first, and we do not not care whether client has received all data.
This is a TCP optimization to avoid TIME_WAIT in TCP connection teardown.
This patch would abort connection on timeout, which usually happens when
client reads a large result set, at slower pace then the server can
write.
The patch also cleans up socket timeout handling, so that Windows
is consistent with another platforms (using nonblocking socket IO
+ waiting in poll/select on single socket, rather than setsockopt).
This makes identifying timeouts easier.
Also removed the superficial shutdown() before closesocket() in a few
places where it was used, because it was never needed , and
reportedly breaks SO_LINGER on Windows.
LOCK_thd_data was used to protect both THD data and
ensure that the THD is not deleted while it was in use
This patch moves the THD delete protection to LOCK_thd_kill,
which already protects the THD for kill.
The benefits are:
- More well defined what LOCK_thd_data protects
- LOCK_thd_data usage is now much simpler and easier to verify
- Less chance of deadlocks in SHOW PROCESS LIST as there is less
chance of interactions between mutexes
- Remove not needed LOCK_thread_count from
thd_get_error_context_description()
- Fewer mutex taken for thd->awake()
Other things:
- Don't take mysys->var mutex in show processlist to check if thread
is kill marked
- thd->awake() now automatically takes the LOCK_thd_kill mutex
(Simplifies code)
- Apc uses LOCK_thd_kill instead of LOCK_thd_data
This is about adding more options to force slave retries
Two new variables has been added:
slave_transaction_retry_errors
- Tells the slave thread to retry transaction for replication when a
query event returns an error from the provided list. Deadlock and
elapsed lock wait timeout errors are automatically added to this list
slave-transaction-retry-interval
- Interval of the slave SQL thread will retry a transaction
in case it failed with a deadlock or elapsed lock wait
timeout or listed in slave_transaction_retry_errors
Other changes:
- Simplifed code for slave_skip_errors (to be aligned with
slave_transaction_retry_errors)
- Renamed print_slave_skip_errors() to make_slave_skip_errors_printable()
- Remove printing error from init_slave_skip_errors as my_bitmap_init()
will do that if needed.
- Generalize has_temporary_error()
- mysql_install_db now prints position to error file, if log-error is used
- Warning about compatibility now mentions MySQL 5.6 and 5.7
- Give warning if --show_compatibility_56 is used
ROOT
DESCRIPTION
===========
If the .pid file is created at a world-writable location,
it can be compromised by replacing the server's pid with
another running server's (or some other non-mysql process)
PID causing abnormal behaviour.
ANALYSIS
========
In such a case, user should be warned that .pid file is
being created at a world-writable location.
FIX
===
A new function is_file_or_dir_world_writable() is defined
and it is called in create_pid_file() before .pid file
creation. If the location is world-writable, a relevant
warning is thrown.
NOTE
====
1. PID file is always created with permission bit 0664, so
for outside world its read-only.
2. Ignoring the case when permission is denied to get the
dir stats since the .pid file creation would fail anyway in
such a case.
This was done to get more information about where time is spent.
Now we can get proper timing for time spent in commit, rollback,
binlog write etc.
Following stages was added:
- Commit
- Commit_implicit
- Rollback
- Rollback implicit
- Binlog write
- Init for update
- This is used instead of "Init" for insert, update and delete.
- Staring cleanup
Following stages where changed:
- "Unlocking tables" stage reset stage to previous stage at end
- "binlog write" stage resets stage to previous stage at end
- "end" -> "end of update loop"
- "cleaning up" -> "Reset for next command"
- Added stage_searching_rows_for_update when searching for rows
to be deleted.
Other things:
- Renamed all stages to start with big letter (before there was no
consitency)
- Increased performance_schema_max_stage_classes from 150 to 160.
- Most of the test changes in performance schema comes from renaming of
stages.
- Removed duplicate output of variables and inital state in a lot of
performance schema tests.
This was done to make it easier to change a default value for a
performance variable without affecting all tests.
- Added start_server_variables.test to check configuration
- Removed some duplicate "closing tables" stages
- Updated position for "stage_init_update" and "stage_updating" for
delete, insert and update to be just before update loop (for more
exact timing).
- Don't set "Checking permissions" twice in a row.
- Remove stage_end stage from creating views (not done for create table
either).
- Updated default performance history size from 10 to 20 because of new
stages
- Ensure that ps_enabled is correct (to be used in a later patch)
The background is that one user had a lot of views and using some complex
queries on information schema temporary memory of more than 2G was used.
- Added new element 'total_alloc' to MEM_ROOT for easier debugging.
- Added MAX_MEMORY_USED to information_schema.processlist.
- Added new status variable "Memory_used_initial" that shows how much MariaDB
uses at startup. This gives the base value for "Memory_used".
- Reuse memory continuously for information schema queries instead of
only freeing memory at query end.
Other things
- Removed some not needed set_notnull() calls for not null columns.
'version' variables.
The warnings occur on Windows build, yet they are also are valid
on 32bit Unix.
Fix is to consistently use 64bit integer on all platforms.
- Fix win64 pointer truncation warnings
(usually coming from misusing 0x%lx and long cast in DBUG)
- Also fix printf-format warnings
Make the above mentioned warnings fatal.
- fix pthread_join on Windows to set return value.
- Added missing delete thd in bootstrap()
- Delete wrong 'delete thd' in start_wsrep_THD()
- Added missing 'delete thd' in case of SCHEDULER_ONE_THREAD_PER_CONNECTION
- Delete wrong dec_thread_running() in destroy_thd() as it caused thread_running
to be wrong.
- Moved reset_killed() to a normal function to make it easier to debug
- Added check of mutex in wsrep_aborting_thd... functions
full server recovery is performed .
We start "mysqld" with --bootstrap
and pass bootstrap script consisting of several FLUSH TABLES FOR export/
UNLOCK TABLES
