trx_rseg_header_create(): Return the block descriptor, and
remove the redundant trx_rsegf_get_new() call. Apparently
the idea of that call was some kind of encapsulation or
abstraction, to discourage the direct use of the constant TRX_RSEG.
This also removes the trx_purge_initiate_truncate() local
variable rseg_header, which was only used in debug builds.
When there is a huge transaction in the undo log, the purge threads
may get stuck in trx_purge_attach_undo_recs() for a long time,
causing the server to hang on a normal shutdown (innodb_fast_shutdown>0).
Apparently the innodb_purge_batch_size does not work correctly, or the
n_pages_handled is not being incremented correctly. We do not fix that
for now, but we will instead check if shutdown has been initiated,
allowing the purge threads to shut down without delays.
GCC 6 and later can optimize away the memset() that is part of
mem_heap_zalloc() in a placement new call. So, instead of relying
on that kind of initialization, explicitly initialize the necessary
fields in the constructors.
que_common_t::que_common_t(): Initialize more fields in the
default constructor.
purge_vcol_info_t::purge_vcol_info_t(): Initialize all fields in
the default constructor.
purge_node_t::purge_node_t(): Initialize all necessary fields.
Reference:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71388https://gcc.gnu.org/ml/gcc/2016-02/msg00207.html
purge_node_t::in_progress: Replaces purge_node_t::done.
Only present in debug builds.
purge_node_t::start(): Moved from the start of row_purge_step().
purge_node_t::end(): Replaces row_purge_end().
trx_purge_attach_undo_recs(): Omit a check from non-debug builds.
If a table has been dropped, rebuilt, or its tablespace has been
discarded or the table is corrupted, it does not make sense to
look up that table again while purging old undo log records.
purge_node_t::purge_node_t(): Replaces row_purge_node_create().
que_common_t::que_common_t(): Constructor.
row_import_update_index_root(): Remove the constant parameter
dict_locked=true, and update the table->def_trx_id in the cache.
purge_node_t::unavailable_table_id: The latest unavailable table ID,
to avoid future lookups.
purge_node_t::def_trx_id: The latest modification of the table
identified by unavailable_table_id, or TRX_ID_MAX.
purge_node_t::is_skipped(): Determine if a table should be skipped.
purge_node_t::skip(): Note that a table should be skipped.
row_drop_table_for_mysql(): Avoid accessing non-existing dictionary tables.
dict_create_or_check_foreign_constraint_tables(): Add debug instrumentation
for creating and dropping a table before the creation of any non-core
dictionary tables.
trx_purge_add_update_undo_to_history(): Adjust a debug assertion, so that
it will not fail due to the test instrumentation.
row_drop_table_for_mysql(): Avoid accessing non-existing dictionary tables.
dict_create_or_check_foreign_constraint_tables(): Add debug instrumentation
for creating and dropping a table before the creation of any non-core
dictionary tables.
trx_purge_add_update_undo_to_history(): Adjust a debug assertion, so that
it will not fail due to the test instrumentation.
Remove the innodb_undo suite, and move and adapt the tests.
Remove unnecessary restarts, and add innodb_page_size_small.inc
for combinations.
innodb.undo_truncate is the merge of innodb_undo.truncate
and innodb_undo.truncate_multi_client.
Add the global status variable innodb_undo_truncations.
Without this, the test innodb.undo_truncate would occasionally
report that truncation did not happen. The test was only waiting
for the history list length to reach 0, but the undo tablespace
truncation would only take place some time after that.
Undo tablespace truncation will only occasionally occur with
innodb_page_size=32k, and typically never occur (with this amount
of undo log operations) with innodb_page_size=64k. We disable
these combinations.
innodb.undo_truncate_recover was formerly called
innodb_undo.truncate_recover.
Implement undo tablespace truncation via normal redo logging.
Implement TRUNCATE TABLE as a combination of RENAME to #sql-ib name,
CREATE, and DROP.
