Bug#25513

  "Federared Transactions Failure"
  Bug occurs when the user performs an operation which inserts more than 
  one row into the federated table and the federated table references a 
  remote table stored within a transactional storage engine. When the
  insert operation for any one row in the statement fails due to 
  constraint violation, the federated engine is unable to perform 
  statement rollback and so the remote table contains a partial commit. 
  The user would expect a statement to perform the same so a statement 
  rollback is expected.
  This bug was fixed by implementing  bulk-insert handling into the
  federated storage engine. This will relieve the bug for most common
  situations by enabling the generation of a multi-row insert into the
  remote table and thus permitting the remote table to perform 
  statement rollback when neccessary.
  The multi-row insert is limited to the maximum packet size between 
  servers and should the size overflow, more than one insert statement 
  will be sent and this bug will reappear. Multi-row insert is disabled
  when an "INSERT...ON DUPLICATE KEY UPDATE" is being performed.
  The bulk-insert handling will offer a significant performance boost 
  when inserting a large number of small rows.
This patch builds on Bug29019 and Bug25511

mysql-test/r/federated_innodb.result

+stop slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+reset master;
+reset slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+start slave;
+stop slave;
+DROP DATABASE IF EXISTS federated;
+CREATE DATABASE federated;
+DROP DATABASE IF EXISTS federated;
+CREATE DATABASE federated;
+create table federated.t1 (a int primary key, b varchar(64))
+engine=myisam;
+create table federated.t1 (a int primary key, b varchar(64))
+engine=federated
+connection='mysql://root@127.0.0.1:SLAVE_PORT/federated/t1';
+insert into federated.t1 values (1,"Larry"), (2,"Curly"), (1,"Moe");
+ERROR 23000: Can't write; duplicate key in table 't1'
+select * from federated.t1;
+a	b
+1	Larry
+2	Curly
+truncate federated.t1;
+alter table federated.t1 engine=innodb;
+insert into federated.t1 values (1,"Larry"), (2,"Curly"), (1,"Moe");
+ERROR 23000: Can't write; duplicate key in table 't1'
+select * from federated.t1;
+a	b
+drop table federated.t1;
+drop table federated.t1;
+DROP TABLE IF EXISTS federated.t1;
+DROP DATABASE IF EXISTS federated;
+DROP TABLE IF EXISTS federated.t1;
+DROP DATABASE IF EXISTS federated;

mysql-test/t/federated_innodb-slave.opt

+--innodb

mysql-test/t/federated_innodb.test

+source include/federated.inc;
+source include/have_innodb.inc;
+
+#
+# Bug#25513 Federated transaction failures
+#
+connection slave;
+create table federated.t1 (a int primary key, b varchar(64))
+  engine=myisam;
+connection master;
+--replace_result $SLAVE_MYPORT SLAVE_PORT
+eval create table federated.t1 (a int primary key, b varchar(64))
+  engine=federated
+  connection='mysql://root@127.0.0.1:$SLAVE_MYPORT/federated/t1';
+
+--error ER_DUP_KEY
+insert into federated.t1 values (1,"Larry"), (2,"Curly"), (1,"Moe");
+select * from federated.t1;
+
+connection slave;
+truncate federated.t1;
+alter table federated.t1 engine=innodb;
+connection master;
+
+--error ER_DUP_KEY
+insert into federated.t1 values (1,"Larry"), (2,"Curly"), (1,"Moe");
+select * from federated.t1;
+
+drop table federated.t1;
+connection slave;
+drop table federated.t1;
+
+
+source include/federated_cleanup.inc;

sql/ha_federated.cc

@@ -352,6 +352,7 @@ static char ident_quote_char= '`';              // Character for quoting
                                                 // identifiers
 static char value_quote_char= '\'';             // Character for quoting
                                                 // literals
+static const int bulk_padding= 64;              // bytes "overhead" in packet
 
 /* Federated storage engine handlerton */
 
@@ -773,7 +774,9 @@ error:
 ha_federated::ha_federated(TABLE *table_arg)
   :handler(&federated_hton, table_arg),
   mysql(0), stored_result(0)
-{}
+{
+  bzero(&bulk_insert, sizeof(bulk_insert));
+}
 
 
 /*
@@ -1584,6 +1587,83 @@ inline uint field_in_record_is_null(TABLE *table,
   DBUG_RETURN(0);
 }
 
