crawlab_feader/FworkSpider/feapder/core/scheduler.py

# -*- coding: utf-8 -*-
"""
Created on 2017-01-09 10:38
---------
@summary: 组装parser、 parser_control 和 collector
---------
@author: Boris
@email: boris_liu@foxmail.com
"""
import threading
import time
from collections import Iterable

import feapder.setting as setting
import feapder.utils.tools as tools
from feapder.buffer.item_buffer import ItemBuffer
from feapder.buffer.request_buffer import RequestBuffer
from feapder.buffer.heartbeat_buffer import HeartBeatBuffer
from feapder.core.base_parser import BaseParser
from feapder.core.collector import Collector
from feapder.core.handle_failed_items import HandleFailedItems
from feapder.core.handle_failed_requests import HandleFailedRequests
from feapder.core.parser_control import PaserControl
from feapder.db.rabbitMq import RabbitMQ
from feapder.network.item import Item
from feapder.network.request import Request
from feapder.utils import metrics
from feapder.utils.log import log


class Scheduler(threading.Thread):
    __custom_setting__ = {}

    def __init__(
        self,
        redis_key=None,
        user=None,
        thread_count=None,
        begin_callback=None,
        end_callback=None,
        keep_alive=None,
        auto_start_requests=None,
        **kwargs
    ):
        """
        @summary: 调度器
        ---------
        @param redis_key: 爬虫request及item存放redis中的文件夹
        @param user: 指定mq特定的程序消费用户标识
        @param thread_count: 线程数，默认为配置文件中的线程数
        @param begin_callback: 爬虫开始回调函数
        @param end_callback: 爬虫结束回调函数
        @param keep_alive: 爬虫是否常驻，默认否
        @param auto_start_requests: 爬虫是否自动添加任务
        ---------
        @result:
        """

        super(Scheduler, self).__init__()

        for key, value in self.__class__.__custom_setting__.items():
            if key == "AUTO_STOP_WHEN_SPIDER_DONE":  # 兼容老版本的配置
                setattr(setting, "KEEP_ALIVE", not value)
            else:
                setattr(setting, key, value)

        self._redis_key = redis_key or setting.REDIS_KEY
        if not self._redis_key:
            raise Exception(
                """
                redis_key 为redis中存放request与item的目录。不能为空，
                可在setting中配置，如 REDIS_KEY = 'test'
                或spider初始化时传参, 如 TestSpider(redis_key='test')
                """
            )

        self._rabbitmq = RabbitMQ()
        self._request_buffer = RequestBuffer(redis_key, user=user)
        self._item_buffer = ItemBuffer(redis_key, user=user)
        self._collector = Collector(redis_key, user=user)
        self._heartbeat_buffer = HeartBeatBuffer(redis_key)

        self._parsers = []
        self._parser_controls = []
        self._parser_control_obj = PaserControl

        # 兼容老版本的参数
        if "auto_stop_when_spider_done" in kwargs:
            self._keep_alive = not kwargs.get("auto_stop_when_spider_done")
        else:
            self._keep_alive = (
                keep_alive if keep_alive is not None else setting.KEEP_ALIVE
            )

        self._auto_start_requests = (
            auto_start_requests
            if auto_start_requests is not None
            else setting.SPIDER_AUTO_START_REQUESTS
        )

        self._begin_callback = (
            begin_callback
            if begin_callback
            else lambda: log.info("\n********** feapder begin **********")
        )
        self._end_callback = (
            end_callback
            if end_callback
            else lambda: log.info("\n********** feapder end **********")
        )

        self._thread_count = (
            setting.SPIDER_THREAD_COUNT if not thread_count else thread_count
        )

        self._spider_id = tools.get_uuid(redis_key, tools.get_current_date())
        self._spider_name = redis_key

        self._is_notify_end = False  # 是否已经通知结束

        # Request 缓存设置
        Request.cached_redis_key = redis_key
        Request.cached_expire_time = setting.RESPONSE_CACHED_EXPIRE_TIME

        self._last_check_task_status_time = 0
        self._user = user

        self.init_metrics()

    def init_metrics(self):
        """
        初始化打点系统
        """
        metrics.init(**setting.METRICS_OTHER_ARGS)

    def add_parser(self, parser):
        parser = parser()  # parser 实例化
        if isinstance(parser, BaseParser):
            self._parsers.append(parser)
        else:
            raise ValueError("类型错误，爬虫需继承feapder.BaseParser")

