The original code comes, as far as I know, from Google (Mark Callaghan's team) with additional work from Percona, Ourdelta and Weldon Whipple.
This code provides the same functionallity, but with a lot of changes to make it faster and better fit the MariaDB infrastucture.
Added new status variables:
- Com_show_client_statistics, Com_show_index_statistics, Com_show_table_statistics, Com_show_user_statistics
- Access_denied_errors, Busy_time (clock time), Binlog_bytes_written, Cpu_time, Empty_queries, Rows_sent, Rows_read
Added new variable / startup option 'userstat' to control if user statistics should be enabled or not
Added my_getcputime(); Returns cpu time used by this thread.
New FLUSH commands:
- FLUSH SLOW QUERY LOG
- FLUSH TABLE_STATISTICS
- FLUSH INDEX_STATISTICS
- FLUSH USER_STATISTICS
- FLUSH CLIENT_STATISTICS
New SHOW commands:
- SHOW CLIENT_STATISTICS
- SHOW USER_STATISTICS
- SHOW TABLE_STATISTICS
- SHOW INDEX_STATISTICS
New Information schemas:
- CLIENT_STATISTICS
- USER_STATISTICS
- INDEX_STATISTICS
- TABLE_STATISTICS
Added support for all new flush commands to mysqladmin
Added handler::ha_... wrappers for all handler read calls to do statistics counting
- Changed all code to use new ha_... calls
- Count number of read rows, changed rows and rows read trough an index
Added counting of number of bytes sent to binary log (status variable Binlog_bytes_written)
Added counting of access denied errors (status variable Access_denied_erors)
Bugs fixed:
- Fixed bug in add_to_status() and add_diff_to_status() where longlong variables where threated as long
- CLOCK_GETTIME was not propely working on Linuxm
client/mysqladmin.cc:
Added support for all new flush commmands and some common combinations:
flush-slow-log
flush-table-statistics
flush-index-statistics
flush-user-statistics
flush-client-statistics
flush-all-status
flush-all-statistics
configure.in:
Added checking if clock_gettime needs the librt.
(Fixes Bug #37639 clock_gettime is never used/enabled in Linux/Unix)
include/my_sys.h:
Added my_getcputime()
include/mysql_com.h:
Added LIST_PROCESS_HOST_LEN & new REFRESH target defines
mysql-test/r/information_schema.result:
New information schema tables added
mysql-test/r/information_schema_all_engines.result:
New information schema tables added
mysql-test/r/information_schema_db.result:
New information schema tables added
mysql-test/r/log_slow.result:
Added testing that flosh slow query logs is accepted
mysql-test/r/status_user.result:
Basic testing of user, client, table and index statistics
mysql-test/t/log_slow.test:
Added testing that flosh slow query logs is accepted
mysql-test/t/status_user-master.opt:
Ensure that we get a fresh restart before running status_user.test
mysql-test/t/status_user.test:
Basic testing of user, client, table and index statistics
mysys/my_getsystime.c:
Added my_getcputime()
Returns cpu time used by this thread.
sql/authors.h:
Updated authors to have core and original MySQL developers first.
sql/event_data_objects.cc:
Updated call to mysql_reset_thd_for_next_command()
sql/event_db_repository.cc:
Changed to use new ha_... calls
sql/filesort.cc:
Changed to use new ha_... calls
sql/ha_partition.cc:
Changed to use new ha_... calls
Fixed comment syntax
sql/handler.cc:
Changed to use new ha_... calls
Reset table statistics
Added code to update global table and index status
Added counting of rows changed
sql/handler.h:
Added table and index statistics variables
Added function reset_statistics()
Added handler::ha_... wrappers for all handler read calls to do statistics counting
Protected all normal read calls to ensure we use the new calls in the server.
Made ha_partition a friend class so that partition code can call the old read functions
sql/item_subselect.cc:
Changed to use new ha_... calls
sql/lex.h:
Added keywords for new information schema tables and flush commands
sql/log.cc:
Added flush_slow_log()
Added counting of number of bytes sent to binary log
Removed not needed test of thd (It's used before, so it's safe to use)
Added THD object to MYSQL_BIN_LOG::write_cache() to simplify statistics counting
sql/log.h:
Added new parameter to write_cache()
Added flush_slow_log() functions.
sql/log_event.cc:
Updated call to mysql_reset_thd_for_next_command()
Changed to use new ha_... calls
sql/log_event_old.cc:
Updated call to mysql_reset_thd_for_next_command()
Changed to use new ha_... calls
sql/mysql_priv.h:
Updated call to mysql_reset_thd_for_next_command()
Added new statistics functions and variables needed by these.
sql/mysqld.cc:
Added new statistics variables and structures to handle these
Added new status variables:
- Com_show_client_statistics, Com_show_index_statistics, Com_show_table_statistics, Com_show_user_statistics
- Access_denied_errors, Busy_time (clock time), Binlog_bytes_written, Cpu_time, Empty_queries, Rows_set, Rows_read
Added new option 'userstat' to control if user statistics should be enabled or not
sql/opt_range.cc:
Changed to use new ha_... calls
sql/opt_range.h:
Changed to use new ha_... calls
sql/opt_sum.cc:
Changed to use new ha_... calls
sql/records.cc:
Changed to use new ha_... calls
sql/set_var.cc:
Added variable 'userstat'
sql/sp.cc:
Changed to use new ha_... calls
sql/sql_acl.cc:
Changed to use new ha_... calls
Added counting of access_denied_errors
sql/sql_base.cc:
Added call to statistics functions
sql/sql_class.cc:
Added usage of org_status_var, to store status variables at start of command
Added functions THD::update_stats(), THD::update_all_stats()
Fixed bug in add_to_status() and add_diff_to_status() where longlong variables where threated as long
sql/sql_class.h:
Added new status variables to status_var
Moved variables that was not ulong in status_var last.
Added variables to THD for storing temporary values during statistics counting
sql/sql_connect.cc:
Variables and functions to calculate user and client statistics
Added counting of access_denied_errors and lost_connections
sql/sql_cursor.cc:
Changed to use new ha_... calls
sql/sql_handler.cc:
Changed to use new ha_... calls
sql/sql_help.cc:
Changed to use new ha_... calls
sql/sql_insert.cc:
Changed to use new ha_... calls
sql/sql_lex.h:
Added SQLCOM_SHOW_USER_STATS, SQLCOM_SHOW_TABLE_STATS, SQLCOM_SHOW_INDEX_STATS, SQLCOM_SHOW_CLIENT_STATS
sql/sql_parse.cc:
Added handling of:
- SHOW CLIENT_STATISTICS
- SHOW USER_STATISTICS
- SHOW TABLE_STATISTICS
- SHOW INDEX_STATISTICS
Added handling of new FLUSH commands:
- FLUSH SLOW QUERY LOGS
- FLUSH TABLE_STATISTICS
- FLUSH INDEX_STATISTICS
- FLUSH USER_STATISTICS
- FLUSH CLIENT_STATISTICS
Added THD parameter to mysql_reset_thd_for_next_command()
Added initialization and calls to user statistics functions
Added increment of statistics variables empty_queries, rows_sent and access_denied_errors.
Added counting of cpu time per query
sql/sql_plugin.cc:
Changed to use new ha_... calls
sql/sql_prepare.cc:
Updated call to mysql_reset_thd_for_next_command()
sql/sql_select.cc:
Changed to use new ha_... calls
Indentation changes
sql/sql_servers.cc:
Changed to use new ha_... calls
sql/sql_show.cc:
Added counting of access denied errors
Added function for new information schema tables:
- CLIENT_STATISTICS
- USER_STATISTICS
- INDEX_STATISTICS
- TABLE_STATISTICS
Changed to use new ha_... calls
sql/sql_table.cc:
Changed to use new ha_... calls
sql/sql_udf.cc:
Changed to use new ha_... calls
sql/sql_update.cc:
Changed to use new ha_... calls
sql/sql_yacc.yy:
Add new show and flush commands
sql/structs.h:
Add name_length to KEY to avoid some strlen
Added cache_name to KEY for fast storage of keyvalue in cache
Added structs USER_STATS, TABLE_STATS, INDEX_STATS
Added function prototypes for statistics functions
sql/table.cc:
Store db+table+index name into keyinfo->cache_name
sql/table.h:
Added new information schema tables
sql/tztime.cc:
Changed to use new ha_... calls
If a thread is killed in the server, we throw "shutdown" only if one is actually in
progress; otherwise, we throw "query interrupted".
Control-C in the mysql command-line client is "incremental" now.
First Control-C sends KILL QUERY (when connected to 5.0+ server, otherwise, see next)
Next Control-C sends KILL CONNECTION
Next Control-C aborts client.
As the first two steps only pertain to an existing query,
Control-C will abort the client right away if no query is running.
client will give more detailed/consistent feedback on Control-C now.
client/mysql.cc:
Extends Control-C handling; enhances up feedback to user.
On 5.0+ servers, we try to be nice and send KILL QUERY first
if Control-C is pressed in the command-line client, but if
that doesn't work, we now give the user the opportunity to
send KILL CONNECTION with another Control-C (and to kill the
client with another Control-C if that somehow doesn't work
either).
mysql-test/t/flush_read_lock_kill.test:
we're getting correct "thread killed" rather than
"in shutdown" error now
mysql-test/t/kill.test:
we're getting correct "thread killed" rather than
"in shutdown" error now
mysql-test/t/rpl000001.test:
we're getting correct "thread killed" rather than
"in shutdown" error now
mysql-test/t/rpl_error_ignored_table.test:
we're getting correct "thread killed" rather than
"in shutdown" error now
sql/records.cc:
make error messages on KILL uniform for rr_*()
by folding that handling into rr_handle_error()
sql/sql_class.h:
Only throw "shutdown" when we have one flagged as being in progress;
otherwise, throw "query interrupted" as it's likely to be "KILL CONNECTION"
or related.
If a thread is killed in the server, we throw "shutdown" only if one is actually in
progress; otherwise, we throw "query interrupted".
Control-C in the mysql command-line client is "incremental" now.
First Control-C sends KILL QUERY (when connected to 5.0+ server, otherwise, see next)
Next Control-C sends KILL CONNECTION
Next Control-C aborts client.
As the first two steps only pertain to an existing query,
Control-C will abort the client right away if no query is running.
client will give more detailed/consistent feedback on Control-C now.
sql/sql_cache.cc:
Use my_hash_init() on Windows as well.
sql/sql_class.h:
Use struct Query_cache_block (not class) for forward declaration,
realing the code to match 6.0 alignment.
Implemented the server infrastructure for the fix:
1. Added a function LEX_STRING *thd_query_string(THD) to return
a LEX_STRING structure instead of char *.
This is the function that must be called in innodb instead of
thd_query()
2. Did some encapsulation in THD : aggregated thd_query and
thd_query_length into a LEX_STRING and made accessor and mutator
methods for easy code updating.
3. Updated the server code to use the new methods where applicable.
Implemented the server infrastructure for the fix:
1. Added a function LEX_STRING *thd_query_string(THD) to return
a LEX_STRING structure instead of char *.
This is the function that must be called in innodb instead of
thd_query()
2. Did some encapsulation in THD : aggregated thd_query and
thd_query_length into a LEX_STRING and made accessor and mutator
methods for easy code updating.
3. Updated the server code to use the new methods where applicable.
Post-push fix.
Problem: After the original bugfix, if a statement is unsafe,
binlog_format=mixed, and engine is statement-only, a warning was
generated and the statement executed. However, it is a fundamental
principle of binlogging that binlog_format=mixed should guarantee
correct logging, no compromise. So correct behavior is to generate
an error and don't execute the statement.
Fix: Generate error instead of warning.
Since issue_unsafe_warnings can only generate one error message,
this allows us to simplify the code a bit too:
decide_logging_format does not have to save the error code for
issue_unsafe_warnings
mysql-test/suite/binlog/r/binlog_statement_insert_delayed.result:
updated result file
mysql-test/suite/binlog/r/binlog_stm_ps.result:
updated result file
mysql-test/suite/binlog/r/binlog_stm_unsafe_warning.result:
updated result file
mysql-test/suite/binlog/r/binlog_unsafe.result:
updated result file
mysql-test/suite/rpl/r/rpl_stm_found_rows.result:
updated result file
mysql-test/suite/rpl/r/rpl_stm_loadfile.result:
updated result file
mysql-test/suite/rpl_ndb/r/rpl_ndb_binlog_format_errors.result:
updated result file
mysql-test/suite/rpl_ndb/t/rpl_ndb_binlog_format_errors.test:
updated test:
- ER_BINLOG_UNSAFE_AND_STMT_ENGINE is now an error.
