From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!news.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: New IEEE Language Popularity Ratings Date: Wed, 10 Aug 2016 21:10:31 +0200 Organization: Aioe.org NNTP Server Message-ID: References: <31c22983-150c-4dab-abba-588e15f75914@googlegroups.com> <87y44514hl.fsf@jester.gateway.pace.com> <87twes1v4l.fsf@jester.gateway.pace.com> <87popg1n4b.fsf@jester.gateway.pace.com> NNTP-Posting-Host: xelDFTENDI+dlkJFd2Ot2w.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 X-Notice: Filtered by postfilter v. 0.8.2 Xref: news.eternal-september.org comp.lang.ada:31367 Date: 2016-08-10T21:10:31+02:00 List-Id: On 2016-08-10 20:43, Paul Rubin wrote: > "Dmitry A. Kazakov" writes: >> No. Actually time constraint is interchangeable with load. If you have >> many thousands of metering devices, then even if they report once in 5 >> minutes, with about 100 variables it does a lot of traffic and load no >> scripting language can handle on either side. > > On the client side that's almost nothing. Client is a small board that has issues with load and multiple connections. There is also a big problem of data consistency. You may read/write infrequently, but there is no guaranty that the server pulls data or ready to be pushed with data in time. That is how it is similar to real-time. > On the server side, scaling > horizontally is the in thing. ;). 30k devices each reporting every 5 > minutes is still just 100 per second which is no big deal for a > reasonable server these days no matter what it's written in. It is a big deal because clients are slow, that inflicts latencies accumulating on the server side. Then if you start 30k threads your server will freeze. Then it is not really scalable because there are usually databases and web portal behind. > 3 million devices gets more interesting. A couple of thousands is already a huge problem for scripting environment, layered XML protocols with an FTP transfer on top, a typical kind of "architecture" used. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de