我有一个复杂的Kafka流应用程序,在同一个流中有两个完全有状态的流:
主要目标是提供一个工作流系统。
详细的逻辑是:
执行
查看所有任务运行
的所有当前状态,并查找要执行的下一个TaskRunsList
并添加下一个任务并发布回Kafka,同时将要完成的任务(WorkerTask
)WorkerTask
并使用简单的Kafka使用者和生产者WorkerTaskResult
)
执行
中的WorkerTaskResult
更改当前TaskRun
并更改状态(主要是运行/成功/失败),还发布回执行
队列(带有Kafka流)如您所见,execution
(带有taskrun
列表)是当前应用程序的状态。
当所有消息都是顺序的(没有并发性,我只能同时拥有taskrun
list的一个更改)时,该流可以很好地工作。当工作流变得并行(并发workertaskresult
可以连接)时,我的执行状态似乎是override并产生一种回滚。
日志输出示例:
2020-04-20 08:05:44,830 INFO reamThread-1 afkaExecutor Stream in with 3264792750: (
state=RUNNING
taskRunList=
[
TaskRun(id=6FiJ3US6jqZbtU3JL2AZD6, taskId=parent, value=null, state=RUNNING),
TaskRun(id=75mtoz5KVRydOo3VJnX68s, taskId=t1, value=null, state=CREATED) # >>>>> t1 is created
]
)
2020-04-20 08:05:44,881 INFO reamThread-1 afkaExecutor WorkerTaskResult: TaskRun(id=75mtoz5KVRydOo3VJnX68s, taskId=t1, value=null, state=RUNNING) # >>>>> worker send running state
2020-04-20 08:05:44,882 INFO reamThread-1 afkaExecutor Stream out with 1805535461 : (
state=RUNNING
taskRunList=
[
TaskRun(id=6FiJ3US6jqZbtU3JL2AZD6, taskId=parent, value=null, state=RUNNING),
TaskRun(id=75mtoz5KVRydOo3VJnX68s, taskId=t1, value=null, state=RUNNING) # >>>>> t1 save the running state
]
)
2020-04-20 08:05:45,047 INFO reamThread-1 afkaExecutor WorkerTaskResult: TaskRun(id=75mtoz5KVRydOo3VJnX68s, taskId=t1, value=null, state=SUCCESS) # >>>>> worker send success
2020-04-20 08:05:45,047 INFO reamThread-1 afkaExecutor Stream out with 578845055 : (
state=RUNNING
taskRunList=
[
TaskRun(id=6FiJ3US6jqZbtU3JL2AZD6, taskId=parent, value=null, state=RUNNING),
TaskRun(id=75mtoz5KVRydOo3VJnX68s, taskId=t1, value=null, state=SUCCESS)
]
)
2020-04-20 08:05:45,153 INFO reamThread-1 afkaExecutor Stream in with 1805535461: (
state=RUNNING
taskRunList=
[
TaskRun(id=6FiJ3US6jqZbtU3JL2AZD6, taskId=parent, value=null, state=RUNNING),
TaskRun(id=75mtoz5KVRydOo3VJnX68s, taskId=t1, value=null, state=RUNNING) # >>>>> OUT OF ORDER AND ROLLBACK TO PREVIOUS VERSION
]
)
2020-04-20 08:05:45,157 INFO reamThread-1 afkaExecutor Stream out with 1889889916 : (
state=RUNNING
taskRunList=
[
TaskRun(id=6FiJ3US6jqZbtU3JL2AZD6, taskId=parent, value=null, state=RUNNING),
TaskRun(id=75mtoz5KVRydOo3VJnX68s, taskId=t1, value=null, state=RUNNING),
TaskRun(id=6k23oBXy9cD0uCJeZ20SpB, taskId=t2, value=null, state=CREATED)
]
)
2020-04-20 08:05:45,209 WARN reamThread-1 KTableSource Detected out-of-order KTable update for execution at offset 10, partition 2.