Note: Orphan #sql-ib*.ibd may be left behind if MariaDB Server 10.2
is killed before the DROP operation is committed. If MariaDB Server 10.2
is killed during TRUNCATE, it is also possible that the old table
was renamed to #sql-ib*.ibd but the data dictionary will refer to the
table using the original name.
In MariaDB Server 10.3, RENAME inside InnoDB is transactional,
and #sql-* tables will be dropped on startup. So, this new TRUNCATE
will be fully crash-safe in 10.3.
ha_mroonga::wrapper_truncate(): Pass table options to the underlying
storage engine, now that ha_innobase::truncate() will need them.
rpl_slave_state::truncate_state_table(): Before truncating
mysql.gtid_slave_pos, evict any cached table handles from
the table definition cache, so that there will be no stale
references to the old table after truncating.
== TRUNCATE TABLE ==
WL#6501 in MySQL 5.7 introduced separate log files for implementing
atomic and crash-safe TRUNCATE TABLE, instead of using the InnoDB
undo and redo log. Some convoluted logic was added to the InnoDB
crash recovery, and some extra synchronization (including a redo log
checkpoint) was introduced to make this work. This synchronization
has caused performance problems and race conditions, and the extra
log files cannot be copied or applied by external backup programs.
In order to support crash-upgrade from MariaDB 10.2, we will keep
the logic for parsing and applying the extra log files, but we will
no longer generate those files in TRUNCATE TABLE.
A prerequisite for crash-safe TRUNCATE is a crash-safe RENAME TABLE
(with full redo and undo logging and proper rollback). This will
be implemented in MDEV-14717.
ha_innobase::truncate(): Invoke RENAME, create(), delete_table().
Because RENAME cannot be fully rolled back before MariaDB 10.3
due to missing undo logging, add some explicit rename-back in
case the operation fails.
ha_innobase::delete(): Introduce a variant that takes sqlcom as
a parameter. In TRUNCATE TABLE, we do not want to touch any
FOREIGN KEY constraints.
ha_innobase::create(): Add the parameters file_per_table, trx.
In TRUNCATE, the new table must be created in the same transaction
that renames the old table.
create_table_info_t::create_table_info_t(): Add the parameters
file_per_table, trx.
row_drop_table_for_mysql(): Replace a bool parameter with sqlcom.
row_drop_table_after_create_fail(): New function, wrapping
row_drop_table_for_mysql().
dict_truncate_index_tree_in_mem(), fil_truncate_tablespace(),
fil_prepare_for_truncate(), fil_reinit_space_header_for_table(),
row_truncate_table_for_mysql(), TruncateLogger,
row_truncate_prepare(), row_truncate_rollback(),
row_truncate_complete(), row_truncate_fts(),
row_truncate_update_system_tables(),
row_truncate_foreign_key_checks(), row_truncate_sanity_checks():
Remove.
row_upd_check_references_constraints(): Remove a check for
TRUNCATE, now that the table is no longer truncated in place.
The new test innodb.truncate_foreign uses DEBUG_SYNC to cover some
race-condition like scenarios. The test innodb-innodb.truncate does
not use any synchronization.
We add a redo log subformat to indicate backup-friendly format.
MariaDB 10.4 will remove support for the old TRUNCATE logging,
so crash-upgrade from old 10.2 or 10.3 to 10.4 will involve
limitations.
== Undo tablespace truncation ==
MySQL 5.7 implements undo tablespace truncation. It is only
possible when innodb_undo_tablespaces is set to at least 2.
The logging is implemented similar to the WL#6501 TRUNCATE,
that is, using separate log files and a redo log checkpoint.
