多worker、多隊列
celery是一個分布式的任務調度模塊，那么怎么實現它的分布式功能呢，celery可以支持多台不同的計算機執行不同的任務或者相同的任務。
如果要說celery的分布式應用的話，就要提到celery的消息路由機制，提到AMQP協議。
簡單理解：
可以有多個"消息隊列"（message Queue），不同的消息可以指定發送給不同的Message Queue，
而這是通過Exchange來實現的，發送消息到"消息隊列"中時，可以指定routiing_key，Exchange通過routing_key來吧消息路由（routes）到不同的"消息隊列"中去。
exchange 對應 一個消息隊列(queue)，即：通過"消息路由"的機制使exchange對應queue，每個queue對應每個worker。
下面我們來看一個列子：
vi tasks.py
#!/usr/bin/env python #-*- coding:utf-8 -*- from celery import Celery app = Celery() app.config_from_object("celeryconfig") # 指定配置文件 @app.task def taskA(x,y): return x + y @app.task def taskB(x,y,z): return x + y + z @app.task def add(x,y): return x + y
編寫配置文件，配置文件一般單獨寫在一個文件中。
vi celeryconfig.py
#!/usr/bin/env python #-*- coding:utf-8 -*- from kombu import Exchange,Queue BROKER_URL = "redis://47.106.106.220:5000/1" CELERY_RESULT_BACKEND = "redis://47.106.106.220:5000/2" CELERY_QUEUES = ( Queue("default",Exchange("default"),routing_key="default"), Queue("for_task_A",Exchange("for_task_A"),routing_key="for_task_A"), Queue("for_task_B",Exchange("for_task_B"),routing_key="for_task_B") ) # 路由 CELERY_ROUTES = { 'tasks.taskA':{"queue":"for_task_A","routing_key":"for_task_A"}, 'tasks.taskB':{"queue":"for_task_B","routing_key":"for_task_B"} }
遠程客戶端上編寫測試腳本
vi test.py from tasks import * re1 = taskA.delay(100, 200) print(re1.result) re2 = taskB.delay(1, 2, 3) print(re2.result) re3 = add.delay(1, 2) print(re3.status)
啟動兩個worker來分別指定taskA、taskB，開兩個窗口分別執行下面語句。
celery -A tasks worker -l info -n workerA.%h -Q for_task_A
celery -A tasks worker -l info -n workerB.%h -Q for_task_B
遠程客戶端上執行腳本可以看到如下輸出：
python test.py 300 6 PENDING
在taskA所在窗口可以看到如下輸出：
....... ....... ....... task_A [tasks] . tasks.add . tasks.taskA . tasks.taskB [2018-05-27 19:23:49,235: INFO/MainProcess] Connected to redis://47.106.106.220:5000/1 [2018-05-27 19:23:49,253: INFO/MainProcess] mingle: searching for neighbors [2018-05-27 19:23:50,293: INFO/MainProcess] mingle: all alone [2018-05-27 19:23:50,339: INFO/MainProcess] celery@workerA.izwz920j4zsv1q15yhii1qz ready. [2018-05-27 19:23:56,051: INFO/MainProcess] sync with celery@workerB.izwz920j4zsv1q15yhii1qz [2018-05-27 19:24:28,855: INFO/MainProcess] Received task: tasks.taskA[8860e78a-b82b-4715-980c-ae125dcab2f9] [2018-05-27 19:24:28,872: INFO/ForkPoolWorker-1] Task tasks.taskA[8860e78a-b82b-4715-980c-ae125dcab2f9] succeeded in 0.0162177120219s: 300
在taskB所在窗口可以看到如下輸出：
....... ....... ....... task_B [tasks] . tasks.add . tasks.taskA . tasks.taskB [2018-05-27 19:23:56,012: INFO/MainProcess] Connected to redis://47.106.106.220:5000/1 [2018-05-27 19:23:56,022: INFO/MainProcess] mingle: searching for neighbors [2018-05-27 19:23:57,064: INFO/MainProcess] mingle: sync with 1 nodes [2018-05-27 19:23:57,064: INFO/MainProcess] mingle: sync complete [2018-05-27 19:23:57,112: INFO/MainProcess] celery@workerB.izwz920j4zsv1q15yhii1qz ready. [2018-05-27 19:24:33,885: INFO/MainProcess] Received task: tasks.taskB[5646d0b7-3dd5-4b7f-8994-252c5ef03973] [2018-05-27 19:24:33,910: INFO/ForkPoolWorker-1] Task tasks.taskB[5646d0b7-3dd5-4b7f-8994-252c5ef03973] succeeded in 0.0235358460341s: 6
我們看到狀態是PENDING，表示沒有執行，這個是因為沒有celeryconfig.py文件中指定改route到哪一個Queue中，所以會被發動到默認的名字celery的Queue中，但是我們還沒有啟動worker執行celery中的任務。下面，我們來啟動一個worker來執行celery隊列中的任務。
celery -A tasks worker -l info -n worker.%h -Q celery
再次在遠程客戶端執行test.py，可以看到結果執行成功，並且剛新啟動的worker窗口有如下輸出：