2020-04-20 08:05:45,313 INFO reamThread-1 afkaExecutor Stream in with 1889889916: (
state=RUNNING
taskRunList=
[
TaskRun(id=6FiJ3US6jqZbtU3JL2AZD6, taskId=parent, value=null, state=RUNNING),
TaskRun(id=75mtoz5KVRydOo3VJnX68s, taskId=t1, value=null, state=RUNNING),
TaskRun(id=6k23oBXy9cD0uCJeZ20SpB, taskId=t2, value=null, state=CREATED)
]
)
2020-04-20 08:05:45,350 INFO reamThread-1 afkaExecutor WorkerTaskResult: TaskRun(id=6k23oBXy9cD0uCJeZ20SpB, taskId=t2, value=null, state=RUNNING)
2020-04-20 08:05:45,350 INFO reamThread-1 afkaExecutor Stream out with 3651399223 : (
state=RUNNING
taskRunList=
[
TaskRun(id=6FiJ3US6jqZbtU3JL2AZD6, taskId=parent, value=null, state=RUNNING),
TaskRun(id=75mtoz5KVRydOo3VJnX68s, taskId=t1, value=null, state=RUNNING),
TaskRun(id=6k23oBXy9cD0uCJeZ20SpB, taskId=t2, value=null, state=RUNNING)
]
)
如果也尝试使用许多不同的方法,如下面的方法:
execution
和workerTaskresult
放在同一主题上,以确保同时只处理相同的1条消息执行
(以便加入WorkerTaskResult
&执行
)或者这里的这个:
我的问题是:
任何线索都很感激,已经被困了好几天了,谢谢
Builder
-> Stream 1
- from KStream<WorkerTaskResult>
- join KTable<Execution>
- to Execution topic
-> Stream 2
- from KTable<Execution> (same than previous)
- multiple output
- to WorkerTaskResult topic (if found an end)
- to Execution & to WorkerTask topic (if found a next task)
- to Execution topic (if detect an Execution end)
任务运行
任务运行
的状态
WorkerTaskResult
或在这个实际版本上,对我来说真正不清楚的是检测到无序KTable更新
在现实世界中的意义是什么?这是否意味着KTable必须每个分区和每个键都有一个生产者才能保持主题的秩序?
编辑2:
同时,我发现了一种新的方式来思考流应用程序似乎正在工作。单元测试正在通过,并且不再检测到无序
。以下是简化的新流程:
Builder
- from KTable<Execution>
- leftJoin KTable<WorkerTaskResult>
- Branch
- If Join > to Execution topic
- If not joint > continue the flow
- Multiple output (same than previous)
- to WorkerTaskResult topic (if found an end)
- to Execution & to WorkerTask topic (if found a next task)
- to Execution topic (if detect an Execution end)
WorkerTaskResult
现在是一个KTable,因此我只保留结果的最后一个版本执行
(我认为这是解决顺序混乱的最重要部分)execution
上的一个新值将在execution
主题上产生一个新值)以下是新的拓扑:
Topologies:
Sub-topology: 0
Source: KSTREAM-SOURCE-0000000000 (topics: [kestra_execution])
--> KTABLE-SOURCE-0000000001
Processor: KTABLE-SOURCE-0000000001 (stores: [execution])
--> KTABLE-TOSTREAM-0000000002, KTABLE-JOINTHIS-0000000007
<-- KSTREAM-SOURCE-0000000000
Source: KSTREAM-SOURCE-0000000004 (topics: [kestra_workertaskresult])
--> KTABLE-SOURCE-0000000005
Processor: KTABLE-SOURCE-0000000005 (stores: [workertaskresult])
--> KTABLE-JOINOTHER-0000000008
<-- KSTREAM-SOURCE-0000000004
Processor: KTABLE-JOINOTHER-0000000008 (stores: [execution])
--> KTABLE-MERGE-0000000006
<-- KTABLE-SOURCE-0000000005
Processor: KTABLE-JOINTHIS-0000000007 (stores: [workertaskresult])
--> KTABLE-MERGE-0000000006
<-- KTABLE-SOURCE-0000000001
Processor: KTABLE-MERGE-0000000006 (stores: [])
--> KTABLE-TOSTREAM-0000000009
