Large transactions and statements may corrupt the binary log if the size of the
cache, which is set by the max_binlog_cache_size, is not enough to store the
the changes.
In a nutshell, to fix the bug, we save the position of the next character in the
cache before starting processing a statement. If there is a problem, we simply
restore the position thus removing any effect of the statement from the cache.
Unfortunately, to avoid corrupting the binary log, we may end up loosing changes
on non-transactional tables if they do not fit in the cache. In such cases, we
store an Incident_log_event in order to stop the slave and alert users that some
changes were not logged.
Precisely, for every non-transactional changes that do not fit into the cache,
we do the following:
a) the statement is *not* logged
b) an incident event is logged after committing/rolling back the transaction,
if any. Note that if a failure happens before writing the incident event to
the binary log, the slave will not stop and the master will not have reported
any error.
c) its respective statement gives an error
For transactional changes that do not fit into the cache, we do the following:
a) the statement is *not* logged
b) its respective statement gives an error
To work properly, this patch requires two additional things. Firstly, callers to
MYSQL_BIN_LOG::write and THD::binlog_query must handle any error returned and
take the appropriate actions such as undoing the effects of a statement. We
already changed some calls in the sql_insert.cc, sql_update.cc and sql_insert.cc
modules but the remaining calls spread all over the code should be handled in
BUG#37148. Secondly, statements must be either classified as DDL or DML because
DDLs that do not get into the cache must generate an incident event since they
cannot be rolled back.
Item_func_spatial_collection::val_str
When the concatenation function for geometry data collections
reads the binary data it was not rigorous in checking that there
is data available, leading to invalid reads and crashes.
Fixed by making checking stricter.
with gcc 4.3.2
Compiling MySQL with gcc 4.3.2 and later produces a number of
warnings, many of which are new with the recent compiler
versions.
This bug will be resolved in more than one patch to limit the
size of changesets. This is the second patch, fixing more
of the warnings.
The assertion in String::copy was added in order to avoid
valgrind errors when the destination was the same as the source.
Eased restriction to allow for the case when str == NULL.
Early patch submitted for discussion.
It is possible for more than one thread to enter the condition
in query_cache_insert(), but the condition predicate is to
signal one thread each time the cache status changes between
the following states: {NO_FLUSH_IN_PROGRESS,FLUSH_IN_PROGRESS,
TABLE_FLUSH_IN_PROGRESS}
Consider three threads THD1, THD2, THD3
THD2: select ... => Got a writer in ::store_query
THD3: select ... => Got a writer in ::store_query
THD1: flush tables => qc status= FLUSH_IN_PROGRESS;
new writers are blocked.
THD2: select ... => Still got a writer and enters cond in
query_cache_insert
THD3: select ... => Still got a writer and enters cond in
query_cache_insert
THD1: flush tables => finished and signal status change.
THD2: select ... => Wakes up and completes the insert.
THD3: select ... => Happily waiting for better times. Why hurry?
This patch is a refactoring of this lock system. It introduces four new methods:
Query_cache::try_lock()
Query_cache::lock()
Query_cache::lock_and_suspend()
Query_cache::unlock()
This change also deprecates wait_while_table_flush_is_in_progress(). All threads are
queued and put on a conditional wait. On each unlock the queue is signalled. This resolve
the issues with left over threads. To assure that no threads are spending unnecessary
time waiting a signal broadcast is issued every time a lock is taken before a full
cache flush.
crashes server!
The problem affects the scenario when index merge is followed by a filesort
and the sort buffer is not big enough for all the sort keys.
In this case the filesort function will read the data to the end through the
index merge quick access method (and thus closing the cursor etc),
but will leave the pointer to the quick select method in place.
It will then create a temporary file to hold the results of the filesort and
will add it as a sort output file (in sort.io_cache).
Note that filesort will copy the original 'sort' structure in an automatic
variable and restore it after it's done.
As a result at exiting filesort() we have a sort.io_cache filled in and
nothing else (as a result of close of the cursors at end of reading data
through index merge).
Now create_sort_index() will note that there is a select and will clean it up
(as it's been used already by filesort() reading the data in). While doing that
a special case in the index merge destructor will clean up the sort.io_cache,
assuming it's an output of the index merge method and is not needed anymore.
As a result the code that tries to read the data back from the filesort output
will get no data in both memory and disk and will crash.
Fixed similarly to how filesort() does it : by copying the sort.io_cache structure
to a local variable, removing the pointer to the io_cache (so that it's not freed
by QUICK_INDEX_MERGE_SELECT::~QUICK_INDEX_MERGE_SELECT) and restoring the original
structure (together with the valid pointer) after the cleanup is done.
This is a safe thing to do because all the structures are already cleaned up by
hitting the end of the index merge's read method (QUICK_INDEX_MERGE_SELECT::get_next())
and the cleanup code being written in a way that tolerates repeating cleanups.
The SQL-mode PAD_CHAR_TO_FULL_LENGTH could prevent a DROP USER
statement from privileges associated with the user being dropped.
What ocurred was that reading from the User and Host fields of
the tables tables_priv or columns_priv would yield values padded
with spaces, causing a failure to match a specified user or host
('user' != 'user ');
The solution is to disregard the PAD_CHAR_TO_FULL_LENGTH mode
when iterating over and matching values in the privileges tables
for a DROP USER statement.
statements missed from general log
A refinement of the test in the previous patch to avoid
using sleep as a means to ensure that timestamps are
added to the log entries.
