MDEV-39091 BACKUP SERVER of ENGINE=RocksDB to the local file system

mysql-test/suite/backup/backup_rocksdb.opt

@@ -0,0 +1 @@
+--plugin-load-add=$HA_ROCKSDB_SO

mysql-test/suite/backup/backup_rocksdb.result

@@ -0,0 +1,61 @@
+CREATE TABLE ti(a INT PRIMARY KEY, b CHAR(255) DEFAULT '' NOT NULL, INDEX(b))
+ENGINE=INNODB;
+INSERT INTO ti SET a=1;
+CREATE TABLE tr(a INT PRIMARY KEY, b CHAR(200)) ENGINE=ROCKSDB;
+INSERT INTO tr VALUES (1,'r-one'),(2,'r-two'),(3,'r-three');
+SET GLOBAL rocksdb_force_flush_memtable_now=1;
+BACKUP SERVER TO 'target_dir';
+INSERT INTO tr VALUES (4,'r-four');
+INSERT INTO ti VALUES (2,'two');
+# restart: --defaults-file=MYSQLTEST_VARDIR/tmp/backup_rocksdb_dir/backup.cnf --datadir=MYSQLTEST_VARDIR/tmp/backup_rocksdb_dir --plugin-load-add=ha_rocksdb.so
+SELECT * FROM ti;
+a	b
+1	
+SELECT * FROM tr;
+a	b
+1	r-one
+2	r-two
+3	r-three
+# restart on the original datadir
+# restart
+SELECT * FROM ti;
+a	b
+1	
+2	two
+SELECT * FROM tr;
+a	b
+1	r-one
+2	r-two
+3	r-three
+4	r-four
+#
+# BACKUP SERVER WITH ... N CONCURRENT (streamed oldgnu tar)
+#
+BACKUP SERVER WITH 2 CONCURRENT 'rstream.bat';
+INSERT INTO tr VALUES (5,'r-five');
+INSERT INTO ti VALUES (3,'three');
+# restart: --defaults-file=MYSQLTEST_VARDIR/tmp/backup_rocksdb_stream/backup.cnf --datadir=MYSQLTEST_VARDIR/tmp/backup_rocksdb_stream --plugin-load-add=ha_rocksdb.so
+SELECT * FROM ti;
+a	b
+1	
+2	two
+SELECT * FROM tr;
+a	b
+1	r-one
+2	r-two
+3	r-three
+4	r-four
+# restart
+SELECT * FROM ti;
+a	b
+1	
+3	three
+2	two
+SELECT * FROM tr;
+a	b
+1	r-one
+2	r-two
+3	r-three
+4	r-four
+5	r-five
+DROP TABLE ti, tr;

mysql-test/suite/backup/backup_rocksdb.test

@@ -0,0 +1,76 @@
+--source include/have_rocksdb.inc
+--source include/have_innodb.inc
+
+CREATE TABLE ti(a INT PRIMARY KEY, b CHAR(255) DEFAULT '' NOT NULL, INDEX(b))
+ENGINE=INNODB;
+INSERT INTO ti SET a=1;
+
+CREATE TABLE tr(a INT PRIMARY KEY, b CHAR(200)) ENGINE=ROCKSDB;
+INSERT INTO tr VALUES (1,'r-one'),(2,'r-two'),(3,'r-three');
+SET GLOBAL rocksdb_force_flush_memtable_now=1;
+
+--let $targetdir=$MYSQLTEST_VARDIR/tmp/backup_rocksdb_dir
+--error 0,1
+--rmdir $targetdir
+--replace_result $targetdir target_dir
+--eval BACKUP SERVER TO '$targetdir'
+--file_exists $targetdir/#rocksdb
+
+INSERT INTO tr VALUES (4,'r-four');
+INSERT INTO ti VALUES (2,'two');
+
+--exec cat $MYSQLTEST_VARDIR/my.cnf >> $targetdir/backup.cnf
+--let $restart_parameters=--defaults-file=$targetdir/backup.cnf --datadir=$targetdir --plugin-load-add=$HA_ROCKSDB_SO
+--source include/restart_mysqld.inc
+
+SELECT * FROM ti;
+SELECT * FROM tr;
+
+--echo # restart on the original datadir
+--let $restart_parameters=
+--source include/restart_mysqld.inc
+SELECT * FROM ti;
+SELECT * FROM tr;
+--rmdir $targetdir
+
+--echo #
+--echo # BACKUP SERVER WITH ... N CONCURRENT (streamed oldgnu tar)
+--echo #
+--remove_files_wildcard $MYSQL_TMP_DIR/. rstream.bat
+--write_file $MYSQL_TMP_DIR/rstream.bat
+#!/bin/sh
+exec cat > $MYSQL_TMP_DIR/$1.tar
+EOF
+--let $script=/bin/sh $MYSQL_TMP_DIR/rstream.bat
+
+--replace_result $script rstream.bat
+eval BACKUP SERVER WITH 2 CONCURRENT '$script';
+--remove_file $MYSQL_TMP_DIR/rstream.bat
+
+INSERT INTO tr VALUES (5,'r-five');
+INSERT INTO ti VALUES (3,'three');
+
+--let $target_directory=$MYSQLTEST_VARDIR/tmp/backup_rocksdb_stream
+--error 0,1
+--rmdir $target_directory
+--mkdir $target_directory
+--exec tar xf $MYSQL_TMP_DIR/1.tar -C $target_directory
+--exec tar xf $MYSQL_TMP_DIR/2.tar -C $target_directory
+--file_exists $target_directory/#rocksdb
+--exec cat $MYSQLTEST_VARDIR/my.cnf >> $target_directory/backup.cnf
+
+--let $restart_parameters=--defaults-file=$target_directory/backup.cnf --datadir=$target_directory --plugin-load-add=$HA_ROCKSDB_SO
+--source include/restart_mysqld.inc
+SELECT * FROM ti;
+SELECT * FROM tr;
+
+--remove_file $MYSQL_TMP_DIR/1.tar
+--remove_file $MYSQL_TMP_DIR/2.tar
+
+--let $restart_parameters=
+--source include/restart_mysqld.inc
+SELECT * FROM ti;
+SELECT * FROM tr;
+
+DROP TABLE ti, tr;
+--rmdir $target_directory

