MDEV-36301 SET GLOBAL innodb_log_file_disabled etc. #4014
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
|
The InnoDB log may be disabled by executing SET GLOBAL innodb_log_file_disabled=ON; in order to speed up any bulk operations, such as setting up a replica. After the execution of SET GLOBAL innodb_log_file_disabled=OFF; has completed (and InnoDB has written a log checkpoint to the newly enabled log), the server should be crash-safe again. log_sys.buf_size_requested: The configured innodb_log_buffer_size. While the log is disabled, we may set log_sys.buf_size (the actual size) differently. log_sys.disabled: The current setting of innodb_log_file_disabled. log_t::attach(): Handle log_sys.disabled. log_t::disabled(): Implements SET innodb_log_file_disabled=ON. Even if the log used to be in persistent memory, here we will set up dummy log_sys.buf and log_sys.flush_buf so that the dummy writes will appear to use file based writes. log_t::skip_write_buf(): A dummy log writer implementation that is used when log_sys.disabled holds and the log is not being resized. log_t::resize_start(): Handle log_sys.disabled, that is, SET GLOBAL innodb_log_file_disabled=OFF when the redo log had previously been disabled. If we are on persistent memory, we will "fake" the dummy log_sys.buf to appear as memory-mapped as well, so that log_t::resize_write() and log_t::resize_write_buf() can assume that both log files are of the same type (memory-mapped or file-based). The dummy log_sys.flush_buf will be stored in log_sys.resize_flush_buf in that case.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Description
innodb_log_file_disabled: A new Boolean parameter, defaultOFF. When setON, dummy log writes will take place and InnoDB will be crash-unsafe. (This has not been properly implemented yet.)log_t::buf_size_requested: A new data member, separate frombuf_size, to reflectinnodb_log_buffer_size. Wheninnodb_log_file_disabled=ON, we may switch to use a dummy buffer with alog_sys.buf_sizethat is much smaller.Release Notes
TBD
How can this PR be tested?
TODO: modify the automated test suite to verify that the PR causes MariaDB to behave as intended.
Basing the PR against the correct MariaDB version
mainbranch.This is a new feature. To simplify fixing any unrelated bugs that are found during testing, this is based in the oldest maintained branch where
log_syshad been significantly refactored (last in #3925).PR quality check