- added test for multiple types of unsafety
sql/share/errmsg.txt:
- Reformulated ER_BINLOG_UNSAFE_AND_STMT_ENGINE to reflect that it
is now an error, not a warning.
- Added "Reason for unsafeness" to ER_BINLOG_UNSAFE_STATEMENT and
ER_BINLOG_UNSAFE_AND_STMT_ENGINE.
sql/sql_class.cc:
In decide_logging_format:
- generate an error immediately in case 3, instead of scheduling a
warning to be generated later. also updated comments accordingly
- in case 7, there is only one unsafe warning error code now, so we
don't need to store it in binlog_unsafe_warning_flags
(see changes in sql_lex.h)
- fixed compilation warning in DBUG_PRINT
In issue_binlog_warning:
- moved array of error codes to sql_lex.h (so that they are
accessible also from decide_logging_format)
- simplified code after the first set of bits in
binlog_unsafe_warning_flags was removed
sql/sql_class.h:
- got rid of enum_binlog_stmt_warning. It's not needed anymore
since we only have one type of unsafe warning (one of them
turned into an error)
- updated comments accordingly
sql/sql_lex.cc:
added initialization of the array of error codes that has been
moved from THD::issue_unsafe_warnings to LEX.
sql/sql_lex.h:
Moved array of error codes from THD::issue_unsafe_warnings to LEX.
Post-push fix.
Problem: After the original bugfix, if a statement is unsafe,
binlog_format=mixed, and engine is statement-only, a warning was
generated and the statement executed. However, it is a fundamental
principle of binlogging that binlog_format=mixed should guarantee
correct logging, no compromise. So correct behavior is to generate
an error and don't execute the statement.
Fix: Generate error instead of warning.
Since issue_unsafe_warnings can only generate one error message,
this allows us to simplify the code a bit too:
decide_logging_format does not have to save the error code for
issue_unsafe_warnings
columns without where/group
Simple SELECT with implicit grouping used to return many rows if
the query was ordered by the aggregated column in the SELECT
list. This was incorrect because queries with implicit grouping
should only return a single record.
The problem was that when JOIN:exec() decided if execution needed
to handle grouping, it was assumed that sum_func_count==0 meant
that there were no aggregate functions in the query. This
assumption was not correct in JOIN::exec() because the aggregate
functions might have been optimized away during JOIN::optimize().
The reason why queries without ordering behaved correctly was
that sum_func_count is only recalculated if the optimizer chooses
to use temporary tables (which it does in the ordered case).
Hence, non-ordered queries were correctly treated as grouped.
The fix for this bug was to remove the assumption that
sum_func_count==0 means that there is no need for grouping. This
was done by introducing variable "bool implicit_grouping" in the
JOIN object.
mysql-test/r/func_group.result:
Add test for BUG#47280
mysql-test/t/func_group.test:
Add test for BUG#47280
sql/opt_sum.cc:
Improve comment for opt_sum_query()
sql/sql_class.h:
Add comment for variables in TMP_TABLE_PARAM
sql/sql_select.cc:
Introduce and use variable implicit_grouping instead of (!group_list && sum_func_count) in places that need to test if grouping is required. Also added comments for: optimization of aggregate fields for implicitly grouped queries (JOIN::optimize) and choice of end_select method (JOIN::execute)
sql/sql_select.h:
Add variable implicit_grouping, which will be TRUE for queries that contain aggregate functions but no GROUP BY clause. Also added comment to sort_and_group variable.
columns without where/group
Simple SELECT with implicit grouping used to return many rows if
the query was ordered by the aggregated column in the SELECT
list. This was incorrect because queries with implicit grouping
should only return a single record.
