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bk commit into 5.2 tree (cbell:1.2610) BUG#31383
From: <cbell(at)mysql.com>
Date: Wed Oct 31 2007 - 17:43:59 EDT
ChangeSet@1.2610, 2007-10-31 17:43:16-04:00, cbell@mysql_cab_desk. +13 -0 BUG#31383 : Consistent Snapshot driver not consistent This patch changes the default driver to use a separate thread to open and lock tables. The default driver opens tables on the prelock() call from the kernel. The snapshot driver initiates the CS read on the lock() call from the kernel and opens tables in the first call to get_data() after the lock is taken. This is due to the fact that the default driver's validity point is at open_and_lock_tables() while the snapshot driver's validity point is at the start of the transaction. mysql-test/r/backup_snapshot.result@1.3, 2007-10-31 17:43:03-04:00, cbell@mysql_cab_desk. +75 -10 BUG#31383 : Consistent Snapshot driver not consistent New result file. mysql-test/t/backup_snapshot.test@1.3, 2007-10-31 17:43:04-04:00, cbell@mysql_cab_desk. +110 -9 BUG#31383 : Consistent Snapshot driver not consistent Test modified to use the get_lock, release_lock functions to stop the CS driver in progress allowing simultaneous inserts from the second connection. This patch makes this test accurately test the CS driver. sql/backup/CMakeLists.txt@1.2, 2007-10-31 17:43:05-04:00, cbell@mysql_cab_desk. +4 -1 BUG#31383 : Consistent Snapshot driver not consistent Added the new be_thread source file and dependency for backup. sql/backup/Makefile.am@1.10, 2007-10-31 17:43:06-04:00, cbell@mysql_cab_desk. +4 -2 BUG#31383 : Consistent Snapshot driver not consistent Added the new be_thread source file and dependency for backup. sql/backup/be_default.cc@1.9, 2007-10-31 17:43:07-04:00, cbell@mysql_cab_desk. +35 -3 BUG#31383 : Consistent Snapshot driver not consistent Added new methods to support using a separate thread to open and lock tables for backup. sql/backup/be_default.h@1.7, 2007-10-31 17:43:07-04:00, cbell@mysql_cab_desk. +7 -10 BUG#31383 : Consistent Snapshot driver not consistent Added new methods to support using a separate thread to open and lock tables for backup. sql/backup/be_snapshot.cc@1.4, 2007-10-31 17:43:08-04:00, cbell@mysql_cab_desk. +26 -18 BUG#31383 : Consistent Snapshot driver not consistent Modifies the CS driver to open and close its own tables while executing in the kernel's thread. sql/backup/be_snapshot.h@1.4, 2007-10-31 17:43:09-04:00, cbell@mysql_cab_desk. +6 -3 BUG#31383 : Consistent Snapshot driver not consistent Added methods and variables for opening and closing tables. sql/backup/be_thread.cc@1.1, 2007-10-31 17:43:11-04:00, cbell@mysql_cab_desk. +202 -0 BUG#31383 : Consistent Snapshot driver not consistent Added new error message for error handling in threads in default and snapshot drivers. sql/backup/be_thread.cc@1.0, 2007-10-31 17:43:11-04:00, cbell@mysql_cab_desk. +0 -0 sql/backup/be_thread.h@1.1, 2007-10-31 17:43:11-04:00, cbell@mysql_cab_desk. +68 -0 BUG#31383 : Consistent Snapshot driver not consistent New source file for mutex initialization