[false,0,B Alpha 1-1:1 REMOTE]
Log out but do not leave the server. Log in:
Server:
[true,34.006,B Alpha 1-1:1]
Client:
[false,0,2e470080# 163950: b_soldier_01.p3d REMOTE]
[false,0.116,B Alpha 1-1:1 REMOTE]
^^^ double init execution right there ^^^
Log out and leave the server, rejoin the server:
Server:
[true,301.946,B Alpha 1-1:1]
Client:
[false,0.221,B Alpha 1-1:1 REMOTE]
Single execution again.