We can simply implement undo tablespace truncation within
a single mini-transaction that reinitializes the undo log
tablespace file. Unfortunately, due to the redo log format
of some operations, currently, the total redo log written by
undo tablespace truncation will be more than the combined size
of the truncated undo tablespace. It should be acceptable
to have a little more than 1 megabyte of log in a single
mini-transaction. This will be fixed in MDEV-17138 in
MariaDB Server 10.4.
recv_sys_t: Add truncated_undo_spaces[] to remember for which undo
tablespaces a MLOG_FILE_CREATE2 record was seen.
namespace undo: Remove some unnecessary declarations.
fil_space_t::is_being_truncated: Document that this flag now
only applies to undo tablespaces. Remove some references.
fil_space_t::is_stopping(): Do not refer to is_being_truncated.
This check is for tablespaces of tables. Potentially used
tablespaces are never truncated any more.
buf_dblwr_process(): Suppress the out-of-bounds warning
for undo tablespaces.
fil_truncate_log(): Write a MLOG_FILE_CREATE2 with a nonzero
page number (new size of the tablespace in pages) to inform
crash recovery that the undo tablespace size has been reduced.
fil_op_write_log(): Relax assertions, so that MLOG_FILE_CREATE2
can be written for undo tablespaces (without .ibd file suffix)
for a nonzero page number.
os_file_truncate(): Add the parameter allow_shrink=false
so that undo tablespaces can actually be shrunk using this function.
fil_name_parse(): For undo tablespace truncation,
buffer MLOG_FILE_CREATE2 in truncated_undo_spaces[].
recv_read_in_area(): Avoid reading pages for which no redo log
records remain buffered, after recv_addr_trim() removed them.
trx_rseg_header_create(): Add a FIXME comment that we could write
much less redo log.
trx_undo_truncate_tablespace(): Reinitialize the undo tablespace
in a single mini-transaction, which will be flushed to the redo log
before the file size is trimmed.
recv_addr_trim(): Discard any redo logs for pages that were
logged after the new end of a file, before the truncation LSN.
If the rec_list becomes empty, reduce n_addrs. After removing
any affected records, actually truncate the file.
recv_apply_hashed_log_recs(): Invoke recv_addr_trim() right before
applying any log records. The undo tablespace files must be open
at this point.
buf_flush_or_remove_pages(), buf_flush_dirty_pages(),
buf_LRU_flush_or_remove_pages(): Add a parameter for specifying
the number of the first page to flush or remove (default 0).
trx_purge_initiate_truncate(): Remove the log checkpoints, the
extra logging, and some unnecessary crash points. Merge the code
from trx_undo_truncate_tablespace(). First, flush all to-be-discarded
pages (beyond the new end of the file), then trim the space->size
to make the page allocation deterministic. At the only remaining
crash injection point, flush the redo log, so that the recovery
can be tested.
trx_purge_add_update_undo_to_history(): Relax the too strict assertion
by removing the condition on srv_fast_shutdown (innodb_fast_shutdown).
Rollback is allowed during any form of shutdown.
trx_purge_stop(): Release purge_sys->latch before attempting to
wake up the purge threads, so that they can actually wake up.
This is a regression of commit a13a636c74
which attempted to fix MDEV-11802 by ensuring that srv_purge_wakeup()
will actually wait until all purge threads wake up.
Due to the purge_sys->latch, the threads might never wake up,
because some purge threads could end up waiting for purge_sys->latch
in trx_undo_prev_version_build() while holding dict_operation_lock
in shared mode. This in turn would block any DDL operations, the
InnoDB master thread, and InnoDB shutdown.
MDEV-14511 tried to avoid some consistency problems related to InnoDB
persistent statistics. The persistent statistics are being written by
an InnoDB internal SQL interpreter that requires the InnoDB data dictionary
cache to be locked.
Before MDEV-14511, the statistics were written during DDL in separate
transactions, which could unnecessarily reduce performance (each commit
would require a redo log flush) and break atomicity, because the statistics
would be updated separately from the dictionary transaction.
However, because it is unacceptable to hold the InnoDB data dictionary
cache locked while suspending the execution for waiting for a
transactional lock (in the mysql.innodb_index_stats or
mysql.innodb_table_stats tables) to be released, any lock conflict
was immediately be reported as "lock wait timeout".