and helper methods for using a thread to open and lock tables in default and snapshot drivers. sql/backup/be_thread.h@1.0, 2007-10-31 17:43:11-04:00, cbell@mysql_cab_desk. +0 -0 sql/backup/data_backup.cc@1.11, 2007-10-31 17:43:09-04:00, cbell@mysql_cab_desk. +0 -31 BUG#31383 : Consistent Snapshot driver not consistent Removed code to call open and lock tables from kernel. sql/share/errmsg.txt@1.112, 2007-10-31 17:43:10-04:00, cbell@mysql_cab_desk. +3 -0 BUG#31383 : Consistent Snapshot driver not consistent Added new error message for error handling in threads in the default driver. sql/sql_class.h@1.396, 2007-10-31 17:43:05-04:00, cbell@mysql_cab_desk. +2 -1 BUG#31383 : Consistent Snapshot driver not consistent Added a new thread for backup. diff -Nrup a/mysql-test/r/backup_snapshot.result b/mysql-test/r/backup_snapshot.result --- a/mysql-test/r/backup_snapshot.result 2007-07-02 13:42:57 -04:00@@ -11,21 +11,73 @@ INSERT INTO bup_snapshot.t1 VALUES ("07
INSERT INTO bup_snapshot.t1 VALUES ("08 Some data to test");
INSERT INTO bup_snapshot.t1 VALUES ("09 Some data to test");
INSERT INTO bup_snapshot.t1 VALUES ("10 Some data to test");
+CREATE TABLE bup_snapshot.t2 (a int) ENGINE=CSV; +INSERT INTO bup_snapshot.t2 VALUES (1), (2), (3), (4), (5); con1: Show that the new data doesn't exist before backup. SELECT * FROM bup_snapshot.t1 WHERE word LIKE '-%'; word SELECT COUNT(*) FROM bup_snapshot.t1; COUNT(*) 10 -con1: Backing up database. +SELECT COUNT(*) FROM bup_snapshot.t2; +COUNT(*) +5 +con2: Getting lock on driver. +SELECT get_lock("backup_cs_locked", 100); +get_lock("backup_cs_locked", 100) +1 +con1: Backing up database. Spawn this and continue... BACKUP DATABASE bup_snapshot TO "bup_snapshot.bak"; +con2: Wait until backup pauses then insert new data. +INSERT INTO bup_snapshot.t1 VALUES("- Dave Mathews"); +INSERT INTO bup_snapshot.t1 VALUES("- Yes"); +INSERT INTO bup_snapshot.t1 VALUES("- Jethro Tull"); +DELETE FROM bup_snapshot.t1 WHERE word LIKE '10%'; +con2: Showing the data after inserts. +SELECT * FROM bup_snapshot.t1 WHERE word LIKE '-%'; +word +- Dave Mathews +- Yes +- Jethro Tull +SELECT COUNT(*) FROM bup_snapshot.t1; +COUNT(*) +12 +con2: Release lock on driver. +SELECT release_lock("backup_cs_locked"); +release_lock("backup_cs_locked") +1 Backup Summary - header = 22 bytes - meta-data = 95 bytes - data = 260 bytes+con1: Dropping the database +DROP TABLE bup_snapshot.t1; +con1: Restoring the database +RESTORE FROM "bup_snapshot.bak"; +Restore Summary + header = 29 bytes + meta-data = 181 bytes + data = 310 bytes + -------------- + total 520 bytes +con1: Showing the data (no new data should be here). +SELECT * FROM bup_snapshot.t1 WHERE word LIKE '-%'; +word +SELECT COUNT(*) FROM bup_snapshot.t1; +COUNT(*) +10 +SELECT COUNT(*) FROM bup_snapshot.t2; +COUNT(*) +5 +con2: Getting lock on driver. +SELECT get_lock("backup_cs_reading", 100); +get_lock("backup_cs_reading", 100) +1 +con1: Backing up database. Spawn this and continue... +BACKUP DATABASE bup_snapshot TO "bup_snapshot.bak"; +con2: Wait until backup pauses then insert new data.
