*additional info in bold. ________________________________ From: Siew Wai Yow <wai_...@hotmail.com> Sent: Monday, June 18, 2018 3:57 PM To: Fabian Hueske Cc: Jörn Franke; user@flink.apache.org Subject: Re: Flink application does not scale as expected, please help!
Hi Fabian, We are using Flink 1.5.0. Any different in scheduler in Flink 1.5.0? "Hence, applications might scale better until tasks are scheduled to different machines." This seems the case. We have 32 vCPU 16 slots in one TM machine, total 5 TM. So the scaling work perfectly 1-2-4-8-16 because all happens in same TM. When scale to 32(which it happen amongst different machine) the performance drop, not even in par with case of parallelism 16. Is this something expected? Thank you. Regards, Yow ________________________________ From: Fabian Hueske <fhue...@gmail.com> Sent: Monday, June 18, 2018 3:47 PM To: Siew Wai Yow Cc: Jörn Franke; user@flink.apache.org Subject: Re: Flink application does not scale as expected, please help! Hi, Which Flink version are you using? Did you try to analyze the bottleneck of the application, i.e., is it CPU, disk IO, or network bound? Regarding the task scheduling. AFAIK, before version 1.5.0, Flink tried to schedule tasks on the same machine to reduce the amount of network transfer. Hence, applications might scale better until tasks are scheduled to different machines. Fabian 2018-06-16 12:20 GMT+02:00 Siew Wai Yow <wai_...@hotmail.com<mailto:wai_...@hotmail.com>>: Hi Jorn, Please find the source @https://github.com/swyow/flink_sample_git Thank you! ________________________________ From: Jörn Franke <jornfra...@gmail.com<mailto:jornfra...@gmail.com>> Sent: Saturday, June 16, 2018 6:03 PM To: Siew Wai Yow Cc: user@flink.apache.org<mailto:user@flink.apache.org> Subject: Re: Flink application does not scale as expected, please help! Can you share the app source on gitlab, github or bitbucket etc? On 16. Jun 2018, at 11:46, Siew Wai Yow <wai_...@hotmail.com<mailto:wai_...@hotmail.com>> wrote: Hi, There is an interesting finding, the reason of low parallelism work much better is because all task being run in same TM, once we scale more, the task is distributed to different TM and the performance worse than the low parallelism case. Is this something expected? The more I scale the less I get? ________________________________ From: Siew Wai Yow <wai_...@hotmail.com<mailto:wai_...@hotmail.com>> Sent: Saturday, June 16, 2018 5:09 PM To: Jörn Franke Cc: user@flink.apache.org<mailto:user@flink.apache.org> Subject: Re: Flink application does not scale as expected, please help! Hi Jorn, the input data is 1kb per record, in production it will have 10 billions of record per day and it will be increased so scalability is quite important to us to handle more data. Unfortunately this is not work as expected even with only 10 millions of testing data. The test application is just a simple jackson map + an empty process. CPU and memory is not an issue as we have 32 vCPU + 100 GB RAM per TM. Network should be fine as well as total TX+RX peak is around 800Mbps while we have 1000Mbps. Do you mind to share your thought? Or mind to test the attach application in your lab? To run the program, sample parameters, "aggrinterval=6000000 loop=7500000 statsd=1 psrc=4 pJ2R=32 pAggr=72 URL=do36.mycompany.com:8127<http://do36.mycompany.com:8127>" * aggrinterval: time in ms for timer to trigger * loop: how many row of data to feed * statsd: to send result to statsd * psrc: source parallelism * pJ2R: parallelism of map operator(JsonRecTranslator) * pAggr: parallelism of process+timer operator(AggregationDuration) Thank you! Yow ________________________________ From: Jörn Franke <jornfra...@gmail.com<mailto:jornfra...@gmail.com>> Sent: Saturday, June 16, 2018 4:46 PM To: Siew Wai Yow Cc: user@flink.apache.org<mailto:user@flink.apache.org> Subject: Re: Flink application does not scale as expected, please help! How large is the input data? If the input data is very small then it does not make sense to scale it even more. The larger the data is the more parallelism you will have. You can modify this behavior of course by changing the partition on the Dataset. On 16. Jun 2018, at 10:41, Siew Wai Yow <wai_...@hotmail.com<mailto:wai_...@hotmail.com>> wrote: Hi, We found that our Flink application with simple logic, which using process function is not scale-able when scale from 8 parallelism onward even though with sufficient resources. Below it the result which is capped at ~250k TPS. No matter how we tune the parallelism of the operators it just not scale, same to increase source parallelism. Please refer to "scaleNotWork.png", 1. fixed source parallelism 4, other operators parallelism 8 2. fixed source parallelism 4, other operators parallelism 16 3. fixed source parallelism 4, other operators parallelism 32 4. fixed source parallelism 6, other operators parallelism 8 5. fixed source parallelism 6, other operators parallelism 16 6. fixed source parallelism 6, other operators parallelism 32 7. fixed source parallelism 6, other operators parallelism 64 performance worse than parallelism 32. Sample source code attached(flink_app_parser_git.zip). It is a simple program, parsing json record into object, and pass it to a empty logic Flink's process function. Rocksdb is in used, and the source is generated by the program itself. This could be reproduce easily. We choose Flink because of it scalability, but this is not the case now, appreciated if anyone could help as this is impacting our projects! thank you. To run the program, sample parameters, "aggrinterval=6000000 loop=7500000 statsd=1 psrc=4 pJ2R=32 pAggr=72 URL=do36.mycompany.com:8127<http://do36.mycompany.com:8127>" * aggrinterval: time in ms for timer to trigger * loop: how many row of data to feed * statsd: to send result to statsd * psrc: source parallelism * pJ2R: parallelism of map operator(JsonRecTranslator) * pAggr: parallelism of process+timer operator(AggregationDuration) We are running in VMWare, 5 Task Managers and each has 32 slots. Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 32 On-line CPU(s) list: 0-31 Thread(s) per core: 1 Core(s) per socket: 1 Socket(s): 32 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 63 Model name: Intel(R) Xeon(R) CPU E5-2640 v3 @ 2.60GHz Stepping: 2 CPU MHz: 2593.993 BogoMIPS: 5187.98 Hypervisor vendor: VMware Virtualization type: full L1d cache: 32K L1i cache: 32K L2 cache: 256K L3 cache: 20480K NUMA node0 CPU(s): 0-31 Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology tsc_reliable nonstop_tsc aperfmperf pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm epb fsgsbase smep dtherm ida arat pln pts total used free shared buff/cache available Mem: 98 24 72 0 1 72 Swap: 3 0 3 Please refer TM.png and JM.png for further details. The test without any checkpoint enable. Thanks. Regards, Yow <flink_app_parser_git.zip> <JM.png> <sample.png> <scaleNotWork.png> <TM.png>