<-- KTABLE-JOINTHIS-0000000007, KTABLE-JOINOTHER-0000000008
Processor: KTABLE-TOSTREAM-0000000009 (stores: [])
--> KSTREAM-FILTER-0000000010, KSTREAM-FILTER-0000000015
<-- KTABLE-MERGE-0000000006
Processor: KSTREAM-FILTER-0000000015 (stores: [])
--> KSTREAM-MAPVALUES-0000000016
<-- KTABLE-TOSTREAM-0000000009
Processor: KSTREAM-MAPVALUES-0000000016 (stores: [])
--> KSTREAM-MAPVALUES-0000000017
<-- KSTREAM-FILTER-0000000015
Processor: KSTREAM-MAPVALUES-0000000017 (stores: [])
--> KSTREAM-FLATMAPVALUES-0000000018, KSTREAM-FILTER-0000000024, KSTREAM-FILTER-0000000019, KSTREAM-MAPVALUES-0000000067
<-- KSTREAM-MAPVALUES-0000000016
Processor: KSTREAM-FLATMAPVALUES-0000000018 (stores: [])
--> KSTREAM-FILTER-0000000042, KSTREAM-FILTER-0000000055, KSTREAM-FILTER-0000000030
<-- KSTREAM-MAPVALUES-0000000017
Processor: KSTREAM-FILTER-0000000042 (stores: [])
--> KSTREAM-MAPVALUES-0000000043
<-- KSTREAM-FLATMAPVALUES-0000000018
Processor: KSTREAM-FILTER-0000000030 (stores: [])
--> KSTREAM-MAPVALUES-0000000031
<-- KSTREAM-FLATMAPVALUES-0000000018
Processor: KSTREAM-FILTER-0000000055 (stores: [])
--> KSTREAM-MAPVALUES-0000000056
<-- KSTREAM-FLATMAPVALUES-0000000018
Processor: KSTREAM-MAPVALUES-0000000043 (stores: [])
--> KSTREAM-FILTER-0000000044, KSTREAM-FILTER-0000000050
<-- KSTREAM-FILTER-0000000042
Processor: KSTREAM-MAPVALUES-0000000031 (stores: [])
--> KSTREAM-FILTER-0000000032, KSTREAM-FILTER-0000000038
<-- KSTREAM-FILTER-0000000030
Processor: KSTREAM-MAPVALUES-0000000056 (stores: [])
--> KSTREAM-FILTER-0000000063, KSTREAM-FILTER-0000000057
<-- KSTREAM-FILTER-0000000055
Processor: KSTREAM-FILTER-0000000024 (stores: [])
--> KSTREAM-MAPVALUES-0000000025
<-- KSTREAM-MAPVALUES-0000000017
Processor: KSTREAM-FILTER-0000000032 (stores: [])
--> KSTREAM-MAPVALUES-0000000033
<-- KSTREAM-MAPVALUES-0000000031
Processor: KSTREAM-FILTER-0000000044 (stores: [])
--> KSTREAM-MAPVALUES-0000000045
<-- KSTREAM-MAPVALUES-0000000043
Processor: KSTREAM-FILTER-0000000057 (stores: [])
--> KSTREAM-MAPVALUES-0000000058
<-- KSTREAM-MAPVALUES-0000000056
Processor: KSTREAM-FILTER-0000000010 (stores: [])
--> KSTREAM-MAPVALUES-0000000011
<-- KTABLE-TOSTREAM-0000000009
Processor: KSTREAM-FILTER-0000000019 (stores: [])
--> KSTREAM-MAPVALUES-0000000020
<-- KSTREAM-MAPVALUES-0000000017
Processor: KSTREAM-FILTER-0000000050 (stores: [])
--> KSTREAM-MAPVALUES-0000000051
<-- KSTREAM-MAPVALUES-0000000043
Processor: KSTREAM-MAPVALUES-0000000025 (stores: [])
--> KSTREAM-FILTER-0000000026
<-- KSTREAM-FILTER-0000000024
Processor: KSTREAM-MAPVALUES-0000000033 (stores: [])
--> KSTREAM-MAPVALUES-0000000034
<-- KSTREAM-FILTER-0000000032
Processor: KSTREAM-MAPVALUES-0000000045 (stores: [])
--> KSTREAM-MAPVALUES-0000000046
<-- KSTREAM-FILTER-0000000044
Processor: KSTREAM-MAPVALUES-0000000058 (stores: [])
