def get_cluster_status():
try:
return requests.get("{}admin/collections?action=CLUSTERSTATUS".format(
SDAP_SOLR_URL)).json()
except (requests.exceptions.ConnectionError, json.decoder.JSONDecodeError):
return False
logging.info("Attempting to aquire lock from {}".format(SDAP_ZK_SOLR))
zk_host, zk_chroot = SDAP_ZK_SOLR.split('/')
zk = KazooClient(hosts=zk_host)
zk.start()
zk.ensure_path(zk_chroot)
zk.chroot = zk_chroot
lock = zk.Lock("/collection-creator", ZK_LOCK_GUID)
try:
with lock: # blocks waiting for lock acquisition
logging.info(
"Lock aquired. Checking for SolrCloud at {}".format(SDAP_SOLR_URL))
# Wait for MAX_RETRIES for the entire Solr cluster to be available.
attempts = 0
status = None
collection_exists = False
while attempts <= MAX_RETRIES:
status = get_cluster_status()
if not status:
# If we can't get the cluster status, my Solr node is not running
attempts += 1
logging.info("Waiting for Solr at {}".format(SDAP_SOLR_URL))
def main():
parser = argparse.ArgumentParser(description=(
"Distributed locking using Zookeeper primarily for scripting. "
"After acquiring the lock, the zk node is printed to STDOUT. This "
"zk node should be passed to unlock. Note: all logs are printed to STDERR"
))
parser.add_argument("-s", "--servers", default='127.0.0.1:2181')
parser.add_argument("-c",
"--chroot",
default='/devops',
type=lambda d: d.rstrip('/'),
help="ZK chroot for the lock path")
parser.add_argument(
"-i",
"--identifier",
default=None,
help="Optional string identifier to add to the lock node "
"OR verify when unlocking")
parser.add_argument(
"action",
choices=["lock", "rlock", "wlock", "unlock", "list"],
help=("lock: acquire a mutex lock. rlock: acquire a read lock "
"wlock: acquire a write lock. unlock: release lock "
"identified by zk node. list: list all lock contenders"))
parser.add_argument(
"lock_path",
type=lambda d: d.rstrip('/'),
help=
("ZK path to lock OR ZK node to unlock. For the unlock"
"action this must be the chrooted zk path to the node e.g."
"lockpick lock -c /devops /mylock"
"lockpick unlock -c /devops /mylock/9d2badeec7684f35b10f4860db42e45c__rlock__0000000022"
))
parser.add_argument('-v', '--verbose', default=0, action='count')
parser.add_argument('-r', '--retry-count', default=3, type=int)
parser.add_argument('-p', '--retry-sleep', default=3, type=int)
args = parser.parse_args()
logger.setLevel(log_level(args.verbose))
zk = KazooClient(hosts=args.servers)
zk.chroot = args.chroot
zk.start()
if args.action == 'unlock':
result = release_lock(zk, args.lock_path, args.identifier)
zk.stop()
if not result:
return 1
elif args.action == 'list':
for contender in list_contenders(zk, args.lock_path):
print contender
else:
l = acquire_lock(zk, args.action, args.lock_path, args.identifier,
args.retry_count, args.retry_sleep)
if l and l.is_acquired:
zk_path = args.lock_path + '/' + l.node
logger.info("Lock {0} with path {1} acquired".format(
args.lock_path, zk_path))
print zk_path
else:
logger.error("Failed to acquire lock within timeout!")
zk.stop()
return 1
zk.stop()
return 0
