Using AWS Lambda functions in Amazon Neptune - database

Question

I created an AWS Lambda function using this example code in AWS neptuneDB documentation. I followed documentation properly and set the all necessary lambda environmentale variables as well. But when I tested the function it raises an error. Could you please help me solve this issue. I wonder why the code in the AWS neptunedb documentation does not work.
code:
import os, sys, backoff, math
from random import randint
from gremlin_python import statics
from gremlin_python.driver.driver_remote_connection import DriverRemoteConnection
from gremlin_python.driver.protocol import GremlinServerError
from gremlin_python.driver import serializer
from gremlin_python.process.anonymous_traversal import traversal
from gremlin_python.process.graph_traversal import __
from gremlin_python.process.strategies import *
from gremlin_python.process.traversal import T
from tornado.websocket import WebSocketClosedError
from tornado import httpclient
from botocore.auth import SigV4Auth
from botocore.awsrequest import AWSRequest
from botocore.credentials import ReadOnlyCredentials
from types import SimpleNamespace
reconnectable_err_msgs = [
'ReadOnlyViolationException',
'Server disconnected',
'Connection refused'
]
retriable_err_msgs = ['ConcurrentModificationException'] + reconnectable_err_msgs
network_errors = [WebSocketClosedError, OSError]
retriable_errors = [GremlinServerError] + network_errors
def prepare_iamdb_request(database_url):
service = 'neptune-db'
method = 'GET'
access_key = os.environ['AWS_ACCESS_KEY_ID']
secret_key = os.environ['AWS_SECRET_ACCESS_KEY']
region = os.environ['AWS_REGION']
session_token = os.environ['AWS_SESSION_TOKEN']
creds = SimpleNamespace(
access_key=access_key, secret_key=secret_key, token=session_token, region=region,
)
request = AWSRequest(method=method, url=database_url, data=None)
SigV4Auth(creds, service, region).add_auth(request)
return httpclient.HTTPRequest(database_url, headers=request.headers.items())
def is_retriable_error(e):
is_retriable = False
err_msg = str(e)
if isinstance(e, tuple(network_errors)):
is_retriable = True
else:
is_retriable = any(retriable_err_msg in err_msg for retriable_err_msg in retriable_err_msgs)
print('error: [{}] {}'.format(type(e), err_msg))
print('is_retriable: {}'.format(is_retriable))
return is_retriable
def is_non_retriable_error(e):
return not is_retriable_error(e)
def reset_connection_if_connection_issue(params):
is_reconnectable = False
e = sys.exc_info()[1]
err_msg = str(e)
if isinstance(e, tuple(network_errors)):
is_reconnectable = True
else:
is_reconnectable = any(reconnectable_err_msg in err_msg for reconnectable_err_msg in reconnectable_err_msgs)
print('is_reconnectable: {}'.format(is_reconnectable))
if is_reconnectable:
global conn
global g
conn.close()
conn = create_remote_connection()
g = create_graph_traversal_source(conn)
#backoff.on_exception(backoff.constant,
tuple(retriable_errors),
max_tries=5,
jitter=None,
giveup=is_non_retriable_error,
on_backoff=reset_connection_if_connection_issue,
interval=1)
def query(**kwargs):
id = kwargs['id']
return (g.V(id)
.fold()
.coalesce(
__.unfold(),
__.addV('User').property(T.id, id)
)
.id().next())
def doQuery(event):
return query(id=str(randint(0, 10000)))
def lambda_handler(event, context):
return doQuery(event)
def create_graph_traversal_source(conn):
return traversal().withRemote(conn)
def create_remote_connection():
print('Creating remote connection')
return DriverRemoteConnection(
connection_string(),
'g',
pool_size=1,
message_serializer=serializer.GraphSONSerializersV2d0())
def connection_string():
database_url = 'wss://{}:{}/gremlin'.format(os.environ['neptuneEndpoint'], os.environ['neptunePort'])
if 'USE_IAM' in os.environ and os.environ['USE_IAM'] == 'true':
return prepare_iamdb_request(database_url)
else:
return database_url
conn = create_remote_connection()
g = create_graph_traversal_source(conn)
error message:
{
"errorMessage": "'GraphTraversal' object is not callable",
"errorType": "TypeError",
"requestId": "69e6ecd3-1291-4d21-a8fa-1fc910525fc1",
"stackTrace": [
" File \"/var/task/lambda_function.py\", line 111, in lambda_handler\n return doQuery(event)\n",
" File \"/var/task/lambda_function.py\", line 108, in doQuery\n return query(id=str(randint(0, 10000)))\n",
" File \"/var/task/backoff/_sync.py\", line 105, in retry\n ret = target(*args, **kwargs)\n",
" File \"/var/task/lambda_function.py\", line 99, in query\n return (g.V(id)\n"
]
}
log output:
LOGS Name: cloudwatch_lambda_agent State: Subscribed Types: [Platform]
Creating remote connection
EXTENSION Name: cloudwatch_lambda_agent State: Ready Events: [INVOKE,SHUTDOWN]
START RequestId: 69e6ecd3-1291-4d21-a8fa-1fc910525fc1 Version: $LATEST
[ERROR] TypeError: 'GraphTraversal' object is not callable
Traceback (most recent call last):
  File "/var/task/lambda_function.py", line 111, in lambda_handler
    return doQuery(event)
  File "/var/task/lambda_function.py", line 108, in doQuery
    return query(id=str(randint(0, 10000)))
  File "/var/task/backoff/_sync.py", line 105, in retry
    ret = target(*args, **kwargs)
  File "/var/task/lambda_function.py", line 99, in query
    return (g.V(id)END RequestId: 69e6ecd3-1291-4d21-a8fa-1fc910525fc1
REPORT RequestId: 69e6ecd3-1291-4d21-a8fa-1fc910525fc1 Duration: 108.64 ms Billed Duration: 109 ms Memory Size: 128 MB Max Memory Used: 88 MB Init Duration: 1025.72 ms