    def _start(self):
        self.spider_begin()  # 启动爬虫 -- start_callback

        # 将失败的item入库
        if setting.RETRY_FAILED_ITEMS:
            handle_failed_items = HandleFailedItems(
                redis_key=self._redis_key,
                item_buffer=self._item_buffer,
                rabbitmq=self._rabbitmq,
                user=self._user
            )
            handle_failed_items.reput_failed_items_to_db()

        self._heartbeat_buffer.start()  # 心跳管理器

        # STEP 3.1 开启 request_buffer -- 任务管理器 负责缓冲添加到数据库中的request
        self._request_buffer.start()
        # STEP 3.2 开启 item_buffer -- 管道管理器 负责缓冲采集的数据添加到数据库
        self._item_buffer.start()
        # STEP 3.4 开启 collector  -- 任务管理 分发任务
        self._collector.start()

        # 启动parser control 线程池
        for i in range(self._thread_count):
            # STEP 3.4 创建执行任务线程池
            parser_control = self._parser_control_obj(
                self._collector,
                self._redis_key,
                self._request_buffer,
                self._item_buffer,
                self._heartbeat_buffer
            )

            for parser in self._parsers:  # step 3.5 把所有待执行任务添加到线程池
                parser_control.add_parser(parser)

            parser_control.start()  # STEP 3.6 开启采集线程
            self._parser_controls.append(parser_control)

        # STEP 3.7下发任务 有消费线程之后开始读取任务
        if setting.RETRY_FAILED_REQUESTS:
            # 重设失败的任务
            handle_failed_requests = HandleFailedRequests(
                redis_key=self._redis_key,
                rabbitmq=self._rabbitmq,
                user=self._user
            )
            handle_failed_requests.reput_failed_requests_to_requests()

        # STEP 3.8下发新任务 ，生产新任务
        if self._auto_start_requests:
            self.__add_task()

    def run(self):
        self._start()

        while True:
            try:
                if self.all_thread_is_done():
                    if not self._is_notify_end:
                        self.spider_end()  # 爬虫结束
                        self._is_notify_end = True

                    if not self._keep_alive:  # 如果不是常驻爬虫 关闭所有线程
                        self._stop_all_thread()
                        break

                else:
                    self._is_notify_end = False

                self.check_task_status()
            except (Exception, BaseException) as e:
                log.exception(e)

            tools.delay_time(1)

    def __add_task(self):
        # 判断任务池中属否还有任务，若有接着抓取，若无则生产新任务
        todo_task_count = self._collector.get_requests_count()
        if todo_task_count:
            log.info("检查到有待做任务 %s 条，不重下发新任务，将接着上回异常终止处继续抓取" % todo_task_count)
        else:
            for parser in self._parsers:
                results = parser.start_requests()
                # 添加request到请求队列，由请求队列统一入库
                if results and not isinstance(results, Iterable):
                    raise Exception("%s.%s返回值必须可迭代" % (parser.name, "start_requests"))

                result_type = 1
                for result in results or []:  # step 对yield 的数据进行判断处理
                    if isinstance(result, Request):  # Request 加入到任务队列
                        result.parser_name = result.parser_name or parser.name
                        self._request_buffer.put_request(result)
                        result_type = 1

                    elif isinstance(result, Item):  # Item 数据，存入到数据管道队列，等待存储
                        self._item_buffer.put_item(result)
                        result_type = 2

                    elif callable(result):  # callable 的 request 可能是更新数据库操作的函数
                        if result_type == 1:
                            self._request_buffer.put_request(result)
                        else:
                            self._item_buffer.put_item(result)
                    else:
                        raise TypeError(
                            "start_requests yield result type error, expect Request、Item、callback func, bug get type: {}".format(
                                type(result)
                            )
                        )

                self._request_buffer.flush()
                self._item_buffer.flush()

    def all_thread_is_done(self):
        # Stress 降低偶然性, 因为各个环节不是并发的，很有可能当时状态为假，但检测下一条时该状态为真。一次检测很有可能遇到这种偶然性
        for i in range(5):
            # STEP 5.1 检测 collector 状态
            if (
                self._collector.is_collector_task()
                or self._collector.get_requests_count() > 0
            ):
                return False

            # STEP 5.2 检测 parser_control 状态
            for parser_control in self._parser_controls:
                if not parser_control.is_not_task():
                    return False

