Three-way deadlock:
T1: SHOW GLOBAL STATUS
-> acquire LOCK_status
T2: STOP SLAVE
-> acquire LOCK_active_mi
-> terminate_slave_thread()
-> -> cond_timedwait for handle_slave_sql to stop
T3: sql slave thread (same applies to io thread)
-> handle_slave_sql(), when exiting
-> -> THD::add_status_to_global()
-> -> -> wait for LOCK_status...
T1: SHOW GLOBAL STATUS
-> for "Slave_heartbeat_period" status variable
-> -> show_heartbeat_period()
-> -> -> wait for LOCK_active_mi
cherry-pick from 5.6:
commit fc8b395898f40387b3468122bd0dae31e29a6fde
Author: Venkatesh Duggirala <venkatesh.duggirala@oracle.com>
Date: Wed Jun 12 21:41:05 2013 +0530
BUG#16904035-SHOW STATUS - EXCESSIVE LOCKING ON LOCK_ACTIVE_MI AND
ACTIVE_MI->RLI->DATA_LOCK
Problem: Excessive locking on lock_active_mi and rli->data_lock
while executing any `show status like 'X'` command.
Analysis: SHOW_FUNCs for Slave_running, Slave_retried_transactions,
Slave_heartbeat_period, Slave_received_heartbeats,
Slave_last_heartbeat are acquiring lock_active_mi and rli->data_lock
to show their variable value. It is ok to show stale data while showing
the status variables i.e., even if they miss one update, it will
not cause any great trouble.
Fix: Remove the locks from the above mentioned SHOW_FUNC functions.
Add a test case
* no --encryption-algorithm option anymore
* encrypt/decrypt methods in the encryption plugin
* ecnrypt/decrypt methods in the encryption_km service
* file_km plugin has --file-key-management-encryption-algorithm
* debug_km always uses aes_cbc
* example_km changes between aes_cbc and aes_ecb for different key versions
XID cache is now based on lock-free hash.
Also fixed lf_hash_destroy() to call alloc destructor.
Note that previous implementation had race condition when thread was accessing
XA owned by different thread. This new implementation doesn't fix it either.
Merge from Percona Server enforced use of a specific storage engine
authored by Stewart Smith.
Modified to be session variable and modifiable only by SUPER. Use
similar implementation as default_storage_engine.
MASTER_GTID_WAIT function needs some status to evaluate its use.
master_gtid_wait_count indicates how many times the function is called.
master_gtid_wait_time indicates how much time in microseconds occurred
waiting (or timing out)
master_gtid_timeouts indicates how many time times this function timed
out rather than all successful gtids events being available.
Show total execution time (r_total_time_ms) for various parts of the
query:
1. time spent in SELECTs
2. time spent reading rows from storage engines
#2 currently gets the data from P_S.
log-tc-size is 24K by default. Page size is 64K on PPC64. But log-tc-
size
must be at least 3 x page size. This is enforced by TC_LOG_MMAP::open()
with a comment: to guarantee non-empty pool.
This all makes server not startable in default configuration on PPC64.
Autosize log-tc-size, so that it's min value= page size * 3, default
value= page size * 6, block size= page size.
Conflicts:
mysql-test/suite/sys_vars/inc/sysvars_server.inc
mysql-test/suite/sys_vars/r/sysvars_server_notembedded.result
mysql-test/t/mysqld--help.test
sql/mysqld.cc
sql/sys_vars.cc
Adjust the configuration options, as discussed on the
maria-developers@ mailing list.
The option to hint a transaction to not be replicated in parallel is
now called @@skip_parallel_replication, consistent with
@@skip_replication.
And the --slave-parallel-mode is now simplified to have just one of
the following values:
none
minimal
conservative
optimistic
aggressive
This reflects successively harder efforts to find opportunities to run
things in parallel on the slave. It allows to extend the server with
more automatic heuristics in the future without having to introduce a
new configuration option for each and every one.
In versions 5.5 and 5.6 the MySQL version is not logged until
server is started and ready to accept connections. Exiting
server before this point will not have server version information
in the log. But in 5.7 code, we log a server version information
just after we prepare server_version string and logging is initialized.
For 5.5 and 5.6 code also adding this code to print server version
information.
Test results:
================
5.5
-----
Server version will be logged as below on server startup:
141218 8:45:48 [Note] /home/praveen/WorkDir/mysql_local/bug20052694/mysql/sql/mysqld (mysqld 5.5.42-debug-log) starting as process 19697 ...
5.6
----
Server version will be logged as below on server startup:
2014-12-18 09:08:43 0 [Note] /home/praveen/WorkDir/mysql_local/bug20052694/mysql-5.6/sql/mysqld (mysqld 5.6.23-debug-log) starting as process 18474 ...
* reset current_thd in THD::~THD, otherwise my_malloc_size_cb_func()
might access THD after it was destroyed.
* remove now redundant set_current_thd(0) calls that follow delete thd.
Stage "Filling schema table" is now properly shown in 'show processlist'
mysys/mf_keycache.c:
Simple cleanup with more comments
sql/lock.cc:
Return to original stage after mysql_lock_tables
Made 'Table lock' as a true stage
sql/sql_show.cc:
Restore original stage after get_schema_tables_result
better fix that doesn't make debug-dbug variable to disappear
from mysqld --help output (this fact is used by have_debug.inc)
and shows correctly what dbug value was set on the command line.
log-tc-size is 24K by default. Page size is 64K on PPC64. But log-tc-size
must be at least 3 x page size. This is enforced by TC_LOG_MMAP::open()
with a comment: to guarantee non-empty pool.
This all makes server not startable in default configuration on PPC64.
Autosize log-tc-size, so that it's min value= page size * 3, default
value= page size * 6, block size= page size.
Implement --semi-sync-master-wait-point=AFTER_SYNC|AFTER_COMMIT.
When AFTER_SYNC, the semi-sync wait will be done earlier, before the storage
engine commit rather than after. This means that a transaction will not be
visible on the master until at least one slave has received it.
Make the binlog dump threads not need to take LOCK_log while sending
binlog events to slave. Instead, a new LOCK_binlog_end_pos is used
just to coordinate tracking the current end-of-log.
This is a pre-requisite for MDEV-162, "Enhanced semisync
replication". It should also help reduce the contention on LOCK_log on
a busy master.
Also does some much-needed refactoring/cleanup of the related code in
the binlog dump thread.
Implement a new mode for parallel replication. In this mode, all transactions
are optimistically attempted applied in parallel. In case of conflicts, the
offending transaction is rolled back and retried later non-parallel.
This is an early-release patch to facilitate testing, more changes to user
interface / options will be expected. The new mode is not enabled by default.
