When using the default innodb_log_buffer_size=2m, mariadb-backup --backup
would spend a lot of time re-reading and re-parsing the log. For reads,
it would be beneficial to memory-map the entire ib_logfile0 to the
address space (typically 48 bits or 256 TiB) and read it from there,
both during --backup and --prepare.
We will introduce the Boolean read-only parameter innodb_log_file_mmap
that will be OFF by default on most platforms, to avoid aggressive
read-ahead of the entire ib_logfile0 in when only a tiny portion would be
accessed. On Linux and FreeBSD the default is innodb_log_file_mmap=ON,
because those platforms define a specific mmap(2) option for enabling
such read-ahead and therefore it can be assumed that the default would
be on-demand paging. This parameter will only have impact on the initial
InnoDB startup and recovery. Any writes to the log will use regular I/O,
except when the ib_logfile0 is stored in a specially configured file system
that is backed by persistent memory (Linux "mount -o dax").
We also experimented with allowing writes of the ib_logfile0 via a
memory mapping and decided against it. A fundamental problem would be
unnecessary read-before-write in case of a major page fault, that is,
when a new, not yet cached, virtual memory page in the circular
ib_logfile0 is being written to. There appears to be no way to tell
the operating system that we do not care about the previous contents of
the page, or that the page fault handler should just zero it out.
Many references to HAVE_PMEM have been replaced with references to
HAVE_INNODB_MMAP.
The predicate log_sys.is_pmem() has been replaced with
log_sys.is_mmap() && !log_sys.is_opened().
Memory-mapped regular files differ from MAP_SYNC (PMEM) mappings in the
way that an open file handle to ib_logfile0 will be retained. In both
code paths, log_sys.is_mmap() will hold. Holding a file handle open will
allow log_t::clear_mmap() to disable the interface with fewer operations.
It should be noted that ever since
commit 685d958e38 (MDEV-14425)
most 64-bit Linux platforms on our CI platforms
(s390x a.k.a. IBM System Z being a notable exception) read and write
/dev/shm/*/ib_logfile0 via a memory mapping, pretending that it is
persistent memory (mount -o dax). So, the memory mapping based log
parsing that this change is enabling by default on Linux and FreeBSD
has already been extensively tested on Linux.
::log_mmap(): If a log cannot be opened as PMEM and the desired access
is read-only, try to open a read-only memory mapping.
xtrabackup_copy_mmap_snippet(), xtrabackup_copy_mmap_logfile():
Copy the InnoDB log in mariadb-backup --backup from a memory
mapped file.
In mariadb-backup --backup there are multiple mechanisms for ensuring that
a sufficient amount of the InnoDB write-ahead log (ib_logfile0) is being
copied at the end of the backup. The backup needs to include the latest
committed transaction. While further transaction commits are blocked by
BACKUP STAGE BLOCK_COMMIT, ongoing transactions may modify the database
contents and write log records. We were unnecessarily copying such log,
which would also cause further effort of rolling back incomplete
transactions after the backup is restored.
backup_wait_for_lsn(): Declare as static, and refactor some code
to separate functions backup_wait_for_lsn_low() and
backup_wait_timeout().
backup_wait_for_commit_lsn(): A new function to determine the current
LSN (within BACKUP STAGE BLOCK_COMMIT) and to wait for the log to be
copied until that. Invoked by BackupStages::stage_block_commit().
xtrabackup_backup_func(): Remove a condition that had already been
checked by a caller of backup_wait_timeout().
server_lsn_after_lock: Declare as a local variable in
BackupStages::stage_block_ddl().
log_copying_thread(), io_watching_thread(): Use metadata_last_lsn
instead of metadata_to_lsn as the stop condition.
BackupStages::stage_block_commit(): Ensure that the log tables
(in particular, mysql.general_log) will have been copied before
the BACKUP STAGE BLOCK_COMMIT is being followed by any further
SQL statements.
Reviewed by: Debarun Banerjee
Tested by: Matthias Leich
As part of commit 685d958e38 (MDEV-14425)
the parameter innodb_log_write_ahead_size was removed, because it was
thought that determining the physical block size would be a sufficient
replacement.
However, we can only determine the physical block size on Linux or
Microsoft Windows. On some file systems, the physical block size
is not relevant. For example, XFS uses a block size of 4096 bytes
even if the underlying block size may be smaller.
