a1s rmr functionality
"""
# ==================================================================================
-# Copyright (c) 2019 Nokia
-# Copyright (c) 2018-2019 AT&T Intellectual Property.
+# Copyright (c) 2019-2020 Nokia
+# Copyright (c) 2018-2020 AT&T Intellectual Property.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
from threading import Thread
from rmr import rmr, helpers
from mdclogpy import Logger
-from a1 import data
+from a1 import data, messages
from a1.exceptions import PolicyTypeNotFound, PolicyInstanceNotFound
mdc_logger = Logger(name=__name__)
RETRY_TIMES = int(os.environ.get("A1_RMR_RETRY_TIMES", 4))
-
-
A1_POLICY_REQUEST = 20010
A1_POLICY_RESPONSE = 20011
A1_POLICY_QUERY = 20012
self.keep_going = True
self.rcv_func = None
self.last_ran = time.time()
- self.work_queue = queue.Queue() # thread safe queue https://docs.python.org/3/library/queue.html
+
+ # see docs/overview#resiliency for a discussion of this
+ self.instance_send_queue = queue.Queue() # thread safe queue https://docs.python.org/3/library/queue.html
# intialize rmr context
if init_func_override:
time.sleep(0.5)
# set the receive function
- # TODO: when policy query is implemented, add A1_POLICY_QUERY
self.rcv_func = (
- rcv_func_override if rcv_func_override else lambda: helpers.rmr_rcvall_msgs(self.mrc, [A1_POLICY_RESPONSE])
+ rcv_func_override
+ if rcv_func_override
+ else lambda: helpers.rmr_rcvall_msgs_raw(self.mrc, [A1_POLICY_RESPONSE, A1_POLICY_QUERY])
)
# start the work loop
self.thread = Thread(target=self.loop)
self.thread.start()
+ def _assert_good_send(self, sbuf, pre_send_summary):
+ """
+ common helper function for _send_msg and _rts_msg
+ """
+ post_send_summary = rmr.message_summary(sbuf)
+ if post_send_summary["message state"] == 0 and post_send_summary["message status"] == "RMR_OK":
+ return True
+ mdc_logger.debug("Message NOT sent!")
+ mdc_logger.debug("Pre-send summary: {0}, Post-send summary: {1}".format(pre_send_summary, post_send_summary))
+ return False
+
+ def _send_msg(self, pay, mtype, subid):
+ """
+ sends a msg
+ """
+ for _ in range(0, RETRY_TIMES):
+ sbuf = rmr.rmr_alloc_msg(self.mrc, len(pay), payload=pay, gen_transaction_id=True, mtype=mtype, sub_id=subid)
+ sbuf.contents.sub_id = subid
+ pre_send_summary = rmr.message_summary(sbuf)
+ mdc_logger.debug("Trying to send message: {}".format(pre_send_summary))
+ sbuf = rmr.rmr_send_msg(self.mrc, sbuf) # send
+ if self._assert_good_send(sbuf, pre_send_summary):
+ rmr.rmr_free_msg(sbuf) # free
+ return
+
+ mdc_logger.debug("A1 did NOT send the message successfully after {} retries!".format(RETRY_TIMES))
+
+ def _rts_msg(self, pay, sbuf_rts, mtype):
+ """
+ sends a message using rts
+ we do not call free here because we may rts many times; it is called after the rts loop
+ """
+ for _ in range(0, RETRY_TIMES):
+ pre_send_summary = rmr.message_summary(sbuf_rts)
+ sbuf_rts = rmr.rmr_rts_msg(self.mrc, sbuf_rts, payload=pay, mtype=mtype)
+ if self._assert_good_send(sbuf_rts, pre_send_summary):
+ break
+ return sbuf_rts # in some cases rts may return a new sbuf
+
+ def _handle_sends(self):
+ # send out all messages waiting for us
+ while not self.instance_send_queue.empty():
+ work_item = self.instance_send_queue.get(block=False, timeout=None)
+ payload = json.dumps(messages.a1_to_handler(*work_item)).encode("utf-8")
+ self._send_msg(payload, A1_POLICY_REQUEST, work_item[1])
+
def loop(self):
"""
This loop runs forever, and has 3 jobs:
mdc_logger.debug("Work loop starting")
while self.keep_going:
- # send out all messages waiting for us
- while not self.work_queue.empty():
- work_item = self.work_queue.get(block=False, timeout=None)
-
- pay = work_item["payload"].encode("utf-8")
- for _ in range(0, RETRY_TIMES):
- # Waiting on an rmr bugfix regarding the over-allocation: https://rancodev.atlassian.net/browse/RICPLT-2490
- sbuf = rmr.rmr_alloc_msg(self.mrc, 4096, pay, True, A1_POLICY_REQUEST)
- # TODO: after next rmr is released, this can be done in the alloc call. but that's not avail in pypi yet
- sbuf.contents.sub_id = work_item["ptid"]
- pre_send_summary = rmr.message_summary(sbuf)
- sbuf = rmr.rmr_send_msg(self.mrc, sbuf) # send
- post_send_summary = rmr.message_summary(sbuf)
- mdc_logger.debug(
- "Pre-send summary: {0}, Post-send summary: {1}".format(pre_send_summary, post_send_summary)
- )
- rmr.rmr_free_msg(sbuf) # free
- if post_send_summary["message state"] == 0 and post_send_summary["message status"] == "RMR_OK":
- mdc_logger.debug("Message sent successfully!")