The problem was that when JOIN:exec() decided if execution needed
to handle grouping, it was assumed that sum_func_count==0 meant
that there were no aggregate functions in the query. This
assumption was not correct in JOIN::exec() because the aggregate
functions might have been optimized away during JOIN::optimize().
The reason why queries without ordering behaved correctly was
that sum_func_count is only recalculated if the optimizer chooses
to use temporary tables (which it does in the ordered case).
Hence, non-ordered queries were correctly treated as grouped.
The fix for this bug was to remove the assumption that
sum_func_count==0 means that there is no need for grouping. This
was done by introducing variable "bool implicit_grouping" in the
JOIN object.
local storage for query cache).
We need more than one pointer in a thread to
represent the query cache and net->query_cache_query can not be used
any more (due to ABI compatibility issues and to different life
time of NET and THD).
This is a backport of the following patch from 6.0:
----------------------------------------------------------
revno: 2476.1157.2
committer: kostja@bodhi.(none)
timestamp: Sat 2007-06-16 13:29:24 +0400
include/mysql.h.pp:
Update the ABI (NET::query_cache_query is now unused).
include/mysql_com.h:
NET::query_cache_query is now unused.
sql/mysql_priv.h:
Update signatures of ex-functios now member functions.
sql/sql_cache.cc:
Introduce THD::query_cache_tls.
sql/sql_cache.h:
Introduce THD::query_cache_tls.
sql/sql_class.cc:
Introduce THD::query_cache_tls.
sql/sql_class.h:
Introduce THD::query_cache_tls.
sql/sql_parse.cc:
Use THD::query_cache_tls.
sql/sql_select.cc:
Use THD::query_cache_tls.
local storage for query cache).
We need more than one pointer in a thread to
represent the query cache and net->query_cache_query can not be used
any more (due to ABI compatibility issues and to different life
time of NET and THD).
This is a backport of the following patch from 6.0:
----------------------------------------------------------
revno: 2476.1157.2
committer: kostja@bodhi.(none)
timestamp: Sat 2007-06-16 13:29:24 +0400
storing and restoring information about foreign keys in the .FRM files and
properly displaying it in SHOW CREATE TABLE output and I_S tables.
The idea of this patch is to change type of Key_part_spec::field_name and
Key::name to LEX_STRING in order to avoid extra strlen() calls during
semantic analysis and statement execution, particularly, in code to be
implemented on the 2nd milestone of WL#148.
Note that since we are not using LEX_STRING everywhere yet (e.g. in
Create_field and KEY) and we want to limit scope of our changes we
have to do strlen() in places where we create Key and Key_part_spec
instances from objects using plain (char*) for strings. These calls
will go away during the process of further (char*) -> LEX_STRING
refactoring.
We have introduced these changes in 6.0 and backported them to 5.5
tree to make people aware of these changes as early as possible and
to simplify merges with mysql-fk and mysql-6.1-fk trees.
No test case is needed since this patch does not introduce any
user visible changes.
sql/sql_class.cc:
Key_part_spec::field_name is now LEX_STRING. Adjusted code accordingly.
sql/sql_class.h:
Changed type of Key_part_spec::field_name and Key::name to LEX_STRING in
order to avoid extra strlen() calls in code responsible for semantic
analysis and statement execution (e.g. in future code responsible for
saving/restoring info about foreign keys).
sql/sql_lex.cc:
Moved null_lex_str from sql_yacc.yy to sql_lex.cc and added its
declaration to sql_lex.h to make it accessible in other SQL-layer
modules (e.g. sql_parse.cc).
sql/sql_lex.h:
Made null_lex_str accessible from outside of sql_lex.cc.
sql/sql_parse.cc:
Key_part_spec::field_name and Key::name are now LEX_STRING. Adjusted
code accordingly.
sql/sql_table.cc:
Adjusted code to accomodate change of type to LEX_STRING for
Key_part_spec::field_name and Key::name.
sql/sql_yacc.yy:
Now Key::name and Key_part_spec::field_name are LEX_STRINGs. Adjusted
grammar to be able properly initialize them. This should allow us to
save on some strlen() calls during later stages of statement execution.
storing and restoring information about foreign keys in the .FRM files and
properly displaying it in SHOW CREATE TABLE output and I_S tables.