INSERT INTO bup_snapshot.t1 VALUES("- Dave Mathews");
INSERT INTO bup_snapshot.t1 VALUES("- Yes");
INSERT INTO bup_snapshot.t1 VALUES("- Jethro Tull");
@@ -39,20 +91,33 @@ word
SELECT COUNT(*) FROM bup_snapshot.t1; COUNT(*) 12 +con2: Release lock on driver. +SELECT release_lock("backup_cs_reading"); +release_lock("backup_cs_reading") +1 +Backup Summary + header = 29 bytes + meta-data = 181 bytes + data = 310 bytes + -------------- + total 520 bytes con1: Dropping the database DROP TABLE bup_snapshot.t1; con1: Restoring the database RESTORE FROM "bup_snapshot.bak"; Restore Summary - header = 22 bytes - meta-data = 95 bytes - data = 260 bytes con1: Showing the data (no new data should be here). SELECT * FROM bup_snapshot.t1 WHERE word LIKE '-%'; word SELECT COUNT(*) FROM bup_snapshot.t1; COUNT(*) 10 +SELECT COUNT(*) FROM bup_snapshot.t2; +COUNT(*) +5 DROP DATABASE bup_snapshot; diff -Nrup a/mysql-test/t/backup_snapshot.test b/mysql-test/t/backup_snapshot.test --- a/mysql-test/t/backup_snapshot.test 2007-07-02 13:42:57 -04:00@@ -3,13 +3,24 @@ # The test is designed to show that a consistent snapshot # backup can be taken while data is being inserted and deleted. # -# TODO -# - Make the test run the insert statements in parallel with the backup -# command using --send and --reap and signals from backup code.+# The following tests test these conditions. # --source include/have_innodb.inc --source include/have_debug.inc +--source.include/have_csv.inc
--disable_warnings
connection con1; -# Create a table and load it with lots of data.+# Setup for tests. +# +# Create a table and load it with lots of data. INSERT INTO bup_snapshot.t1 VALUES ("01 Some data to test"); @@ -37,19 +51,42 @@ INSERT INTO bup_snapshot.t1 VALUES ("08 INSERT INTO bup_snapshot.t1 VALUES ("09 Some data to test"); INSERT INTO bup_snapshot.t1 VALUES ("10 Some data to test"); +# Use a non-CS supported table to show driver can coexist with default driver # While a consistent snapshot backup is executed, # no external inserts should be visible to the transaction.
---echo con1: Backing up database.
connection con2;
---echo con2: Inserting new data.
INSERT INTO bup_snapshot.t1 VALUES("- Dave Mathews");
INSERT INTO bup_snapshot.t1 VALUES("- Yes");
INSERT INTO bup_snapshot.t1 VALUES("- Jethro Tull");
@@ -59,8 +96,13 @@ DELETE FROM bup_snapshot.t1 WHERE word L
SELECT * FROM bup_snapshot.t1 WHERE word LIKE '-%';
SELECT COUNT(*) FROM bup_snapshot.t1;
+--echo con2: Release lock on driver. +reap;
@@ -73,9 +115,68 @@ RESTORE FROM "bup_snapshot.bak";
--echo con1: Showing the data (no new data should be here).
SELECT * FROM bup_snapshot.t1 WHERE word LIKE '-%';
SELECT COUNT(*) FROM bup_snapshot.t1;
-DROP DATABASE bup_snapshot;
---exec rm $MYSQLTEST_VARDIR/master-data/bup_snapshot.bak
+remove_file $MYSQLTEST_VARDIR/master-data/bup_snapshot.bak; diff -Nrup a/sql/backup/CMakeLists.txt b/sql/backup/CMakeLists.txt --- a/sql/backup/CMakeLists.txt 2007-10-03 12:56:57 -04:00 IF(NOT SOURCE_SUBLIBS)
diff -Nrup a/sql/backup/Makefile.am b/sql/backup/Makefile.am --- a/sql/backup/Makefile.am 2007-10-05 09:12:28 -04:00@@ -108,14 +108,14 @@ result_t Engine::get_backup(const uint32 } Backup::Backup(const Table_list &tables, THD *t_thd, thr_lock_type lock_type): - Backup_driver(tables){ DBUG_PRINT("default_backup",("Creating backup driver")); m_thd= t_thd; /* save current thread */ cur_table= NULL; /* flag current table as null */ tbl_num= 0; /* set table number to 0 */ mode= INITIALIZE; /* initialize read */ - lock_called= FALSE; /* lock has not been called */@@ -126,6 +126,24 @@ Backup::Backup(const Table_list &tables, } /**+ * prelock() (given that thr_lock() is blocking). + */ +result_t Backup::prelock() +{ + DBUG_ENTER("Default_backup::open_tables"); + lock_state= LOCK_IN_PROGRESS; + pthread_t th; + if (pthread_create(&th, &connection_attrib, + backup_thread_for_locking, this)) + SET_STATE_TO_ERROR_AND_DBUG_RETURN; + DBUG_RETURN(OK); +} + +/**
namespace default_backup { @@ -78,9 +80,9 @@ class Engine: public Backup_engine
protected:
- my_bool lock_called; ///< Checks to see if locks have been reached.
