On Windows systems, occurrences of ERROR_SHARING_VIOLATION due to
conflicting share modes between processes accessing the same file can
result in CreateFile failures.
mysys' my_open() already incorporates a workaround by implementing
wait/retry logic on Windows.
But this does not help if files are opened using shell redirection like
mysqltest traditionally did it, i.e via
--echo exec "some text" > output_file
In such cases, it is cmd.exe, that opens the output_file, and it
won't do any sharing-violation retries.
This commit addresses the issue by introducing a new built-in command,
'write_line', in mysqltest. This new command serves as a brief alternative
to 'write_file', with a single line output, that also resolves variables
like "exec" would.
Internally, this command will use my_open(), and therefore retry-on-error
logic.
Hopefully this will eliminate the very sporadic "can't open file because
it is used by another process" error on CI.
- InnoDB fails to find the space id from the page0 of
the tablespace. In that case, InnoDB can use
doublewrite buffer to recover the page0 and write
into the file.
- buf_dblwr_t::init_or_load_pages(): Loads only the pages
which are valid.(page lsn >= checkpoint). To do that,
InnoDB has to open the redo log before system
tablespace, read the latest checkpoint information.
recv_dblwr_t::find_first_page():
1) Iterate the doublewrite buffer pages and find the 0th page
2) Read the tablespace flags, space id from the 0th page.
3) Read the 1st, 2nd and 3rd page from tablespace file and
compare the space id with the space id which is stored
in doublewrite buffer.
4) If it matches then we can write into the file.
5) Return space which matches the pages from the file.
SysTablespace::read_lsn_and_check_flags(): Remove the
retry logic for validating the first page. After
restoring the first page from doublewrite buffer,
assign tablespace flags by reading the first page.
recv_recovery_read_max_checkpoint(): Reads the maximum
checkpoint information from log file
recv_recovery_from_checkpoint_start(): Avoid reading
the checkpoint header information from log file
Datafile::validate_first_page(): Throw error in case
of first page validation fails.
buf_flush_page_cleaner(): A continue or break inside DBUG_EXECUTE_IF
actually is a no-op. Use an explicit call to _db_keyword_() to
actually avoid advancing the checkpoint.
buf_flush_list_now_set(): Invoke os_aio_wait_until_no_pending_writes()
to ensure that the page write to the system tablespace is completed.
- innodb.doublewrite_debug should avoid the checkpoint
before killing the server. So used debug sync and
innodb_flush_sync to avoid the checkpoint completely.
Test case allowed to skip on MSAN builder due to extra
checkpoint.
- Split the doublewrite test into two test (doublewrite,
doublewrite_debug) to reduce the execution time of the test
- Removed big_test tag for the newly added test case
- Made doublewrite test as non-debug test
- Added search pattern to make sure that InnoDB uses doublewrite buffer
- Replaced all kill_mysqld.inc with shutdown_mysqld.inc and
zero shutdown timeout
- Removed the case where fsp_flags got corrupted. Because from commit
3da5d047b8 (MDEV-31851) onwards,
doublewrite buffer removes the conversion the fsp flags from buggy
10.1 format
Thanks to Marko Mäkelä for providing the non-debug test