On Linux, we failed to determine the physical block size if
innodb_log_file_buffered=OFF was not requested or possible.
This will be fixed.
log_sys.write_size: The value of the reintroduced parameter
innodb_log_write_ahead_size. To keep it simple, this is read-only
and a power of two between 512 and 4096 bytes, so that the previous
alignment guarantees are fulfilled. This will replace the previous
log_sys.get_block_size().
log_sys.block_size, log_t::get_block_size(): Remove.
log_t::set_block_size(): Ensure that write_size will not be less
than the physical block size. There is no point to invoke this
function with 512 or less, because that is the minimum value of
write_size.
innodb_params_adjust(): Add some disabled code for adjusting
the minimum value and default value of innodb_log_write_ahead_size
to reflect the log_sys.write_size.
log_t::set_recovered(): Mark the recovery completed. This is the
place to adjust some things if we want to allow write_size>4096.
log_t::resize_write_buf(): Refer to write_size.
log_t::resize_start(): Refer to write_size instead of get_block_size().
log_write_buf(): Simplify some arithmetics and remove a goto.
log_t::write_buf(): Refer to write_size. If we are writing less than
that, do not switch buffers, but keep writing to the same buffer.
Move some code to improve the locality of reference.
recv_scan_log(): Refer to write_size instead of get_block_size().
os_file_create_func(): For type==OS_LOG_FILE on Linux, always invoke
os_file_log_maybe_unbuffered(), so that log_sys.set_block_size() will
be invoked even if we are not attempting to use O_DIRECT.
recv_sys_t::find_checkpoint(): Read the entire log header
in a single 12 KiB request into log_sys.buf.
Tested with:
./mtr --loose-innodb-log-write-ahead-size=4096
./mtr --loose-innodb-log-write-ahead-size=2048
As all MariaDB Server errors now have a dedicated web page, the
perror utility is extended to include a link to the KB page of
the corresponding error code.
All new code of the whole pull request, including one or several
files that are either new files or modified ones, are contributed
under the BSD-new license. I am contributing on behalf of my
employer Amazon Web Services, Inc.
MariaDB-backup needs to check for SLAVE MONITOR as that is
what is returned by SHOW GRANTS.
Update test to ensure that warnings about missing privileges
do not occur when the backup is successful.
Reviewer: Andrew Hutchings
Thanks Eugene for reporting the issue.
this fixes galera.galera_sst_mariabackup_table_options
Note that `man snprintf` says
The functions snprintf() and vsnprintf() do not write more
than size bytes (including the terminating null byte
('\0')). If the output was truncated due to this limit, then
the return value is the number of characters (excluding the
terminating null byte) which would have been written to the
final string if enough space had been available.
- ZLIB_LIBRARIES, not ZLIB_LIBRARY
- ZLIB_INCLUDE_DIRS, not ZLIB_INCLUDE_DIR
For building libmariadb, ZLIB_LIBRARY/ZLIB_INCLUDE_DIR are still defined
This workaround will be removed later.
Problem:
========
mariabackup --prepare fails to write the pages in encrypted format.
This issue happens only for default encrypted table when
innodb_encrypt_tables variable is enabled.
Fix:
====
backup process should write the value of innodb_encrypt_tables
variable in configuration file. prepare should enable the
variable based on configuration file.
I checked all stack overflow potential problems found with
gcc -Wstack-usage=16384
and
clang -Wframe-larger-than=16384 -no-inline
Fixes:
Added '#pragma clang diagnostic ignored "-Wframe-larger-than="'
to a lot of function to where stack usage large but resonable.
- Added stack check warnings to BUILD scrips when using clang and debug.
Function changed to use malloc instead allocating things on stack:
- read_bootstrap_query() now allocates line_buffer (20000 bytes) with
malloc() instead of using stack. This has a small performance impact
but this is not releant for bootstrap.
- mroonga grn_select() used 65856 bytes on stack. Changed it to use
malloc().
- Wsrep_schema::replay_transaction() and
Wsrep_schema::recover_sr_transactions().
- Connect zipOpen3()
Not fixed:
- mroonga/vendor/groonga/lib/expr.c grn_proc_call() uses
43712 byte on stack. However this is not easy to fix as the stack
used is caused by a lot of code generated by defines.
- Most changes in mroonga/groonga where only adding of pragmas to disable
stack warnings.
- rocksdb/options/options_helper.cc uses 20288 of stack space.
