Uploaded image for project: 'MariaDB Server'
  1. MariaDB Server
  2. MDEV-18115

Remove dummy tablespace for the redo log

Details

    Description

      In InnoDB, redo log file operations unnecessarily go through the fil_io() API. It would be cleaner to just have the log file descriptors straight inside log_sys.log.

      Most redo log writes are synchronous. The only exception is writing the checkpoint header block, which uses asynchronous I/O. It might be better to dedicate the io_handler_thread() for data file operations only, and not let them deal with the redo log checkpoint write completion.

      Attachments

        Issue Links

          blocks

          Task - A task that needs to be done. MDEV-14425 Change the InnoDB redo log format to reduce write amplification

          • Blocker - Blocks development and/or testing work, production could not run.
          • Closed

          Task - A task that needs to be done. MDEV-16526 Overhaul the InnoDB page flushing

          • Major - Major loss of function.
          • Closed

          Task - A task that needs to be done. MDEV-21382 use fdatasync() for redo log where appropriate

          • Major - Major loss of function.
          • Closed
          relates to

          Bug - A problem which impairs or prevents the functions of the product. MDEV-13542 Crashing on a corrupted page is unhelpful

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-31170 Document MDEV-18115, Remove dummy tablespace for the redo log

          • Major - Major loss of function.
          • Closed

          New Feature - A new feature of the product, which has yet to be developed. MDEV-26603 asynchronous redo log write

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-31124 Innodb_data_written miscounts doublewrites

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed

          Activity

            Ascending order - Click to sort in descending order
            marko Marko Mäkelä added a comment -

            The attached remove_log_tablespace.patch is a starting point. Some stubs will have to be written, and log_sys.log must store the redo log file handle(s).

            As far as I understand, moving the redo log out of fil_io() should reduce some contention on fil_system.mutex.

            marko Marko Mäkelä added a comment - The attached remove_log_tablespace.patch is a starting point. Some stubs will have to be written, and log_sys.log must store the redo log file handle(s). As far as I understand, moving the redo log out of fil_io() should reduce some contention on fil_system.mutex .
            kevg Eugene Kosov (Inactive) added a comment -

            Note for myself: open a ticket for improving redo log error handling. We barely can do something about `write()` and `fsync()` errors but `read()` could be handled somehow without crashing.

            kevg Eugene Kosov (Inactive) added a comment - Note for myself: open a ticket for improving redo log error handling. We barely can do something about `write()` and `fsync()` errors but `read()` could be handled somehow without crashing.
            marko Marko Mäkelä added a comment -

            For improving read() handling there already exists MDEV-13542.

            marko Marko Mäkelä added a comment - For improving read() handling there already exists MDEV-13542 .
            marko Marko Mäkelä added a comment -

            Nice work!

            marko Marko Mäkelä added a comment - Nice work!
            marko Marko Mäkelä added a comment -

            Starting with this change, the counter Innodb_data_written no longer counts writes to the InnoDB redo log file ib_logfile0. Those writes continue to be part of Innodb_os_log_written.

            marko Marko Mäkelä added a comment - Starting with this change, the counter Innodb_data_written no longer counts writes to the InnoDB redo log file ib_logfile0 . Those writes continue to be part of Innodb_os_log_written .

            People

              kevg Eugene Kosov (Inactive)
              marko Marko Mäkelä
              Votes:
              0 Vote for this issue
              Watchers:
              6 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved:

                Git Integration

                  Error rendering 'com.xiplink.jira.git.jira_git_plugin:git-issue-webpanel'. Please contact your Jira administrators.