mysql-test/suite/backup/suite.pm

@@ -13,6 +13,7 @@ my $have_tar = `tar --version 2>&1` =~ /tar .*\d\.\d/;
 sub skip_combinations {
   my %skip;
   $skip{'backup_stream.test'} = 'needs cat,tar' unless $have_cat && $have_tar;
+  $skip{'backup_rocksdb.test'} = 'needs cat,tar' unless $have_cat && $have_tar;
   %skip;
 }
 

storage/rocksdb/CMakeLists.txt

@@ -99,6 +99,8 @@ SET(ROCKSDB_SE_SOURCES
   rdb_sst_info.h
   rdb_converter.cc
   rdb_converter.h
+  rdb_backup_server.cc
+  rdb_backup_server.h
 )
 
 # MariaDB: the following is added in build_rocksdb.cmake, when appropriate:

storage/rocksdb/ha_rocksdb.cc

@@ -73,6 +73,7 @@
 /* MyRocks includes */
 #include "./event_listener.h"
 #include "./ha_rocksdb_proto.h"
+#include "./rdb_backup_server.h"
 #include "./logger.h"
 #include "./nosql_access.h"
 #include "./rdb_cf_manager.h"
@@ -371,6 +372,41 @@ static std::string rdb_normalize_dir(std::string dir) {
   return dir;
 }
 
