Connection Compression Control mysqlshow ,  mysqlslap , and  mysqltest , and  mysql_upgrade . MySQL Shell also offers these command-line options from its 8.0.20 release. Configuration parameters that enable specifying compression algorithms are string-valued and take a list of one or more comma-separated compression algorithm names, in any order, chosen from the following items (not case-sensitive): Because  uncompressed  is an algorithm name that may or may not be configured, it is possible to configure MySQL  not  to permit uncompressed connections. Examples: [mysqld] protocol_compression_algorithms=zlib,zstd,uncompressed To set and persist the  protocol_compression_algorithms  system variable to that value at runtime, use this statement: SET PERSIST protocol_compression_algorithms=’zlib,zstd,uncompressed’; SET PERSIST  sets the value for the running MySQL instance. It also saves the value, causing it to carry over to subsequent server restarts. To change the value for the running MySQL instance without having it carry over to subsequent restarts, use the  GLOBAL  keyword rather than  PERSIST . See Section 13.7.6.1, “SET Syntax for Variable Assignment” . [mysqld] protocol_compression_algorithms=zstd Or, to make the change at runtime: •The  MYSQL_OPT_COMPRESSION_ALGORITHMS  and  MYSQL_OPT_ZSTD_COMPRESSION_LEVEL  options for the  mysql_options()  function configure permitted compression algorithms and  zstd  compression level for client programs that use the MySQL C API. •The  MASTER_COMPRESSION_ALGORITHMS  and  MASTER_ZSTD_COMPRESSION_LEVEL  options for the CHANGE MASTER TO  statement configure permitted compression algorithms and  zstd  compression level for replica servers participating in source/replica replication. From MySQL 8.0.23, use the statement  CHANGE REPLICATION SOURCE TO  and the options  SOURCE_COMPRESSION_ALGORITHMS and  SOURCE_ZSTD_COMPRESSION_LEVEL  instead. •The  group_replication_recovery_compression_algorithms  and group_replication_recovery_zstd_compression_level  system variables configure permitted compression algorithms and  zstd  compression level for Group Replication recovery connections when a new member joins a group and connects to a donor. • zlib : Permit connections that use the  zlib  compression algorithm. • zstd : Permit connections that use the  zstd  compression algorithm (zstd 1.3). • uncompressed : Permit uncompressed connections. •To configure which compression algorithms the server permits for incoming connections, set the protocol_compression_algorithms  system variable. By default, the server permits all available algorithms. To configure that setting explicitly at startup, use these lines in the server  my.cnf  file: •To permit only incoming connections that use  zstd  compression, configure the server at startup like this: 378 Note