Janus is a messaging server optimized to unicast over TCP to thousands of clients subscribed to topics of interest.
The ultimate goal is to maintain a latency of less than 2 seconds for 20 thousand clients on Amazon EC2 (small instance).
Janus is available under the MIT license.
1) Unicast to 20K clients in < 1s (max latency) nets you a $1000 bounty if you are the first person to achieve this. Unicast in < 2s (max latency) nets you a $500 bounty.
2) Final proof has to be from EC2, one small instance for the server and one for the bots.
3) {packet, 0}, -smp disabled
4) TCP, not UDP.
5) No change of the protocol unless I agree to it.
Note that SMP is disabled since Amazon EC2 small instances have a single core.
Janus requires at least OTP R13B01.
Create a soft link from janus/mochiweb to your Mochiweb installation.
1) ‘make run1’ to start the server
2) ‘make sh’ in a different window to run clients
3) ‘bot:test(flashbot, 20000).’ to run 20k bots on the same machine
4) ‘bot:test(flashbot, 20000, ’host’, 8081).’ if the server is somewhere else
You should see output like this if everything goes well (MacBook Pro Core2Duo, 2.93Ghz, SSD):
([email protected])5> bot:test(flashbot,10000).
=INFO REPORT==== 15-Jul-2009::19:44:20 ===
setup: 5055.70ms, n: 10000, run: 7524.29ms
1.8690ms | min
500.0000ms | 2125 - 21.25%
1000.0000ms | 5010 - 50.10%
1500.0000ms | 2865 - 28.65%
1269.7850ms | max
ok
([email protected])5> bot:test(flashbot,20000).
=INFO REPORT==== 15-Jul-2009::19:44:55 ===
setup: 14293.01ms, n: 20000, run: 21956.94ms
2.4850ms | min
500.0000ms | 478 - 2.39%
1000.0000ms | 2283 - 11.42%
1500.0000ms | 7154 - 35.77%
2000.0000ms | 1574 - 7.87%
2500.0000ms | 3301 - 16.50%
3000.0000ms | 2779 - 13.89%
3500.0000ms | 2431 - 12.16%
3277.0740ms | max
ok
On Leopard:
cat /etc/sysctl.conf
kern.maxfiles=102400
kern.maxfilesperproc=40960
net.inet.ip.portrange.hifirst=10000
net.inet.ip.portrange.first=10000
grep ulimit ~/.bash_profile
ulimit -n 30720
Also, you won’t be able to go past 1024 clients with Erlang
on Mac OSX, even with kernel poll enabled (+K true).
Edit FD_SETSIZE in /usr/include/sys/select.h, i.e. change
__DARWIN_FD_SETSIZE in /usr/include/sys/_structs.h
and recompile Erlang with —enable-kernel-poll.
On Linux:
echo "8192 61000" > /proc/sys/net/ipv4/ip_local_port_range
echo "<your user name> - nofile 32768" >>
/etc/security/limits.conf
ulimit -n 32768