#### 27.12.11.15 The replication\_group\_communication\_information Table

 This table shows group configuration options for the whole replication group. The table is available only when Group Replication is installed.

 The `replication_group_communication_information` table has these columns:

* `WRITE_CONCURRENCY`

   The maximum number of consensus instances that the group can execute in parallel. The default value is 10. See [Section 18.5.1.3, “Using Group Replication Group Write Consensus”](group-replication-group-write-consensus.html).

* `COMMUNICATION_PROTOCOL`

   The Group Replication communication protocol version, which determines what messaging capabilities are used. This is set to accommodate the oldest MySQL Server version that you want the group to support. See [Section 18.5.1.4, “Setting a Group's Communication Protocol Version”](group-replication-communication-protocol.html).

* `WRITE_CONSENSUS_LEADERS_PREFERRED`

   The leader or leaders that Group Replication has instructed the group communication engine to use to drive consensus. For a group in single-primary mode with the [`group_replication_paxos_single_leader`](group-replication-options.html#sysvar_group_replication_paxos_single_leader) system variable set to `ON` and the communication protocol version set to 8.0.27 or above, the single consensus leader is the group’s primary. Otherwise, all group members are used as leaders, so they are all shown here. See [Section 18.7.3, “Single Consensus Leader”](group-replication-single-consensus-leader.html).

* `WRITE_CONSENSUS_LEADERS_ACTUAL`

   The actual leader or leader that the group communication engine is using to drive consensus. If a single consensus leader is in use for the group, and the primary is currently unhealthy, the group communication selects an alternative consensus leader. In this situation, the group member specified here can differ from the preferred group member.

 The `replication_group_communication_information` table has no indexes.

[`TRUNCATE TABLE`](truncate-table.html) is not permitted for the `replication_group_communication_information` table.