+
+/**
+  @brief Construct the INSERT statement.
+  
+  @details This method will construct the INSERT statement and appends it to
+  the supplied query string buffer.
+  
+  @return
+    @retval FALSE       No error
+    @retval TRUE        Failure
+*/
+
+bool ha_federated::append_stmt_insert(String *query)
+{
+  char insert_buffer[FEDERATED_QUERY_BUFFER_SIZE];
+  Field **field;
+  uint tmp_length;
+
+  /* The main insert query string */
+  String insert_string(insert_buffer, sizeof(insert_buffer), &my_charset_bin);
+  DBUG_ENTER("ha_federated::append_stmt_insert");
+
+  insert_string.length(0);
+
+  if (replace_duplicates)
+    insert_string.append(STRING_WITH_LEN("REPLACE INTO "));
+  else if (ignore_duplicates && !insert_dup_update)
+    insert_string.append(STRING_WITH_LEN("INSERT IGNORE INTO "));
+  else
+    insert_string.append(STRING_WITH_LEN("INSERT INTO "));
+  append_ident(&insert_string, share->table_name, share->table_name_length, 
+               ident_quote_char);
+  insert_string.append(FEDERATED_OPENPAREN);
+  tmp_length= insert_string.length() - strlen(FEDERATED_COMMA);
+
+  /*
+    loop through the field pointer array, add any fields to both the values
+    list and the fields list that match the current query id
+  */
+  for (field= table->field; *field; field++)
+  {
+    /* append the field name */
+    append_ident(&insert_string, (*field)->field_name, 
+                 strlen((*field)->field_name), ident_quote_char);
+
+    /* append commas between both fields and fieldnames */
+    /*
+      unfortunately, we can't use the logic
+      if *(fields + 1) to make the following
+      appends conditional because we may not append
+      if the next field doesn't match the condition:
+      (((*field)->query_id && (*field)->query_id == current_query_id)
+    */
+    insert_string.append(FEDERATED_COMMA);
+  }
+
+  /*
+    remove trailing comma
+  */
+  insert_string.length(insert_string.length() - strlen(FEDERATED_COMMA));
+
+  /*
+    if there were no fields, we don't want to add a closing paren
+    AND, we don't want to chop off the last char '('
+    insert will be "INSERT INTO t1 VALUES ();"
+  */
+  if (insert_string.length() > tmp_length)
+  {
+    insert_string.append(FEDERATED_CLOSEPAREN);
+  }
+
+  insert_string.append(FEDERATED_VALUES);
+
+  DBUG_RETURN(query->append(insert_string));
+}
+
+
 /*
   write_row() inserts a row. No extra() hint is given currently if a bulk load
   is happeneding. buf() is a byte array of data. You can use the field
@@ -1600,13 +1680,14 @@ inline uint field_in_record_is_null(TABLE *table,
 
 int ha_federated::write_row(byte *buf)
 {
-  char insert_buffer[FEDERATED_QUERY_BUFFER_SIZE];
   char values_buffer[FEDERATED_QUERY_BUFFER_SIZE];
   char insert_field_value_buffer[STRING_BUFFER_USUAL_SIZE];
   Field **field;
+  uint tmp_length;
+  int error= 0;
+  bool use_bulk_insert;
+  bool auto_increment_update_required= table->next_number_field;
 
-  /* The main insert query string */
-  String insert_string(insert_buffer, sizeof(insert_buffer), &my_charset_bin);
   /* The string containing the values to be added to the insert */
   String values_string(values_buffer, sizeof(values_buffer), &my_charset_bin);
   /* The actual value of the field, to be added to the values_string */
@@ -1614,7 +1695,6 @@ int ha_federated::write_row(byte *buf)
                                    sizeof(insert_field_value_buffer),
                                    &my_charset_bin);
   values_string.length(0);
-  insert_string.length(0);
   insert_field_value_string.length(0);
   DBUG_ENTER("ha_federated::write_row");
 
@@ -1624,19 +1704,19 @@ int ha_federated::write_row(byte *buf)
 
   /*
     start both our field and field values strings
+    We must disable multi-row insert for "INSERT...ON DUPLICATE KEY UPDATE"
+    Ignore duplicates is always true when insert_dup_update is true.
+    When replace_duplicates == TRUE, we can safely enable multi-row insert.
+    When performing multi-row insert, we only collect the columns values for
+    the row. The start of the statement is only created when the first
+    row is copied in to the bulk_insert string.
   */
-  if (replace_duplicates)
-    insert_string.append(STRING_WITH_LEN("REPLACE INTO "));
-  else if (ignore_duplicates && !insert_dup_update)
-    insert_string.append(STRING_WITH_LEN("INSERT IGNORE INTO "));
-  else
-    insert_string.append(STRING_WITH_LEN("INSERT INTO "));
-  append_ident(&insert_string, share->table_name,
-               share->table_name_length, ident_quote_char);
-  insert_string.append(FEDERATED_OPENPAREN);
+  if (!(use_bulk_insert= bulk_insert.str && 
+        (!insert_dup_update || replace_duplicates)))
+    append_stmt_insert(&values_string);
 
-  values_string.append(FEDERATED_VALUES);
   values_string.append(FEDERATED_OPENPAREN);
+  tmp_length= values_string.length();
 
   /*
     loop through the field pointer array, add any fields to both the values
@@ -1655,9 +1735,6 @@ int ha_federated::write_row(byte *buf)
 
       insert_field_value_string.length(0);
     }
-    /* append the field name */
-    append_ident(&insert_string, (*field)->field_name, 
-                 strlen((*field)->field_name), ident_quote_char);
 
     /* append the value */
     values_string.append(insert_field_value_string);
@@ -1671,32 +1748,61 @@ int ha_federated::write_row(byte *buf)
       if the next field doesn't match the condition:
       (((*field)->query_id && (*field)->query_id == current_query_id)
     */
-    insert_string.append(FEDERATED_COMMA);
     values_string.append(FEDERATED_COMMA);
   }
 
-  /*
-    remove trailing comma
-  */
-  insert_string.length(insert_string.length() - strlen(FEDERATED_COMMA));
   /*
     if there were no fields, we don't want to add a closing paren
     AND, we don't want to chop off the last char '('
     insert will be "INSERT INTO t1 VALUES ();"
   */
-  if (table->s->fields)
+  if (values_string.length() > tmp_length)
   {
     /* chops off leading commas */
     values_string.length(values_string.length() - strlen(FEDERATED_COMMA));
-    insert_string.append(FEDERATED_CLOSEPAREN);
   }
   /* we always want to append this, even if there aren't any fields */
   values_string.append(FEDERATED_CLOSEPAREN);
 
-  /* add the values */
-  insert_string.append(values_string);
+  if (use_bulk_insert)
+  {
+    /*
+      Send the current bulk insert out if appending the current row would
+      cause the statement to overflow the packet size, otherwise set
+      auto_increment_update_required to FALSE as no query was executed.
+    */
+    if (bulk_insert.length + values_string.length() + bulk_padding >
+        mysql->net.max_packet_size && bulk_insert.length)
+    {
+      error= mysql_real_query(mysql, bulk_insert.str, bulk_insert.length);
+      bulk_insert.length= 0;
+    }
+    else
+      auto_increment_update_required= FALSE;
+      
+    if (bulk_insert.length == 0)
+    {
+      char insert_buffer[FEDERATED_QUERY_BUFFER_SIZE];
+      String insert_string(insert_buffer, sizeof(insert_buffer), 
+                           &my_charset_bin);
+      insert_string.length(0);
+      append_stmt_insert(&insert_string);
+      dynstr_append_mem(&bulk_insert, insert_string.ptr(), 
+                        insert_string.length());
+    }
+    else
+      dynstr_append_mem(&bulk_insert, ",", 1);
+
+    dynstr_append_mem(&bulk_insert, values_string.ptr(), 
+                      values_string.length());
+  }  
+  else
+  {
+    error= mysql_real_query(mysql, values_string.ptr(), 
+                            values_string.length());
+  }
   
-  if (mysql_real_query(mysql, insert_string.ptr(), insert_string.length()))
+  if (error)
   {
     DBUG_RETURN(stash_remote_error());
   }
@@ -1704,12 +1810,79 @@ int ha_federated::write_row(byte *buf)
     If the table we've just written a record to contains an auto_increment
     field, then store the last_insert_id() value from the foreign server
   */
-  if (table->next_number_field)
+  if (auto_increment_update_required)
     update_auto_increment();
 
