From: Igor Munkin <imun@tarantool.org> To: Alexander Turenko <alexander.turenko@tarantool.org> Cc: tarantool-patches@dev.tarantool.org Subject: Re: [Tarantool-patches] [PATCH 0/1] fix box.info:memory() Date: Thu, 16 Jul 2020 21:16:58 +0300 [thread overview] Message-ID: <20200716181658.GO5559@tarantool.org> (raw) In-Reply-To: <20200709010828.nlfq6sbavluwu6wf@tkn_work_nb> Sasha, Thanks for your explanation! On 09.07.20, Alexander Turenko wrote: <snipped> > > > > I have no idea why it is implemented in such complex way, maybe Sasha > > does? Why box.info.memory yields an empty "callable" table on each > > lookup? Why it can't just return a function to be called or a table with > > memory metrics as a result of the lookup? Unfortunately the latter > > approach breaks the backward compatibility but the first one can save > > some time on short-term objects creation (I guess no one checks > > box.info.memory type). Thoughts? Please also consider the comments I > > left for the patch itself. > > I don't see a reason. The history of src/box/lua/info.c changes shows > that this way was initially implemented for box.info.phia() (which was > renamed later to box.info.vinyl()). Then box.info.memory(), > box.info.gc() and box.info.sql() were added in the same way. > box.info.phia() was moved from box.phia(). > > I agree with you. We should define a case to estimate impact of > replacing a table + metamethod with a function. Not even to make a > decision whether it worth to change, but to imagine the situation at > whole. > > I would consider metrics collection case using tarantool/metrics every > minute when default metrics are enabled. I guess it'll call > box.info.vinyl(), box.info.memory() and box.info.gc() once for each > metrics collection. So the proposed change will safe 3 extra short-term > object creations per minute. > > I don't see a case when those functions should be called more often and > become a part of hot path. So I would say that reducing of GC object > allocations here does not look worthful for me considering possible > impact of subtle differences (like serialization of `box.info` or other > differences we can miss) that may fail some scripts or tools. Yes, it's definitely not a part of the hot path, *but* still implicitly affects the platform performance a little. Maybe we need to file an issue for such investigation? It would be nice to look on this part under the particular workload. > <snipped> -- Best regards, IM
next prev parent reply other threads:[~2020-07-16 18:27 UTC|newest] Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <20200629121118.21596-1-arkholga@tarantool.org> 2020-06-29 12:11 ` [Tarantool-patches] [PATCH 1/1] box: fixed box.info:memory() Olga Arkhangelskaia 2020-07-01 21:34 ` Igor Munkin 2020-07-02 10:01 ` Olga Arkhangelskaia 2020-07-09 1:08 ` Alexander Turenko 2020-07-09 13:57 ` Olga Arkhangelskaia 2020-07-15 14:40 ` Alexander Turenko 2020-07-16 17:56 ` Igor Munkin 2020-07-16 20:29 ` Olga Arkhangelskaia 2020-07-16 20:56 ` Alexander Turenko 2020-07-16 21:04 ` Igor Munkin 2020-07-17 6:38 ` Olga Arkhangelskaia 2020-07-01 21:34 ` [Tarantool-patches] [PATCH 0/1] fix box.info:memory() Igor Munkin 2020-07-09 1:08 ` Alexander Turenko 2020-07-09 14:02 ` Olga Arkhangelskaia 2020-07-16 18:16 ` Igor Munkin [this message] 2020-07-16 18:29 ` Alexander Turenko 2020-07-17 6:18 ` Kirill Yukhin
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20200716181658.GO5559@tarantool.org \ --to=imun@tarantool.org \ --cc=alexander.turenko@tarantool.org \ --cc=tarantool-patches@dev.tarantool.org \ --subject='Re: [Tarantool-patches] [PATCH 0/1] fix box.info:memory()' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox