Hello everybody and Michael, I have sent two emails in the list that probably will arrive in later(??), if you have not got them already, so I am sorry if you receive them later. Michael, this is exactly what I was discussing also with Julien today. It is ok to have some generic benchmarks but as one person who was judging the linpack that it was not related to an application, thus we should have some benchmarks related to applications. My proposal was let’s discuss which applications consume the largest percentage of core-hours on the supercomputers across various sites and let’s try to mimic their I/O through IOR or whatever else, but first through IOR as it is a ready solution and well known. If not possible, we could check other solutions. For example, we already did test today the md-real and I was mentioning that I would like also to create less files but larger ones, because this could mimic cases that users are doing data assimilation, they run multiple models with various parameters and they don’t save large data as they execute a model for example 100 times the same moment. About the duration of the benchmark, one personal concern is not to be complicated like linpack neither to take long time and make it difficult for the people to find resources etc. I assume that 3 hours is more than enough. But I agree, that it depends. However, if I create a lot of data, I know that I will disturb other users on Lustre, I do not want to do that for 3 hours. About safe data, how would you check that? About pmem and future, the benchmark (suite) could be updated, this moment not many people have access on this, right? Of course, this does not mean that we should not get ready for this, but I am saying let’s get ready first for the basic ones and we’ll get involve, just my opinion. Everybody wants to have a benchmark suite that will help to next procurement, right? I hope to have nice discussions at BOF with all the people who will be there. Best regards, George ________________________________________ George Markomanolis, PhD Computational Scientist KAUST Supercomputing Laboratory (KSL) King Abdullah University of Science & Technology Al Khawarizmi Bldg. (1) Room 0123 Thuwal Kingdom of Saudi Arabia Mob: +966 56 325 9012 Office: +966 12 808 0393<tel:%2B966%2012%20808%200683> From: IO-500 <io-500-bounces(a)vi4io.org&gt; on behalf of Michael Kluge <michael.kluge(a)tu-dresden.de&gt; Date: Sunday, 18 June 2017 at 9:01 PM To: &quot;io-500(a)vi4io.org&quot; <io-500(a)vi4io.org&gt; Subject: Re: [IO-500] Detailed benchmark proposal Hi all, IOR has an option to allocate a certain amount of the hosts memory. I suggest that we set this to 90-95 percent and the total amount of data written as twice the size of the main memory? Otherwise, the 10+ PB main memory of SUMMIT would make the list useless ;) If I read everything correctly the current run rules define an execution time of 5 minutes and just count the numbers of bytes/iops/files touched during this time. I agree that most of the time our users do I/O in bursts. Is the benchmark basically only about “who can write the most data with one file per process in 5 mins”? Why 5 minutes and not “how long does it take to dump 80% of the main memory to some redundant permanent storage” (with fsync())? Do we want to define some rules about how safe the data has to be? Should it be OK if this data ends up in a single burst buffer and there is no copy somewhere? I would recommend that the results are only valid if data survives one failure of one of the storage devices used. For example: For the mdtest-workload I could imagine a file system that has directory locking turned off and is using an SSD/NVRAM backend and thus would just behave like the “IOR hard” workload. Another point is that I am more a fan of application driven benchmarks. The numbers above do not tell me anything about my applications, so why should I actually run the benchmark? Just to to be “on the list”? Application driven benchmarks (something like SPEC CPU, but SPEC I/O), that scale with the machine (and with the machines main memory) could actually become a standard that also the industry could use to advertise their systems. In addition, if we as a site have I/O patterns that are close to one of the benchmarks, we could put some weight on this benchmark and adjust our tenders and the industry partner would know how to design the storage system with respect to our special requirements. Just because they know the I/O pattern because it is a standard and they know how to deal with it. One more thing that the current approach does not deal with at all is the fact that in very near future applications will access permanent storage using interfaces that IOR does not cover and store data by using mov() instructions in the CPU. Thus, if the list is established using some combination of IOR+MDTEST+POSIX, I think it has no chance to reflect the really fast I/O subsystems that are coming like http://pmem.io/ Sorry for the lengthy statement … Regards, Michael -- Dr.-Ing. Michael Kluge Technische Universität Dresden Center for Information Services and High Performance Computing (ZIH) D-01062 Dresden Germany Contact: Falkenbrunnen, Room 240 Phone: (+49) 351 463-34217 Fax: (+49) 351 463-37773 e-mail: michael.kluge@tu-dresden.de<mailto:michael.kluge@tu-dresden.de> WWW: http://www.tu-dresden.de/zih Von: IO-500 [mailto:io-500-bounces@vi4io.org] Im Auftrag von John Bent Gesendet: Freitag, 16. Juni 2017 22:30 An: io-500(a)vi4io.org Betreff: [IO-500] Detailed benchmark proposal All, Sorry for the long silence on the mailing list. However, we have made some substantial progress recently as we prepare for our ISC BOF next week. For those of you at ISC, please join us from 11 to 12 on Tuesday<x-apple-data-detectors://0> in Substanz 1&2. The progress that we have made recently happened because a bunch of us were attending a German workshop last month at Dagstuhl and had multiple discussions about the benchmark. Here’s the highlights from what was discussed and the progress that we made at Dagstuhl: 1. General agreement that the IOR-hard, IOR-easy, mdtest-hard, mdtest-easy approach is appropriate. 2. We should add a ‘find’ command as this is a popular and important workload. 3. The multiple bandwidth measurements should be combined via geometric mean into one bandwidth. 4. The multiple IOPs measurements should also be combined via geometric mean into one IOPs. 5. The bandwidth and the IOPs should be multiplied to create one final score. 6. The ranking uses that final score but the webpage can be sorted using other metrics. 7. The webpage should allow filtering as well so, for example, people can look at only the HDD results. 8. We should separate the write/create phases from the read/stat phases to help ensure that caching is avoided 9. Nathan Hjelm volunteered to combine the mdtest and IOR benchmarks into one git repo and has now done so. This removes the #ifdef mess from mdtest and now they both share the nice modular IOR backend So the top-level summary of the benchmark in pseudo-code has become: # write/create phase bw1 = ior_easy -write [user supplies their own parameters maximizing data writes that can be done in 5 minutes] md1 = md_test_easy -create [user supplies their own parameters maximizing file creates that can be done in 5 minutes] bw2 = ior_hard -write [we supply parameters: unaligned strided into single shared file] md2 = md_test_hard -create [we supply parameters: creates of 3900 byte files into single shared directory] # read/stat phase bw3 = ior_easy -read [cross-node read of everything that was written in bw1] md3 = md_test_easy -stat [cross-node stat of everything that was created in md1] bw4 = ior_hard -read md4 = md_test_hard -stat # find phase md5 = [we supply parameters to find a subset of the files that were created in the tests] # score phase bw = geo_mean( bw1 bw2 bw3 bw4) md = geo_mean( md1 md2 md3 md4 bd5) total = bw * md Now we are moving on to precisely define what the parameters should look like for the hard tests and to create a standard so that people can start running it on their systems. By doing so, we will define the formal process so we can actually make this an official benchmark. Please see the attached file in which we’ve started precisely defining these parameters. Let’s start iterating please on this file to get these parameters correct. Thanks, John ________________________________ This message and its contents including attachments are intended solely for the original recipient. If you are not the intended recipient or have received this message in error, please notify me immediately and delete this message from your computer system. Any unauthorized use or distribution is prohibited. Please consider the environment before printing this email.