   DBUG_RETURN(0);
 }
 
+
+/**
+  @brief Prepares the storage engine for bulk inserts.
+  
+  @param[in] rows       estimated number of rows in bulk insert 
+                        or 0 if unknown.
+  
+  @details Initializes memory structures required for bulk insert.
+*/
+
+void ha_federated::start_bulk_insert(ha_rows rows)
+{
+  uint page_size;
+  DBUG_ENTER("ha_federated::start_bulk_insert");
+
+  dynstr_free(&bulk_insert);
+  
+  /**
+    We don't bother with bulk-insert semantics when the estimated rows == 1
+    The rows value will be 0 if the server does not know how many rows
+    would be inserted. This can occur when performing INSERT...SELECT
+  */
+  
+  if (rows == 1)
+    DBUG_VOID_RETURN;
+
+  page_size= (uint) my_getpagesize();
+
+  if (init_dynamic_string(&bulk_insert, NULL, page_size, page_size))
+    DBUG_VOID_RETURN;
+  
+  bulk_insert.length= 0;
+  DBUG_VOID_RETURN;
+}
+
+
+/**
+  @brief End bulk insert.
+  
+  @details This method will send any remaining rows to the remote server.
+  Finally, it will deinitialize the bulk insert data structure.
+  
+  @return Operation status
+  @retval       0       No error
+  @retval       != 0    Error occured at remote server. Also sets my_errno.
+*/
+
+int ha_federated::end_bulk_insert()
+{
+  int error= 0;
+  DBUG_ENTER("ha_federated::end_bulk_insert");
+  
+  if (bulk_insert.str && bulk_insert.length)
+  {
+    if (mysql_real_query(mysql, bulk_insert.str, bulk_insert.length))
+      error= stash_remote_error();
+    else
+    if (table->next_number_field)
+      update_auto_increment();
+  }
+
+  dynstr_free(&bulk_insert);
+  
+  DBUG_RETURN(my_errno= error);
+}
+
+
 /*
   ha_federated::update_auto_increment
 
@@ -2451,7 +2624,6 @@ int ha_federated::info(uint flag)
 {
   char error_buffer[FEDERATED_QUERY_BUFFER_SIZE];
   char status_buf[FEDERATED_QUERY_BUFFER_SIZE];
-  char escaped_table_name[FEDERATED_QUERY_BUFFER_SIZE];
   int error;
   uint error_code;
   MYSQL_RES *result= 0;

sql/ha_federated.h

@@ -159,6 +159,7 @@ class ha_federated: public handler
   char remote_error_buf[FEDERATED_QUERY_BUFFER_SIZE];
   bool ignore_duplicates, replace_duplicates;
   bool insert_dup_update;
+  DYNAMIC_STRING bulk_insert;
 
 private:
   /*
@@ -173,6 +174,14 @@ private:
                              bool records_in_range);
   int stash_remote_error();
 
+  bool append_stmt_insert(String *query);
+
+  int read_next(byte *buf, MYSQL_RES *result);
+  int index_read_idx_with_result_set(byte *buf, uint index,
+                                     const byte *key,
+                                     uint key_len,
+                                     ha_rkey_function find_flag,
+                                     MYSQL_RES **result);
 public:
   ha_federated(TABLE *table_arg);
   ~ha_federated()
@@ -258,6 +267,8 @@ public:
   int open(const char *name, int mode, uint test_if_locked);    // required
   int close(void);                                              // required
 
+  void start_bulk_insert(ha_rows rows);
+  int end_bulk_insert();
   int write_row(byte *buf);
   int update_row(const byte *old_data, byte *new_data);
   int delete_row(const byte *buf);
@@ -301,14 +312,7 @@ public:
 
   THR_LOCK_DATA **store_lock(THD *thd, THR_LOCK_DATA **to,
                              enum thr_lock_type lock_type);     //required
-  virtual bool get_error_message(int error, String *buf);
-
-  int read_next(byte *buf, MYSQL_RES *result);
-  int index_read_idx_with_result_set(byte *buf, uint index,
-                                     const byte *key,
-                                     uint key_len,
-                                     ha_rkey_function find_flag,
-                                     MYSQL_RES **result);
+  bool get_error_message(int error, String *buf);
 };
 
 bool federated_db_init(void);