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MySQL Connector/J 8.0.24 has been released
Posted by: Nawaz Nazeer Ahamed
Date: April 20, 2021 07:04AM

Dear MySQL users,

MySQL Connector/J 8.0.24 is the latest General Availability release of the
MySQL Connector/J 8.0 series.  It is suitable for use with MySQL Server
versions 8.0 and 5.7.  It supports the Java Database Connectivity (JDBC)
4.2 API, and implements the X DevAPI.

This release includes the following new features and changes, also described in
more detail on

As always, we recommend that you check the "CHANGES" file in the download
archive to be aware of changes in behavior that might affect your application.

To download MySQL Connector/J 8.0.24 GA, see the "General Availability (GA)
Releases" tab at


Changes in MySQL Connector/J 8.0.24 (2021-04-20, General Availability)

     * Functionality Added or Changed

     * Bugs Fixed

Functionality Added or Changed

     * X DevAPI: For X Protocol connections, the Server now
       provides three new kinds of notifications for

          + Server shutdown: This is due to a server shutdown.
            It causes Connector/J to terminate all active and
            idle sessions connected to the server in the
            connection pool with the error message "Server
            shutdown in progress".

          + Connection idle: This is due to the connection
            idling for longer than the relevant timeout
            settings. It causes Connector/J to close the current
            connection with the error message "IO Read error:
            read_timeout exceeded".

          + Connection killed: This is due to the connection
            being killed by another client session. It causes
            Connector/J to close the connection in the current
            session with the error message "Session was killed".

     * A new connection property, scrollTolerantForwardOnly, has
       been introduced, which preserved the legacy behavior of
       Connector/J 8.0.17 and earlier by tolerating backward and
       absolute cursor movements on result sets of type
       ResultSet.TYPE_FORWARD_ONLY. This is for maintaining
       compatibility with legacy code that took advantage of the
       old behavior. See the description for
       scrollTolerantForwardOnly for details. (Bug #31747910)
       References: See also: Bug #30474158.

     * Connector/J now supports "userless" authentication for
       JDBC connections: When the user for the connection is
       unspecified, Connector/J uses the name of the OS user who
       runs the application for authentication with the MySQL
       server. See Connector/J: Obtaining a connection from the
       for more details.

     * Starting from this release, whenever an authentication
       plugin is explicitly set for the connection property
       the specified plugin takes precedence over
       the server's default when Connector/J negotiates a plugin
       with the server. There is no behavioral change for
       Connector/J if no value is explicitly set for the
       property, in which case the server's choice of default
       plugin takes precedence over the implicit default of
       mysql_native_password for Connector/J. See the
       description of defaultAuthenticationPlugin
       for details.

     * In the past, for JDBC connections, when the server closed
       a session because a client was idling beyond the period
       specified by the server's wait_timeout system variable,
       Connector/J returned a generic IO error. Connector/J now
       relays a clearer error message from the server.

Bugs Fixed

     * X DevAPI: Concurrently getting and closing multiple
       sessions from the same X DevAPI Client object might
       result in a ConcurrentModificationException thrown by
       Connector/J at the closing of a session. (Bug #31699993)

     * X DevAPI: Under some specific conditions, when using
       Deflate as the algorithm for compression of X Protocol
       connections, Connector/J threw an
       AssertionFailedException (ASSERTION FAILED: Unknown
       message type: 57). It was because when a compressed
       packet was just a few bytes longer than the size of some
       internal buffer used by a Java InflaterInputStream, the
       leftover bytes from the inflate procedure were being
       discarded by Connector/J, causing inflation of subsequent packets
       to fail. With this fix, no data bytes are discarded, and
       the inflation works as expected. (Bug #31510398, Bug

     * When a SecurityManager was in place, connections to a
       MySQL Server could not be established unless the client
       had been properly configured to use SASL-based LDAP
       authentication. It was because the
       AuthenticationLdapSaslClientPlugin in Connector/J
       requires a special permission to load the provider
       MySQLScramShaSasl when a SecurityManager is in place; but
       since the provider was loaded by a static initializer
       during initialization for the plugin, the lack of the
       permission was causing an error and then failures for all
       connections, even if the plugin was never used or
       enabled. This fix changes how the provider is loaded: the
       loading now happens only at the plugin instance's
       initialization and the initialization was deferred to the
       time when the plugin is actually needed, so that
       connections that do not use SASL-based LDAP
       authentication are unaffected by security settings
       regarding the plugin. (Bug #32526663, Bug #102188)

     * When using Connector/J 8.0.23,
       ResultSetMetaData.getColumnClassName() did not return the
       correct class name corresponding to DATETIME columns.
       (Bug #32405590, Bug #102321)

     * Creation of an UpdatableResultSet failed with a
       NullPointerException when it was generated by querying a
       view with a derived value. (Bug #32338451, Bug #102131)

     * Using getLong() on the CHAR_OCTET_LENGTH column of the
       ResultSet for DatabaseMetaData.getProcedureColumns() (or
       getFunctionColumns()) resulted in a NumberOutOfRange
       exception when the column's value exceeded 2^32 − 1. With
       this patch, the value of 2^32 − 1 is returned in the
       situation. (Bug #32329915, Bug #102076)

     * Connections to a server could not be established when the
       user supplied an implementation of the
       ConnectionPropertiesTransform interface using the
       connection property propertiesTransform. This was because
       Connector/J called PropertyKey.PORT.getKeyName() instead
       of PropertyKey.HOST.getKeyName() for getting the host
       name, and that has been corrected by this fix. (Bug
       #32151143, Bug #101596)

     * A NullPointerException was returned when a statement that
       could not be used as a ServerPreparedStatement was
       executed and the connection property useUsageAdvisor
       was set to true. With this fix, a SQLException
       is returned instead. (Bug #32141210, Bug #101558)

     * Using the setSessionMaxRows() method on a closed
       connection resulted in a NullPointerException. With this
       fix, a SQLNonTransientConnectionException is thrown
       instead, with the error message "No operations allowed
       after connection closed." (Bug #22508715)

     * Using the setObject() method for a target type of
       Types.TIME resulted in a SQLException when the value to
       be set had a fractional part, or when the value did not
       fit any pattern described in Date and Time Literals
       This patch introduced a new logic that can
       handle fractional parts; also, it performs the conversion
       according to the patterns of the literals and, when
       needed, the target data type. (Bug #20391832)

Enjoy and thanks for the support!

On Behalf of the MySQL Engineering Team,
Nawaz Nazeer Ahamed

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MySQL Connector/J 8.0.24 has been released
April 20, 2021 07:04AM

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