webapplib.py

import logging
import time

logger = logging.getLogger(__name__)

def useful():
    logger.debug('Hello from webapplib!')
    time.sleep(0.01)

webapptest.py

import logging
from random import choice
import threading
import webapplib

logger = logging.getLogger(__name__)
root = logging.getLogger()
root.setLevel(logging.DEBUG)

class Request:
    def __init__(self, method, ip):
        self.method = method
        self.ip = ip

REQUESTS = [
    Request('GET', '192.168.2.20'),
    Request('POST', '192.168.2.20'),
    Request('GET', '192.168.2.21'),
    Request('POST', '192.168.2.21'),
    Request('GET', '192.168.2.22'),
    Request('POST', '192.168.2.22'),
]

formatter = logging.Formatter('%(asctime)s %(threadName)-11s %(appName)s %(name)-9s %(ip)s %(method)-4s %(message)s')

tlocal = threading.local()

class InjectingFilter(logging.Filter):
    def __init__(self, app):
        self.app = app

    def filter(self, record):
        record.method = tlocal.request.method
        record.ip = tlocal.request.ip
        record.appName = appName = tlocal.appName
        return appName == self.app.name
        
class WebApp:
    def __init__(self, name):
        self.name = name
        handler = logging.FileHandler(name + '.log', 'w')
        f = InjectingFilter(self)
        handler.setFormatter(formatter)
        handler.addFilter(f)
        root.addHandler(handler)
        self.num_requests = 0

    def process_request(self, request):
        tlocal.request = request
        tlocal.appName = self.name
        tname = threading.currentThread().getName()
        self.num_requests += 1
        logger.debug('Request processing started')
        webapplib.useful()
        logger.debug('Request processing finished')

def main():
    app1 = WebApp('app1')
    app2 = WebApp('app2')
    apps = [app1, app2]
    threads = []
    #Add a common handler which will capture all events
    handler = logging.FileHandler('app.log', 'w')
    handler.setFormatter(formatter)
    root.addHandler(handler)
    #while True:
    for i in xrange(1000):
        try:
            app = choice(apps)
            request = choice(REQUESTS)
            t = threading.Thread(target=app.process_request, args=(request,))
            threads.append(t)
            t.start()
        except KeyboardInterrupt:
            break    
    for t in threads:
        t.join()
    for app in apps:
        print '%s processed %s requests' % (app.name, app.num_requests)
    
if __name__ == '__main__':
    main()