# ==================================================================================
-# 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.
# See the License for the specific language governing permissions and
# limitations under the License.
# ==================================================================================
+"""
+A1 RMR functionality
+"""
import os
import queue
import time
import json
-from rmr import rmr, helpers
-from a1 import get_module_logger
-from a1 import data
+from threading import Thread
+from ricxappframe.rmr import rmr, helpers
+from mdclogpy import Logger
+from a1 import data, messages
from a1.exceptions import PolicyTypeNotFound, PolicyInstanceNotFound
-logger = get_module_logger(__name__)
+mdc_logger = Logger(name=__name__)
-RETRY_TIMES = int(os.environ.get("RMR_RETRY_TIMES", 4))
+RETRY_TIMES = int(os.environ.get("A1_RMR_RETRY_TIMES", 4))
+A1_POLICY_REQUEST = 20010
+A1_POLICY_RESPONSE = 20011
+A1_POLICY_QUERY = 20012
-_SEND_QUEUE = queue.Queue() # thread safe queue https://docs.python.org/3/library/queue.html
+# Note; yes, globals are bad, but this is a private (to this module) global
+# No other module can import/access this (well, python doesn't enforce this, but all linters will complain)
+__RMR_LOOP__ = None
-def _init_rmr():
- """
- init an rmr context
- This gets monkeypatched out for unit testing
+
+class _RmrLoop:
"""
- # rmr.RMRFL_MTCALL puts RMR into a multithreaded mode, where a receiving thread populates an
- # internal ring of messages, and receive calls read from that
- # currently the size is 2048 messages, so this is fine for the foreseeable future
- mrc = rmr.rmr_init(b"4562", rmr.RMR_MAX_RCV_BYTES, rmr.RMRFL_MTCALL)
+ Class represents an rmr loop that constantly reads from rmr and performs operations
+ based on waiting messages. This launches a thread, it should probably only be called
+ once; the public facing method to access these ensures this.
- while rmr.rmr_ready(mrc) == 0:
- time.sleep(0.5)
+ TODO: the xapp frame has a version of this looping structure. See if A1 can switch to that.
+ """
- return mrc
+ def __init__(self, init_func_override=None, rcv_func_override=None):
+ """
+ Init
+ Parameters
+ ----------
+ init_func_override: function (optional)
+ Function that initializes RMR and answers an RMR context.
+ Supply an empty function to skip initializing RMR.
-def _send(mrc, payload, message_type=0):
- """
- Sends a message up to RETRY_TIMES
- If the message is sent successfully, it returns the transactionid
- Does nothing otherwise
- """
- # TODO: investigate moving this below and allocating the space based on the payload size
- sbuf = rmr.rmr_alloc_msg(mrc, 4096)
- payload = payload if isinstance(payload, bytes) else payload.encode("utf-8")
-
- # retry RETRY_TIMES to send the message
- for _ in range(0, RETRY_TIMES):
- # setup the send message
- rmr.set_payload_and_length(payload, sbuf)
- rmr.generate_and_set_transaction_id(sbuf)
- sbuf.contents.state = 0
- sbuf.contents.mtype = message_type
- pre_send_summary = rmr.message_summary(sbuf)
- logger.debug("Pre message send summary: %s", pre_send_summary)
- transaction_id = pre_send_summary["transaction id"] # save the transactionid because we need it later
-
- # send
- sbuf = rmr.rmr_send_msg(mrc, sbuf)
+ rcv_func_override: function (optional)
+ Function that receives messages from RMR and answers a list.
+ Supply a trivial function to skip reading from RMR.
+ """
+ self.keep_going = True
+ self.rcv_func = None
+ self.last_ran = time.time()
+
+ # 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:
+ self.mrc = init_func_override()
+ else:
+ mdc_logger.debug("Waiting for rmr to initialize..")
+ # rmr.RMRFL_MTCALL puts RMR into a multithreaded mode, where a receiving thread populates an
+ # internal ring of messages, and receive calls read from that
+ # currently the size is 2048 messages, so this is fine for the foreseeable future
+ self.mrc = rmr.rmr_init(b"4562", rmr.RMR_MAX_RCV_BYTES, rmr.RMRFL_MTCALL)
+ while rmr.rmr_ready(self.mrc) == 0:
+ time.sleep(0.5)
+
+ # set the receive function
+ self.rcv_func = (
+ 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)
- logger.debug("Post message send summary: %s", rmr.message_summary(sbuf))
-
- # check success or failure
if post_send_summary["message state"] == 0 and post_send_summary["message status"] == "RMR_OK":
- # we are good
- logger.debug("Message sent successfully!")
