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  1. Percona XtraBackup
  2. PXB-1651

Buffer pool dump creates a (null) file during prepare stage of Mysql8.0.12 data

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    Details

    • Type: Bug
    • Status: Done
    • Priority: High
    • Resolution: Fixed
    • Affects Version/s: 8.0-2-alpha2
    • Fix Version/s: 8.0-2-alpha2
    • Component/s: None
    • Labels:
      None
    • Environment:

      CentOS7.5, PXB8.0, MS8.0.12

      Description

      1. Start mysql8.0.12 server

      2. Run PXB8.0 to create the backup

      ./xtrabackup --user=root --password='' --backup --target-dir=$HOME/dbbackup_80 -S $HOME/mysql-8.0.12-linux-glibc2.12-x86_64/socket.sock --datadir=$HOME/mysql-8.0.12-linux-glibc2.12-x86_64/data
      

      Backup directory contents after backup completion:

      -rw-r----- 1 mchawla mchawla 12582912 Sep 13 12:19 ibdata1
      drwxr-x--- 2 mchawla mchawla     4096 Sep 13 12:19 sys
      drwxr-x--- 2 mchawla mchawla     4096 Sep 13 12:19 emp
      -rw-r----- 1 mchawla mchawla 25165824 Sep 13 12:19 mysql.ibd
      -rw-r----- 1 mchawla mchawla 10485760 Sep 13 12:19 undo_002
      -rw-r----- 1 mchawla mchawla 10485760 Sep 13 12:19 undo_001
      drwxr-x--- 2 mchawla mchawla     4096 Sep 13 12:19 mysql
      drwxr-x--- 2 mchawla mchawla     4096 Sep 13 12:19 test
      -rw-r----- 1 mchawla mchawla       19 Sep 13 12:19 xtrabackup_binlog_info
      -rw-r----- 1 mchawla mchawla     2560 Sep 13 12:19 xtrabackup_logfile
      -rw-r----- 1 mchawla mchawla      103 Sep 13 12:19 xtrabackup_checkpoints
      -rw-r----- 1 mchawla mchawla     3369 Sep 13 12:19 ib_buffer_pool
      -rw-r----- 1 mchawla mchawla      476 Sep 13 12:19 backup-my.cnf
      -rw-r----- 1 mchawla mchawla      614 Sep 13 12:19 xtrabackup_info
      -rw-r----- 1 mchawla mchawla       39 Sep 13 12:19 xtrabackup_tablespaces
      

      3. Run PXB8.0 to prepare the backup

      ./xtrabackup --prepare --target-dir=$HOME/dbbackup_80
      

      Backup directory contents after prepare completion:

      drwxr-x--- 2 mchawla mchawla     4096 Sep 13 12:19 sys
      drwxr-x--- 2 mchawla mchawla     4096 Sep 13 12:19 emp
      -rw-r----- 1 mchawla mchawla 25165824 Sep 13 12:19 mysql.ibd
      -rw-r----- 1 mchawla mchawla 10485760 Sep 13 12:19 undo_002
      -rw-r----- 1 mchawla mchawla 10485760 Sep 13 12:19 undo_001
      drwxr-x--- 2 mchawla mchawla     4096 Sep 13 12:19 mysql
      drwxr-x--- 2 mchawla mchawla     4096 Sep 13 12:19 test
      -rw-r----- 1 mchawla mchawla       19 Sep 13 12:19 xtrabackup_binlog_info
      -rw-r----- 1 mchawla mchawla     3369 Sep 13 12:19 ib_buffer_pool
      -rw-r----- 1 mchawla mchawla      476 Sep 13 12:19 backup-my.cnf
      -rw-r----- 1 mchawla mchawla      614 Sep 13 12:19 xtrabackup_info
      -rw-rw-r-- 1 mchawla mchawla        1 Sep 13 12:20 xtrabackup_master_key_id
      -rw-rw-r-- 1 mchawla mchawla       19 Sep 13 12:20 xtrabackup_binlog_pos_innodb
      -rw-r----- 1 mchawla mchawla  8388608 Sep 13 12:20 xtrabackup_logfile
      -rw-r----- 1 mchawla mchawla      103 Sep 13 12:20 xtrabackup_checkpoints
      -rw-r----- 1 mchawla mchawla 50331648 Sep 13 12:20 ib_logfile1
      -rw-r----- 1 mchawla mchawla 50331648 Sep 13 12:20 ib_logfile0
      -rw-r----- 1 mchawla mchawla 12582912 Sep 13 12:20 ibtmp1
      -rw-rw-r-- 1 mchawla mchawla       15 Sep 13 12:20 (null)
      -rw-r----- 1 mchawla mchawla 12582912 Sep 13 12:20 ibdata1
      -rw-r----- 1 mchawla mchawla       39 Sep 13 12:20 xtrabackup_tablespaces
      

