Didn’t see the earlier response – John if you are seeing 25% cpu utilization that indicates that something is wrong with architecture of the solution rather than the language.
It would suggest that you have bottlenecks elsewhere – network, memory, database, disk. We have seen that the sweet spot of well designed servers is somewhere between 4 and 8 CPUs and 8-16G RAM, after that the performance gain is not so good – not because of the language – but because of all the other constraints on the system - wanting to databases/disk/network etc. We have HPC compute clusters at work – and to really make use of the large CPU/memory machines (last time I checked it was around 200 cores and 1Tb RAM) not just the coding but the underlying algorithm has to suit parallelisation, and care has to be taken to avoid writing to disk at any point in the operations. From: Mithun Bhattacharya <mit...@gmail.com> Sent: 20 December 2020 22:29 To: mod_perl list <modperl@perl.apache.org> Subject: Re: suggestions for perl as web development language [EXT] Running individual functions in independent threads can't be a solution for performance optimization - at least I have never heard such a thing, maybe others can pitch in. On Sun, Dec 20, 2020 at 4:15 PM John Dunlap <j...@lariat.co<mailto:j...@lariat.co>> wrote: I have no doubt that our application can be optimized. We do so whenever we encounter poor performance and we will continue to do so. The point is that Perl didn't do a lot to help us in this regard. Languages like elixir use immutable data structures and will automatically run individual function calls in separate threads. Perl, by contrast, will only have a single thread per request. On Sun, Dec 20, 2020, 3:33 PM Mithun Bhattacharya <mit...@gmail.com<mailto:mit...@gmail.com>> wrote: You would have to define poor system performance - are you doing anything cpu intensive at all ? Maybe your RAM is being the bottleneck ? On Sun, Dec 20, 2020 at 2:28 PM John Dunlap <j...@lariat.co<mailto:j...@lariat.co>> wrote: It's extremely inefficient by comparison. We host our application on beefy servers with 32 cores and 64G of ram and I commonly see poor system performance with less than 25% cpu utilization. On Sun, Dec 20, 2020, 2:22 PM Mithun Bhattacharya <mit...@gmail.com<mailto:mit...@gmail.com>> wrote: Agreed prefork is recommended but what is the problem with that ? On Sun, Dec 20, 2020 at 12:47 PM John Dunlap <j...@lariat.co<mailto:j...@lariat.co>> wrote: Our app segfaults at random of we use anything other than prefork. On Sun, Dec 20, 2020, 1:32 PM Mithun Bhattacharya <mit...@gmail.com<mailto:mit...@gmail.com>> wrote: I am confused - you like threads so Perl is bad ? I am very happy forking away and yes I work a lot with non thread safe DBI connections without any issues. On Sun, Dec 20, 2020 at 11:53 AM John Dunlap <j...@lariat.co<mailto:j...@lariat.co>> wrote: In my opinion, no one should build new projects in Perl. The world is increasingly trending towards parallelism and higher numbers of cpu cores and Perl is poorly positioned to leverage these advancements. Many of Perl's dependencies are not thread safe and mod_perl forces you to use mpm_prefork. My organization has started moving away from Perl to Elixir for these reasons. On Tue, Aug 4, 2020, 3:37 AM James Smith <j...@sanger.ac.uk<mailto:j...@sanger.ac.uk>> wrote: Perl is a great solution for web development. Others will disagree but the best way I still believe is using mod_perl - but only if you use it's full power - and you probably need a special sort of mind set to use - but that can be said for any language. From experience - it may be fractionally slower than small "standalone" apps that dancer etc are good at, but it is (a) much, much more stable {dancer etc does not cope well with either large requests or lots of small requests}, and (b) if you have a large code base and/or a large number of services then it generally uses much less compute power than the others {can easily handle multiple services on a single apache instance} Where it really gains is the hooks into the apache process - being able to add functionality easily at any stage in the request process, from path translation, AAA stages, pre-processing, to post-processing and logging, and also to interact with other languages at any stage - e.g. can handle pre-processing & post-processing around a script written in another language (e.g. PHP, Java) or produced by another webserver integrated by mod_proxy. It isn't really a framework though like dancer or mojolicious and thus has its own advantages and disadvantages. You would to some extent have to roll your own code to produce the pages themselves although there are libraries out there to do lots of it. We have an in house library whose embryonic stages were written over 20 years ago - and has now been stable for around 12-13 years and works strong... James -----Original Message----- From: Wesley Peng <m...@yonghua.org<mailto:m...@yonghua.org>> Sent: 04 August 2020 06:43 To: modperl@perl.apache.org<mailto:modperl@perl.apache.org> Subject: suggestions for perl as web development language [EXT] greetings, My team use all of perl, ruby, python for scripting stuff. perl is stronger for system admin tasks, and data analysis etc. But for web development, it seems to be not as popular as others. It has less selective frameworks, and even we can't get the right people to do the webdev job with perl. Do you think in today we will give up perl/modperl as web development language, and choose the alternatives instead? Thanks & Regards -- The Wellcome Sanger Institute is operated by Genome Research Limited, a charity registered in England with number 1021457 and a company registered in England with number 2742969, whose registered office is 215 Euston Road, London, NW1 2BE. -- The Wellcome Sanger Institute is operated by Genome Research Limited, a charity registered in England with number 1021457 and a company registered in England with number 2742969, whose registered office is 215 Euston Road, London, NW1 2BE.
