Authentication Plugins Log level 6 is available as of MySQL 8.0.18. On the client side, messages can be logged to the standard output by setting the AUTHENTICATION_LDAP_CLIENT_LOG  environment variable. The permitted and default values are the same as for  authentication_ldap_sasl_log_status . The  AUTHENTICATION_LDAP_CLIENT_LOG  environment variable applies only to SASL LDAP authentication. It has no effect for simple LDAP authentication because the client plugin in that case is mysql_clear_password , which knows nothing about LDAP operations. For SASL LDAP authentication, the maximum size of the pool of connections to the LDAP server. To disable connection pooling, set this variable to 0. This variable is used in conjunction with  authentication_ldap_sasl_init_pool_size . See the description of that variable. For SASL LDAP authentication, whether to enable LDAP search referral. See LDAP Search Referral. This variable can be set to override the default OpenLDAP referral configuration; see LDAP Pluggable Authentication and ldap.conf 1367 • authentication_ldap_sasl_referral • authentication_ldap_sasl_max_pool_size Command-Line Format --authentication-ldap-sasl- referral[={OFF|ON}] Introduced 8.0.20 System Variable authentication_ldap_sasl_referral Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Boolean Default Value OFF Command-Line Format --authentication-ldap-sasl-max-pool- size=# System Variable authentication_ldap_sasl_max_pool_size Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 1000 Minimum Value 0 Maximum Value 32767 Option Value Types of Messages Logged 6 Same as previous level plus debugging messages from LDAP library