....... ....... ....... [tasks] . tasks.add . tasks.taskA . tasks.taskB [2018-05-27 19:25:44,596: INFO/MainProcess] Connected to redis://47.106.106.220:5000/1 [2018-05-27 19:25:44,611: INFO/MainProcess] mingle: searching for neighbors [2018-05-27 19:25:45,660: INFO/MainProcess] mingle: sync with 2 nodes [2018-05-27 19:25:45,660: INFO/MainProcess] mingle: sync complete [2018-05-27 19:25:45,711: INFO/MainProcess] celery@worker.izwz920j4zsv1q15yhii1qz ready. [2018-05-27 19:25:45,868: INFO/MainProcess] Received task: tasks.add[f9c5ca2b-623e-4c0a-9c45-a99fb0b79ed5] [2018-05-27 19:25:45,880: INFO/ForkPoolWorker-1] Task tasks.add[f9c5ca2b-623e-4c0a-9c45-a99fb0b79ed5] succeeded in 0.0107084610499s: 3
Celery與定時任務
在celery中執行定時任務非常簡單，只需要設置celery對象中的CELERYBEAT_SCHEDULE屬性即可。
下面我們接着在celeryconfig.py中添加CELERYBEAT_SCHEDULE變量：
cat celeryconfig.py #!/usr/bin/env python #-*- coding:utf-8 -*- from kombu import Exchange,Queue BROKER_URL = "redis://47.106.106.220:5000/1" CELERY_RESULT_BACKEND = "redis://47.106.106.220:5000/2" CELERY_QUEUES = ( Queue("default",Exchange("default"),routing_key="default"), Queue("for_task_A",Exchange("for_task_A"),routing_key="for_task_A"), Queue("for_task_B",Exchange("for_task_B"),routing_key="for_task_B") ) CELERY_ROUTES = { 'tasks.taskA':{"queue":"for_task_A","routing_key":"for_task_A"}, 'tasks.taskB':{"queue":"for_task_B","routing_key":"for_task_B"} }
# 新增加的定時任務部分 CELERY_TIMEZONE = 'UTC' CELERYBEAT_SCHEDULE = { 'taskA_schedule' : { 'task':'tasks.taskA', 'schedule':2, 'args':(5,6) }, 'taskB_scheduler' : { 'task':"tasks.taskB", "schedule":10, "args":(10,20,30) }, 'add_schedule': { "task":"tasks.add", "schedule":5, "args":(1,2) } }
還是按之前啟動三個worker
celery -A tasks worker -l info -n workerA.%h -Q for_task_A celery -A tasks worker -l info -n workerB.%h -Q for_task_B celery -A tasks worker -l info -n worker.%h -Q celery
啟動定時任務
[root@izwz920j4zsv1q15yhii1qz scripts]# celery -A tasks beat celery beat v4.1.1 (latentcall) is starting. __ - ... __ - _ LocalTime -> 2018-05-27 19:39:29 Configuration -> . broker -> redis://47.106.106.220:5000/1 . loader -> celery.loaders.app.AppLoader . scheduler -> celery.beat.PersistentScheduler . db -> celerybeat-schedule . logfile -> [stderr]@%WARNING . maxinterval -> 5.00 minutes (300s)
在之前啟動worker的三個窗口分別可以看到定時任務正在運行：
celery -A tasks worker -l info -n workerA.%h -Q for_task_A [2018-05-27 19:41:27,432: INFO/ForkPoolWorker-1] Task tasks.taskA[60f41780-c9a2-477b-be46-6620ef07631f] succeeded in 0.00289130600868s: 11 [2018-05-27 19:41:29,428: INFO/MainProcess] Received task: tasks.taskA[27220f52-dde2-471a-a87c-3f533d67217c] ......
...... celery -A tasks worker -l info -n workerB.%h -Q for_task_B [2018-05-27 19:41:18,420: INFO/ForkPoolWorker-1] Task tasks.taskB[b6f9aee3-e6b4-4f10-9428-457d9bb844cf] succeeded in 0.00282042898471s: 60 [2018-05-27 19:41:28,416: INFO/MainProcess] Received task: tasks.taskB[44dfea0b-b725-4874-bea2-9b66e8da573b]
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...... celery -A tasks worker -l info -n worker.%h -Q celery [2018-05-27 19:41:23,428: INFO/ForkPoolWorker-1] Task tasks.add[315a9cca-3c95-4517-9289-2ece15cd46a4] succeeded in 0.00355823297286s: 3 [2018-05-27 19:41:28,423: INFO/MainProcess] Received task: tasks.add[c4a1b2c7-ecb7-4af4-85c1-a341b3ec6726]
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