Release Notes for MariaDB Enterprise Server 10.2.31-6

This sixth release of MariaDB Enterprise Server 10.2 is a maintenance release, including a variety of fixes.

MariaDB Enterprise Server 10.2.31-6 was released on 2020-03-02.

Fixed Security Vulnerabilities

CVE (with cve.mitre.org link)

CVSS base score

CVE-2020-2574

5.9

Notable Changes

  • The systemd start and stop timeout for the MariaDB service is now set to 900 seconds (15 minutes). (MDEV-17571)

  • For MariaDB Enterprise Cluster (Galera Library 25.3.29):

    • Setting socket.recv_buf_size was not effective because it was done after the socket was connected or accepted. The default value also caused TCP receive buffer auto-tuning to be disabled. This lead to sub-optimal performance in high bandwidth WAN clusters. The default value for socket.recv_buf_size has been changed to auto, which lets the kernel tune the TCP receive buffer. A new variable socket.send_buf_size with default value auto was added to allow send buffer tuning.

Issues Fixed

Can result in data loss

  • An ALTER TABLE ... RENAME could fail without an error and result in a dropped table. (MENT-416)

Can result in crashes, hangs, stalls

Can result in unexpected behavior

  • Executing TRUNCATE or OPTIMIZE on InnoDB tables could lead to an unexpected SQL Error (1118): Row size too large, when innodb_strict_mode=ON (default). (MDEV-21429)

  • Queries which use window functions and implicit grouping could return wrong results. (MDEV-21318)

  • Queries which use DISTINCT COUNT(*) OVER() in the expression returned wrong results. (MDEV-16579)

  • Inefficient thread handling in the thread pool, impacting any application that uses the thread pool. (MDEV-21343)

  • The MariaDB Enterprise Server config file mariadb-enterprise.cnf was not registered as a config file in RPM packages. (MENT-591)

  • ALTER USER IF EXISTS generated a SQL syntax error. (MENT-643)

  • A query using GROUP BY with an expression containing a field of a view could return wrong results. (MDEV-20922)

  • Running the script mysql_tzinfo_to_sql for MariaDB Enterprise Cluster could result in inconsistent timezone information across different nodes. (MDEV-21209)

  • Using the --use-memory option with mariabackup would cause it to run out of memory. (MDEV-20679)

  • For MariaDB Enterprise Cluster (Galera Library 25.3.29):

    • GCS delivered a JOIN message even if the node was in a DONOR state.

    • GCache could contain mixed histories from different clusters.

    • GComm socket timestamping/liveness checking produced false positives during replication of large transactions, which caused excessive amounts of broken connections.

    • Large transactions were able to monopolize bandwidth when segmentation was configured, causing delayed in messages relayed by segment representative. The fix implements fair queuing of messages.

    • Due to a bug in quorum computation, two primary conflicting primary components were formed when the group merged and partitioned again while the new primary view was forming.

Interface Changes

  • innodb_spin_wait_delay system variable default value changed from 6 to 4, matching the default of MariaDB Enterprise Server 10.4 and 10.3.

Platforms

In alignment to the enterprise lifecycle, MariaDB Enterprise Server 10.2.31-6 is provided for:

  • Red Hat Enterprise Linux 8

  • Red Hat Enterprise Linux 7

  • Red Hat Enterprise Linux 6

  • CentOS 8

  • CentOS 7

  • CentOS 6

  • Ubuntu 18.04

  • Ubuntu 16.04

  • Debian 10

  • Debian 9

  • Debian 8

  • SUSE Linux Enterprise Server 15

  • SUSE Linux Enterprise Server 12

  • Microsoft Windows

Note

CentOS 6, Debian 8, and Red Hat Enterprise Linux 6 are no longer supported as per the MariaDB Engineering Policy. Older releases are available from the MariaDB Downloads page. Instructions for installation are included as a README file within the download.