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Author SHA1 Message Date
Alfranio Correia
3f5a9c7ea0 BUG#57275 binlog_cache_size affects trx- and stmt-cache and gets twice the expected memory
After the WL#2687, the binlog_cache_size and max_binlog_cache_size affect both the
stmt-cache and the trx-cache. This means that the resource used is twice the amount
expected/defined by the user.
      
The binlog_cache_use is incremented when the stmt-cache or the trx-cache is used
and binlog_cache_disk_use is incremented when the disk space from the stmt-cache or the
trx-cache is used. This behavior does not allow to distinguish which cache may be harming
performance due to the extra disk accesses and needs to have its in-memory cache
increased.
      
To fix the problem, we introduced two new options and status variables related to the
stmt-cache:
      
  Options:
      
    . binlog_stmt_cache_size
    . max_binlog_stmt_cache_size
      
    Status Variables:
      
    . binlog_stmt_cache_use
    . binlog_stmt_cache_disk_use

So there are

  . binlog_cache_size that defines the size of the transactional cache for
  updates to transactional engines for the binary log.

  . binlog_stmt_cache_size that defines the size of the statement cache for
  updates to non-transactional engines for the binary log.

  . max_binlog_cache_size that sets the total size of the transactional
  cache.

  . max_binlog_stmt_cache_size that sets the total size of the statement
  cache.

  . binlog_cache_use that identifies the number of transactions that used the
  temporary transactional binary log cache.

  . binlog_cache_disk_use that identifies the number of transactions that used
  the temporary transactional binary log cache but that exceeded the value of
  binlog_cache_size.

  . binlog_stmt_cache_use that identifies the number of statements that used the
  temporary non-transactional binary log cache.

  . binlog_stmt_cache_disk_use that identifies the number of statements that used
  the temporary non-transactional binary log cache but that exceeded the value of
  binlog_stmt_cache_size.

include/my_sys.h:
  Updated message on disk_writes' usage.
mysql-test/extra/binlog_tests/binlog_cache_stat.test:
  Updated the test case and added code to check the new status variables
  binlog_stmt_cache_use and binlog_stmt_cache_disk_use.
mysql-test/extra/rpl_tests/rpl_binlog_max_cache_size.test:
  Updated the test case to use the new system variables max_binlog_stmt_cache_size and binlog_stmt_cache_size.
mysql-test/r/mysqld--help-notwin.result:
  Updated the result file.
mysql-test/suite/binlog/r/binlog_mixed_cache_stat.result:
  Updated the result file.
mysql-test/suite/binlog/r/binlog_row_cache_stat.result:
  Updated the result file.
mysql-test/suite/binlog/r/binlog_stm_cache_stat.result:
  Updated the result file.
mysql-test/suite/rpl/r/rpl_mixed_binlog_max_cache_size.result:
  Update the result file.
mysql-test/suite/rpl/r/rpl_row_binlog_max_cache_size.result:
  Update the result file.
mysql-test/suite/rpl/r/rpl_stm_binlog_max_cache_size.result:
  Updated the result file.
mysql-test/suite/sys_vars/inc/binlog_stmt_cache_size_basic.inc:
  Added a test case to check the binlog_stmt_cache_size.
mysql-test/suite/sys_vars/r/binlog_stmt_cache_size_basic_32.result:
  Updated the result file.
mysql-test/suite/sys_vars/r/binlog_stmt_cache_size_basic_64.result:
  Updated the result file.
mysql-test/suite/sys_vars/r/max_binlog_stmt_cache_size_basic.result:
  Updated the result file.
mysql-test/suite/sys_vars/t/binlog_stmt_cache_size_basic_32.test:
  Added a test case to check the binlog_stmt_cache_size.
mysql-test/suite/sys_vars/t/binlog_stmt_cache_size_basic_64.test:
  Added a test case to check the binlog_stmt_cache_size.
mysql-test/suite/sys_vars/t/max_binlog_cache_size_func-master.opt:
  Removed because there is no test case max_binlog_cache_size_func.
mysql-test/suite/sys_vars/t/max_binlog_stmt_cache_size_basic.test:
  Added a test case to check the system variable max_binlog_stmt_cache_size.
sql/log.cc:
  There two main changes in here:
  
    . Changed the set_write_error() as an error message is set according
    to the type of the cache.
  
    . Created the function set_binlog_cache_info where references to the
    appropriate status and system variables are set and the server can
    smoothly compute statistics and set the maximum size for each cache.
sql/log.h:
  Changed the signature of the function in order to identify the error message
  to be printed out as there is a different error code for each type of cache.
sql/mysqld.cc:
  Added new status variables binlog_stmt_cache_use and binlog_stmt_cache_disk_use.
sql/mysqld.h:
  Added new system variables max_binlog_stmt_cache_size and binlog_stmt_cache_size.
sql/share/errmsg-utf8.txt:
  Added new error message related to the statement cache.
sql/sys_vars.cc:
  Added new system variables max_binlog_stmt_cache_size and binlog_stmt_cache_size.
2010-11-05 17:42:37 +00:00
Alfranio Correia
2d84c1553c BUG#56343 binlog_cache_use status is bigger than expected
The binlog_cache_use is incremented twice when changes to a transactional table
are committed, i.e. TC_LOG_BINLOG::log_xid calls is called. The problem happens
because log_xid calls both binlog_flush_stmt_cache and binlog_flush_trx_cache
without checking if such caches are empty thus unintentionally increasing the
binlog_cache_use value twice.