(no reason to fix except to get rid of the compiler warning)
- Causes using alloca() where the allocation size is resonable.
- An issue in libmariadb (reported to connectors).
Because the Red Hat Enterprise Linux 8 core repository does not include
libpmem, let us implement the necessary subset ourselves.
pmem_persist(): Implement for 64-bit x86, ARM, POWER, RISC-V, Loongarch
in a way that should be compatible with the https://github.com/pmem/pmdk/
implementation of pmem_persist().
The CMake option WITH_INNODB_PMEM can be used for enabling or disabling
this interface at compile time. By default, it is enabled on all applicable
systems that are covered by our CI system.
Note: libpmem had not been previously enabled for Loongarch in our
Debian packaging. It was enabled for RISC-V, but we will not enable it
by default on RISC-V or Loongarch because we lack CI coverage.
The generated code for x86_64 was reviewed and tested on two
Intel implementations: one that only supports clflush, and
another that supports both clflushopt and clwb.
The generated machine code was also reviewed on https://godbolt.org
using various compiler versions. Godbolt helpfully includes an option
to compile to binary code and display the encoding, which was
useful on POWER.
Reviewed by: Vladislav Vaintroub
On Microsoft Windows, ReadFile() as well as WriteFile() limit the size
of the request to DWORD, which is 32 bits (at most 4 GiB - 1) also on
64-bit systems.
On FreeBSD, sysctl debug.iosize_max_clamp could limit the size of a
write request to INT_MAX. The size of a read request is always limited
to INT_MAX. This would allow the request size to be 4095 bytes more than
the Linux limit (0x7ffff000 according to "man 2 read" and "man 2 write").
On OpenBSD, Solaris and possibly NetBSD, the read request size is limited
to SSIZE_T_MAX, which would be half the current maximum
innodb_log_buffer_size. This should be not much of an issue anyway,
because on contemporary 64-bit platforms, the virtual addresses are
limited to 48 bits.
IBM AIX documentation mentions OFF_MAX which would apply when
a 64-bit application is running on a 32-bit kernel.
Let us declare innodb_log_buffer_size as 32-bit unsigned and make the
maximum 0x7ffff000, to be compatible with the least common
denominator (Linux).
The maximum innodb_sort_buffer_size already was 64 MiB,
which is not a problem.
SyncFileIO::execute(): Assert that the size of a synchronous read or
write request is limited to the maximum.
Reviewed by: Vladislav Vaintroub
The problem happened when running mariabackup agains a pre-MDEV-30971 server,
i.e. not having yet the system variable @@aria_log_dir_path.
As a result, backup_start() called the function backup_files_from_datadir()
with a NULL value, which further caused a crash.
Fix:
Perform this call:
backup_files_from_datadir(.., aria_log_dir_path, ..)
only if aria_log_dir_path is not NULL. Otherwise,
assume that Aria log files are in their default location,
so they've just copied by the previous call:
backup_files_from_datadir(.., fil_path_to_mysql_datadir, ..)
Thanks to Walter Doekes for a patch proposal.
Some fixes related to commit f838b2d799 and
Rows_log_event::do_apply_event() and Update_rows_log_event::do_exec_row()
for system-versioned tables were provided by Nikita Malyavin.
This was required by test versioning.rpl,trx_id,row.
The log_sys.lsn_lock is a very contended resource with a small
critical section in log_sys.append_prepare(). On many processor
microarchitectures, replacing the system call based log_sys.lsn_lock
with a pure spin lock would fare worse during high concurrency workloads,
wasting a significant amount of CPU cycles in the spin loop.
On other microarchitectures, we would see a significant amount of time
being spent in native_queued_spin_lock_slowpath() in the Linux kernel,
plus context switching between user and kernel address space. This was
pointed out by Steve Shaw from Intel Corporation.
Depending on the workload and the hardware implementation, it may be
useful to use a pure spin lock in log_sys.append_prepare().
We will introduce a parameter. The statement
SET GLOBAL INNODB_LOG_SPIN_WAIT_DELAY=50;
would enable a spin lock that will execute that many MY_RELAX_CPU()
operations (such as the x86 PAUSE instruction) between successive
attempts of acquiring the spin lock. The use of a system call based
log_sys.lsn_lock (which is the default setting) can be enabled by
SET GLOBAL INNODB_LOG_SPIN_WAIT_DELAY=0;
This patch will also introduce #ifdef LOG_LATCH_DEBUG
(part of cmake -DWITH_INNODB_EXTRA_DEBUG=ON) for more accurate
tracking of log_sys.latch ownership and reorganize the fields of
log_sys to improve the locality of reference and to reduce the
chances of false sharing.