To fix MDEV-14941, an attempt to reduce these lock conflicts by acquiring
transactional locks on the user tables in both the statistics and DDL
operations was made, but it would still not entirely prevent lock conflicts
on the mysql.innodb_index_stats and mysql.innodb_table_stats tables.
Fixing the remaining problems would require a change that is too intrusive
for a GA release series, such as MariaDB 10.2.
Thefefore, we revert the change MDEV-14511. To silence the
MDEV-13201 assertion, we use the pre-existing flag trx_t::internal.
row_quiesce_table_start(), row_quiesce_table_complete():
Use the more appropriate predicate srv_undo_sources for skipping
purge control. (This change alone is insufficient; it is possible
that this predicate will change during the call to trx_purge_stop()
or trx_purge_run().)
trx_purge_stop(), trx_purge_run(): Tolerate PURGE_STATE_EXIT.
It is very well possible to initiate shutdown soon after the statement
FLUSH TABLES FOR EXPORT has been submitted to execution.
srv_purge_coordinator_thread(): Ensure that the wait for purge_sys->event
in trx_purge_stop() will terminate when the coordinator thread exits.
Introduce the debug flag trx_t::persistent_stats to suppress the
assertion for the updates of persistent statistics during fast
shutdown.
dict_stats_exec_sql(): Do execute the statement even though shutdown
has been initiated.
Replace all references in InnoDB and XtraDB error log messages
to bugs.mysql.com with references to https://jira.mariadb.org/.
The original merge
commit 4274d0bf57
was accidentally reverted by the subsequent merge
commit 3b35d745c3
The thd_destructor_proxy detects that no transactions are active and
starts srv_shutdown_bg_undo_sources(), but fails to take into account
that new transactions can still start, especially be slave but also
by other threads. In addition there is no mutex when checking for
active transaction so this is not safe.
We relax the failing InnoDB debug assertion by allowing the execution
of user transactions after the purge thread has been shut down.
FIXME: If innodb_fast_shutdown=0, we should somehow guarantee that no
new transactions can start after thd_destructor_proxy observed that
trx_sys_any_active_transactions() did not hold.
While the primary purpose of innodb_force_recovery is to allow
data to be rescued from an InnoDB instance that would crash due
to some data corruption, the settings 1, 2, or 3 are relatively
safe to use and there is no need to prevent write transactions
in these modes.
The setting innodb_force_recovery=4 and above can cause database
corruption. For those modes, we already set the flag
high_level_read_only to disable modifications, except DROP TABLE.
MODIFICATIONS_NOT_ALLOWED_MSG_FORCE_RECOVERY: Remove. There is no
need to spam the error log for each refused DML operation. It suffices
to return an error to the client. There will be messages at startup
if innodb_read_only or innodb_force_recovery are preventing writes.
The original intention of the setting innodb_force_recovery=3 was to
disable background activity that could create trouble, most notably,
the rollback of incomplete transactions, and the purge of transaction
history.
MySQL 5.6 introduced more background threads, it is creating
dict_stats_thread and fts_optimize_thread even though these threads
are at least as non-essential as the rollback and purge. These
threads are in fact worse, because they can create new transactions
on their own.
innobase_start_or_create_for_mysql(): Do not create any internal
undo log sources unless innodb_force_recovery<3.
When a slow shutdown is performed soon after spawning some work for
background threads that can create or commit transactions, it is possible
that new transactions are started or committed after the purge has finished.
This is violating the specification of innodb_fast_shutdown=0, namely that
the purge must be completed. (None of the history of the recent transactions
would be purged.)
Also, it is possible that the purge threads would exit in slow shutdown
while there exist active transactions, such as recovered incomplete
transactions that are being rolled back. Thus, the slow shutdown could
fail to purge some undo log that becomes purgeable after the transaction
commit or rollback.
srv_undo_sources: A flag that indicates if undo log can be generated
or the persistent, whether by background threads or by user SQL.