WHERE and GROUP BY clause
Loose index scan may use range conditions on the argument of
the MIN/MAX aggregate functions to find the beginning/end of
the interval that satisfies the range conditions in a single go.
These range conditions may have open or closed minimum/maximum
values. When the comparison returns 0 (equal) the code should
check the type of the min/max values of the current interval
and accept or reject the row based on whether the limit is
open or not.
There was a wrong composite condition on checking this and it was
not working in all cases.
Fixed by simplifying the conditions and reversing the logic.
While reading a binary log that is being used by a master or was not properly
closed, most likely due to a crash, the following warning message is being
printed out: "Warning: this binlog was not closed properly. Most probably mysqld
crashed writing it.". This was scaring our users as the message was not taking
into account the possibility of the file is being just used by the master.
To avoid unnecessarily scaring our users, we replace the original message by the
following one: Warning: "this binlog is either is use or was not closed properly.".
with gcc 4.3.2
Compiling MySQL with gcc 4.3.2 and later produces a number of
warnings, many of which are new with the recent compiler
versions.
This bug will be resolved in more than one patch to limit the
size of changesets. This is the second patch, fixing more
of the warnings.
Range analysis did not request sorted output from the storage engine,
which cause partitioned handlers to process one partition at a time
while reading key prefixes in ascending order, causing values to be
missed. Fixed by always requesting sorted order during range analysis.
This fix is introduced in 6.0 by the fix for bug no 41136.
with gcc 4.3.2
Compiling MySQL with gcc 4.3.2 and later produces a number of
warnings, many of which are new with the recent compiler
versions.
This bug will be resolved in more than one patch to limit the
size of changesets. This is the first patch, fixing a number
of the warnings, predominantly "suggest using parentheses
around && in ||", and empty for and while bodies.
with gcc 4.3.2
Compiling MySQL with gcc 4.3.2 and later produces a number of
warnings, many of which are new with the recent compiler
versions.
This bug will be resolved in more than one patch to limit the
size of changesets. This is the first patch, fixing a number
of the warnings, predominantly "suggest using parentheses
around && in ||", and empty for and while bodies.
variable. The problem was that THD::connect_utime could be
used without being initialized when the main thread is used
to handle connections (--thread-handling=no-threads).
mysqlbinlog --database parameter was being ignored when processing
row events. As such no event filtering would take place.
This patch addresses this by deploying a call to shall_skip_database
when table_map_events are handled (as these contain also the name of
the database). All other rows events referencing the table id for the
filtered map event, will also be skipped.
uninitialized variable used as subscript
Grouping select from a "constant" InnoDB table (a table
of a single row) joined with other tables caused a crash.
The problem is that when a optimization of read-only transactions
(bypass 2-phase commit) was implemented, it removed the code that
reseted the XID once a transaction wasn't active anymore:
sql/sql_parse.cc:
- bzero(&thd->transaction.stmt, sizeof(thd->transaction.stmt));
- if (!thd->active_transaction())
- thd->transaction.xid_state.xid.null();
+ thd->transaction.stmt.reset();
This mostly worked fine as the transaction commit and rollback
functions (in handler.cc) reset the XID once the transaction is
ended. But those functions wouldn't reset the XID in case of
a empty transaction, leading to a assertion when a new starting
a new XA transaction.
The solution is to ensure that the XID state is reset when empty
transactions are ended (by either commit or rollback). This is
achieved by reorganizing the code so that the transaction cleanup
routine is invoked whenever a transaction is ended.
Holding on to the temporary inno hash index latch is an optimization in
many cases, but a pessimization in some others.
Release temporary latches for those corner cases we (or rather, or customers,
thanks!) have identified, that is, when we are about to do something that
might take a really long time, like REPAIR or filesort.
The crash happens because of uninitialized
lex->ssl_cipher, lex->x509_subject, lex->x509_issuer variables.
The fix is to add initialization of these variables for
stored procedures&functions.
The server was not cleaning the last IO error and error number when
resetting slave.
This patch addresses this issue by backporting into 5.1 part of the
patch in BUG 34654. A fix for this issue had already been pushed into
6.0 as part of the aforementioned bug, however the patch also included
some refactoring. The fix for 5.1 does not take into account the
refactoring part.
the problem is in the TIMESTAMP(14) fields of the access-control tables.
The TIMESTAMP(14) syntax is marked as DEPRECATED since 5.2.
Fixed by just changed the check to 6.0 as it's done in the 5.1 branch.
per-file comments:
sql/sql_parse.cc
Bug#44394 Assertion Failure
now it's deprecated since 6.0
always rollsback.
There is failure on pushbuild machines which are using old compilers complaining about
ULLONG_MAX declaration. Changing this to ULONGLONG_MAX to solve the problem.
or database name in logs
Problem was that InnoDB used filenam_to_tablename,
which do not handle partitions (due to the '#' in
the filename).
Solution is to add a new function for explaining
what the filename means: explain_filename.
It expands the database, table, partition and subpartition
parts and uses errmsg.txt for localization.
It also converts from my_charset_filename to system_charset_info
(i.e. human readable form for non ascii characters).
http://lists.mysql.com/commits/70370
2773 Mattias Jonsson 2009-03-25
It has three different output styles.
NOTE: This is the server side ONLY part (introducing the explain_filename
function). There will be a patch for InnoDB using this function to solve
the bug.