- break
-
- # read our mailbox and update statuses
- for msg in self.rcv_func():
+ # Update 3/20/2020
+ # We now handle our sends in a thread (that will just exit when it's done) because there is a difference between how send works in SI95 vs NNG.
+ # Send_msg via NNG formerly never blocked.
+ # However under SI95 this send may block for some arbitrary period of time on the first send to an endpoint for which a connection is not established
+ # If this send takes too long, this loop blocks, and the healthcheck will fail, which will cause A1s healthcheck to fail, which will cause Kubernetes to whack A1 and all kinds of horrible things happen.
+ # Therefore, now under SI95, we thread this.
+ Thread(target=self._handle_sends).start()
+
+ # read our mailbox
+ for (msg, sbuf) in self.rcv_func():
+ # TODO: in the future we may also have to catch SDL errors
try:
- pay = json.loads(msg["payload"])
- pti = pay["policy_type_id"]
- pii = pay["policy_instance_id"]
- data.set_policy_instance_status(pti, pii, pay["handler_id"], pay["status"])
- except (PolicyTypeNotFound, PolicyInstanceNotFound, KeyError, TypeError, json.decoder.JSONDecodeError):
- # TODO: in the future we may also have to catch SDL errors
- mdc_logger.debug("Dropping malformed or non applicable message: {0}".format(msg))
-
- # TODO: what's a reasonable sleep time? we don't want to hammer redis too much, and a1 isn't a real time component
+ mtype = msg["message type"]
+ except (KeyError, TypeError, json.decoder.JSONDecodeError):
+ mdc_logger.debug("Dropping malformed policy ack/query message: {0}".format(msg))
+
+ if mtype == A1_POLICY_RESPONSE:
+ try:
+ # got a policy response, update status
+ pay = json.loads(msg["payload"])
+ data.set_policy_instance_status(
+ pay["policy_type_id"], pay["policy_instance_id"], pay["handler_id"], pay["status"]
+ )
+ mdc_logger.debug("Successfully received status update: {0}".format(pay))
+ except (PolicyTypeNotFound, PolicyInstanceNotFound):
+ mdc_logger.debug("Received a response for a non-existent instance")
+ except (KeyError, TypeError, json.decoder.JSONDecodeError):
+ mdc_logger.debug("Dropping malformed policy ack message: {0}".format(msg))
+
+ elif mtype == A1_POLICY_QUERY:
+ try:
+ # got a query, do a lookup and send out all instances
+ pti = json.loads(msg["payload"])["policy_type_id"]
+ instance_list = data.get_instance_list(pti) # will raise if a bad type
+ mdc_logger.debug("Received a query for a good type: {0}".format(msg))
+ for pii in instance_list:
+ instance = data.get_policy_instance(pti, pii)
+ payload = json.dumps(messages.a1_to_handler("CREATE", pti, pii, instance)).encode("utf-8")
+ sbuf = self._rts_msg(payload, sbuf, A1_POLICY_REQUEST)
+ except (PolicyTypeNotFound):
+ mdc_logger.debug("Received a query for a non-existent type: {0}".format(msg))
+ except (KeyError, TypeError, json.decoder.JSONDecodeError):
+ mdc_logger.debug("Dropping malformed policy query message: {0}".format(msg))
+
+ else:
+ mdc_logger.debug("Received message type {0} but A1 does not handle this".format(mtype))
+
+ # we must free each sbuf
+ rmr.rmr_free_msg(sbuf)
+
self.last_ran = time.time()
time.sleep(1)
+ mdc_logger.debug("RMR Thread Ending!")
+
# Public
__RMR_LOOP__.keep_going = False
-def queue_work(item):
+def queue_instance_send(item):
"""
push an item into the work queue
currently the only type of work is to send out messages
"""
- __RMR_LOOP__.work_queue.put(item)
+ __RMR_LOOP__.instance_send_queue.put(item)
def healthcheck_rmr_thread(seconds=30):
Code Review / ric-plt / a1.git / blobdiff