Group Replication System Variables The value of this system variable can be changed while Group Replication is running, but the change only takes effect after you stop and restart Group Replication on the group member. group_replication_communication_debug_options  configures the level of debugging messages to provide for the different Group Replication components, such as the Group Communication System (GCS) and the group communication engine (XCom, a Paxos variant). The debug information is stored in the  GCS_DEBUG_TRACE  file in the data directory. The set of available options, specified as strings, can be combined. The following options are available: Setting the debug level to  GCS_DEBUG_NONE  only has an effect when provided without any other option. Setting the debug level to  GCS_DEBUG_ALL  overrides all other options. This system variable should have the same value on all group members. You cannot change the value of this system variable while Group Replication is running. You must stop Group Replication, change the value of the system variable, then restart Group Replication, on each of the group members. During 3801 • group_replication_communication_max_message_size • GCS_DEBUG_ALL  enables all debugging levels for both GCS and XCom. • XCOM_DEBUG_TRACE  enables trace information in XCom. • XCOM_DEBUG_BASIC  enables basic debugging information in XCom. • GCS_DEBUG_TRACE  enables trace information in GCS. • GCS_DEBUG_BASIC  enables basic debugging information in GCS. • GCS_DEBUG_NONE  disables all debugging levels for both GCS and XCom. GCS_DEBUG_TRACE XCOM_DEBUG_BASIC XCOM_DEBUG_TRACE GCS_DEBUG_ALL Command-Line Format --group-replication-communication- max-message-size=# Introduced 8.0.16 System Variable Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 10485760 Minimum Value 0 Maximum Value 1073741824 Unit bytes