80 lines
2.4 KiB
Python
80 lines
2.4 KiB
Python
"""离线检测定时调度器
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使用 APScheduler 在 Django 进程中启动后台线程，每 30 秒检测一次终端心跳超时。
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"""
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import logging
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from apscheduler.schedulers.background import BackgroundScheduler
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from django.utils.timezone import now
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logger = logging.getLogger(__name__)
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CHECK_INTERVAL_SECONDS = 30 # 检测间隔：30 秒
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_scheduler: BackgroundScheduler | None = None
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def _check_offline_terminals():
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"""检测超时心跳的终端(3 分钟内未心跳)，标记为离线并推送 WebSocket 通知"""
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from datetime import timedelta
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from apps.core.models import AiSmartTerminal
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HEARTBEAT_TIMEOUT = timedelta(minutes=3)
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threshold = now() - HEARTBEAT_TIMEOUT
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offline_terminals = AiSmartTerminal.objects.filter(
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online_status=1,
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last_heartbeat_time__isnull=False,
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last_heartbeat_time__lt=threshold,
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)
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if not offline_terminals.exists():
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return
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offline_list = list(offline_terminals.values("stcd", "stnm"))
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count = offline_terminals.update(online_status=0)
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logger.warning("标记 %d 个终端为离线:", count)
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for t in offline_list:
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logger.warning(" - %s (%s)", t["stcd"], t["stnm"])
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# WebSocket 推送离线通知
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try:
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from asgiref.sync import async_to_sync
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from channels.layers import get_channel_layer
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channel_layer = get_channel_layer()
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if channel_layer is not None:
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async_to_sync(channel_layer.group_send)(
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"terminal_status",
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{
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"type": "terminal.status",
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"data": {
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"event": "offline",
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"count": count,
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"terminals": offline_list,
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},
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},
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)
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except Exception:
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logger.exception("WebSocket 推送失败")
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def start_offline_checker():
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"""启动离线检测后台调度器（仅在主进程中启动一次）"""
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global _scheduler
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if _scheduler is not None:
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return # 已启动，避免重复
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_scheduler = BackgroundScheduler(daemon=True)
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_scheduler.add_job(
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_check_offline_terminals,
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"interval",
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seconds=CHECK_INTERVAL_SECONDS,
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id="check_terminal_offline",
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replace_existing=True,
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)
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_scheduler.start()
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logger.info("离线检测调度器已启动，每 %d 秒检测一次", CHECK_INTERVAL_SECONDS)
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