When a spin lock is being used, it will be maintained in the
most significant bit of log_sys.buf_free. This is useful, because that is
one of the fields that is covered by the lock. For IA-32 or AMD64, we
implement the spin lock specially via log_t::lsn_lock_bts(), employing the
i386 LOCK BTS instruction. A straightforward std::atomic::fetch_or() would
translate into an inefficient loop around LOCK CMPXCHG.
mtr_t::spin_wait_delay: The value of innodb_log_spin_wait_delay.
mtr_t::finisher: Pointer to the currently used mtr_t::finish_write()
implementation. This allows to avoid introducing conditional branches.
We no longer invoke log_sys.is_pmem() at the mini-transaction level,
but we would do that in log_write_up_to().
mtr_t::finisher_update(): Update finisher when spin_wait_delay is
changed from or to 0 (the spin lock is changed to log_sys.lsn_lock or
vice versa).
If mariabackup with backup locks is used on SST we do not
pause and desync galera provider at all. If WSREP_MODE_BF_MARIABACKUP
case provider is paused and desync at BLOCK_COMMIT phase. In
other cases provider is paused and desync at BLOCK_DDL phase.
Added support to BACKUP STAGE to maria-backup
This is a port of the code from ES 10.6
See MDEV-5336 for backup stages description.
The following old options are not supported by the new code:
--rsync ; This is because rsync will not work on tables
that are in used.
--no-backup-locks ; This is disabled as mariadb-backup will always
use backup locks for better performance.
Apparently, invoking fcntl(fd, F_SETFL, O_DIRECT) will lead to
unexpected behaviour on Linux bcachefs and possibly other file systems,
depending on the operating system version. So, let us avoid doing that,
and instead just attempt to pass the O_DIRECT flag to open(). This should
make us compatible with NetBSD, IBM AIX, as well as Solaris and its
derivatives.
This fix does not change the fact that we had only implemented
innodb_log_file_buffering=OFF on systems where we can determine the
physical block size (typically 512 or 4096 bytes).
Currently, those operating systems are Linux and Microsoft Windows.
HAVE_FCNTL_DIRECT, os_file_set_nocache(): Remove.
OS_FILE_OVERWRITE, OS_FILE_CREATE_PATH: Remove (never used parameters).
os_file_log_buffered(), os_file_log_maybe_unbuffered(): Helper functions.
os_file_create_simple_func(): When applicable, initially attempt to
open files in O_DIRECT mode.
os_file_create_func(): When applicable, initially attempt to
open files in O_DIRECT mode.
For type==OS_LOG_FILE && create_mode != OS_FILE_CREATE
we will first invoke stat(2) on the file name to find out if the size
is compatible with O_DIRECT. If create_mode == OS_FILE_CREATE, we will
invoke fstat(2) on the created log file afterwards, and may close and
reopen the file in O_DIRECT mode if applicable.
create_temp_file(): Support O_DIRECT. This is only used if O_TMPFILE is
available and innodb_disable_sort_file_cache=ON (non-default value).
Notably, that setting never worked on Microsoft Windows.
row_merge_file_create_mode(): Split from row_merge_file_create_low().
Create a temporary file in the specified mode.
Reviewed by: Vladislav Vaintroub
- Use "new" math library WOLFSSL_SP_MATH_ALL, which is now promoted by
WolfSSL for faster performance. "fastmath" we used previously is going
to be deprecated, it was not really always fast.
- Optimize common RSA math operations with WOLFSSL_HAVE_SP_RSA
- Incorporate assembly optimizations, currently for Intel x64 only
This patch significantly reduces execution time for SSL tests like
main.ssl-big and main.ssl_connect, which now run 2 to 3 times faster.
Notably, when this patch is applied to 11.4, server startup in with
ephemeral certificates becomes approximately 10x faster due to optimized
wolfSSL_EVP_PKEY_keygen().
Additionally, refactored WolfSSL by removing old workarounds and
consolidating wolfssl and wolfcrypt into a single library wolfssl, just
like it was done in WolfSSL's own CMake.
