import fcntl
import time
import threading
+import timer
global_client_object = None
def __init__(self):
self.lock = threading.Lock()
self.service_roots = None
+ self._cache_lock = threading.Lock()
+ self._cache = []
+ # default 256 megabyte cache
+ self.cache_max = 256 * 1024 * 1024
def shuffled_service_roots(self, hash):
if self.service_roots == None:
self.lock.acquire()
- keep_disks = arvados.api().keep_disks().list().execute()['items']
- roots = (("http%s://%s:%d/" %
- ('s' if f['service_ssl_flag'] else '',
- f['service_host'],
- f['service_port']))
- for f in keep_disks)
- self.service_roots = sorted(set(roots))
- logging.debug(str(self.service_roots))
- self.lock.release()
+ try:
+ keep_disks = arvados.api().keep_disks().list().execute()['items']
+ roots = (("http%s://%s:%d/" %
+ ('s' if f['service_ssl_flag'] else '',
+ f['service_host'],
+ f['service_port']))
+ for f in keep_disks)
+ self.service_roots = sorted(set(roots))
+ logging.debug(str(self.service_roots))
+ finally:
+ self.lock.release()
+
+ # Build an ordering with which to query the Keep servers based on the
+ # contents of the hash.
+ # "hash" is a hex-encoded number at least 8 digits
+ # (32 bits) long
+
+ # seed used to calculate the next keep server from 'pool'
+ # to be added to 'pseq'
seed = hash
+
+ # Keep servers still to be added to the ordering
pool = self.service_roots[:]
+
+ # output probe sequence
pseq = []
+
+ # iterate while there are servers left to be assigned
while len(pool) > 0:
if len(seed) < 8:
- if len(pseq) < len(hash) / 4: # first time around
+ # ran out of digits in the seed
+ if len(pseq) < len(hash) / 4:
+ # the number of servers added to the probe sequence is less
+ # than the number of 4-digit slices in 'hash' so refill the
+ # seed with the last 4 digits and then append the contents
+ # of 'hash'.
seed = hash[-4:] + hash
else:
+ # refill the seed with the contents of 'hash'
seed += hash
+
+ # Take the next 8 digits (32 bytes) and interpret as an integer,
+ # then modulus with the size of the remaining pool to get the next
+ # selected server.
probe = int(seed[0:8], 16) % len(pool)
+
+ print seed[0:8], int(seed[0:8], 16), len(pool), probe
+
+ # Append the selected server to the probe sequence and remove it
+ # from the pool.
pseq += [pool[probe]]
pool = pool[:probe] + pool[probe+1:]
+
+ # Remove the digits just used from the seed
seed = seed[8:]
logging.debug(str(pseq))
return pseq
+ class CacheSlot(object):
+ def __init__(self, locator):
+ self.locator = locator
+ self.ready = threading.Event()
+ self.content = None
+
+ def get(self):
+ self.ready.wait()
+ return self.content
+
+ def set(self, value):
+ self.content = value
+ self.ready.set()
+
+ def size(self):
+ if self.content == None:
+ return 0
+ else:
+ return len(self.content)
+
+ def cap_cache(self):
+ '''Cap the cache size to self.cache_max'''
+ self._cache_lock.acquire()
+ try:
+ self._cache = filter(lambda c: not (c.ready.is_set() and c.content == None), self._cache)
+ sm = sum([slot.size() for slot in self._cache])
+ while sm > self.cache_max:
+ del self._cache[-1]
+ sm = sum([slot.size() for a in self._cache])
+ finally:
+ self._cache_lock.release()
+
+ def reserve_cache(self, locator):
+ '''Reserve a cache slot for the specified locator,
+ or return the existing slot.'''
+ self._cache_lock.acquire()
+ try:
+ # Test if the locator is already in the cache
+ for i in xrange(0, len(self._cache)):
+ if self._cache[i].locator == locator:
+ n = self._cache[i]
+ if i != 0:
+ # move it to the front
+ del self._cache[i]
+ self._cache.insert(0, n)
+ return n, False
+
+ # Add a new cache slot for the locator
+ n = KeepClient.CacheSlot(locator)
+ self._cache.insert(0, n)
+ return n, True
+ finally:
+ self._cache_lock.release()
+
def get(self, locator):
+ #logging.debug("Keep.get %s" % (locator))
+
if re.search(r',', locator):
return ''.join(self.get(x) for x in locator.split(','))
if 'KEEP_LOCAL_STORE' in os.environ:
return KeepClient.local_store_get(locator)
expect_hash = re.sub(r'\+.*', '', locator)
- for service_root in self.shuffled_service_roots(expect_hash):
- url = service_root + expect_hash
- api_token = config.get('ARVADOS_API_TOKEN')
- headers = {'Authorization': "OAuth2 %s" % api_token,
- 'Accept': 'application/octet-stream'}
- blob = self.get_url(url, headers, expect_hash)
- if blob:
- return blob
- for location_hint in re.finditer(r'\+K@([a-z0-9]+)', locator):
- instance = location_hint.group(1)
- url = 'http://keep.' + instance + '.arvadosapi.com/' + expect_hash
- blob = self.get_url(url, {}, expect_hash)
- if blob:
- return blob
+
+ slot, first = self.reserve_cache(expect_hash)
+ #logging.debug("%s %s %s" % (slot, first, expect_hash))
+
+ if not first:
+ v = slot.get()
+ return v
+
+ try:
+ for service_root in self.shuffled_service_roots(expect_hash):
+ url = service_root + expect_hash
+ api_token = config.get('ARVADOS_API_TOKEN')
+ headers = {'Authorization': "OAuth2 %s" % api_token,
+ 'Accept': 'application/octet-stream'}
+ blob = self.get_url(url, headers, expect_hash)
+ if blob:
+ slot.set(blob)
+ self.cap_cache()
+ return blob
+
+ for location_hint in re.finditer(r'\+K@([a-z0-9]+)', locator):
+ instance = location_hint.group(1)
+ url = 'http://keep.' + instance + '.arvadosapi.com/' + expect_hash
+ blob = self.get_url(url, {}, expect_hash)
+ if blob:
+ slot.set(blob)
+ self.cap_cache()
+ return blob
+ except:
+ slot.set(None)
+ self.cap_cache()
+ raise
+
+ slot.set(None)
+ self.cap_cache()
raise arvados.errors.NotFoundError("Block not found: %s" % expect_hash)
def get_url(self, url, headers, expect_hash):
h = httplib2.Http()
try:
- resp, content = h.request(url.encode('utf-8'), 'GET',
- headers=headers)
+ logging.info("Request: GET %s" % (url))
+ with timer.Timer() as t:
+ resp, content = h.request(url.encode('utf-8'), 'GET',
+ headers=headers)
+ logging.info("Received %s bytes in %s msec (%s MiB/sec)" % (len(content),
+ t.msecs,
+ (len(content)/(1024*1024))/t.secs))
if re.match(r'^2\d\d$', resp['status']):
m = hashlib.new('md5')
m.update(content)
projects / arvados.git / blobdiff