mariadb/extra/mariabackup/xtrabackup.h
Vladislav Vaintroub 27c24808f7 MDEV-15636 mariabackup --lock-ddl-per-table hangs if ALTER table is running
concurrently.

There is a deadlock between

C1 mariabackup's connection that holds MDL locks
C2 Online ALTER TABLE that wants to have MDL exclusively
   and tries to upgrade its mdl lock.
C3 another mariabackup's connection that does FLUSH TABLES (or FTWRL)

C3 waits waits for C2,  which waits for C1, which waits for C3,
thus the deadlock.


MDL locks cannot be released until FLUSH  succeeds, because
otherwise it would allow ALTER to sneak in, causing backup to abort and
breaking lock-ddl-per-table's promise.

The fix here workarounds the deadlock, by killing connections in
"Waiting for metadata lock" status (i.e ALTER). This killing continues
until FTWRL succeeds.

Killing connections is skipped in case --no-locks parameter
was  passed to backup, because there won't be a FLUSH.

For the reference,in Percona's xtrabackup --lock-ddl-per-connection
silently implies --no-lock ie FLUSH is always skipped there.

A rather large part of fix is introducing DBUG capability to start
a query  the new connection at the right moment of backup
compensating somewhat for mariabackup' lack of send_query or DBUG_SYNC.
2018-04-01 14:26:06 +00:00

198 lines
5.7 KiB
C

/******************************************************
Copyright (c) 2011-2015 Percona LLC and/or its affiliates.
Declarations for xtrabackup.cc
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*******************************************************/
#ifndef XB_XTRABACKUP_H
#define XB_XTRABACKUP_H
#include <my_getopt.h>
#include "datasink.h"
#include "xbstream.h"
#include "changed_page_bitmap.h"
struct xb_delta_info_t
{
xb_delta_info_t(page_size_t page_size, ulint space_id)
: page_size(page_size), space_id(space_id) {}
page_size_t page_size;
ulint space_id;
};
/* value of the --incremental option */
extern lsn_t incremental_lsn;
extern char *xtrabackup_target_dir;
extern char *xtrabackup_incremental_dir;
extern char *xtrabackup_incremental_basedir;
extern char *innobase_data_home_dir;
extern char *innobase_buffer_pool_filename;
extern char *xb_plugin_dir;
extern uint opt_protocol;
extern ds_ctxt_t *ds_meta;
extern ds_ctxt_t *ds_data;
/* The last checkpoint LSN at the backup startup time */
extern lsn_t checkpoint_lsn_start;
extern xb_page_bitmap *changed_page_bitmap;
extern char *xtrabackup_incremental;
extern my_bool xtrabackup_incremental_force_scan;
extern lsn_t metadata_from_lsn;
extern lsn_t metadata_to_lsn;
extern lsn_t metadata_last_lsn;
extern xb_stream_fmt_t xtrabackup_stream_fmt;
extern ibool xtrabackup_stream;
extern char *xtrabackup_tables;
extern char *xtrabackup_tables_file;
extern char *xtrabackup_databases;
extern char *xtrabackup_databases_file;
extern char *xtrabackup_tables_exclude;
extern char *xtrabackup_databases_exclude;
extern ibool xtrabackup_compress;
extern my_bool xtrabackup_backup;
extern my_bool xtrabackup_prepare;
extern my_bool xtrabackup_copy_back;
extern my_bool xtrabackup_move_back;
extern my_bool xtrabackup_decrypt_decompress;
extern char *innobase_data_file_path;
extern longlong innobase_page_size;
extern int xtrabackup_parallel;
extern my_bool xb_close_files;
extern const char *xtrabackup_compress_alg;
#ifdef __cplusplus
extern "C"{
#endif
extern uint xtrabackup_compress_threads;
extern ulonglong xtrabackup_compress_chunk_size;
#ifdef __cplusplus
}
#endif
extern my_bool xtrabackup_export;
extern char *xtrabackup_extra_lsndir;
extern ulint xtrabackup_log_copy_interval;
extern char *xtrabackup_stream_str;
extern long xtrabackup_throttle;
extern longlong xtrabackup_use_memory;
extern my_bool opt_galera_info;
extern my_bool opt_slave_info;
extern my_bool opt_no_lock;
extern my_bool opt_safe_slave_backup;
extern my_bool opt_rsync;
extern my_bool opt_force_non_empty_dirs;
extern my_bool opt_noversioncheck;
extern my_bool opt_no_backup_locks;
extern my_bool opt_decompress;
extern my_bool opt_remove_original;
extern my_bool opt_lock_ddl_per_table;
extern char *opt_incremental_history_name;
extern char *opt_incremental_history_uuid;
extern char *opt_user;
extern char *opt_password;
extern char *opt_host;
extern char *opt_defaults_group;
extern char *opt_socket;
extern uint opt_port;
extern char *opt_log_bin;
extern const char *query_type_names[];
enum query_type_t {QUERY_TYPE_ALL, QUERY_TYPE_UPDATE,
QUERY_TYPE_SELECT};
extern TYPELIB query_type_typelib;
extern ulong opt_lock_wait_query_type;
extern ulong opt_kill_long_query_type;
extern uint opt_kill_long_queries_timeout;
extern uint opt_lock_wait_timeout;
extern uint opt_lock_wait_threshold;
extern uint opt_debug_sleep_before_unlock;
extern uint opt_safe_slave_backup_timeout;
extern const char *opt_history;
enum binlog_info_enum { BINLOG_INFO_OFF, BINLOG_INFO_LOCKLESS, BINLOG_INFO_ON,
BINLOG_INFO_AUTO};
extern ulong opt_binlog_info;
void xtrabackup_io_throttling(void);
my_bool xb_write_delta_metadata(const char *filename,
const xb_delta_info_t *info);
/************************************************************************
Checks if a table specified as a name in the form "database/name" (InnoDB 5.6)
or "./database/name.ibd" (InnoDB 5.5-) should be skipped from backup based on
the --tables or --tables-file options.
@return TRUE if the table should be skipped. */
my_bool
check_if_skip_table(
/******************/
const char* name); /*!< in: path to the table */
/************************************************************************
Checks if a database specified by path should be skipped from backup based on
the --databases, --databases_file or --databases_exclude options.
@return TRUE if the table should be skipped. */
my_bool
check_if_skip_database_by_path(
const char* path /*!< in: path to the db directory. */
);
/************************************************************************
Check if parameter is set in defaults file or via command line argument
@return true if parameter is set. */
bool
check_if_param_set(const char *param);
#if defined(HAVE_OPENSSL)
extern my_bool opt_ssl_verify_server_cert;
#endif
my_bool
xb_get_one_option(int optid,
const struct my_option *opt __attribute__((unused)),
char *argument);
const char*
xb_get_copy_action(const char *dflt = "Copying");
void mdl_lock_init();
void mdl_lock_table(ulint space_id);
void mdl_unlock_all();
bool ends_with(const char *str, const char *suffix);
#endif /* XB_XTRABACKUP_H */