Changes in MySQL 5.7.41 (2023-01-17, General Availability)

• Compilation Notes

• Functionality Added or Changed

• Bugs Fixed

Compilation Notes

• Upgraded the bundled lz4 library from version 1.9.3 to version 1.9.4. (Bug #34809802)

Functionality Added or Changed

• Important Change: The linked OpenSSL library for MySQL Server has been updated to version 1.1.1s. Issues fixed in OpenSSL version 1.1.1s are described at https://www.openssl.org/news/cl111.txt. (Bug #34828308)

• The linked curl library for MySQL Server (Enterprise Edition) has been updated to version 7.86.0. (Bug #34828111)

Bugs Fixed

• Replication: Issuing STOP SLAVE SQL_THREAD while the SQL thread was handling a transaction caused replication to stop immediately, instead of waiting 60 seconds for the event group to complete before shutting down the SQL thread as expected.

  The root cause of this issue was due to the internal variable storing the last event start time not being reset after the SQL thread was restarted.

  We fix this by resetting the variable holding the last event start time whenever the SQL thread is started. (Bug #33646899)

• Replication: The relay_log_space_limit system variable is a 64-bit value, but its valid maximum was specified internally as that of a 32-bit value. (Bug #106323, Bug #33799840)

• Some remote connections to the server were not handled correctly. This issue arose as the result of a previous fix for an issue with require_secure_transport. (Bug #34857411)

  References: This issue is a regression of: Bug #34094706.

• The linked OpenLDAP library for MySQL Server (Enterprise edition) was updated to version 2.5.13. (Bug #34815046)

• The bundled zlib library has been upgraded to zlib 1.2.13; zlib 1.2.13 is now the minimum zlib version supported. (Bug #34711762, Bug #34711758)

• Stack overruns could be erroneously reported when using the thread pool under heavy load. The race condition causing this in the thread pool has been avoided with an additional thread group ID check. (Bug #34414959)

• Data and GTIDs backed up by mysqldump were inconsistent when the options --single-transaction and --set-gtid-purged=ON were both used. This was because GTID_EXECUTED was fetched at the end of the dump, at which point the GTIDs on the server could have increased already. With this fix, a FLUSH TABLES WITH READ LOCK is performed at the beginning of the dump, and GTID_EXECUTED fetched immediately after, to ensure that its value is consistent with the snapshot taken by mysqldump.

  Our thanks to Marcelo Altmann for the contribution.

  Limitation: This fix adds a requirement for the RELOAD privilege when using --single-transaction to execute FLUSH TABLES WITH READ LOCK; the MySQL team is investigating a solution. (Bug #33630199, Bug #105761)

• In prepared statements, some types of subqueries could cause a server exit. (Bug #33100586)

• The audit_log server-side plugin always logged an entire multiple query, rather than logging only the specific part of the query that was executed. Changing when the query length is set resolves the issue. (Bug #107390, Bug #34207811)