Although not explicitly mentioned in the bug, the binlog_cache_disk_use presents
the same problem.

The binlog_cache_use and binlog_cache_disk_use are status variables that are
incremented when transactional (i.e. trx-cache) or non-transactional (i.e.
stmt-cache) changes are committed. They are used to compute the ratio between
the use of disk and memory while gathering updates for a transaction.

The problem reported is fixed by avoiding incrementing the binlog_cache_use
and binlog_cache_disk_use if a cache is empty. We also have decided to increment
both variables when a cache is truncated as the cache is used although its
content is discarded and is not written to the binary log.

In this patch, we take the opportunity to re-organize the code around the
function binlog_flush_trx_cache and binlog_flush_stmt_cache.

mysql-test/extra/binlog_tests/binlog_cache_stat.test:
  Updated the test case with comments and additional tests to check both
  transactional and non-transactional changes and what happens when a 
  is transaction either committed or aborted.
mysql-test/suite/binlog/r/binlog_innodb.result:
  Updated the result file.
mysql-test/suite/binlog/r/binlog_mixed_cache_stat.result:
  Updated the result file.
mysql-test/suite/binlog/r/binlog_row_cache_stat.result:
  Updated the result file.
mysql-test/suite/binlog/r/binlog_stm_cache_stat.result:
  Updated the result file.
mysql-test/suite/binlog/t/binlog_mixed_cache_stat.test:
  Updated the test case with a new source file.
mysql-test/suite/binlog/t/binlog_row_cache_stat.test:
  Updated the test case with a new source file.
mysql-test/suite/binlog/t/binlog_stm_cache_stat.test:
  Updated the test case with a new source file.
sql/log.cc:
  There are four changes in here:
  
    . Computed statistics on binlog_cache_use and binlog_cache_disk_use while
    resting the cache.
  
    . Refactored the code so binlog_flush_cache handles both the trx-cache and
    stmt-cache.
  
    . There are functions that encapsulate the calls to binlog_flush_cache and
    make easier to read the code.
  
    . binlog_commit_flush_stmt_cache is now taking into account the result:
    success or error.
sql/log_event.h:
  Guaranteed Xid_log_event is always classified as a transactional event.
2010-11-05 13:58:05 +00:00
Alfranio Correia
8504580ced BUG#56343 binlog_cache_use status is bigger than expected
The binlog_cache_use is incremented twice when changes to a transactional table
are committed, i.e. TC_LOG_BINLOG::log_xid calls is called. The problem happens
because log_xid calls both binlog_flush_stmt_cache and binlog_flush_trx_cache
without checking if such caches are empty thus unintentionally increasing the
binlog_cache_use value twice.

To fix the problem we avoided incrementing the binlog_cache_use if the cache is
empty. We also decided to increment binlog_cache_use when the cache is truncated
as the cache is used although its content is discarded and is not written to the
binary log.

Note that binlog_cache_use is incremented for both types of cache, transactional
and non-transactional and that the behavior presented in this patch also applies
to the binlog_cache_disk_use.

Finally, we re-organized the code around the functions binlog_flush_trx_cache and
binlog_flush_stmt_cache.

mysql-test/extra/binlog_tests/binlog_cache_stat.test:
  Updated the test case with comments and additional tests to check both
  transactional and non-transactional changes and what happens when a 
  is transaction either committed or aborted.
mysql-test/suite/binlog/r/binlog_innodb.result:
  Updated the result file.
mysql-test/suite/binlog/r/binlog_mixed_cache_stat.result:
  Updated the result file.
mysql-test/suite/binlog/r/binlog_row_cache_stat.result:
  Updated the result file.
mysql-test/suite/binlog/r/binlog_stm_cache_stat.result:
  Updated the result file.
mysql-test/suite/binlog/t/binlog_mixed_cache_stat.test:
  Updated the test case with a new source file.
mysql-test/suite/binlog/t/binlog_row_cache_stat.test:
  Updated the test case with a new source file.
mysql-test/suite/binlog/t/binlog_stm_cache_stat.test:
  Updated the test case with a new source file.
sql/log_event.cc:
  Introduced debug information to check if Query_log_event("BEGIN"),
  Query_log_event("COMMIT") and Query_log_event("ROLLBACK").
sql/log_event.h:
  Guaranteed Xid_log_event is always classified as a transactional event.
2010-10-06 09:34:49 +01:00