From: dennisb55@... Date: 2018-08-01T03:41:53+00:00 Subject: [ruby-core:88247] [Ruby trunk Feature#14718] Use jemalloc by default? Issue #14718 has been updated by bluz71 (Dennis B). sam.saffron (Sam Saffron) wrote: > After spending a bit too much time thinking about this, I would like to recommend **against** any jemalloc related changes and instead to double down on Eric's https://bugs.ruby-lang.org/issues/14759 for the next release of Ruby (which I think should be backported to 2.5/2.4) I was as big a supporter of changing to jemalloc as anyone (and I still use it in production myself); but a little while ago I came to the same conclusion. Ruby should not default to using jemalloc. Implementing [#14759](https://bugs.ruby-lang.org/issues/14759) is the appropriate, and safe, medium-term solution **until** Guilds land. In the meantime hopefully the glibc folks can do their analysis and improve RSS behaviour especially with the Ruby-based [Fluentd](https://www.fluentd.org/) application causing grief to the Red Hat folks (an excellent pain point motivator to fix glibc). If glibc were fixed then `M_ARENA_MAX=2` should only be applied to older glibc versions effected, via a runtime check? I think most of the core promoters of this issue: Mike Perham, Sam, Eric and myself would prefer that 14759 be done instead, and possibly close this one? ---------------------------------------- Feature #14718: Use jemalloc by default? https://bugs.ruby-lang.org/issues/14718#change-73270 * Author: mperham (Mike Perham) * Status: Open * Priority: Normal * Assignee: * Target version: ---------------------------------------- I know Sam opened #9113 4 years ago to suggest this but I'm revisiting the topic to see if there's any movement here for Ruby 2.6 or 2.7. I supply a major piece of Ruby infrastructure (Sidekiq) and I keep hearing over and over how Ruby is terrible with memory, a huge memory hog with their Rails apps. My users switch to jemalloc and a miracle occurs: their memory usage drops massively. Some data points: https://twitter.com/brandonhilkert/status/987400365627801601 https://twitter.com/d_jones/status/989866391787335680 https://github.com/mperham/sidekiq/issues/3824#issuecomment-383072469 Redis moved to jemalloc many years ago and it solved all of their memory issues too. Their conclusion: the glibc allocator "sucks really really hard". http://oldblog.antirez.com/post/everything-about-redis-24.html This is a real pain point for the entire Rails community and would improve Ruby's reputation immensely if we can solve this problem. ---Files-------------------------------- glibc_arena_2.png (7.23 KB) jemalloc.png (21.1 KB) glibc-arena-2.log (60.3 KB) glibc.log (62.3 KB) jemalloc-3-5.log (58.5 KB) glibc.png (9.03 KB) -- https://bugs.ruby-lang.org/ Unsubscribe: