MySQL Community Server 5.7.15 has been released

[Jocelyn Ramilison]

Dear MySQL users,

MySQL Server 5.7.15, a new version of the popular Open Source
Database Management System, has been released. MySQL 5.7.15 is
recommended for use on production systems.

For an overview of what's new in MySQL 5.7, please see

http://dev.mysql.com/doc/refman/5.7/en/mysql-nutshell.html

For information on installing MySQL 5.7.15 on new servers, please see
the MySQL installation documentation at

http://dev.mysql.com/doc/refman/5.7/en/installing.html

MySQL Server 5.7.15 is available in source and binary form for a number of
platforms from our download pages at

http://dev.mysql.com/downloads/mysql/

MySQL Server 5.7.15 is also available from our repository for Linux
platforms, go here for details:

http://dev.mysql.com/downloads/repo/

Windows packages are available via the Installer for Windows or .ZIP
(no-install) packages for more advanced needs. The point and click
configuration wizards and all MySQL products are available in the
unified Installer for Windows:

http://dev.mysql.com/downloads/installer/

5.7.15 also comes with a web installer as an alternative to the full
installer.

The web installer doesn't come bundled with any actual products
and instead relies on download-on-demand to fetch only the
products you choose to install. This makes the initial download
much smaller but increases install time as the individual products
will need to be downloaded.

We welcome and appreciate your feedback, bug reports, bug fixes,
patches, etc.:

http://bugs.mysql.com/report.php

The following section lists the changes in MySQL 5.7 since
the release of MySQL 5.7.14. It may also be viewed online at

http://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-15.html

Enjoy!

Changes in MySQL 5.7.15 (2016-09-06)

    Security Notes

      * The validate_password plugin now supports the capability
        of rejecting passwords that match the current session
        user name, either forward or in reverse. To enable
        control over this capability, the plugin exposes a
        validate_password_check_user_name system variable. By
        default, this variable is disabled; the default will
        change to enabled in MySQL 8.0. For more information, see
        Password Validation Plugin Options and Variables
 (http://dev.mysql.com/doc/refman/5.7/en/validate-password-options-variables.html).

    Test Suite Notes

      * In mysql-test-run.pl, a limit of 50 was imposed on the
        number of workers for parallel testing, which on systems
        with more than 50 CPUs resulted in exhaustion of unique
        thread IDs. The ID-exhaustion problem has been corrected,
        and the limit of 50 on number of workers has been lifted.
        Thanks to Daniel Black for the patch on which this change
        was based. Additionally, these changes were made:

           + To avoid idle workers, the number of parallel
             workers now is limited to the number of tests.

           + Previously, if --parallel=auto was given and the
             MTR_MAX_PARALLEL environment variable was not set, a
             limit of 8 was imposed on the number of parallel
             workers. This limit has been lifted.
        (Bug #22342399, Bug #79585)

    Functionality Added or Changed

      * InnoDB: A new dynamic configuration option,
        innodb_deadlock_detect, can be used to disable deadlock
        detection. On high concurrency systems, deadlock
        detection can cause a slowdown when numerous threads wait
        for the same lock. At times, it may be more efficient to
        disable deadlock detection and rely on the
        innodb_lock_wait_timeout setting for transaction rollback
        when a deadlock occurs. (Bug #23477773)

      * The systemd support script for the unit file
        (mysqld_pre_systemd) now assists in creating the error
        log file only if its location matches the pattern
        /var/log/mysql*.log. In other cases, the error log
        directory must be writable or the error log must be
        present and writable for the user running the mysqld
        process. Also, mysqld_pre_systemd now avoids creating
        insecure temporary files. (Bug #24516262)

      * The CMake WITH_LZ4 option has been added to control which
        LZ4 library is used during compilation. By default
        WITH_LZ4 is set to bundled, so the library provided with
        MySQL is used. Setting WITH_LZ4 to system uses the LZ4
        library from the operating system. (Bug #23607230)

    Bugs Fixed

      * InnoDB: An ALTER TABLE ... ENCRYPTION='Y', ALGORITHM=COPY
        operation on a table residing in the system tablespace
        raised an assertion. (Bug #24381804)

      * InnoDB: Creating an encrypted table on a Fusion-io disk
        with an innodb_flush_method setting of O_DIRECT caused a
        fatal error. (Bug #24329079, Bug #82073)

      * InnoDB: An operation that dropped and created a full-text
        search table raised an assertion. (Bug #24315031)

      * InnoDB: Accessing full-text search auxiliary tables while
        dropping the indexed table raised an assertion. (Bug
        #24009272)

      * InnoDB: An online DDL operation on a table with indexed
        BLOB columns raised an assertion during logging of table
        modifications. (Bug #23760086)

      * InnoDB: In some cases, code that locates a buffer pool
        chunk corresponding to given pointer returned the wrong
        chunk.
        Thanks to Alexey Kopytov for the patch. (Bug #23631471,
        Bug #79378)

      * Replication: The addition of the
        transaction-write-set-extraction=XXH64 option uses xxHash
        symbols from liblz4. Although the xxHash symbols are
        exported by liblz4, the header file is not part of the
        API, so compilation failed when building with
        WITH_LZ4=system. The fix ensures that xxHash is built
        separately from liblz4 so that it is available both when
        using the system and bundled LZ4 libraries. (Bug #82426,
        Bug #24399819)
        References: See also: Bug #23607230.

      * Replication: mysqlbinlog --read-from-remote-server log1
        log2 was opening a new connection for log2 without
        freeing the connection used for log1. Thanks to Laurynas
        Biveinis for the contribution. (Bug #81675, Bug
        #23540182)

      * Replication: The MTR binary log test suite failed to
        clean up copied files. Thanks to Daniel Black for the
        contribution. (Bug #80881, Bug #23016254)

      * Replication: With binlog_row_image=FULL, when updating
        single tables temporary tables were unnecessarily being
        used. The fix ensures single table update follows the
        same pattern as multi-table update. (Bug #79867, Bug
        #22510353)

      * mysqld_safe attempted to read my.cnf in the data
        directory, although that is no longer a standard option
        file location. (Bug #24482156)

      * For mysqld_safe, the argument to --malloc-lib now must be
        one of the directories /usr/lib, /usr/lib64,
        /usr/lib/i386-linux-gnu, or /usr/lib/x86_64-linux-gnu. In
        addition, the --mysqld and --mysqld-version options can
        be used only on the command line and not in an option
        file. (Bug #24464380)

      * It was possible to write log files ending with .ini or
        .cnf that later could be parsed as option files. The
        general query log and slow query log can no longer be
        written to a file ending with .ini or .cnf. (Bug
        #24388753)

      * Privilege escalation was possible by exploiting the way
        REPAIR TABLE used temporary files. (Bug #24388746)

      * The client library failed to build on Solaris using the
        Cstd library. (Bug #24353920)

      * If the basedir system variable was set at server startup
        from the command line or option file, the value was not
        normalized (on Windows, / was not replaced with /). (Bug
        #23747899, Bug #82125)

      * kevent statement timer subsystem deinitialization was
        revised to avoid a mysqld hang during shutdown on OS X
        10.12. (Bug #23744004, Bug #82097)

      * For accounts for which multiple GRANT statements applied,
        mysqlpump could fail to dump them all. (Bug #23721446)

      * The MYSQL_ADD_PLUGIN macro had a spelling error that
        caused MYSQL_SERVER not to be defined. (Bug #23508762,
        Bug #81666)

      * In-place ALTER TABLE operations which when executed
        separately caused no table rebuild could when combined
        into a single statement result in a table rebuild. (Bug
        #23475211, Bug #81587)

      * For keyring plugins, the data access layer is now created
        only as necessary, not once per operation, which improves
        keyring performance. (Bug #23337926)

      * A blank server name in CREATE SERVER statements produced
        a server exit rather than an error. (Bug #23295288)

      * The optimizer failed to check a function return value for
        an area calculation, leading to a server exit. (Bug
        #23280059)

      * The server could fail to free memory allocated for
        execution of queries that used generated columns. (Bug
        #23205454)
        References: This issue is a regression of: Bug #22392268.

      * mysqlpump output for triggers that contained multiple
        statements in the trigger body failed to load correctly.
        (Bug #23072245)

      * Queries that satisfied the following conditions could
        return different results than in MySQL 5.6: 1) A subquery
        appeared in the select list; 2) The subquery contained a
        WHERE condition that referenced a value in the outer
        query; 3) The outer query contained a GROUP BY that
        required creation of a temporary table. (Bug #23049975)

      * Passwords that were rejected by the validate_password
        plugin were written by the server to the error log as
        cleartext. (Bug #22922023)

      * A prepared statement that used a parameter in the select
        list of a derived table that was part of a join could
        cause a server exit. (Bug #22392374, Bug #24380263)

      * MEDIUMINT columns used in operations with long integer
        values could result in buffer overflow. (Bug #19984392)

      * A spurious ER_NO_SUCH_TABLE error could occur when
        attempting to execute a prepared CREATE TABLE ... SELECT
        statement that used a temporary table in the FROM clause
        and called a stored function. The same error could occur
        for a nonprepared version of the statement if used in a
        stored procedure when the procedure was re-executed. (Bug
        #16672723, Bug #68972)

      * EINTR handling in the client library has been fixed so
        that interrupted read and write calls are retried.
        Previously, EINTR was ignored. (Bug #82019, Bug
        #23703570)

On Behalf of the MySQL/ORACLE RE Team
Hery Ramilison