def bench_cache_lifetime(minutes):
"Attempts to find how long a given memcached key can be expected to live"
from pylons import g
from r2.lib.cache import PyMemcache as Memcache
# we'll create an independent connection to memcached for this
# test
mc = Memcache(g.memcaches)
# set N keys, and tell them not to live for longer than this test
mc.set_multi(dict(('bench_cache_%d' % x, x) for x in xrange(minutes)),
time=minutes * 60)
# and every minute, check to see that the keys are still present,
# until we find one missing
for x in xrange(minutes):
if mc.get('bench_cache_%d' % x, None) is not None:
sleep(60)
else:
# we found one missing
return x - 1
else:
# we're out of numbers, and we didn't find any missing
# keys. Since we only set N keys, we can't check for anything
# else
print(("Cache lifetime is greater than %d minutes. Try again with a" +
" higher 'minutes' value") % minutes)
return None
def bench_cache_lifetime(minutes):
"Attempts to find how long a given memcached key can be expected to live"
from pylons import g
from r2.lib.cache import PyMemcache as Memcache
# we'll create an independent connection to memcached for this
# test
mc = Memcache(g.memcaches)
# set N keys, and tell them not to live for longer than this test
mc.set_multi(dict( ('bench_cache_%d' % x, x)
for x in xrange(minutes) ),
time=minutes*60)
# and every minute, check to see that the keys are still present,
# until we find one missing
for x in xrange(minutes):
if mc.get('bench_cache_%d' % x, None) is not None:
sleep(60)
else:
# we found one missing
return x-1
else:
# we're out of numbers, and we didn't find any missing
# keys. Since we only set N keys, we can't check for anything
# else
print (("Cache lifetime is greater than %d minutes. Try again with a"+
" higher 'minutes' value") % minutes)
return None
def monitor_cache_lifetime(minutes,
retest=10,
ntest=-1,
cache_name="memcaches",
verbose=False):
# list of list of active memcache test keys
keys = []
period = 60 # 1 minute cycle time
data = DataLogger()
# we'll create an independent connection to memcached for this test
mc = Memcache(getattr(g, cache_name))
counter = 0
while ntest:
if counter == 0 or (retest and counter % retest == 0):
randstr = random.random()
newkeys = [("%s_lifetime_%s_%d" % (cache_name, randstr, x), x + 1)
for x in xrange(minutes)]
# set N keys, and tell them not to live for longer than this test
mc.set_multi(
dict(newkeys),
#time = minutes * period)
time=(minutes + 1) * period)
# add the list in reverse order since we'll be poping.
newkeys.reverse()
keys.append(newkeys)
# wait for the next key to (potentially) expire
counter += 1
time.sleep(period)
for k in keys:
key, age = k.pop()
if mc.get(key) is None or k == []:
if verbose:
print "cache expiration: %d seconds" % (period * age)
data.add(period * age)
AppServiceMonitor.set_cache_lifetime(data, key=cache_name)
# wipe out the list for removal by the subsequent filter
while k:
k.pop()
# clear out any empty key lists
if [] in keys:
keys = filter(None, keys)
ntest -= 1
def monitor_cache_lifetime(minutes, retest = 10, ntest = -1,
cache_name = "memcaches", verbose = False):
# list of list of active memcache test keys
keys = []
period = 60 # 1 minute cycle time
data = DataLogger()
# we'll create an independent connection to memcached for this test
mc = Memcache(getattr(g, cache_name))
counter = 0
while ntest:
if counter == 0 or (retest and counter % retest == 0):
randstr = random.random()
newkeys = [("%s_lifetime_%s_%d" % (cache_name, randstr, x), x+1)
for x in xrange(minutes)]
# set N keys, and tell them not to live for longer than this test
mc.set_multi(dict(newkeys),
#time = minutes * period)
time = (minutes+1) * period)
# add the list in reverse order since we'll be poping.
newkeys.reverse()
keys.append(newkeys)
# wait for the next key to (potentially) expire
counter += 1
time.sleep(period)
for k in keys:
key, age = k.pop()
if mc.get(key) is None or k == []:
if verbose:
print "cache expiration: %d seconds" % (period * age)
data.add(period * age)
AppServiceMonitor.set_cache_lifetime(data, key = cache_name)
# wipe out the list for removal by the subsequent filter
while k: k.pop()
# clear out any empty key lists
if [] in keys:
keys = filter(None, keys)
ntest -= 1