The idea of this patch is to change type of Key_part_spec::field_name and
Key::name to LEX_STRING in order to avoid extra strlen() calls during
semantic analysis and statement execution, particularly, in code to be
implemented on the 2nd milestone of WL#148.
Note that since we are not using LEX_STRING everywhere yet (e.g. in
Create_field and KEY) and we want to limit scope of our changes we
have to do strlen() in places where we create Key and Key_part_spec
instances from objects using plain (char*) for strings. These calls
will go away during the process of further (char*) -> LEX_STRING
refactoring.
We have introduced these changes in 6.0 and backported them to 5.5
tree to make people aware of these changes as early as possible and
to simplify merges with mysql-fk and mysql-6.1-fk trees.
No test case is needed since this patch does not introduce any
user visible changes.
"have_profiling"
1) Renamed have_community_features server system variable to
have_profiling.
2) Removed eable-community-features configure option and
ENABLE_COMMUNITY_FEATURES macro.
3) Removed COMMUNITY_SERVER macro and replaced its usage by
ENABLED_PROFILING.
Only --enable-profiling is now needed to enable profiling.
It was the only existing "community feature", so there was
no need for both configure options.
Using --enable-community-features will give a warning message
since it no longer exists.
"have_profiling"
1) Renamed have_community_features server system variable to
have_profiling.
2) Removed eable-community-features configure option and
ENABLE_COMMUNITY_FEATURES macro.
3) Removed COMMUNITY_SERVER macro and replaced its usage by
ENABLED_PROFILING.
Only --enable-profiling is now needed to enable profiling.
It was the only existing "community feature", so there was
no need for both configure options.
Using --enable-community-features will give a warning message
since it no longer exists.
Backport from 6.0 to 5.1.
Only those sync points are included, which are used in debug_sync.test.
The Debug Sync Facility allows to place synchronization points
in the code:
open_tables(...)
DEBUG_SYNC(thd, "after_open_tables");
lock_tables(...)
When activated, a sync point can
- Send a signal and/or
- Wait for a signal
Nomenclature:
- signal: A value of a global variable that persists
until overwritten by a new signal. The global
variable can also be seen as a "signal post"
or "flag mast". Then the signal is what is
attached to the "signal post" or "flag mast".
- send a signal: Assign the value (the signal) to the global
variable ("set a flag") and broadcast a
global condition to wake those waiting for
a signal.
- wait for a signal: Loop over waiting for the global condition until
the global value matches the wait-for signal.
Please find more information in the top comment in debug_sync.cc
or in the worklog entry.
.bzrignore:
WL#4259 - Debug Sync Facility
Added the symbolic link libmysqld/debug_sync.cc.
CMakeLists.txt:
WL#4259 - Debug Sync Facility
Added definition for ENABLED_DEBUG_SYNC.
configure.in:
WL#4259 - Debug Sync Facility
Added definition for ENABLED_DEBUG_SYNC.
include/my_sys.h:
WL#4259 - Debug Sync Facility
Added definition for the DEBUG_SYNC_C macro.
libmysqld/CMakeLists.txt:
WL#4259 - Debug Sync Facility
Added sql/debug_sync.cc.
libmysqld/Makefile.am:
WL#4259 - Debug Sync Facility
Added sql/debug_sync.cc.
mysql-test/include/have_debug_sync.inc:
WL#4259 - Debug Sync Facility
New include file.
mysql-test/mysql-test-run.pl:
WL#4259 - Debug Sync Facility
Added option --debug_sync_timeout.
mysql-test/r/debug_sync.result:
WL#4259 - Debug Sync Facility
New test result.
mysql-test/r/have_debug_sync.require:
WL#4259 - Debug Sync Facility
New require file.
mysql-test/t/debug_sync.test:
WL#4259 - Debug Sync Facility
New test file.
mysys/my_static.c:
WL#4259 - Debug Sync Facility
Added definition for debug_sync_C_callback_ptr.
mysys/thr_lock.c:
WL#4259 - Debug Sync Facility
Added sync point "wait_for_lock".
sql/CMakeLists.txt:
WL#4259 - Debug Sync Facility
Added debug_sync.cc and debug_sync.h.
sql/Makefile.am:
WL#4259 - Debug Sync Facility
Added debug_sync.cc and debug_sync.h.
sql/debug_sync.cc:
WL#4259 - Debug Sync Facility
New source file.
sql/debug_sync.h:
WL#4259 - Debug Sync Facility
New header file.
sql/mysqld.cc:
WL#4259 - Debug Sync Facility
Added opt_debug_sync_timeout.
