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  1. MariaDB Server
  2. MDEV-25734

mbstream breaks page compression on XFS

Details

    Description

      As InnoDB page compression uses “hole punching,” and it seems like ignored by somehow. mariabackup SST method leaves compressed data from donor to decompressed on joiner node. mariabackup SST not copying compressed files so page compression seems not beneficial in this case.

      MariaDB [tt]> show create table t1\G
      		 
      *************************** 1. row ***************************
      		 
             Table: t1
      		 
      Create Table: CREATE TABLE `t1` (
      		 
        `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
      		 
        `msg` varchar(100) DEFAULT NULL,
      		 
        UNIQUE KEY `id` (`id`)
      		 
      ) ENGINE=InnoDB AUTO_INCREMENT=34209256 DEFAULT CHARSET=latin1 `PAGE_COMPRESSED`='ON'
      		 
      1 row in set (0.005 sec)
      		 
       
      		 
      +--------------+------------+------------+
      		 
      | TABLE_SCHEMA | TABLE_NAME | ROW_FORMAT |
      		 
      +--------------+------------+------------+
      		 
      | tt           | t1         | Dynamic    |
      		 
      +--------------+------------+------------+
      		 
       
      		 
      MariaDB [tt]> show global variables like '%compression%';
      		 
      +------------------------------------------+------------------+
      		 
      | Variable_name                            | Value            |
      		 
      +------------------------------------------+------------------+
      		 
      | column_compression_threshold             | 100              |
      		 
      | column_compression_zlib_level            | 6                |
      		 
      | column_compression_zlib_strategy         | DEFAULT_STRATEGY |
      		 
      | column_compression_zlib_wrap             | OFF              |
      		 
      | innodb_compression_algorithm             | zlib             |
      		 
      | innodb_compression_default               | ON               |
      		 
      | innodb_compression_failure_threshold_pct | 5                |
      		 
      | innodb_compression_level                 | 1                |
      		 
      | innodb_compression_pad_pct_max           | 50               |
      		 
      +------------------------------------------+------------------+
      		 
      9 rows in set (0.001 sec)

      page compression is enabled. Where size of tablespace file is:

      $ ls -lrth /var/lib/mysql/tt/t1.ibd
      		 
      2.1G /var/lib/mysql/tt/t1.ibd
      		 
       
      		 
      $ du -hs --block-size=1 /var/lib/mysql/tt/t1.ibd
      		 
      1098792960	/var/lib/mysql/tt/t1.ibd
      		 
       
      		 
      $ du -hs /var/lib/mysql/tt/t1.ibd
      		 
      1.1G	/var/lib/mysql/tt/t1.ibd

      Now, let's try mariabackup:

      mariabackup --backup --target-dir=/home/vagrant/backup/ -u root -p'xxxx'
      		 
      .
      		 
      [00] 2021-05-19 20:08:13 completed OK!

      Let's verify backup table t1 tablespace file size again:

      $ ls -la /home/vagrant/backup/tt/t1.ibd
      		 
      -rw-r-----. 1 root root 2231369728 May 19 20:08 /home/vagrant/backup/tt/t1.ibd
      		 
       
      		 
      $ du -hs --block-size=1 /home/vagrant/backup/tt/t1.ibd
      		 
      2214154240	/home/vagrant/backup/tt/t1.ibd
      		 
       
      		 
      $ du -hs /home/vagrant/backup/tt/t1.ibd
      		 
      2.1G	/home/vagrant/backup/tt/t1.ibd

      As per https://dev.mysql.com/doc/refman/5.7/en/innodb-page-compression.html
      Preserving page compression when moving a page-compressed tablespace file from one host to another requires a utility that preserves sparse files

      I think that is related xtrabackup report https://jira.percona.com/browse/PXB-1557

      Attachments

        Issue Links

          relates to

          Bug - A problem which impairs or prevents the functions of the product. MDEV-16129 InnoDB page compression not working as documented

          • Major - Major loss of function.
          • Open

          Task - A task that needs to be done. MDEV-22839 ROW_FORMAT=COMPRESSED vs PAGE_COMPRESSION=1 - size comparison

          • Major - Major loss of function.
          • Open

          Bug - A problem which impairs or prevents the functions of the product. MDEV-13023 mariabackup does not preserve "holes punched" for tables with page_compressed=1

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-15527 page_compressed compressed page partially during import tablespace

          • Major - Major loss of function.
          • Closed

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            People

              serg Sergei Golubchik
              muhammad.irfan Muhammad Irfan
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              19 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved:

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