      Issue: There is a (null) file created.

       

      The logs indicate that the (null) file is created by the buffer pool dump:

      InnoDB: Loading buffer pool(s) from /home/mchawla/dbbackup_80/(null)
      InnoDB: Cannot open '/home/mchawla/dbbackup_80/(null)' for reading: No such file or directory
      InnoDB: xtrabackup: Last MySQL binlog file position 1020, file name binlog.000003xtrabackup: starting shutdown with innodb_fast_shutdown = 1
      InnoDB: FTS optimize thread exiting.
      InnoDB: Starting shutdown...
      InnoDB: Dumping buffer pool(s) to /home/mchawla/dbbackup_80/(null)
      InnoDB: Buffer pool(s) dump completed at 180913 12:20:40
      

      4. Run PXB8.0 to restore the backup

      ./xtrabackup --copy-back --target-dir=$HOME/dbbackup_80 --datadir=$HOME/mysql-8.0.12-linux-glibc2.12-x86_64/data
      

      The (null) file is copied in the mysql data directory:

      -rw-r----- 1 mchawla mchawla 10485760 Sep 13 12:27 undo_001
      -rw-r----- 1 mchawla mchawla 10485760 Sep 13 12:27 undo_002
      -rw-r----- 1 mchawla mchawla 50331648 Sep 13 12:27 ib_logfile0
      -rw-r----- 1 mchawla mchawla 50331648 Sep 13 12:27 ib_logfile1
      -rw-r----- 1 mchawla mchawla 12582912 Sep 13 12:27 ibdata1
      -rw-r----- 1 mchawla mchawla       15 Sep 13 12:27 (null)
      -rw-r----- 1 mchawla mchawla       39 Sep 13 12:27 xtrabackup_tablespaces
      -rw-r----- 1 mchawla mchawla     3369 Sep 13 12:27 ib_buffer_pool
      drwxr-x--- 2 mchawla mchawla     4096 Sep 13 12:27 sys
      -rw-r----- 1 mchawla mchawla 25165824 Sep 13 12:27 mysql.ibd
      drwxr-x--- 2 mchawla mchawla     4096 Sep 13 12:27 mysql
      drwxr-x--- 2 mchawla mchawla     4096 Sep 13 12:27 test
      -rw-r----- 1 mchawla mchawla 12582912 Sep 13 12:27 ibtmp1
      drwxr-x--- 2 mchawla mchawla     4096 Sep 13 12:27 emp
      -rw-r----- 1 mchawla mchawla      614 Sep 13 12:27 xtrabackup_info
      -rw-r----- 1 mchawla mchawla       19 Sep 13 12:27 xtrabackup_binlog_pos_innodb
      -rw-r----- 1 mchawla mchawla        1 Sep 13 12:27 xtrabackup_master_key_id
      

      Attached logs:

      1. backup.log
      2. prepare.log
      3. restore.log

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          Attachments

          1. backup.log
            5 kB
            Manish Chawla
          2. prepare.log
            7 kB
            Manish Chawla
          3. restore.log
            10 kB
            Manish Chawla

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              People

              • Assignee:
                sergei.glushchenko Sergei Glushchenko
                Reporter:
                manish.chawla Manish Chawla
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                  Updated:
                  Resolved:

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