- rmr.rmr_free_msg(sbuf)
- return transaction_id
+ 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
- # we failed all RETRY_TIMES
- logger.debug("Send failed all %s times, stopping", RETRY_TIMES)
- rmr.rmr_free_msg(sbuf)
- return None
+ 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:
+ - send out any messages that have to go out (create instance, delete instance)
+ - read a1s mailbox and update the status of all instances based on acks from downstream policy handlers
+ - clean up the database (eg delete the instance) under certain conditions based on those statuses (NOT DONE YET)
+ """
+ # loop forever
+ mdc_logger.debug("Work loop starting")
+ while self.keep_going:
+
+ # 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:
+ 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)
-def _update_all_statuses(mrc):
- """
- get all waiting messages, and try to parse them as status updates
- (currently, those are the only messages a1 should get, this may have to be revisited later)
- """
- for msg in helpers.rmr_rcvall_msgs(mrc, [21024]):
- try:
- pay = json.loads(msg["payload"])
- data.set_status(pay["policy_type_id"], pay["policy_instance_id"], pay["handler_id"], pay["status"])
- except (PolicyTypeNotFound, PolicyInstanceNotFound, KeyError):
- logger.debug("Dropping malformed or non applicable message")
- logger.debug(msg)
+ mdc_logger.debug("RMR Thread Ending!")
# Public
-def queue_work(item):
+def start_rmr_thread(init_func_override=None, rcv_func_override=None):
"""
- push an item into the work queue
- currently the only type of work is to send out messages
+ Start a1s rmr thread
+
+ Parameters
+ ----------
+ init_func_override: function (optional)
+ Function that initializes RMR and answers an RMR context.
+ Supply an empty function to skip initializing RMR.
+
+ rcv_func_override: function (optional)
+ Function that receives messages from RMR and answers a list.
+ Supply a trivial function to skip reading from RMR.
"""
- _SEND_QUEUE.put(item)
+ global __RMR_LOOP__
+ if __RMR_LOOP__ is None:
+ __RMR_LOOP__ = _RmrLoop(init_func_override, rcv_func_override)
-class RmrLoop:
+def stop_rmr_thread():
"""
- class represents an rmr loop meant to be called as a longstanding separate thread
+ stops the rmr thread
"""
+ __RMR_LOOP__.keep_going = False
- def __init__(self, real_init=True):
- self._rmr_is_ready = False
- self._keep_going = True
- self._real_init = real_init # useful for unit testing to turn off initialization
- def rmr_is_ready(self):
- """returns whether rmr has been initialized"""
- return self._rmr_is_ready
+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__.instance_send_queue.put(item)
- def stop(self):
- """sets a flag for the loop to end"""
- self._keep_going = False
- def loop(self):
- """
- This loop runs in an a1 thread forever, and has 3 jobs:
- - send out any messages that have to go out (create instance, delete instance)
- - read a1s mailbox and update the status of all instances based on acks from downstream policy handlers
- - clean up the database (eg delete the instance) under certain conditions based on those statuses (NOT DONE YET)
- """
+def healthcheck_rmr_thread(seconds=30):
+ """
+ returns a boolean representing whether the rmr loop is healthy, by checking two attributes:
+ 1. is it running?,
+ 2. is it stuck in a long (> seconds) loop?
+ """
+ return __RMR_LOOP__.thread.is_alive() and ((time.time() - __RMR_LOOP__.last_ran) < seconds)
- # get a context
- mrc = None
- logger.debug("Waiting for rmr to initialize...")
- if self._real_init:
- mrc = _init_rmr()
- self._rmr_is_ready = True
- logger.debug("Rmr is ready")
- # loop forever
- logger.debug("Work loop starting")
- while self._keep_going:
- """
- We never raise an exception here. Log and keep moving
- Bugs will eventually be caught be examining logs.
- """
- try:
- # First, send out all messages waiting for us
- while not _SEND_QUEUE.empty():
- work_item = _SEND_QUEUE.get(block=False, timeout=None)
- _send(mrc, payload=work_item["payload"], message_type=work_item["msg type"])
-
- # Next, update all statuses waiting in a1s mailbox
- _update_all_statuses(mrc)
-
- # TODO: next body of work is to try to clean up the database for any updated statuses
-
- except Exception as e:
- logger.debug("Polling thread encountered an unexpected exception, but it will continue:")
- logger.exception(e)
-
- time.sleep(1)
+def replace_rcv_func(rcv_func):
+ """purely for the ease of unit testing to test different rcv scenarios"""
+ __RMR_LOOP__.rcv_func = rcv_func
Code Review / ric-plt / a1.git / blobdiff