THD *m_thd; ///< Pointer to current thread struct.
- TABLE_LIST *tables_in_backup; ///< List of tables used in backup.
};
/** diff -Nrup a/sql/backup/be_snapshot.cc b/sql/backup/be_snapshot.cc --- a/sql/backup/be_snapshot.cc 2007-07-02 13:42:59 -04:00 DBUG_RETURN(OK);
-/**
- * @brief End backup process.
- *
- * This method unlocks all of the tables.
- *
- * @retval backup::OK all tables unlocked.
- */
-result_t Backup::end()
-{
- DBUG_ENTER("Snapshot_backup::end");
- end_active_trans(m_thd);
- DBUG_RETURN(OK);
-}
-
result_t Backup::lock() { DBUG_ENTER("Snapshot_backup::lock()"); @@ -104,14 +90,36 @@ result_t Backup::lock()
int res= begin_trans(m_thd);
DBUG_RETURN(OK);
-result_t Backup::unlock()
/** diff -Nrup a/sql/backup/be_snapshot.h b/sql/backup/be_snapshot.h --- a/sql/backup/be_snapshot.h 2007-07-02 13:42:59 -04:00{ public:
Backup(const Table_list &tables, THD *t_thd):
- default_backup::Backup(tables, t_thd, TL_READ) {};
- result_t unlock(); + result_t unlock() { return backup::OK; }; + private: + my_bool tables_open; ///< Indicates if tables are open };
/**
--- /dev/null Wed Dec 31 16:00:00 196900@@ -0,0 +1,202 @@ +/* Copyright (C) 2004-2007 MySQL AB + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +/** + * @file + * + * @brief Contains the thread methods for online backup. + * + * The methods in this class are used to initialize the mutexes + * for the backup threads. Helper methods are included to make thread + * calls easier for the driver code. + */ + +#include "be_thread.h" + +/** + * @brief Creates a new THD object. + * + * Creates a new THD object for use in running as a separate thread. + * + * @returns Pointer to new THD object or 0 if error. + * + * @TODO Move this method to a location where ha_ndbcluster_binlog.cc can + * use it and replace code in ndb_binlog_thread_func(void *arg) to + * call this function. + */ +THD *create_new_thd() +{ + THD *thd; + DBUG_ENTER("Create new THD object"); + + thd= new THD; + if (unlikely(!thd)) + { + delete thd; + DBUG_RETURN(0); + } + + thd->thread_stack = (char*)&thd; // remember where our stack is + pthread_mutex_lock(&LOCK_thread_count); + thd->thread_id= thread_id++; + pthread_mutex_unlock(&LOCK_thread_count); + if (unlikely(thd->store_globals())) // for a proper MEM_ROOT + { + delete thd; + DBUG_RETURN(0); + } + + thd->init_for_queries(); // opening tables needs a proper LEX + thd->command= COM_DAEMON; + thd->system_thread= SYSTEM_THREAD_BACKUP; + thd->version= refresh_version; + thd->set_time(); + thd->main_security_ctx.host_or_ip= ""; + thd->client_capabilities= 0; + my_net_init(&thd->net, 0); + thd->main_security_ctx.master_access= ~0; + thd->main_security_ctx.priv_user= 0; + thd->real_id= pthread_self(); + /* + Making this thread visible to SHOW PROCESSLIST is useful for + troubleshooting a backup job (why does it stall etc). + */ + pthread_mutex_lock(&LOCK_thread_count); + threads.append(thd); + pthread_mutex_unlock(&LOCK_thread_count); + lex_start(thd); + mysql_reset_thd_for_next_command(thd); + DBUG_RETURN(thd); +} + +/** + @brief Lock tables in driver. + + This method creates a new THD for use in the new thread. It calls + the method to open and lock the tables. + */ +pthread_handler_t backup_thread_for_locking(void *arg) +{ + Backup_thread_driver *drv= static_cast<Backup_thread_driver *>(arg); + pthread_mutex_t