def connect(self):
if self.isconnected and self.conn.ping():
return True
try:
with open(self.lockfile) as master:
config = master.read().split('\n')[0].split(',')
if len(config) < 2:
logging.error('[CacheClient] ERROR. Lock file is corrupt.')
return False
self.host = config[0]
self.port = config[1]
pool = redis.ConnectionPool(host=self.host, port=self.port, db=0, decode_responses=True)
if self.isconnected:
self.conn.connection_pool = pool
logging.info('[CacheClient] Switched over to new master at %s on port %s', self.host, self.port)
else:
self.conn = redis.StrictRedis(host=self.host, port=self.port, connection_pool=pool, decode_responses=True)
self.conn.client_setname(getUID())
logging.info('[CacheClient] Connected as client to master at %s on port %s', self.host, self.port)
self.isconnected = True
return True
except FileNotFoundError as ex:
logging.error('[CacheClient] ERROR. Service is not running. No lockfile found: %s (Returning False)', self.lockfile)
return False
except redis.BusyLoadingError as ex:
logging.error('[CacheClient] Service is loading.')
self.isconnected = True
return True
def removeItems(self, key, itemlist):
nullvalue = getUID()
pipe = self.pipeline()
for index in itemlist:
pipe.lset(key, index, nullvalue)
pipe.lrem(key, 0, nullvalue)
pipe.execute()
def removeItems(self, key, itemlist):
nullvalue = getUID()
pipe = self.pipeline()
for index in itemlist:
pipe.lset(key, index, nullvalue)
pipe.lrem(key, 0, nullvalue)
pipe.execute()
def __init__(self, name):
settings = systemsettings()
self._name_app = name
self.lockfile = '%s_%s.lock' % (self._name_app, 'RedisService')
self.isconnected = False
self.host = None
self.port = None
self.pool = None
connect_wait = 0
while True:
try:
with open(self.lockfile, 'r') as conn:
conn_string = conn.read().split(',')
if len(conn_string) < 5:
raise OverlayNotAvailable
host = conn_string[0]
port = conn_string[1]
ttl = float(conn_string[3])
state = conn_string[4]
ts = dt.now()
if ts.timestamp() > ttl:
logging.warning("Overlay Service Master has expired. Using this at risk!")
self.pool = redis.ConnectionPool(host=host, port=port, db=0, decode_responses=True)
redis.StrictRedis.__init__(self, connection_pool=self.pool, decode_responses=True)
logging.info('Connection is open... Checking to see if I can connect')
self.host = host
self.port = port
# If set name suceeds. The Db is connected. O/W handle the error below accordingly
self.client_setname(getUID())
logging.info('[Redis Client] Connected as client to master at %s on port %s', host, port)
self.isconnected = True
break
except FileNotFoundError:
logging.warning('[Redis Client] No Lockfile Found. Service unavailable: %s', self.lockfile)
raise OverlayNotAvailable
except redis.ReadOnlyError as e:
logging.warning('[Redis Client] Connecting as read only')
self.isconnected = True
break
except redis.BusyLoadingError as e:
logging.warning('[Redis Client] Current Master is starting up. Standing by.....')
time.sleep(5)
connect_wait += (dt.now()-start).total_seconds()
continue
except redis.RedisError:
logging.warning('[Redis Client] Service is not running. Cannot get master from lockfile: %s', self.lockfile)
raise OverlayNotAvailable
def lock_acquire(self, key, hold_time=30):
""" Acquires a lock for the given key (concurrency control)
"""
timeout = int(hold_time * 1.5)
while True:
lock = self.get(key + ':LOCK')
if lock is None:
logging.info('Acquiring Lock for %s', key)
unique_key = getUID()
self.set(key + ':LOCK', unique_key)
self.expire(key + ':LOCK', hold_time)
return unique_key # Return unique key for this process
timeout -= 1
if timeout == 0:
logging.warning('Timedout waiting to aqcuire lock on %s', key)
break
logging.info('Waiting to acquire Lock for %s.....', key)
time.sleep(3)
return None
def lock_acquire(self, key, hold_time=30):
""" Acquires a lock for the given key (concurrency control)
"""
timeout = int(hold_time * 1.5)
while True:
lock = self.get(key + ':LOCK')
if lock is None:
logging.info('Acquiring Lock for %s', key)
unique_key = getUID()
self.set(key + ':LOCK', unique_key)
self.expire(key + ':LOCK', hold_time)
return unique_key # Return unique key for this process
timeout -= 1
if timeout == 0:
logging.warning('Timedout waiting to aqcuire lock on %s', key)
break
logging.info('Waiting to acquire Lock for %s.....', key)
time.sleep(3)
return None
def __init__(self, name):
settings = systemsettings()
self._name_app = name
self.lockfile = '%s_%s.lock' % (self._name_app, 'RedisService')
self.isconnected = False
self.host = None
self.port = None
self.pool = None
connect_wait = 0
while True:
try:
with open(self.lockfile, 'r') as conn:
conn_string = conn.read().split(',')
if len(conn_string) < 5:
raise OverlayNotAvailable
host = conn_string[0]
port = conn_string[1]
ttl = float(conn_string[3])
state = conn_string[4]
ts = dt.now()
if ts.timestamp() > ttl:
logging.warning(
"Overlay Service Master has expired. Using this at risk!"
)
self.pool = redis.ConnectionPool(host=host,
port=port,
db=0,
decode_responses=True)
redis.StrictRedis.__init__(self,
connection_pool=self.pool,
decode_responses=True)
logging.info(
'Connection is open... Checking to see if I can connect')
self.host = host
self.port = port
# If set name suceeds. The Db is connected. O/W handle the error below accordingly
self.client_setname(getUID())
logging.info(
'[Redis Client] Connected as client to master at %s on port %s',
host, port)
self.isconnected = True
break
except FileNotFoundError:
logging.warning(
'[Redis Client] No Lockfile Found. Service unavailable: %s',
self.lockfile)
raise OverlayNotAvailable
except redis.ReadOnlyError as e:
logging.warning('[Redis Client] Connecting as read only')
self.isconnected = True
break
except redis.BusyLoadingError as e:
logging.warning(
'[Redis Client] Current Master is starting up. Standing by.....'
)
time.sleep(5)
connect_wait += (dt.now() - start).total_seconds()
continue
except redis.RedisError:
logging.warning(
'[Redis Client] Service is not running. Cannot get master from lockfile: %s',
self.lockfile)
raise OverlayNotAvailable