+/** Create a RocksDB checkpoint (a consistent, hardlink-based
+snapshot of the live database) in @checkpoint_dir.
+@return HA_EXIT_SUCCESS on success
+@return HA_EXIT_FAILURE otherwise (my_error() has already been
+raised via rdb_error_to_mysql()). */
+int rdb_create_checkpoint(const char *checkpoint_dir_raw)
+{
+  if (!checkpoint_dir_raw || rdb == nullptr)
+    return HA_EXIT_FAILURE;
+
+  std::string checkpoint_dir = rdb_normalize_dir(checkpoint_dir_raw);
+  // NO_LINT_DEBUG
+  sql_print_information("RocksDB: creating checkpoint in directory : %s\n",
+                        checkpoint_dir.c_str());
+  rocksdb::Checkpoint *checkpoint;
+  auto status = rocksdb::Checkpoint::Create(rdb, &checkpoint);
+  // We can only return HA_EXIT_FAILURE/HA_EXIT_SUCCESS here which is why
+  // the return code is ignored, but by calling into rdb_error_to_mysql,
+  // it will call my_error for us, which will propogate up to the client.
+  int rc __attribute__((__unused__));
+  if (status.ok()) {
+    status = checkpoint->CreateCheckpoint(checkpoint_dir.c_str());
+
+    delete checkpoint;
+    if (status.ok()) {
+      // NO_LINT_DEBUG
+      sql_print_information("RocksDB: created checkpoint in directory : %s\n",
+                            checkpoint_dir.c_str());
+      return HA_EXIT_SUCCESS;
+    }
+  }
+  rc = ha_rocksdb::rdb_error_to_mysql(status);
+  return HA_EXIT_FAILURE;
+}
+
 static int rocksdb_create_checkpoint(
     THD *const thd MY_ATTRIBUTE((__unused__)),
     struct st_mysql_sys_var *const var MY_ATTRIBUTE((__unused__)),
@@ -379,36 +415,7 @@ static int rocksdb_create_checkpoint(
   char buf[FN_REFLEN];
   int len = sizeof(buf);
   const char *const checkpoint_dir_raw = value->val_str(value, buf, &len);
-  if (checkpoint_dir_raw) {
-    if (rdb != nullptr) {
-      std::string checkpoint_dir = rdb_normalize_dir(checkpoint_dir_raw);
-      // NO_LINT_DEBUG
-      sql_print_information("RocksDB: creating checkpoint in directory : %s\n",
-                            checkpoint_dir.c_str());
-      rocksdb::Checkpoint *checkpoint;
-      auto status = rocksdb::Checkpoint::Create(rdb, &checkpoint);
-      // We can only return HA_EXIT_FAILURE/HA_EXIT_SUCCESS here which is why
-      // the return code is ignored, but by calling into rdb_error_to_mysql,
-      // it will call my_error for us, which will propogate up to the client.
-      int rc __attribute__((__unused__));
-      if (status.ok()) {
-        status = checkpoint->CreateCheckpoint(checkpoint_dir.c_str());
-        delete checkpoint;
-        if (status.ok()) {
-          // NO_LINT_DEBUG
-          sql_print_information(
-              "RocksDB: created checkpoint in directory : %s\n",
-              checkpoint_dir.c_str());
-          return HA_EXIT_SUCCESS;
-        } else {
-          rc = ha_rocksdb::rdb_error_to_mysql(status);
-        }
-      } else {
-        rc = ha_rocksdb::rdb_error_to_mysql(status);
-      }
-    }
-  }
-  return HA_EXIT_FAILURE;
+  return rdb_create_checkpoint(checkpoint_dir_raw);
 }
 
 /* This method is needed to indicate that the
@@ -725,6 +732,20 @@ static int rmdir_force(const char *dir) {
 }
 
 
+/** Remove a RocksDB checkpoint directory @checkpoint_dir.
+The server owns these files, so removal always happens here rather
+than by unlinking from the backup code directly. */
+void rdb_remove_checkpoint(const char *checkpoint_dir) {
+  if (unlink(checkpoint_dir) == 0)
+    return;
+
+  rmdir_force(checkpoint_dir);
+}
+
+/* Return the configured RocksDB data directory (rocksdb_datadir). */
+const char *rdb_get_datadir() { return rocksdb_datadir; }
+
+
 static void rocksdb_remove_mariabackup_checkpoint(
     my_core::THD *const,
     struct st_mysql_sys_var *const ,
@@ -733,10 +754,7 @@ static void rocksdb_remove_mariabackup_checkpoint(
 
   mariabackup_checkpoint_dir.append("/mariabackup-checkpoint");
 
-  if (unlink(mariabackup_checkpoint_dir.c_str())  == 0)
-    return;
-
-  rmdir_force(mariabackup_checkpoint_dir.c_str());
+  rdb_remove_checkpoint(mariabackup_checkpoint_dir.c_str());
 }
 
 
@@ -5342,6 +5360,11 @@ static int rocksdb_init_func(void *const p) {
   */
   rocksdb_hton->check_version = rocksdb_check_version;
 
+  /* BACKUP SERVER hooks (see rdb_backup_server.cc) */
+  rocksdb_hton->backup_start = rocksdb_backup_start;
+  rocksdb_hton->backup_step = rocksdb_backup_step;
+  rocksdb_hton->backup_end = rocksdb_backup_end;
+
   rocksdb_hton->flags = HTON_TEMPORARY_NOT_SUPPORTED |
                         HTON_SUPPORTS_EXTENDED_KEYS | HTON_CAN_RECREATE;
 

storage/rocksdb/ha_rocksdb_proto.h

@@ -66,6 +66,13 @@ void rdb_get_global_perf_counters(Rdb_perf_counters *counters)
 
 void rdb_queue_save_stats_request();
 
+/** BACKUP SERVER: RocksDB checkpoint helpers, shared between the
+ROCKSDB_CREATE_CHECKPOINT and ROCKSDB_REMOVE_MARIABACKUP_CHECKPOINT
+system variables and the handlerton backup hooks. */
+int rdb_create_checkpoint(const char *checkpoint_dir);
+void rdb_remove_checkpoint(const char *checkpoint_dir);
+const char *rdb_get_datadir();
+
 /*
   Access to singleton objects.
 */