Added calls to debug_sync_init() and debug_sync_end().
Fixed a purecov comment (unrelated).
sql/set_var.cc:
WL#4259 - Debug Sync Facility
Added server variable "debug_sync".
sql/set_var.h:
WL#4259 - Debug Sync Facility
Added declaration for server variable "debug_sync".
sql/share/errmsg.txt:
WL#4259 - Debug Sync Facility
Added error messages ER_DEBUG_SYNC_TIMEOUT and ER_DEBUG_SYNC_HIT_LIMIT.
sql/sql_base.cc:
WL#4259 - Debug Sync Facility
Added sync points "after_flush_unlock" and "before_lock_tables_takes_lock".
sql/sql_class.cc:
WL#4259 - Debug Sync Facility
Added initialization for debug_sync_control to THD::THD.
Added calls to debug_sync_init_thread() and debug_sync_end_thread().
sql/sql_class.h:
WL#4259 - Debug Sync Facility
Added element debug_sync_control to THD.
storage/myisam/myisamchk.c:
Fixed a typo in an error message string (unrelated).
Backport from 6.0 to 5.1.
Only those sync points are included, which are used in debug_sync.test.
The Debug Sync Facility allows to place synchronization points
in the code:
open_tables(...)
DEBUG_SYNC(thd, "after_open_tables");
lock_tables(...)
When activated, a sync point can
- Send a signal and/or
- Wait for a signal
Nomenclature:
- signal: A value of a global variable that persists
until overwritten by a new signal. The global
variable can also be seen as a "signal post"
or "flag mast". Then the signal is what is
attached to the "signal post" or "flag mast".
- send a signal: Assign the value (the signal) to the global
variable ("set a flag") and broadcast a
global condition to wake those waiting for
a signal.
- wait for a signal: Loop over waiting for the global condition until
the global value matches the wait-for signal.
Please find more information in the top comment in debug_sync.cc
or in the worklog entry.
NOTE: Backporting the patch to next-mr.
WL#4828 Augment DBUG_ENTER/DBUG_EXIT to crash MySQL in different functions
-------
The assessment of the replication code in the presence of faults is extremely
import to increase reliability. In particular, one needs to know if servers
will either correctly recovery or print out appropriate error messages thus
avoiding unexpected problems in a production environment.
In order to accomplish this, the current patch refactories the debug macros
already provided in the source code and introduces three new macros that
allows to inject faults, specifically crashes, while entering or exiting a
function or method. For instance, to crash a server while returning from
the init_slave function (see module sql/slave.cc), one needs to do what
follows:
1 - Modify the source replacing DBUG_RETURN by DBUG_CRASH_RETURN;
DBUG_CRASH_RETURN(0);
2 - Use the debug variable to activate dbug instructions:
SET SESSION debug="+d,init_slave_crash_return";
The new macros are briefly described below:
DBUG_CRASH_ENTER (function) is equivalent to DBUG_ENTER which registers the
beginning of a function but in addition to it allows for crashing the server
while entering the function if the appropriate dbug instruction is activate.
In this case, the dbug instruction should be "+d,function_crash_enter".
DBUG_CRASH_RETURN (value) is equivalent to DBUG_RETURN which notifies the
end of a function but in addition to it allows for crashing the server
while returning from the function if the appropriate dbug instruction is
activate. In this case, the dbug instruction should be
"+d,function_crash_return". Note that "function" should be the same string
used by either the DBUG_ENTER or DBUG_CRASH_ENTER.
DBUG_CRASH_VOID_RETURN (value) is equivalent to DBUG_VOID_RETURN which
notifies the end of a function but in addition to it allows for crashing
the server while returning from the function if the appropriate dbug
instruction is activate. In this case, the dbug instruction should be
"+d,function_crash_return". Note that "function" should be the same string
used by either the DBUG_ENTER or DBUG_CRASH_ENTER.
