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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:07:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:07:14 +0000 |
commit | a175314c3e5827eb193872241446f2f8f5c9d33c (patch) | |
tree | cd3d60ca99ae00829c52a6ca79150a5b6e62528b /sql/semisync_master.h | |
parent | Initial commit. (diff) | |
download | mariadb-10.5-9e4947182e0b875da38088fdd168e775f473b8ad.tar.xz mariadb-10.5-9e4947182e0b875da38088fdd168e775f473b8ad.zip |
Adding upstream version 1:10.5.12.upstream/1%10.5.12upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'sql/semisync_master.h')
-rw-r--r-- | sql/semisync_master.h | 673 |
1 files changed, 673 insertions, 0 deletions
diff --git a/sql/semisync_master.h b/sql/semisync_master.h new file mode 100644 index 00000000..9f0acf57 --- /dev/null +++ b/sql/semisync_master.h @@ -0,0 +1,673 @@ +/* Copyright (C) 2007 Google Inc. + Copyright (c) 2008 MySQL AB, 2009 Sun Microsystems, Inc. + Use is subject to license terms. + + 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 St, Fifth Floor, Boston, MA 02110-1335 USA */ + + +#ifndef SEMISYNC_MASTER_H +#define SEMISYNC_MASTER_H + +#include "semisync.h" +#include "semisync_master_ack_receiver.h" + +#ifdef HAVE_PSI_INTERFACE +extern PSI_mutex_key key_LOCK_rpl_semi_sync_master_enabled; +extern PSI_mutex_key key_LOCK_binlog; +extern PSI_cond_key key_COND_binlog_send; +#endif + +struct Tranx_node { + char log_name[FN_REFLEN]; + my_off_t log_pos; + struct Tranx_node *next; /* the next node in the sorted list */ + struct Tranx_node *hash_next; /* the next node during hash collision */ +}; + +/** + @class Tranx_node_allocator + + This class provides memory allocating and freeing methods for + Tranx_node. The main target is performance. + + @section ALLOCATE How to allocate a node + The pointer of the first node after 'last_node' in current_block is + returned. current_block will move to the next free Block when all nodes of + it are in use. A new Block is allocated and is put into the rear of the + Block link table if no Block is free. + + The list starts up empty (ie, there is no allocated Block). + + After some nodes are freed, there probably are some free nodes before + the sequence of the allocated nodes, but we do not reuse it. It is better + to keep the allocated nodes are in the sequence, for it is more efficient + for allocating and freeing Tranx_node. + + @section FREENODE How to free nodes + There are two methods for freeing nodes. They are free_all_nodes and + free_nodes_before. + + 'A Block is free' means all of its nodes are free. + @subsection free_nodes_before + As all allocated nodes are in the sequence, 'Before one node' means all + nodes before given node in the same Block and all Blocks before the Block + which containing the given node. As such, all Blocks before the given one + ('node') are free Block and moved into the rear of the Block link table. + The Block containing the given 'node', however, is not. For at least the + given 'node' is still in use. This will waste at most one Block, but it is + more efficient. + */ +#define BLOCK_TRANX_NODES 16 +class Tranx_node_allocator +{ +public: + /** + @param reserved_nodes + The number of reserved Tranx_nodes. It is used to set 'reserved_blocks' + which can contain at least 'reserved_nodes' number of Tranx_nodes. When + freeing memory, we will reserve at least reserved_blocks of Blocks not + freed. + */ + Tranx_node_allocator(uint reserved_nodes) : + reserved_blocks(reserved_nodes/BLOCK_TRANX_NODES + + (reserved_nodes%BLOCK_TRANX_NODES > 1 ? 2 : 1)), + first_block(NULL), last_block(NULL), + current_block(NULL), last_node(-1), block_num(0) {} + + ~Tranx_node_allocator() + { + Block *block= first_block; + while (block != NULL) + { + Block *next= block->next; + free_block(block); + block= next; + } + } + + /** + The pointer of the first node after 'last_node' in current_block is + returned. current_block will move to the next free Block when all nodes of + it are in use. A new Block is allocated and is put into the rear of the + Block link table if no Block is free. + + @return Return a Tranx_node *, or NULL if an error occurred. + */ + Tranx_node *allocate_node() + { + Tranx_node *trx_node; + Block *block= current_block; + + if (last_node == BLOCK_TRANX_NODES-1) + { + current_block= current_block->next; + last_node= -1; + } + + if (current_block == NULL && allocate_block()) + { + current_block= block; + if (current_block) + last_node= BLOCK_TRANX_NODES-1; + return NULL; + } + + trx_node= &(current_block->nodes[++last_node]); + trx_node->log_name[0] = '\0'; + trx_node->log_pos= 0; + trx_node->next= 0; + trx_node->hash_next= 0; + return trx_node; + } + + /** + All nodes are freed. + + @return Return 0, or 1 if an error occurred. + */ + int free_all_nodes() + { + current_block= first_block; + last_node= -1; + free_blocks(); + return 0; + } + + /** + All Blocks before the given 'node' are free Block and moved into the rear + of the Block link table. + + @param node All nodes before 'node' will be freed + + @return Return 0, or 1 if an error occurred. + */ + int free_nodes_before(Tranx_node* node) + { + Block *block; + Block *prev_block= NULL; + + block= first_block; + while (block != current_block->next) + { + /* Find the Block containing the given node */ + if (&(block->nodes[0]) <= node && &(block->nodes[BLOCK_TRANX_NODES]) >= node) + { + /* All Blocks before the given node are put into the rear */ + if (first_block != block) + { + last_block->next= first_block; + first_block= block; + last_block= prev_block; + last_block->next= NULL; + free_blocks(); + } + return 0; + } + prev_block= block; + block= block->next; + } + + /* Node does not find should never happen */ + DBUG_ASSERT(0); + return 1; + } + +private: + uint reserved_blocks; + + /** + A sequence memory which contains BLOCK_TRANX_NODES Tranx_nodes. + + BLOCK_TRANX_NODES The number of Tranx_nodes which are in a Block. + + next Every Block has a 'next' pointer which points to the next Block. + These linking Blocks constitute a Block link table. + */ + struct Block { + Block *next; + Tranx_node nodes[BLOCK_TRANX_NODES]; + }; + + /** + The 'first_block' is the head of the Block link table; + */ + Block *first_block; + /** + The 'last_block' is the rear of the Block link table; + */ + Block *last_block; + + /** + current_block always points the Block in the Block link table in + which the last allocated node is. The Blocks before it are all in use + and the Blocks after it are all free. + */ + Block *current_block; + + /** + It always points to the last node which has been allocated in the + current_block. + */ + int last_node; + + /** + How many Blocks are in the Block link table. + */ + uint block_num; + + /** + Allocate a block and then assign it to current_block. + */ + int allocate_block() + { + Block *block= (Block *)my_malloc(PSI_INSTRUMENT_ME, sizeof(Block), MYF(0)); + if (block) + { + block->next= NULL; + + if (first_block == NULL) + first_block= block; + else + last_block->next= block; + + /* New Block is always put into the rear */ + last_block= block; + /* New Block is always the current_block */ + current_block= block; + ++block_num; + return 0; + } + return 1; + } + + /** + Free a given Block. + @param block The Block will be freed. + */ + void free_block(Block *block) + { + my_free(block); + --block_num; + } + + + /** + If there are some free Blocks and the total number of the Blocks in the + Block link table is larger than the 'reserved_blocks', Some free Blocks + will be freed until the total number of the Blocks is equal to the + 'reserved_blocks' or there is only one free Block behind the + 'current_block'. + */ + void free_blocks() + { + if (current_block == NULL || current_block->next == NULL) + return; + + /* One free Block is always kept behind the current block */ + Block *block= current_block->next->next; + while (block_num > reserved_blocks && block != NULL) + { + Block *next= block->next; + free_block(block); + block= next; + } + current_block->next->next= block; + if (block == NULL) + last_block= current_block->next; + } +}; + +/** + This class manages memory for active transaction list. + + We record each active transaction with a Tranx_node, each session + can have only one open transaction. Because of EVENT, the total + active transaction nodes can exceed the maximum allowed + connections. +*/ +class Active_tranx + :public Trace { +private: + + Tranx_node_allocator m_allocator; + /* These two record the active transaction list in sort order. */ + Tranx_node *m_trx_front, *m_trx_rear; + + Tranx_node **m_trx_htb; /* A hash table on active transactions. */ + + int m_num_entries; /* maximum hash table entries */ + mysql_mutex_t *m_lock; /* mutex lock */ + + inline void assert_lock_owner(); + + inline unsigned int calc_hash(const unsigned char *key, size_t length); + unsigned int get_hash_value(const char *log_file_name, my_off_t log_file_pos); + + int compare(const char *log_file_name1, my_off_t log_file_pos1, + const Tranx_node *node2) { + return compare(log_file_name1, log_file_pos1, + node2->log_name, node2->log_pos); + } + int compare(const Tranx_node *node1, + const char *log_file_name2, my_off_t log_file_pos2) { + return compare(node1->log_name, node1->log_pos, + log_file_name2, log_file_pos2); + } + int compare(const Tranx_node *node1, const Tranx_node *node2) { + return compare(node1->log_name, node1->log_pos, + node2->log_name, node2->log_pos); + } + +public: + Active_tranx(mysql_mutex_t *lock, unsigned long trace_level); + ~Active_tranx(); + + /* Insert an active transaction node with the specified position. + * + * Return: + * 0: success; non-zero: error + */ + int insert_tranx_node(const char *log_file_name, my_off_t log_file_pos); + + /* Clear the active transaction nodes until(inclusive) the specified + * position. + * If log_file_name is NULL, everything will be cleared: the sorted + * list and the hash table will be reset to empty. + */ + void clear_active_tranx_nodes(const char *log_file_name, + my_off_t log_file_pos); + + /* Given a position, check to see whether the position is an active + * transaction's ending position by probing the hash table. + */ + bool is_tranx_end_pos(const char *log_file_name, my_off_t log_file_pos); + + /* Given two binlog positions, compare which one is bigger based on + * (file_name, file_position). + */ + static int compare(const char *log_file_name1, my_off_t log_file_pos1, + const char *log_file_name2, my_off_t log_file_pos2); + +}; + +/** + The extension class for the master of semi-synchronous replication +*/ +class Repl_semi_sync_master + :public Repl_semi_sync_base { + Active_tranx *m_active_tranxs; /* active transaction list: the list will + be cleared when semi-sync switches off. */ + + /* True when init_object has been called */ + bool m_init_done; + + /* This cond variable is signaled when enough binlog has been sent to slave, + * so that a waiting trx can return the 'ok' to the client for a commit. + */ + mysql_cond_t COND_binlog_send; + + /* Mutex that protects the following state variables and the active + * transaction list. + * Under no cirumstances we can acquire mysql_bin_log.LOCK_log if we are + * already holding m_LOCK_binlog because it can cause deadlocks. + */ + mysql_mutex_t LOCK_binlog; + + /* This is set to true when m_reply_file_name contains meaningful data. */ + bool m_reply_file_name_inited; + + /* The binlog name up to which we have received replies from any slaves. */ + char m_reply_file_name[FN_REFLEN]; + + /* The position in that file up to which we have the reply from any slaves. */ + my_off_t m_reply_file_pos; + + /* This is set to true when we know the 'smallest' wait position. */ + bool m_wait_file_name_inited; + + /* NULL, or the 'smallest' filename that a transaction is waiting for + * slave replies. + */ + char m_wait_file_name[FN_REFLEN]; + + /* The smallest position in that file that a trx is waiting for: the trx + * can proceed and send an 'ok' to the client when the master has got the + * reply from the slave indicating that it already got the binlog events. + */ + my_off_t m_wait_file_pos; + + /* This is set to true when we know the 'largest' transaction commit + * position in the binlog file. + * We always maintain the position no matter whether semi-sync is switched + * on switched off. When a transaction wait timeout occurs, semi-sync will + * switch off. Binlog-dump thread can use the three fields to detect when + * slaves catch up on replication so that semi-sync can switch on again. + */ + bool m_commit_file_name_inited; + + /* The 'largest' binlog filename that a commit transaction is seeing. */ + char