我正在做一些流处理框架之间的基准比较,
我在这方面选择了wordcount这样的“hello world”任务(有些曲折),并测试了flink和hazelcast jet到目前为止,结果是flink需要80+s才能完成,而jet只需要30+s
我知道Flink很受欢迎,我做错什么了?真的很好奇
我的示例代码在这里
https://github.com/chinw/stream-processing-compare
以下是详细信息(规格、管道、日志)
测试的wordcount管道
Source (read from file, 5MB)
-> Process: Split line into words (Here here is a bomb, every word emit 1000 times)
-> Group/Count
-> Sink (do nothing)
我的本地结果
macbook pro(13英寸,2020,四个thunderbolt 3端口)
2 ghz四核intel core i5(8个逻辑处理器)
16 gb 3733 mhz lpddr4x
jdk 11号
喷气机4.4
管道:
digraph DAG {
"items" [localParallelism=1];
"fused(flat-map, filter)" [localParallelism=8];
"group-and-aggregate-prepare" [localParallelism=8];
"group-and-aggregate" [localParallelism=8];
"do-nothing-sink" [localParallelism=1];
"items" -> "fused(flat-map, filter)" [queueSize=1024];
"fused(flat-map, filter)" -> "group-and-aggregate-prepare" [label="partitioned", queueSize=1024];
subgraph cluster_0 {
"group-and-aggregate-prepare" -> "group-and-aggregate" [label="distributed-partitioned", queueSize=1024];
}
"group-and-aggregate" -> "do-nothing-sink" [queueSize=1024];
}
日志:
Start time: 2021-04-18T13:52:52.106
Duration: 00:00:36.459
Jet: finish in 36.45935081 seconds.
Start time: 2021-04-19T16:51:53.806
Duration: 00:00:30.143
Jet: finish in 30.625740453 seconds.
Start time: 2021-04-19T16:52:48.906
Duration: 00:00:37.207
Jet: finish in 37.862554137 seconds.
scala 2.11的flink 1.12.2 flink-config.yaml
配置:
jobmanager.rpc.address: localhost
jobmanager.rpc.port: 6123
jobmanager.memory.process.size: 2096m
taskmanager.memory.process.size: 12288m
taskmanager.numberOfTaskSlots: 8
parallelism.default: 8
管道:
{
"nodes" : [ {
"id" : 1,
"type" : "Source: Custom Source",
"pact" : "Data Source",
"contents" : "Source: Custom Source",
"parallelism" : 1
}, {
"id" : 2,
"type" : "Flat Map",
"pact" : "Operator",
"contents" : "Flat Map",
"parallelism" : 8,
"predecessors" : [ {
"id" : 1,
"ship_strategy" : "REBALANCE",
"side" : "second"
} ]
}, {
"id" : 4,
"type" : "Keyed Aggregation",
"pact" : "Operator",
"contents" : "Keyed Aggregation",
"parallelism" : 8,
"predecessors" : [ {
"id" : 2,
"ship_strategy" : "HASH",
"side" : "second"
} ]
}, {
"id" : 5,
"type" : "Sink: Unnamed",
"pact" : "Data Sink",
"contents" : "Sink: Unnamed",
"parallelism" : 8,
"predecessors" : [ {
"id" : 4,
"ship_strategy" : "FORWARD",
"side" : "second"
} ]
} ]
}
日志:
❯ flink run -c chiw.spc.flink.FlinkWordCountKt stream-processing-compare-1.0-SNAPSHOT.jar
Job has been submitted with JobID 163ce849a663e45f3c3028a98f260e7c
Program execution finished
Job with JobID 163ce849a663e45f3c3028a98f260e7c has finished.
Job Runtime: 88614 ms
❯ flink run -c chiw.spc.flink.FlinkWordCountKt stream-processing-compare-1.0-SNAPSHOT.jar
Job has been submitted with JobID fcf12488204969299e4e5d7f23f4ea6e
Program execution finished
Job with JobID fcf12488204969299e4e5d7f23f4ea6e has finished.
Job Runtime: 90165 ms
❯ flink run -c chiw.spc.flink.FlinkWordCountKt stream-processing-compare-1.0-SNAPSHOT.jar
Job has been submitted with JobID 37e349e4fad90cd7405546d30239afa4
Program execution finished
Job with JobID 37e349e4fad90cd7405546d30239afa4 has finished.
Job Runtime: 78908 ms
非常感谢你的帮助!
2条答案
按热度按时间guykilcj1#
我不认为你做错了什么,我们的测试显示jet比spark和flink快得多,字数是我们用来衡量这一点的例子之一。
e5nszbig2#
考虑到您的炸弹创建了大量的小项目(而不是较小数量的大项目),我对jet为什么在这里可能有优势的最好猜测是它的单生产者单消费者(spsc)队列加上类似于协同程序的并发性。
有8个平面Map阶段和8个聚合阶段。jet将在总共8个线程上执行此操作(假设您有8个线程)
availableProcessors
),因此在操作系统级别上几乎不会进行线程调度。数据将以大块的形式在线程之间移动:flatMap
将一次排队1024个,然后每个聚合器将提取所有指定给它的项。通过spsc队列进行通信时不会受到其他线程的任何干扰:每个聚合处理器有8个输入队列,其中一个专用于每个平面Map器。在flink中,每个stage都会启动另外8个线程,我还注意到sink的并行度是8,所以这是24个线程,另一个是源线程。操作系统必须在8个物理内核上调度它们。通信将发生在多个生产者单消费者(mpsc)队列上,这意味着所有平面Map器线程必须协调,以便一次只有一个线程将一个项目排入任何给定的聚合器,而争用将导致所有线程中的热cas循环。
为了证实这种怀疑,试着收集一些分析数据。如果上面的故事是正确的,您应该看到flink花费了大量cpu时间来排队处理数据。