Even when this flag is clear, active transactions that already exist
in the system may be committed or rolled back.
innodb_shutdown(): Renamed from innobase_shutdown_for_mysql().
Do not return an error code; the operation never fails.
Clear the srv_undo_sources flag, and also ensure that the background
DROP TABLE queue is empty.
srv_purge_should_exit(): Do not allow the purge to exit if
srv_undo_sources are active or the background DROP TABLE queue is not
empty, or in slow shutdown, if any active transactions exist
(and are being rolled back).
srv_purge_coordinator_thread(): Remove some previous workarounds
for this bug.
innobase_start_or_create_for_mysql(): Set buf_page_cleaner_is_active
and srv_dict_stats_thread_active directly. Set srv_undo_sources before
starting the purge subsystem, to prevent immediate shutdown of the purge.
Create dict_stats_thread and fts_optimize_thread immediately
after setting srv_undo_sources, so that shutdown can use this flag to
determine if these subsystems were started.
dict_stats_shutdown(): Shut down dict_stats_thread. Backported from 10.2.
srv_shutdown_table_bg_threads(): Remove (unused).
Significantly reduce the amount of InnoDB, XtraDB and Mariabackup
code changes by defining pfs_os_file_t as something that is
transparently compatible with os_file_t.
This merge reverts commit 6ca4f693c1ce472e2b1bf7392607c2d1124b4293
from current 5.6.36 innodb.
Bug #23481444 OPTIMISER CALL ROW_SEARCH_MVCC() AND READ THE
INDEX APPLIED BY UNCOMMITTED ROW
Problem:
========
row_search_for_mysql() does whole table traversal for range query
even though the end range is passed. Whole table traversal happens
when the record is not with in transaction read view.
Solution:
=========
Convert the innodb last record of page to mysql format and compare
with end range if the traversal of row_search_mvcc() exceeds 100,
no ICP involved. If it is out of range then InnoDB can avoid the
whole table traversal. Need to refactor the code little bit to
make it compile.
Reviewed-by: Jimmy Yang <jimmy.yang@oracle.com>
Reviewed-by: Knut Hatlen <knut.hatlen@oracle.com>
Reviewed-by: Dmitry Shulga <dmitry.shulga@oracle.com>
RB: 14660
srv_sys_t::n_threads_active[]: Protect writes by both the mutex and
by atomic memory access.
srv_active_wake_master_thread_low(): Reliably wake up the master
thread if there is work to do. The trick is to atomically read
srv_sys->n_threads_active[].
srv_wake_purge_thread_if_not_active(): Atomically read
srv_sys->n_threads_active[] (and trx_sys->rseg_history_len),
so that the purge should always be triggered when there is work to do.
trx_commit_in_memory(): Invoke srv_wake_purge_thread_if_not_active()
whenever a transaction is committed. Purge could have been prevented by
the read view of the currently committing transaction, even if it is
a read-only transaction.
trx_purge_add_update_undo_to_history(): Do not wake up the purge.
This is only called by trx_undo_update_cleanup(), as part of
trx_write_serialisation_history(), which in turn is only called by
trx_commit_low() which will always call trx_commit_in_memory().
Thus, the added call in trx_commit_in_memory() will cover also
this use case where a committing read-write transaction added
some update_undo log to the purge queue.
trx_rseg_mem_restore(): Atomically modify trx_sys->rseg_history_len.
Simplify the tests that are present in MySQL 5.7. Make the table
smaller while generating enough undo log. Do not unnecessarily
drop tables.
trx_purge_initiate_truncate(): Remove two crash injection points
(before and after normal redo log checkpoint), because they are
not adding any value. Clarify some messages.
trx_sys_create_rsegs(): Display the number of active undo tablespaces.
srv_undo_tablespaces_init(): When initializing the data files, do not
leave srv_undo_tablespaces_active at 0.
