| # Licensed to the Apache Software Foundation (ASF) under one or more |
| # contributor license agreements. See the NOTICE file distributed with |
| # this work for additional information regarding copyright ownership. |
| # The ASF licenses this file to You under the Apache License, Version 2.0 |
| # (the "License"); you may not use this file except in compliance with |
| # the License. You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| |
| from urlparse import urlparse |
| import logging |
| import httplib |
| import sys |
| from ssl import SSLError |
| from HeartbeatHandlers import HeartbeatStopHandlers |
| from ambari_agent.AmbariConfig import AmbariConfig |
| from ambari_commons.inet_utils import ensure_ssl_using_protocol |
| |
| ERROR_SSL_WRONG_VERSION = "SSLError: Failed to connect. Please check openssl library versions. \n" +\ |
| "Refer to: https://bugzilla.redhat.com/show_bug.cgi?id=1022468 for more details." |
| LOG_REQUEST_MESSAGE = "GET %s -> %s, body: %s" |
| |
| logger = logging.getLogger(__name__) |
| |
| ensure_ssl_using_protocol( |
| AmbariConfig.get_resolved_config().get_force_https_protocol_name(), |
| AmbariConfig.get_resolved_config().get_ca_cert_file_path() |
| ) |
| |
| class NetUtil: |
| |
| DEFAULT_CONNECT_RETRY_DELAY_SEC = 10 |
| HEARTBEAT_IDLE_INTERVAL_DEFAULT_MIN_SEC = 1 |
| HEARTBEAT_IDLE_INTERVAL_DEFAULT_MAX_SEC = 10 |
| MINIMUM_INTERVAL_BETWEEN_HEARTBEATS = 0.1 |
| |
| # Url within server to request during status check. This url |
| # should return HTTP code 200 |
| SERVER_STATUS_REQUEST = "{0}/ca" |
| # For testing purposes |
| DEBUG_STOP_RETRIES_FLAG = False |
| |
| # Stop implementation |
| # Typically, it waits for a certain time for the daemon/service to receive the stop signal. |
| # Received the number of seconds to wait as an argument |
| # Returns true if the application is stopping, false if continuing execution |
| stopCallback = None |
| |
| def __init__(self, config, stop_callback=None): |
| if stop_callback is None: |
| stop_callback = HeartbeatStopHandlers() |
| self.stopCallback = stop_callback |
| self.config = config |
| self.connect_retry_delay = int(config.get('server','connect_retry_delay', |
| default=self.DEFAULT_CONNECT_RETRY_DELAY_SEC)) |
| |
| def checkURL(self, url): |
| """Try to connect to a given url. Result is True if url returns HTTP code 200, in any other case |
| (like unreachable server or wrong HTTP code) result will be False. |
| |
| Additionally returns body of request, if available |
| """ |
| logger.info("Connecting to " + url) |
| responseBody = "" |
| |
| ssl_verify_cert = self.config.get("security","ssl_verify_cert", "0") != "0" |
| |
| try: |
| parsedurl = urlparse(url) |
| |
| if sys.version_info >= (2,7,9) and not ssl_verify_cert: |
| import ssl |
| ca_connection = httplib.HTTPSConnection(parsedurl[1], context=ssl._create_unverified_context()) |
| else: |
| ca_connection = httplib.HTTPSConnection(parsedurl[1]) |
| |
| ca_connection.request("GET", parsedurl[2]) |
| response = ca_connection.getresponse() |
| status = response.status |
| |
| if status == 200: |
| responseBody = response.read() |
| logger.debug(LOG_REQUEST_MESSAGE, url, str(status), responseBody) |
| return True, responseBody |
| else: |
| logger.warning(LOG_REQUEST_MESSAGE, url, str(status), responseBody) |
| return False, responseBody |
| except SSLError as slerror: |
| logger.error(str(slerror)) |
| logger.error(ERROR_SSL_WRONG_VERSION) |
| return False, responseBody |
| |
| except Exception, e: |
| logger.warning("Failed to connect to " + str(url) + " due to " + str(e) + " ") |
| return False, responseBody |
| |
| def try_to_connect(self, server_url, max_retries, logger=None): |
| """Try to connect to a given url, sleeping for connect_retry_delay seconds |
| between retries. No more than max_retries is performed. If max_retries is -1, connection |
| attempts will be repeated forever until server is not reachable |
| |
| Returns count of retries |
| """ |
| connected = False |
| if logger is not None: |
| logger.debug("Trying to connect to %s", server_url) |
| |
| retries = 0 |
| while (max_retries == -1 or retries < max_retries) and not self.DEBUG_STOP_RETRIES_FLAG: |
| server_is_up, responseBody = self.checkURL(self.SERVER_STATUS_REQUEST.format(server_url)) |
| if server_is_up: |
| connected = True |
| break |
| else: |
| if logger is not None: |
| logger.warn('Server at {0} is not reachable, sleeping for {1} seconds...'.format(server_url, |
| self.connect_retry_delay)) |
| retries += 1 |
| |
| if 0 == self.stopCallback.wait(self.connect_retry_delay): |
| #stop waiting |
| if logger is not None: |
| logger.info("Stop event received") |
| self.DEBUG_STOP_RETRIES_FLAG = True |
| |
| return retries, connected, self.DEBUG_STOP_RETRIES_FLAG |
| |
| def get_agent_heartbeat_idle_interval_sec(self, heartbeat_idle_interval_min, heartbeat_idle_interval_max, cluster_size): |
| """ |
| Returns the interval in seconds to be used between agent heartbeats when |
| there are pending stages which requires higher heartbeat rate to reduce the latency |
| between the completion of the last command of the current stage and the starting of first |
| command of next stage. |
| |
| The heartbeat intervals for elevated heartbeats is calculated as a function of the size of the cluster. |
| |
| Using a higher hearbeat rate in case of large clusters will cause agents to flood |
| the server with heartbeat messages thus the calculated heartbeat interval is restricted to |
| [heartbeat_idle_interval_min, heartbeat_idle_interval_max] range. |
| |
| :param cluster_size: the number of nodes the cluster consists of |
| :return: the heartbeat interval in seconds |
| """ |
| |
| heartbeat_idle_interval = cluster_size // heartbeat_idle_interval_max |
| |
| if heartbeat_idle_interval < heartbeat_idle_interval_min: |
| return heartbeat_idle_interval_min |
| |
| if heartbeat_idle_interval > heartbeat_idle_interval_max: |
| return heartbeat_idle_interval_max |
| |
| return heartbeat_idle_interval |