            # STEP 5.3 检测 item_buffer 状态
            if (
                self._item_buffer.get_items_count() > 0
                or self._item_buffer.is_adding_to_db()
            ):
                return False

            # STEP 5.4 检测 request_buffer 状态
            if (
                self._request_buffer.get_requests_count() > 0
                or self._request_buffer.is_adding_to_db()
            ):
                return False

            # 检测 heartbeat_buffer 状态
            if (
                self._heartbeat_buffer.get_items_count() > 0
                or self._heartbeat_buffer.is_adding_to_db()
            ):
                return False

            tools.delay_time(1)  # 休眠1秒

        return True

    @tools.run_safe_model("check_task_status")
    def check_task_status(self):
        """
        检查任务状态 预警
        """
        # step 每分钟检查一次
        now_time = time.time()
        if now_time - self._last_check_task_status_time > 60:
            self._last_check_task_status_time = now_time
        else:
            return

        # 检查失败任务数量 超过1000 报警
        failed_count = self._request_buffer.get_failed_requests_count()
        if failed_count > setting.WARNING_FAILED_COUNT:
            # 发送报警
            msg = "《%s》爬虫当前失败任务 %s, 请检查爬虫是否正常" % (self._spider_name, failed_count)
            log.error(msg)
            self.send_msg(
                msg,
                level="error",
                message_prefix="《%s》爬虫当前失败任务数报警" % (self._spider_name),
            )

        # parser_control 实时统计已做任务数及失败任务数，若成功率<0.5 则报警
        failed_task_count, success_task_count = PaserControl.get_task_status_count()
        total_count = success_task_count + failed_task_count
        if total_count > 0:
            task_success_rate = success_task_count / total_count
            if task_success_rate < 0.5:
                # 发送报警
                msg = "《%s》爬虫当前任务成功数%s, 失败数%s, 成功率 %.2f, 请检查爬虫是否正常" % (
                    self._spider_name,
                    success_task_count,
                    failed_task_count,
                    task_success_rate,
                )
                log.error(msg)
                self.send_msg(
                    msg,
                    level="error",
                    message_prefix="《%s》爬虫当前任务成功率报警" % (self._spider_name),
                )

        # 检查入库失败次数
        if self._item_buffer.export_falied_times > setting.EXPORT_DATA_MAX_FAILED_TIMES:
            msg = "《{}》爬虫导出数据失败，失败次数：{}， 请检查爬虫是否正常".format(
                self._spider_name, self._item_buffer.export_falied_times
            )
            log.error(msg)
            self.send_msg(
                msg,
                level="error",
                message_prefix="《%s》爬虫导出数据失败" % (self._spider_name)
            )

    def _stop_all_thread(self):
        # 关闭任务管理器
        self._request_buffer.stop()
        # 关闭数据管道
        self._item_buffer.stop()
        # 关闭任务管理
        self._collector.stop()
        # 停止 parser_controls
        for parser_control in self._parser_controls:
            parser_control.stop()

        # 关闭心跳管理
        self._heartbeat_buffer.stop()
        # 记录爬虫停止时间
        self._started.clear()

    def send_msg(self, msg, level="debug", message_prefix=""):
        # log.debug("发送报警 level:{} msg{}".format(level, msg))
        tools.send_msg(msg=msg, level=level, message_prefix=message_prefix)

    def spider_begin(self):
        """
        @summary: start_monitor_task 方式启动，此函数与spider_end不在同一进程内，变量不可共享
        ---------
        ---------
        @result:
        """
        if self._begin_callback:
            self._begin_callback()

        for parser in self._parsers:
            parser.start_callback()  # 任务开始回调

    def spider_end(self):
        if self._end_callback:  # 任务结束回调
            self._end_callback()

        for parser in self._parsers:
            if not self._keep_alive:
                parser.close()  # 爬虫自定义 close

            parser.end_callback()  # 调用结束回调函数

        if not self._keep_alive:
            # 关闭webdirver
            Request.render_downloader and Request.render_downloader.close_all()

            metrics.close()  # 关闭打点
        else:
            metrics.flush()

        if self._keep_alive:
            log.info("爬虫不自动结束，等待下一轮任务...")
        else:
            log.info("《%s》爬虫结束" % (self._spider_name,))

    def join(self, timeout=None):
        """
        重写线程的join
        """
        if not self._started.is_set():
            return

        super().join()