THR_LOCK_driver_thread= drv->THR_LOCK_driver_thread; + pthread_cond_t COND_driver_thread_wait= drv->COND_driver_thread_wait; + + DBUG_PRINT("info", ("Default_backup - lock_tables_in_separate_thread")); + + /* + Turn off condition variable check for lock. + */ + pthread_mutex_lock(&THR_LOCK_driver_thread); + drv->lock_state= LOCK_NOT_STARTED; + pthread_mutex_unlock(&THR_LOCK_driver_thread); + + my_thread_init(); + pthread_detach_this_thread(); + + /* + First, create a new THD object. + */ + DBUG_PRINT("info",("Online backup creating THD struct for thread")); + THD *thd= create_new_thd(); + drv->lock_thd= thd; + if (thd == 0) + { + pthread_mutex_lock(&THR_LOCK_driver_thread); + drv->lock_state= LOCK_ERROR; + pthread_mutex_unlock(&THR_LOCK_driver_thread); + return (0); + } + + if (thd->killed) + goto end; + + /* + Now open and lock the tables. + */ + DBUG_PRINT("info",("Online backup open tables in thread")); + if (!drv->tables_in_backup) + { + DBUG_PRINT("info",("Online backup locking error no tables to lock")); + return (0); + } + + /* + As locking tables can be a long operation, we need to support + killing the thread. In this case, we need to close the tables + and exit. + */ + if (!thd->killed && open_and_lock_tables(thd, drv->tables_in_backup)) + { + DBUG_PRINT("info",("Online backup locking thread dying")); + close_thread_tables(thd); + return (0); + } + + if (thd->killed) + goto end; + + /* + Part of work is done. Rest until woken up. + */ + pthread_mutex_lock(&THR_LOCK_driver_thread); + drv->lock_state= LOCK_ACQUIRED; + thd->enter_cond(&COND_driver_thread_wait, &THR_LOCK_driver_thread, + "Online backup driver thread: holding table locks"); + while (!thd->killed) + pthread_cond_wait(&COND_driver_thread_wait, &THR_LOCK_driver_thread); + thd->exit_cond("Online backup driver thread: terminating"); + + DBUG_PRINT("info",("Online backup driver thread locking thread terminating")); + +end: + /* + Cleanup and return. + */ + close_thread_tables(thd); + net_end(&thd->net); + my_thread_end(); + delete thd; + pthread_exit(0); + return (0); +} + +/* + Constructor for backup_thread_driver class. +*/ +Backup_thread_driver::Backup_thread_driver(const backup::Table_list &tables): + Backup_driver(tables) +{ + /* + Initialize the thread mutex and cond variable. + */ + pthread_mutex_init(&THR_LOCK_driver_thread, MY_MUTEX_INIT_FAST); + pthread_cond_init(&COND_driver_thread_wait, NULL); + lock_state= LOCK_NOT_STARTED; + lock_thd= NULL; // set to 0 as precaution for get_data being called too soon +}; + +/* + Destructor for backup_thread_driver class. +*/ +Backup_thread_driver::~Backup_thread_driver() +{ + /* + Destroy the thread mutex and cond variable. + */ + pthread_mutex_destroy(&THR_LOCK_driver_thread); + pthread_cond_destroy(&COND_driver_thread_wait); +}; + diff -Nrup a/sql/backup/be_thread.h b/sql/backup/be_thread.h --- /dev/null Wed Dec 31 16:00:00 196900@@ -0,0 +1,68 @@ +#ifndef _BACKUP_THREAD_H +#define _BACKUP_THREAD_H + +#include "../mysql_priv.h" +#include "archive.h" +#include "api_types.h" +#include "backup_engine.h" + +/** + Macro for error handling. +*/ +#define SET_STATE_TO_ERROR_AND_DBUG_RETURN { \ + int state= ERROR; \ + DBUG_PRINT("error",("driver got an error at %s:%d",__FILE__,__LINE__)); \ + DBUG_RETURN(backup::ERROR); } + +/** + Locking of tables goes through several states. +*/ +typedef enum { + LOCK_NOT_STARTED, + LOCK_IN_PROGRESS, + LOCK_ACQUIRED, + LOCK_ERROR +} LOCK_STATE; + +/** + create_new_thd + + This method creates a new THD object. +*/ +THD *create_new_thd(); + +/** + backup_thread_for_locking + + This method creates a new thread and opens and locks the tables. +*/ +pthread_handler_t backup_thread_for_locking(void *arg); + +/** + * @class Backup_thread_driver + * + * @brief Adds variables for using a locking thread for opening tables. + * + * The Backup_thread_driver class extends the Backup_driver class by adding + * a mutex and condition variable for using a thread to open and lock the + * tables. + * + * @see <backup driver> and <backup thread driver> + */ +class Backup_thread_driver : public Backup_driver +{ +public: + + Backup_thread_driver(const backup::Table_list &tables); + ~Backup_thread_driver(); + + pthread_mutex_t THR_LOCK_driver_thread; ///< mutex for thread variables + pthread_cond_t COND_driver_thread_wait; ///< condition variable for wait + TABLE_LIST *tables_in_backup; ///< List of tables used in backup + THD *lock_thd; ///< Locking thread pointer + LOCK_STATE lock_state; ///< Current state of the lock call + +}; // Backup_thread_driver class + +#endif + diff -Nrup a/sql/backup/data_backup.cc b/sql/backup/data_backup.cc --- a/sql/backup/data_backup.cc 2007-09-11 05:29:29 -04:00 DBUG_PRINT("backup/data",("initializing scheduler"));
for (uint no=0; no < info.img_count; ++no) @@ -418,12 +415,6 @@ int write_table_data(THD*, Backup_info &
inactive.push_back(p);
}
- if (!def_or_snap_used)
- def_or_snap_used= ((i->type() == Image_info::DEFAULT_IMAGE) ||
- (i->type() == Image_info::SNAPSHOT_IMAGE));
- if (def_or_snap_used)
- get_default_snapshot_tables(&p->drv(), NULL,
- &table_list, &table_list_last);
}
/*
if (sch.prepare())
goto error;
- /*
- Open tables for default and snapshot drivers.
- */
- if (table_list)
- {
- if (open_and_lock_tables(::current_thd, table_list))
- {
- DBUG_PRINT("backup",
- ( "error on open tables for default and snapshot drivers!" ));
- info.report_error(ER_BACKUP_OPEN_TABLES, "backup");
- DBUG_RETURN(ERROR);
- }
- if (table_list_last)
- table_list_last->next_global= NULL; // break lists
- }
-
while (sch.prepare_count > 0)
if (sch.step())
goto error;
@@ -548,12 +523,6 @@ int write_table_data(THD*, Backup_info & DBUG_PRINT("backup/data",("-- DONE --")); } - - /* - If the default or snapshot drivers are used, close the tables. - */ - if (def_or_snap_used) - close_thread_tables(::current_thd); info.data_size= s.bytes - start_bytes; diff -Nrup a/sql/share/errmsg.txt b/sql/share/errmsg.txt --- a/sql/share/errmsg.txt 2007-10-17 09:57:35 -04:00@@ -6195,6 +6195,9 @@ ER_BACKUP_SEND_DATA_RETRY ER_BACKUP_OPEN_TABLES eng "Open and lock tables failed in %-.64s" +ER_BACKUP_THREAD_INIT --- a/sql/sql_class.h 2007-09-13 04:56:30 -04:00@@ -936,7 +936,8 @@ enum enum_thread_type SYSTEM_THREAD_SLAVE_SQL= 4, SYSTEM_THREAD_NDBCLUSTER_BINLOG= 8, SYSTEM_THREAD_EVENT_SCHEDULER= 16, - SYSTEM_THREAD_EVENT_WORKER= 32 + SYSTEM_THREAD_EVENT_WORKER= 32, + SYSTEM_THREAD_BACKUP= 64 }; -- MySQL Code Commits Mailing List For list archives: http://lists.mysql.com/commits To unsubscribe: http://lists.mysql.com/commits?unsub=lists@pantek.comReceived on Wed Oct 31 17:44:29 2007 This archive was generated by hypermail 2.1.8 : Thu Jul 03 2008 - 11:15:14 EDT |
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