Timeline for MySQL 8.0.30+: redo_log_capacity vs log_file_size?
Current License: CC BY-SA 4.0
9 events
| when toggle format | what | by | license | comment | |
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| Mar 24, 2023 at 9:52 | vote | accept | myxal | ||
| Feb 18, 2023 at 18:16 | comment | added | Bill Karwin | I don't think you're using it wrong. I would guess the documentation is wrong. | |
| Feb 18, 2023 at 10:09 | comment | added | myxal | I'm aware of the changes that introduced the naw variable - the documentation page you refer to even links to the dedicated redo logs page which I linked to, and quoted from in the OP. I'm specifically asking if the backwards compatibility feature that quoted paragraph claims to be in MySQL 8.0.30+, is broken, or if I'm using it wrong. | |
| Feb 17, 2023 at 22:11 | comment | added | Bill Karwin | Both in the old system and the new system, InnoDB is only writing to a single file at a time. The others are "spare". There is no difference in performance between one file, two files, or many files in the log group. The reason they now use 32 files by default is to support online resizing. You should read the blog I linked to. | |
| Feb 17, 2023 at 20:40 | comment | added | Rick James | I have perceived (without much proof) that a large value for files_in_group hurts performance. Maybe that is what is happening now? | |
| Feb 17, 2023 at 20:37 | comment | added | Rick James |
Hmmm... My 8.0.32 (Ubuntu) has 32 x 3MB = 100MB; most are ..._tmp.
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| Feb 17, 2023 at 19:30 | comment | added | Bill Karwin |
I haven't used it much, I've just upgraded my laptop to 8.0.32. I sum up the files in $datadir/#innodb_redo and they total 100MB. The files appear to be preallocated, like the old ib_logfiles were. There are 32 files, each 1/32nd of the total capacity.
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| Feb 17, 2023 at 19:27 | comment | added | Rick James | Does that mean that the setting is a "max"? But it initially allocates only the 100 MiB that the OP observed? | |
| Feb 17, 2023 at 17:56 | history | answered | Bill Karwin | CC BY-SA 4.0 |