--> KSTREAM-MAPVALUES-0000000059
<-- KSTREAM-FILTER-0000000057
Processor: KSTREAM-FILTER-0000000026 (stores: [])
--> KSTREAM-FILTER-0000000027
<-- KSTREAM-MAPVALUES-0000000025
Processor: KSTREAM-FILTER-0000000038 (stores: [])
--> KSTREAM-MAPVALUES-0000000039
<-- KSTREAM-MAPVALUES-0000000031
Processor: KSTREAM-FILTER-0000000063 (stores: [])
--> KSTREAM-MAPVALUES-0000000064
<-- KSTREAM-MAPVALUES-0000000056
Processor: KSTREAM-MAPVALUES-0000000011 (stores: [])
--> KSTREAM-FILTER-0000000012
<-- KSTREAM-FILTER-0000000010
Processor: KSTREAM-MAPVALUES-0000000020 (stores: [])
--> KSTREAM-FILTER-0000000021
<-- KSTREAM-FILTER-0000000019
Processor: KSTREAM-MAPVALUES-0000000034 (stores: [])
--> KSTREAM-FILTER-0000000035
<-- KSTREAM-MAPVALUES-0000000033
Processor: KSTREAM-MAPVALUES-0000000046 (stores: [])
--> KSTREAM-FILTER-0000000047
<-- KSTREAM-MAPVALUES-0000000045
Processor: KSTREAM-MAPVALUES-0000000051 (stores: [])
--> KSTREAM-FILTER-0000000052
<-- KSTREAM-FILTER-0000000050
Processor: KSTREAM-MAPVALUES-0000000059 (stores: [])
--> KSTREAM-FILTER-0000000060
<-- KSTREAM-MAPVALUES-0000000058
Processor: KSTREAM-MAPVALUES-0000000067 (stores: [])
--> KSTREAM-FILTER-0000000068
<-- KSTREAM-MAPVALUES-0000000017
Processor: KSTREAM-FILTER-0000000012 (stores: [])
--> KSTREAM-PEEK-0000000013
<-- KSTREAM-MAPVALUES-0000000011
Processor: KSTREAM-FILTER-0000000021 (stores: [])
--> KSTREAM-PEEK-0000000022
<-- KSTREAM-MAPVALUES-0000000020
Processor: KSTREAM-FILTER-0000000027 (stores: [])
--> KSTREAM-PEEK-0000000028
<-- KSTREAM-FILTER-0000000026
Processor: KSTREAM-FILTER-0000000035 (stores: [])
--> KSTREAM-PEEK-0000000036
<-- KSTREAM-MAPVALUES-0000000034
Processor: KSTREAM-FILTER-0000000047 (stores: [])
--> KSTREAM-PEEK-0000000048
<-- KSTREAM-MAPVALUES-0000000046
Processor: KSTREAM-FILTER-0000000052 (stores: [])
--> KSTREAM-PEEK-0000000053
<-- KSTREAM-MAPVALUES-0000000051
Processor: KSTREAM-FILTER-0000000060 (stores: [])
--> KSTREAM-PEEK-0000000061
<-- KSTREAM-MAPVALUES-0000000059
Processor: KSTREAM-FILTER-0000000068 (stores: [])
--> KSTREAM-PEEK-0000000069
<-- KSTREAM-MAPVALUES-0000000067
Processor: KSTREAM-MAPVALUES-0000000039 (stores: [])
--> KSTREAM-FILTER-0000000040
<-- KSTREAM-FILTER-0000000038
Processor: KSTREAM-MAPVALUES-0000000064 (stores: [])
--> KSTREAM-TRANSFORM-0000000065
<-- KSTREAM-FILTER-0000000063
Processor: KSTREAM-FILTER-0000000040 (stores: [])
--> KSTREAM-SINK-0000000041
<-- KSTREAM-MAPVALUES-0000000039
Processor: KSTREAM-PEEK-0000000013 (stores: [])
--> KSTREAM-SINK-0000000014
<-- KSTREAM-FILTER-0000000012
Processor: KSTREAM-PEEK-0000000022 (stores: [])
--> KSTREAM-SINK-0000000023
<-- KSTREAM-FILTER-0000000021
Processor: KSTREAM-PEEK-0000000028 (stores: [])
--> KSTREAM-SINK-0000000029
<-- KSTREAM-FILTER-0000000027
Processor: KSTREAM-PEEK-0000000036 (stores: [])
--> KSTREAM-SINK-0000000037
<-- KSTREAM-FILTER-0000000035
Processor: KSTREAM-PEEK-0000000048 (stores: [])
--> KSTREAM-SINK-0000000049
<-- KSTREAM-FILTER-0000000047
Processor: KSTREAM-PEEK-0000000053 (stores: [])
--> KSTREAM-SINK-0000000054
<-- KSTREAM-FILTER-0000000052
Processor: KSTREAM-PEEK-0000000061 (stores: [])
--> KSTREAM-SINK-0000000062
<-- KSTREAM-FILTER-0000000060
Processor: KSTREAM-PEEK-0000000069 (stores: [])
--> KSTREAM-SINK-0000000070
<-- KSTREAM-FILTER-0000000068
Processor: KSTREAM-TRANSFORM-0000000065 (stores: [workertask_deduplication])
--> KSTREAM-SINK-0000000066
<-- KSTREAM-MAPVALUES-0000000064
Processor: KTABLE-TOSTREAM-0000000002 (stores: [])
--> log-executionStream
<-- KTABLE-SOURCE-0000000001
Sink: KSTREAM-SINK-0000000014 (topic: kestra_execution)
<-- KSTREAM-PEEK-0000000013
Sink: KSTREAM-SINK-0000000023 (topic: kestra_execution)
<-- KSTREAM-PEEK-0000000022
Sink: KSTREAM-SINK-0000000029 (topic: kestra_execution)
<-- KSTREAM-PEEK-0000000028
Sink: KSTREAM-SINK-0000000037 (topic: kestra_execution)
<-- KSTREAM-PEEK-0000000036
Sink: KSTREAM-SINK-0000000041 (topic: kestra_workertaskresult)
<-- KSTREAM-FILTER-0000000040
Sink: KSTREAM-SINK-0000000049 (topic: kestra_execution)
<-- KSTREAM-PEEK-0000000048
Sink: KSTREAM-SINK-0000000054 (topic: kestra_execution)
<-- KSTREAM-PEEK-0000000053
Sink: KSTREAM-SINK-0000000062 (topic: kestra_execution)
<-- KSTREAM-PEEK-0000000061
Sink: KSTREAM-SINK-0000000066 (topic: kestra_workertask)
<-- KSTREAM-TRANSFORM-0000000065
Sink: KSTREAM-SINK-0000000070 (topic: kestra_execution)
<-- KSTREAM-PEEK-0000000069
Processor: log-executionStream (stores: [])
--> none
<-- KTABLE-TOSTREAM-0000000002
目前,我还不清楚该解决方案是否能够适应任何并发,以及是否能够在下一次发生顺序混乱(这意味着执行是在上一次发生的回滚,从而导致同一任务的多次执行)。
KafkaStreams支持这种模式吗?
大体上是的。您只需要确保您不会以“无限循环”结束,即在某个点输入记录应该“终止”并且不再对输出主题产生任何内容。对于您的情况,执行
最终将不再创建新的任务
(通过反馈循环)。
将此流设计成并发安全的好方法是什么
总要看具体应用……对于您的情况,如果我正确理解了应用程序的设计,您基本上有两个输入主题(execution
和WorkerTaskResult
)和两个输出主题(execution
和WorkerTask
)。当处理输入主题时,来自每个输入的消息可以修改共享状态(即,任务的状态)。
此外,还有一个“外部应用程序”,它读取WorkerTask
主题并写入WorkerTaskResult
主题?因此,在整个数据流中实际上存在第二个循环?我假设还有其他上游应用程序也会将新数据推入execution
主题?
+-----------------+
| |
v |
upstream producers ---> "Execution" --+ |
| |
v |
KS-App --+
^ |
| |
+--> "WorkerTaskResult" --+ +--> "WorkerTask" --+
| |
+------------------------ outside app <----------------+
我不清楚的是ATM:
执行
?WorkerTaskResult
从“外部应用程序”传播哪些状态更改?也许你可以更新你的问题,我可以尝试相应地更新我的答案。
更新(基于编辑%1和%2)
你可以这么说。对于每个输入记录,table()
运算符将输入的时间戳与表中当前条目的时间戳进行比较。如果输入记录具有较小的时间戳,则记录警告(仍将应用更新):警告的原因是,表只存储每个键的一个条目,并且表只希望在时间上向前移动。如果更新顺序不对,这可能会导致意外的结果,从而导致警告日志。每个分区使用一个生成器或每个键使用一个生成器将避免每个键的数据无序(假设生成器只发送有序数据)。
如果我完全了解您的应用程序的新版本,我不是100%肯定atm。但一般来说,您希望确保避免数据竞争,并使execution
的更新线性化。
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