def exposed_replicate(self, blk_id, dst):
try:
opath = path.join(self._data_dir, blk_id)
conn = connect(dst)
conn.root.write(blk_id, open(opath).read())
logging.info("Successfully replicated block %s to %s" % (blk_id, dst))
except:
logging.error("Failed to replicate block %s to %s" % (blk_id, dst))
def cat(self, file):
block_info = self.conn.root.fetch_metadata(file)
for blk_id in block_info:
if len(block_info[blk_id]) > 0:
host = random.sample(block_info[blk_id], 1)[0]
data_conn = connect(host)
print data_conn.root.read(blk_id)
else:
raise Exception("No hosts available for block %s" % file)
def start_data_service(config, port):
data_dir = path.join(path.abspath(config['dataserver.root.dir']), 'storage')
id_file = path.join(path.abspath(config['dataserver.root.dir']), 'id')
nameserver_address = config['nameserver.address']
dataserver_address = cat_host(gethostname(), port)
mkdirp(data_dir)
if os.path.exists(id_file):
id = open(id_file, 'r').read()
_refresh_blocks(data_dir)
else:
nameserver_conn = connect(nameserver_address)
id = nameserver_conn.root.new_ds_id(dataserver_address)
open(id_file, 'w').write(id)
logging.info("ID is %s" % id)
DataServer._id = id
DataServer._data_dir = data_dir
DataServer._config = config
t = threading.Thread(target=start_rpyc_dataserver, args=[port])
t.daemon = True
t.start()
nameserver_conn = connect(nameserver_address)
nameserver_conn.root.register(id, dataserver_address)
nameserver_conn.close()
dataserver_conn = connect(dataserver_address)
try:
while t.isAlive():
dataserver_conn.root.send_heartbeat()
dataserver_conn.root.send_block_report()
t.join(3)
except:
logging.info("Caught exception, unregistering")
nameserver_conn = connect(nameserver_address)
nameserver_conn.root.unregister(id, dataserver_address)
def put(self, src, dst):
bytesWritten = 0
numBytes = os.path.getsize(src)
f = open(src, 'r')
while bytesWritten < numBytes:
block_info = self.conn.root.new_block(dst)
data_conn = connect(block_info["address"])
payload = f.read(self._block_size)
if payload == "": break
try:
data_conn.root.write(block_info["id"], payload)
bytesWritten += self._block_size
except:
self.conn.root.rm(dst)
raise Exception("Failed to write %s to %s, removed" % (src, dst))
def _add_replicas(blk_id, ids, num_replicas):
if len(ids) == 0:
logging.error("Unable to replicate %s because there are currently 0 replicas" % blk_id)
return
replicas_to_add = min(num_replicas - len(ids), _num_alive_servers() - len(ids))
if replicas_to_add == 0:
logging.error("Unable to replicate %s because there is no host is available for replication" % blk_id)
return
logging.debug("Adding %d replicas for %s" % (replicas_to_add, blk_id))
src = dataserver_metadata[random.sample(ids, 1)[0]]["address"]
new_ids = list(ids)
for i in range(0, replicas_to_add):
(id, metadata) = _random_dataserver(exclude=new_ids)
conn = connect(src)
conn.root.replicate(blk_id, metadata["address"])
logging.info("Replicating %s from %s to %s" % (blk_id, src, metadata["address"]))
new_ids.append(id)
def __init__(self, *args):
super(DataServer, self).__init__(args)
self._ns_conn = connect(self._config['nameserver.address'])
def __init__(self, config):
self.config = config
self.conn = connect(config["nameserver.address"])