Do not display that number; let trx_sys_create_rsegs() display it once
the final number is known.
innodb_params_adjust(): Adjust parameters after startup.
innobase_init(): Do not allow innodb_max_undo_size to be less
than SRV_UNDO_TABLESPACE_SIZE_IN_PAGES. This avoids unnecessary
repeated truncation of undo tablespaces when using
innodb_page_size=32k or innodb_page_size=64k.
InnoDB divides the allocation of undo logs into rollback segments.
The DB_ROLL_PTR system column of clustered indexes can address up to
128 rollback segments (TRX_SYS_N_RSEGS). Originally, InnoDB only
created one rollback segment. In MySQL 5.5 or in the InnoDB Plugin
for MySQL 5.1, all 128 rollback segments were created.
MySQL 5.7 hard-codes the rollback segment IDs 1..32 for temporary undo logs.
On upgrade, unless a slow shutdown (innodb_fast_shutdown=0)
was performed on the old server instance, these rollback segments
could be in use by transactions that are in XA PREPARE state or
transactions that were left behind by a server kill followed by a
normal shutdown immediately after restart.
Persistent tables cannot refer to temporary undo logs or vice versa.
Therefore, we should keep two distinct sets of rollback segments:
one for persistent tables and another for temporary tables. In this way,
all 128 rollback segments will be available for both types of tables,
which could improve performance. Also, MariaDB 10.2 will remain more
compatible than MySQL 5.7 with data files from earlier versions of
MySQL or MariaDB.
trx_sys_t::temp_rsegs[TRX_SYS_N_RSEGS]: A new array of temporary
rollback segments. The trx_sys_t::rseg_array[TRX_SYS_N_RSEGS] will
be solely for persistent undo logs.
srv_tmp_undo_logs. Remove. Use the constant TRX_SYS_N_RSEGS.
srv_available_undo_logs: Change the type to ulong.
trx_rseg_get_on_id(): Remove. Instead, let the callers refer to
trx_sys directly.
trx_rseg_create(), trx_sysf_rseg_find_free(): Remove unneeded parameters.
These functions only deal with persistent undo logs.
trx_temp_rseg_create(): New function, to create all temporary rollback
segments at server startup.
trx_rseg_t::is_persistent(): Determine if the rollback segment is for
persistent tables.
trx_sys_is_noredo_rseg_slot(): Remove. The callers must know based on
context (such as table handle) whether the DB_ROLL_PTR is referring to
a persistent undo log.
trx_sys_create_rsegs(): Remove all parameters, which were always passed
as global variables. Instead, modify the global variables directly.
enum trx_rseg_type_t: Remove.
trx_t::get_temp_rseg(): A method to ensure that a temporary
rollback segment has been assigned for the transaction.
trx_t::assign_temp_rseg(): Replaces trx_assign_rseg().
trx_purge_free_segment(), trx_purge_truncate_rseg_history():
Remove the redundant variable noredo=false.
Temporary undo logs are discarded immediately at transaction commit
or rollback, not lazily by purge.
trx_purge_mark_undo_for_truncate(): Remove references to the
temporary rollback segments.
trx_purge_mark_undo_for_truncate(): Remove a check for temporary
rollback segments. Only the dedicated persistent undo log tablespaces
can be truncated.
trx_undo_get_undo_rec_low(), trx_undo_get_undo_rec(): Add the
parameter is_temp.
trx_rseg_mem_restore(): Split from trx_rseg_mem_create().
Initialize the undo log and the rollback segment from the file
data structures.
trx_sysf_get_n_rseg_slots(): Renamed from
trx_sysf_used_slots_for_redo_rseg(). Count the persistent
rollback segment headers that have been initialized.
trx_sys_close(): Also free trx_sys->temp_rsegs[].
get_next_redo_rseg(): Merged to trx_assign_rseg_low().
trx_assign_rseg_low(): Remove the parameters and access the
global variables directly. Revert to simple round-robin, now that
the whole trx_sys->rseg_array[] is for persistent undo log again.
get_next_noredo_rseg(): Moved to trx_t::assign_temp_rseg().
srv_undo_tablespaces_init(): Remove some parameters and use the
global variables directly. Clarify some error messages.
