Moved semisync from a plugin to normal server

Part of MDEV-13073 AliSQL Optimize performance of semisync

Did the following renames to match other similar variables
key_ss_mutex_LOCK_binlog_       > key_LOCK_bing
key_ss_cond_COND_binlog_send_  -> key_COND_binlog_send
COND_binlog_send_              -> COND_binlog_send
LOCK_binlog_                   -> LOCK_binlog

debian/mariadb-server-10.2.install does not install semisync libs.

1 files changed, 636 insertions, 0 deletions

diff --git a/sql/semisync_master.h b/sql/semisync_master.h
new file mode 100644
index 00000000000..ff1e3dd48b4
--- /dev/null
+++ b/sql/semisync_master.h
@@ -0,0 +1,636 @@
+/* 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  02110-1301  USA */
+
+
+#ifndef SEMISYNC_MASTER_H
+#define SEMISYNC_MASTER_H
+
+#include "semisync.h"
+
+#ifdef HAVE_PSI_INTERFACE
+extern PSI_mutex_key key_LOCK_binlog;
+extern PSI_cond_key key_COND_binlog_send;
+#endif
+
+extern PSI_stage_info stage_waiting_for_semi_sync_ack_from_slave;
+
+struct TranxNode {
+  char             log_name_[FN_REFLEN];
+  my_off_t          log_pos_;
+  struct TranxNode *next_;            /* the next node in the sorted list */
+  struct TranxNode *hash_next_;    /* the next node during hash collision */
+};
+
+/**
+  @class TranxNodeAllocator
+
+  This class provides memory allocating and freeing methods for
+  TranxNode. 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 TranxNode.
+
+  @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 TranxNodeAllocator
+{
+public:
+  /**
+    @param reserved_nodes
+      The number of reserved TranxNodes. It is used to set 'reserved_blocks'
+      which can contain at least 'reserved_nodes' number of TranxNodes.  When
+      freeing memory, we will reserve at least reserved_blocks of Blocks not
+      freed.
+   */
+  TranxNodeAllocator(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) {}
+
+  ~TranxNodeAllocator()
+  {
+    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 TranxNode *, or NULL if an error occurred.
+   */
+  TranxNode *allocate_node()
+  {
+    TranxNode *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(TranxNode* 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 TranxNodes.
+
+   BLOCK_TRANX_NODES The number of TranxNodes 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;
+    TranxNode 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(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 TranxNode, each session
+   can have only one open transaction. Because of EVENT, the total
+   active transaction nodes can exceed the maximum allowed
+   connections.
+*/
+class ActiveTranx
+  :public Trace {
+private:
+
+  TranxNodeAllocator allocator_;
+  /* These two record the active transaction list in sort order. */
+  TranxNode       *trx_front_, *trx_rear_;
+
+  TranxNode      **trx_htb_;        /* A hash table on active transactions. */
+
+  int              num_entries_;              /* maximum hash table entries */
+  mysql_mutex_t *lock_;                                     /* mutex lock */
+
+  inline void assert_lock_owner();
+
+  inline unsigned int calc_hash(const unsigned char *key,unsigned int 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 TranxNode *node2) {
+    return compare(log_file_name1, log_file_pos1,
+                   node2->log_name_, node2->log_pos_);
+  }
+  int compare(const TranxNode *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 TranxNode *node1, const TranxNode *node2) {
+    return compare(node1->log_name_, node1->log_pos_,
+                   node2->log_name_, node2->log_pos_);
+  }
+
+public:
+  ActiveTranx(mysql_mutex_t *lock, unsigned long trace_level);
+  ~ActiveTranx();
+
+  /* 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.
+   * 
+   * Return:
+   *  0: success;  non-zero: error
+   */
+  int 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 ReplSemiSyncMaster
+  :public ReplSemiSyncBase {
+ private:
+  ActiveTranx    *active_tranxs_;  /* active transaction list: the list will
+                                      be cleared when semi-sync switches off. */
+
+  /* True when initObject has been called */
+  bool 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 LOCK_binlog_ because it can cause deadlocks.
+   */
+  mysql_mutex_t LOCK_binlog;
+
+  /* This is set to true when reply_file_name_ contains meaningful data. */
+  bool            reply_file_name_inited_;
+
+  /* The binlog name up to which we have received replies from any slaves. */
+  char            reply_file_name_[FN_REFLEN];
+
+  /* The position in that file up to which we have the reply from any slaves. */
+  my_off_t        reply_file_pos_;
+
+  /* This is set to true when we know the 'smallest' wait position. */
+  bool            wait_file_name_inited_;
+
+  /* NULL, or the 'smallest' filename that a transaction is waiting for
+   * slave replies.
+   */
+  char            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        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            commit_file_name_inited_;
+
+  /* The 'largest' binlog filename that a commit transaction is seeing.       */
+  char            commit_file_name_[FN_REFLEN];
+
+  /* The 'largest' position in that file that a commit transaction is seeing. */
+  my_off_t        commit_file_pos_;
+
+  /* All global variables which can be set by parameters. */
+  volatile bool            master_enabled_;      /* semi-sync is enabled on the master */
+  unsigned long           wait_timeout_;      /* timeout period(ms) during tranx wait */
+
+  bool            state_;                    /* whether semi-sync is switched */
+
+  void lock();
+  void unlock();
+  void cond_broadcast();
+  int  cond_timewait(struct timespec *wait_time);
+
+  /* Is semi-sync replication on? */
+  bool is_on() {
+    return (state_);
+  }
+
+  void set_master_enabled(bool enabled) {
+    master_enabled_ = enabled;
+  }
+
+  /* Switch semi-sync off because of timeout in transaction waiting. */
+  int 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:
+  ReplSemiSyncMaster();
+  ~ReplSemiSyncMaster() {}
+
+  void cleanup();
+
+  bool getMasterEnabled() {
+    return master_enabled_;
+  }
+  void setTraceLevel(unsigned long trace_level) {
+    trace_level_ = trace_level;
+    if (active_tranxs_)
+      active_tranxs_->trace_level_ = trace_level;
+  }
+
+  /* Set the transaction wait timeout period, in milliseconds. */
+  void setWaitTimeout(unsigned long wait_timeout) {
+    wait_timeout_ = wait_timeout;
+  }
+
+  /* Initialize this class after MySQL parameters are initialized. this
+   * function should be called once at bootstrap time.
+   */
+  int initObject();
+
+  /* Enable the object to enable semi-sync replication inside the master. */
+  int enableMaster();
+
+  /* Enable the object to enable semi-sync replication inside the master. */
+  int disableMaster();
+
+  /* Add a semi-sync replication slave */
+  void add_slave();
+    
+  /* Remove a semi-sync replication slave */
+  void remove_slave();
+
+  /* Is the slave servered by the thread requested semi-sync */
+  bool is_semi_sync_slave();
+
+  /* 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 reportReplyBinlog(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 commitTrx(const char* trx_wait_binlog_name,
+                my_off_t trx_wait_binlog_pos);
+
+  /* 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:
+   *  header   - (IN)  the header buffer
+   *  size     - (IN)  size of the header buffer
+   *
+   * Return:
+   *  size of the bytes reserved for header
+   */
+  int reserveSyncHeader(unsigned char *header, unsigned long size);
+
+  /* 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:
+   *  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
+   *  server_id     - (IN)  master server id number
+   *
+   * Return:
+   *  0: success;  non-zero: error
+   */
+  int updateSyncHeader(unsigned char *packet,
+                       const char *log_file_name,
+		       my_off_t log_file_pos,
+		       uint32 server_id);
+
+  /* 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 writeTranxInBinlog(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.
+   * 
+   * Input:
+   *  net          - (IN)  the connection to master
+   *  server_id    - (IN)  master server id number
+   *  event_buf    - (IN)  pointer to the event packet
+   *
+   * Return:
+   *  0: success;  non-zero: error
+   */
+  int readSlaveReply(NET *net, uint32 server_id, const char *event_buf);
+
+  /* Export internal statistics for semi-sync replication. */
+  void setExportStats();
+
+  /* 'reset master' command is issued from the user and semi-sync need to
+   * go off for that.
+   */
+  int resetMaster();
+};
+
+enum rpl_semi_sync_master_wait_point_t {
+  SEMI_SYNC_MASTER_WAIT_POINT_AFTER_BINLOG_SYNC,
+  SEMI_SYNC_MASTER_WAIT_POINT_AFTER_STORAGE_COMMIT,
+};
+
+/* 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;
+
+/*
+  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 ReplSemiSyncMaster repl_semisync_master;
+
+int semi_sync_master_init();
+void semi_sync_master_deinit();
+
+#endif /* SEMISYNC_MASTER_H */