<div id="docs-body">
 <div class="section">
  <div class="titlepage">
   <div>
    <div>
     <h3 class="title">
      <a name="group-replication-server-states">
      </a>
      20.4.2 Group Replication Server States
     </h3>
    </div>
   </div>
  </div>
  <a class="indexterm" name="idm46045133688736">
  </a>
  <p>
   The state of a Group Replication group member shows its current
      role in the group. The Performance Schema table
   <a class="link" href="performance-schema-replication-group-members-table.html" title="29.12.11.16 The replication_group_members Table">
    <code class="literal">
     replication_group_members
    </code>
   </a>
   shows the
      state for each member in a group. If the group is fully functional
      and all members are communicating properly, all members report the
      same state for all other members. However, a member that has left
      the group or is part of a network partition cannot report accurate
      information on the other servers. In this situation, the member
      does not attempt to guess the status of the other servers, and
      instead reports them as unreachable.
  </p>
  <p>
   A group member can be in the following states:
  </p>
  <div class="variablelist">
   <dl class="variablelist">
    <dt>
     <span class="term">
      <code class="literal">
       ONLINE
      </code>
     </span>
    </dt>
    <dd>
     <p>
      The server is an active member of a group and in a fully
            functioning state. Other group members can connect to it, as
            can clients if applicable. A member is only fully
            synchronized with the group, and participating in it, when
            it is in the
      <code class="literal">
       ONLINE
      </code>
      state.
     </p>
    </dd>
    <dt>
     <span class="term">
      <code class="literal">
       RECOVERING
      </code>
     </span>
    </dt>
    <dd>
     <p>
      The server has joined a group and is in the process of
            becoming an active member. Distributed recovery is currently
            taking place, where the member is receiving state transfer
            from a donor using a remote cloning operation or the donor's
            binary log. This state is
     </p>
     <p>
      For more information, see
      <a class="xref" href="group-replication-distributed-recovery.html" title="20.5.4 Distributed Recovery">
       Section 20.5.4, “Distributed Recovery”
      </a>
      .
     </p>
    </dd>
    <dt>
     <span class="term">
      <code class="literal">
       OFFLINE
      </code>
     </span>
    </dt>
    <dd>
     <p>
      The Group Replication plugin is loaded but the member does
            not belong to any group. This status may briefly occur while
            a member is joining or rejoining a group.
     </p>
    </dd>
    <dt>
     <span class="term">
      <code class="literal">
       ERROR
      </code>
     </span>
    </dt>
    <dd>
     <p>
      The member is in an error state and is not functioning
            correctly as a group member. A member can enter error state
            either while applying transactions or during the recovery
            phase. A member in this state does not participate in the
            group's transactions. For more information on possible
            reasons for error states, see
      <a class="xref" href="group-replication-responses-failure.html" title="20.7.7 Responses to Failure Detection and Network Partitioning">
       Section 20.7.7, “Responses to Failure Detection and Network Partitioning”
      </a>
      .
     </p>
     <p>
      Depending on the exit action set by
      <a class="link" href="group-replication-system-variables.html#sysvar_group_replication_exit_state_action">
       <code class="literal">
        group_replication_exit_state_action
       </code>
      </a>
      ,
            the member is in read-only mode
            (
      <a class="link" href="server-system-variables.html#sysvar_super_read_only">
       <code class="literal">
        super_read_only=ON
       </code>
      </a>
      ) and
            could also be in offline mode
            (
      <a class="link" href="server-system-variables.html#sysvar_offline_mode">
       <code class="literal">
        offline_mode=ON
       </code>
      </a>
      ). Note
            that a server in offline mode following the
      <code class="literal">
       OFFLINE_MODE
      </code>
      exit action is displayed
            with
      <code class="literal">
       ERROR
      </code>
      status, not
      <code class="literal">
       OFFLINE
      </code>
      . A server with the exit action
      <code class="literal">
       ABORT_SERVER
      </code>
      shuts down and is removed
            from the view of the group. For more information, see
      <a class="xref" href="group-replication-responses-failure-exit.html" title="20.7.7.4 Exit Action">
       Section 20.7.7.4, “Exit Action”
      </a>
      .
     </p>
     <p>
      While a member is joining or rejoining a replication group,
            its status can be displayed as
      <code class="literal">
       ERROR
      </code>
      before the group completes the compatibility checks and
            accepts it as a member.
     </p>
    </dd>
    <dt>
     <span class="term">
      <code class="literal">
       UNREACHABLE
      </code>
     </span>
    </dt>
    <dd>
     <p>
      The local failure detector suspects that the member cannot
            be contacted, because the group's messages are timing out.
            This can happen if a member is disconnected involuntarily,
            for example. If you see this status for other servers, it
            can also mean that the member where you query this table is
            part of a partition, where a subset of the group's servers
            can contact each other but cannot contact the other servers
            in the group. For more information, see
      <a class="xref" href="group-replication-network-partitioning.html" title="20.7.8 Handling a Network Partition and Loss of Quorum">
       Section 20.7.8, “Handling a Network Partition and Loss of Quorum”
      </a>
      .
     </p>
    </dd>
   </dl>
  </div>
  <p>
   See
   <a class="xref" href="group-replication-replication-group-members.html" title="20.4.3 The replication_group_members Table">
    Section 20.4.3, “The replication_group_members Table”
   </a>
   for an example of the Performance Schema table contents.
  </p>
 </div>
 <br/>
</div>