Adjust the test innodb.log_file. Apparently, before these changes,
InnoDB somehow ignored missing dedicated undo tablespace files that
are pointed by the TRX_SYS header page, possibly losing part of
essential transaction system state.
Also, remove empty .ic files that were not removed by my MySQL commit.
Problem:
InnoDB used to support a compilation mode that allowed to choose
whether the function definitions in .ic files are to be inlined or not.
This stopped making sense when InnoDB moved to C++ in MySQL 5.6
(and ha_innodb.cc started to #include .ic files), and more so in
MySQL 5.7 when inline methods and functions were introduced
in .h files.
Solution:
Remove all references to UNIV_NONINL and UNIV_MUST_NOT_INLINE from
all files, assuming that the symbols are never defined.
Remove the files fut0fut.cc and ut0byte.cc which only mattered when
UNIV_NONINL was defined.
Starting with MySQL 5.7, temporary tables in InnoDB are handled
differently from persistent tables. Because temporary tables are
private to a connection, concurrency control and multi-versioning
(MVCC) are not applicable. For performance reasons, purge is
disabled as well. Rollback is supported for temporary tables;
that is why we have the temporary undo logs in the first place.
Because MVCC and purge are disabled for temporary tables, we should
discard all temporary undo logs already at transaction commit,
just like we discard the persistent insert_undo logs. Before this
change, update_undo logs were being preserved.
trx_temp_undo_t: A wrapper for temporary undo logs, comprising
a rollback segment and a single temporary undo log.
trx_rsegs_t::m_noredo: Use trx_temp_undo_t.
(Instead of insert_undo, update_undo, there will be a single undo.)
trx_is_noredo_rseg_updated(), trx_is_rseg_assigned(): Remove.
trx_undo_add_page(): Remove the parameter undo_ptr.
Acquire and release the rollback segment mutex inside the function.
trx_undo_free_last_page(): Remove the parameter trx.
trx_undo_truncate_end(): Remove the parameter trx, and add the
parameter is_temp. Clean up the code a bit.
trx_undo_assign_undo(): Split the parameter undo_ptr into rseg, undo.
trx_undo_commit_cleanup(): Renamed from trx_undo_insert_cleanup().
Replace the parameter undo_ptr with undo.
This will discard the temporary undo or insert_undo log at
commit/rollback.
trx_purge_add_update_undo_to_history(), trx_undo_update_cleanup():
Remove 3 parameters. Always operate on the persistent update_undo.
trx_serialise(): Renamed from trx_serialisation_number_get().
trx_write_serialisation_history(): Simplify the code flow.
If there are no persistent changes, do not update MONITOR_TRX_COMMIT_UNDO.
trx_commit_in_memory(): Simplify the logic, and add assertions.
trx_undo_page_report_modify(): Keep a direct reference to the
persistent update_undo log.
trx_undo_report_row_operation(): Simplify some code.
Always assign TRX_UNDO_INSERT for temporary undo logs.
trx_prepare_low(): Keep only one parameter. Prepare all 3 undo logs.
trx_roll_try_truncate(): Remove the parameter undo_ptr.
Try to truncate all 3 undo logs of the transaction.
trx_roll_pop_top_rec_of_trx_low(): Remove.
trx_roll_pop_top_rec_of_trx(): Remove the redundant parameter
trx->roll_limit. Clear roll_limit when exhausting the undo logs.
Consider all 3 undo logs at once, prioritizing the persistent
undo logs.
row_undo(): Minor cleanup. Let trx_roll_pop_top_rec_of_trx()
reset the trx->roll_limit.
InnoDB undo logs currently always use the innodb_page_size,
whether they are stored in the system tablespace, in a
dedicated undo tablespace, or in the temporary tablespace.
Remove redundant page_size parameters.
