Simple Redis chat experiment

redischat.py

# Monkey patching with redis-py didn't work out so well
#from gevent import monkey; monkey.patch_all()
import gevent
import redis
import time
import random

client = redis.Redis(host='localhost', port=6379, db=0)
client.flushdb()

chat_message = ['Hello Planet', 'How are you today?', 'I am fine.', 'I love meatballs', 'Ok, bye-bye']
num_users = 20
num_channels = int(num_users * 0.5)

# Time spent chatting before ending conversation
min_chat_time = 20 
max_chat_time = 60

# Conversations to retry
max_retries = 2 

# Time spent idling between sending chat messages
min_idle_time = 5
max_idle_time = 20

# Max chat messages to store
chat_backlog = 50


channels = []

for i in xrange(num_channels):
    channels.append('chat_channel_%d' % i)

requests = {}
total_requests = 0

def log_call():
    global total_requests
    t = int(time.time())
    requests.setdefault(t, 0)
    requests[t] += 1
    total_requests += 1

def show_stats():
    while True:
        rps = requests.setdefault(int(time.time()) - 1, 0)
        print "Total %d Requests/sec %d" % (total_requests, rps)
        gevent.sleep(1)

def username(id): return 'username_%d' % id

def chat_user(user_id, channel, retries):
    if retries > max_retries:
        return

    # Get all messages to display
    messages = client.lrange(channel, 0, chat_backlog - 1); log_call()
    
    # Add ourselves to channel list
    client.sadd(channel + "_list", username(user_id)); log_call()

    # Get all users in channel
    client.smembers(channel + "_list"); log_call()

    end_time = time.time() + random.randrange(min_chat_time, max_chat_time)
    while (end_time > time.time()):
        client.lpush(channel, random.choice(chat_message)); log_call()
        client.ltrim(channel, 0, chat_backlog - 1); log_call()
        gevent.sleep(random.randrange(min_idle_time, max_idle_time))

    # Remove ourselves to channel list
    client.srem(channel + "_list", username(user_id)); log_call()
    
    retries += 1
    chat_user(user_id, channel, retries)


gevent.spawn(show_stats)

print "Spawning %d users..." % num_users
spawned_users = []
for user_id in xrange(num_users):
    spawned_users.append(gevent.spawn(chat_user, user_id, random.choice(channels), 0))

print "Waiting for all users to finish..."
gevent.joinall(spawned_users)
print "Test completed"