To inject other faults, for instance, wrong return values, one should rely
on the macros already available. The current patch also removes a set of
macros that were either not being used or were redundant as other macros
could be used to provide the same feature. In the future, we also consider
dynamic instrumentation of the code.
BUG#45747 DBUG_CRASH_* is not setting the strict option
---------
When combining DBUG_CRASH_* with "--debug=d:t:i:A,file" the server crashes
due to a call to the abort function in the DBUG_CRASH_* macro althought the
appropriate keyword has not been set.
NOTE: Backporting the patch to next-mr.
WL#4828 Augment DBUG_ENTER/DBUG_EXIT to crash MySQL in different functions
-------
The assessment of the replication code in the presence of faults is extremely
import to increase reliability. In particular, one needs to know if servers
will either correctly recovery or print out appropriate error messages thus
avoiding unexpected problems in a production environment.
In order to accomplish this, the current patch refactories the debug macros
already provided in the source code and introduces three new macros that
allows to inject faults, specifically crashes, while entering or exiting a
function or method. For instance, to crash a server while returning from
the init_slave function (see module sql/slave.cc), one needs to do what
follows:
1 - Modify the source replacing DBUG_RETURN by DBUG_CRASH_RETURN;
DBUG_CRASH_RETURN(0);
2 - Use the debug variable to activate dbug instructions:
SET SESSION debug="+d,init_slave_crash_return";
The new macros are briefly described below:
DBUG_CRASH_ENTER (function) is equivalent to DBUG_ENTER which registers the
beginning of a function but in addition to it allows for crashing the server
while entering the function if the appropriate dbug instruction is activate.
In this case, the dbug instruction should be "+d,function_crash_enter".
DBUG_CRASH_RETURN (value) is equivalent to DBUG_RETURN which notifies the
end of a function but in addition to it allows for crashing the server
while returning from the function if the appropriate dbug instruction is
activate. In this case, the dbug instruction should be
"+d,function_crash_return". Note that "function" should be the same string
used by either the DBUG_ENTER or DBUG_CRASH_ENTER.
DBUG_CRASH_VOID_RETURN (value) is equivalent to DBUG_VOID_RETURN which
notifies the end of a function but in addition to it allows for crashing
the server while returning from the function if the appropriate dbug
instruction is activate. In this case, the dbug instruction should be
"+d,function_crash_return". Note that "function" should be the same string
used by either the DBUG_ENTER or DBUG_CRASH_ENTER.
To inject other faults, for instance, wrong return values, one should rely
on the macros already available. The current patch also removes a set of
macros that were either not being used or were redundant as other macros
could be used to provide the same feature. In the future, we also consider
dynamic instrumentation of the code.
BUG#45747 DBUG_CRASH_* is not setting the strict option
---------
When combining DBUG_CRASH_* with "--debug=d:t:i:A,file" the server crashes
due to a call to the abort function in the DBUG_CRASH_* macro althought the
appropriate keyword has not been set.
trigger, merge table
The problem with break statements is that they have very
local effects. Hence a break statement within the inner loop
of a nested-loops join caused execution to proceed to the
next table even though a serious error occurred. The problem
was fixed by breaking out the inner loop into its own
method. The change empowers all errors to terminate the
execution.
The errors that will now halt multi-DELETE execution
altogether are
- triggers returning errors
- handler errors
- server being killed
mysql-test/r/delete.result:
Bug#46958: Test result.
mysql-test/t/delete.test:
Bug#46958: Test case.
sql/sql_class.h:
Bug#46958: New method declaration.
sql/sql_delete.cc:
Bug#46958: New method implementation.
trigger, merge table
The problem with break statements is that they have very
local effects. Hence a break statement within the inner loop
of a nested-loops join caused execution to proceed to the
next table even though a serious error occurred. The problem
was fixed by breaking out the inner loop into its own
method. The change empowers all errors to terminate the
execution.
The errors that will now halt multi-DELETE execution
altogether are
- triggers returning errors
- handler errors
- server being killed