TrxUndoRsegsIterator::set_next(): return bool instead of page_size.
TrxUndoRsegsIterator::m_purge_sys: Remove. There is only one purge_sys.
purge_sys_t: Renamed from trx_purge_t. Define a constructor and
destructor. Allocate rseg_iter, purge_queue inline.
purge_sys->trx: Remove. Use purge_sys->sess->trx instead.
purge_sys->view_active: Remove. Access to purge_sys->view is always
protected by purge_sys->latch.
trx_purge_sys_create(): Replaced by purge_sys_t::purge_sys_t().
trx_purge_sys_close(): Replaced by purge_sys_t::~purge_sys_t().
InnoDB needs to collect transactions from the persistent data files
in trx_rseg_array_init() before trx_lists_init_at_db_start() is
executed. But there is no need to create purge_sys->purge_queue
separately from purge_sys.
trx_sys_init_at_db_start(): Change the return type to void.
Remove the direct call to trx_rseg_array_init(). It will be called
by trx_lists_init_at_db_start(), which we are calling.
Initialize the purge system read view.
trx_lists_init_at_db_start(): Call trx_purge_sys_create(), which will
invoke trx_rseg_array_init() to read the undo log segments.
trx_purge_sys_create(): Remove the parameters. Do not initialize
the purge system read view, because trx_sys->rw_trx_list has not
been recovered yet. The purge_sys->view will be initialized at
the end of trx_sys_init_at_db_start().
trx_rseg_array_init(): Remove the parameter. Use purge_sys->purge_queue
directly.
innobase_start_or_create_for_mysql(): Remove the local variable
purge_queue. Do not call trx_purge_sys_create(), because it will be
called by trx_sys_init_at_db_start().
In MySQL 5.7, there is some redundant code for supposedly handling
an upgrade from an earlier version of InnoDB.
An upgrade of InnoDB between major versions should include a
slow shutdown (innodb_fast_shutdown=0) of the previous version.
A comment in trx_lists_init_at_db_start() confused clean shutdown
and slow shutdown. A clean shutdown does not necessarily guarantee
that there are no active transactions. A slow shutdown guarantees
that.
Because there was no code to handle rollback of recovered transactions
that happened to use the rollback segment slots that MySQL 5.7.2
repurposed for temporary undo logs, the upgrade is not working in all
cases, and we may as well remove the code to handle purging.
trx_sys_t::pending_purge_rseg_array: Remove.
trx_undo_get_undo_rec_low(): Define as static. Remove the parameter
is_redo_rseg.
trx_undo_get_undo_rec(), trx_rseg_get_on_id(): Remove the parameter
is_redo_rseg.
trx_rseg_mem_free(): Remove the second parameter.
trx_sys_get_nth_rseg(): Replace with trx_rseg_get_on_id().
trx_rseg_schedule_pending_purge(): Remove.
The function trx_purge_stop() was calling os_event_reset(purge_sys->event)
before calling rw_lock_x_lock(&purge_sys->latch). The os_event_set()
call in srv_purge_coordinator_suspend() is protected by that X-latch.
It would seem a good idea to consistently protect both os_event_set()
and os_event_reset() calls with a common mutex or rw-lock in those
cases where os_event_set() and os_event_reset() are used
like condition variables, tied to changes of shared state.
For each os_event_t, we try to document the mutex or rw-lock that is
being used. For some events, frequent calls to os_event_set() seem to
try to avoid hangs. Some events are never waited for infinitely, only
timed waits, and os_event_set() is used for early termination of these
waits.
os_aio_simulated_put_read_threads_to_sleep(): Define as a null macro
on other systems than Windows. TODO: remove this altogether and disable
innodb_use_native_aio on Windows.
os_aio_segment_wait_events[]: Initialize only if innodb_use_native_aio=0.
log_write_flush_to_disk_low(): Invoke log_mutex_enter() at the end, to
avoid race conditions when changing the system state. (No potential
race condition existed before MySQL 5.7.)