m_commit_file_name[FN_REFLEN]; + + /* The 'largest' position in that file that a commit transaction is seeing. */ + my_off_t m_commit_file_pos; + + /* All global variables which can be set by parameters. */ + volatile bool m_master_enabled; /* semi-sync is enabled on the master */ + unsigned long m_wait_timeout; /* timeout period(ms) during tranx wait */ + + bool m_state; /* whether semi-sync is switched */ + + /*Waiting for ACK before/after innodb commit*/ + ulong m_wait_point; + + void lock(); + void unlock(); + void cond_broadcast(); + int cond_timewait(struct timespec *wait_time); + + /* Is semi-sync replication on? */ + bool is_on() { + return (m_state); + } + + void set_master_enabled(bool enabled) { + m_master_enabled = enabled; + } + + /* Switch semi-sync off because of timeout in transaction waiting. */ + void switch_off(); + + /* Switch semi-sync on when slaves catch up. */ + int try_switch_on(int server_id, + const char *log_file_name, my_off_t log_file_pos); + + public: + Repl_semi_sync_master(); + ~Repl_semi_sync_master() {} + + void cleanup(); + + bool get_master_enabled() { + return m_master_enabled; + } + void set_trace_level(unsigned long trace_level) { + m_trace_level = trace_level; + if (m_active_tranxs) + m_active_tranxs->m_trace_level = trace_level; + } + + /* Set the transaction wait timeout period, in milliseconds. */ + void set_wait_timeout(unsigned long wait_timeout) { + m_wait_timeout = wait_timeout; + } + + /*set the ACK point, after binlog sync or after transaction commit*/ + void set_wait_point(unsigned long ack_point) + { + m_wait_point = ack_point; + } + + ulong wait_point() //no cover line + { + return m_wait_point; //no cover line + } + + /* Initialize this class after MySQL parameters are initialized. this + * function should be called once at bootstrap time. + */ + int init_object(); + + /* Enable the object to enable semi-sync replication inside the master. */ + int enable_master(); + + /* Disable the object to disable semi-sync replication inside the master. */ + void disable_master(); + + /* Add a semi-sync replication slave */ + void add_slave(); + + /* Remove a semi-sync replication slave */ + void remove_slave(); + + /* It parses a reply packet and call report_reply_binlog to handle it. */ + int report_reply_packet(uint32 server_id, const uchar *packet, + ulong packet_len); + + /* In semi-sync replication, reports up to which binlog position we have + * received replies from the slave indicating that it already get the events. + * + * Input: + * server_id - (IN) master server id number + * log_file_name - (IN) binlog file name + * end_offset - (IN) the offset in the binlog file up to which we have + * the replies from the slave + * + * Return: + * 0: success; non-zero: error + */ + int report_reply_binlog(uint32 server_id, + const char* log_file_name, + my_off_t end_offset); + + /* Commit a transaction in the final step. This function is called from + * InnoDB before returning from the low commit. If semi-sync is switch on, + * the function will wait to see whether binlog-dump thread get the reply for + * the events of the transaction. Remember that this is not a direct wait, + * instead, it waits to see whether the binlog-dump thread has reached the + * point. If the wait times out, semi-sync status will be switched off and + * all other transaction would not wait either. + * + * Input: (the transaction events' ending binlog position) + * trx_wait_binlog_name - (IN) ending position's file name + * trx_wait_binlog_pos - (IN) ending position's file offset + * + * Return: + * 0: success; non-zero: error + */ + int commit_trx(const char* trx_wait_binlog_name, + my_off_t trx_wait_binlog_pos); + + /*Wait for ACK after writing/sync binlog to file*/ + int wait_after_sync(const char* log_file, my_off_t log_pos); + + /*Wait for ACK after commting the transaction*/ + int wait_after_commit(THD* thd, bool all); + + /*Wait after the transaction is rollback*/ + int wait_after_rollback(THD *thd, bool all); + /*Store the current binlog position in m_active_tranxs. This position should + * be acked by slave*/ + int report_binlog_update(THD *thd, const char *log_file,my_off_t log_pos); + + int dump_start(THD* thd, + const char *log_file, + my_off_t log_pos); + + void dump_end(THD* thd); + + /* Reserve space in the replication event packet header: + * . slave semi-sync off: 1 byte - (0) + * . slave semi-sync on: 3 byte - (0, 0xef, 0/1} + * + * Input: + * packet - (IN) the header buffer + * + * Return: + * size of the bytes reserved for header + */ + int reserve_sync_header(String* packet); + + /* Update the sync bit in the packet header to indicate to the slave whether + * the master will wait for the reply of the event. If semi-sync is switched + * off and we detect that the slave is catching up, we switch semi-sync on. + * + * Input: + * THD - (IN) current dump thread + * packet - (IN) the packet containing the replication event + * log_file_name - (IN) the event ending position's file name + * log_file_pos - (IN) the event ending position's file offset + * need_sync - (IN) identify if flush_net is needed to call. + * server_id - (IN) master server id number + * + * Return: + * 0: success; non-zero: error + */ + int update_sync_header(THD* thd, unsigned char *packet, + const char *log_file_name, + my_off_t log_file_pos, + bool* need_sync); + + /* Called when a transaction finished writing binlog events. + * . update the 'largest' transactions' binlog event position + * . insert the ending position in the active transaction list if + * semi-sync is on + * + * Input: (the transaction events' ending binlog position) + * log_file_name - (IN) transaction ending position's file name + * log_file_pos - (IN) transaction ending position's file offset + * + * Return: + * 0: success; non-zero: error + */ + int write_tranx_in_binlog(const char* log_file_name, my_off_t log_file_pos); + + /* Read the slave's reply so that we know how much progress the slave makes + * on receive replication events. + */ + int flush_net(THD* thd, const char *event_buf); + + /* Export internal statistics for semi-sync replication. */ + void set_export_stats(); + + /* 'reset master' command is issued from the user and semi-sync need to + * go off for that. + */ + int after_reset_master(); + + /*called before reset master*/ + int before_reset_master(); + + void check_and_switch(); + + mysql_mutex_t LOCK_rpl_semi_sync_master_enabled; +}; + +enum rpl_semi_sync_master_wait_point_t { + SEMI_SYNC_MASTER_WAIT_POINT_AFTER_BINLOG_SYNC, + SEMI_SYNC_MASTER_WAIT_POINT_AFTER_STORAGE_COMMIT, +}; + +extern Repl_semi_sync_master repl_semisync_master; +extern Ack_receiver ack_receiver; + +/* System and status variables for the master component */ +extern my_bool rpl_semi_sync_master_enabled; +extern my_bool rpl_semi_sync_master_status; +extern ulong rpl_semi_sync_master_wait_point; +extern ulong rpl_semi_sync_master_clients; +extern ulong rpl_semi_sync_master_timeout; +extern ulong rpl_semi_sync_master_trace_level; +extern ulong rpl_semi_sync_master_yes_transactions; +extern ulong rpl_semi_sync_master_no_transactions; +extern ulong rpl_semi_sync_master_off_times; +extern ulong rpl_semi_sync_master_wait_timeouts; +extern ulong rpl_semi_sync_master_timefunc_fails; +extern ulong rpl_semi_sync_master_num_timeouts; +extern ulong rpl_semi_sync_master_wait_sessions; +extern ulong rpl_semi_sync_master_wait_pos_backtraverse; +extern ulong rpl_semi_sync_master_avg_trx_wait_time; +extern ulong rpl_semi_sync_master_avg_net_wait_time; +extern ulonglong rpl_semi_sync_master_net_wait_num; +extern ulonglong rpl_semi_sync_master_trx_wait_num; +extern ulonglong rpl_semi_sync_master_net_wait_time; +extern ulonglong rpl_semi_sync_master_trx_wait_time; +extern unsigned long long rpl_semi_sync_master_request_ack; +extern unsigned long long rpl_semi_sync_master_get_ack; + +/* + This indicates whether we should keep waiting if no semi-sync slave + is available. + 0 : stop waiting if detected no avaialable semi-sync slave. + 1 (default) : keep waiting until timeout even no available semi-sync slave. +*/ +extern char rpl_semi_sync_master_wait_no_slave; +extern Repl_semi_sync_master repl_semisync_master; + +extern PSI_stage_info stage_waiting_for_semi_sync_ack_from_slave; +extern PSI_stage_info stage_reading_semi_sync_ack; +extern PSI_stage_info stage_waiting_for_semi_sync_slave; + +void semi_sync_master_deinit(); + +#endif /* SEMISYNC_MASTER_H */ |