Chapter 29 Topology

This chapter describes the Topology view. Topology is only available on the navigation bar if a replication topology, InnoDB Cluster, or NDB Cluster is selected.

The Topology tab graphically displays the replication topology of the selected group.

Figure 29.1 Replication Topology Graph

Example of Topology showing many MySQL instances communicating with one another. The figure content is described in the surrounding text.

The Topology view contains the following:

Topology graph: graphically displays the replication setup, enabling you to reposition the nodes for better visibility, and zoom in and out using your mouse wheel.
Tooltips: For information on an individual node or channel, hover the mouse cursor over the node or channel. A tooltip is displayed containing information about the node or channel. The node tooltip displays the ID, Name, and Status of the node, while the channel tooltip displays the name of the channel.
Legend : displays the meaning of each of the graphical elements.
- Nodes:
  - Node OK
  - Replication Issues
  - Node/Replication Down
  - Node Unmonitored
- Links:
  - Async Fetch OK
  - Async Fetch Down
  - Semi-Sync Fetch OK
  - Semi-Sync Fetch Down
  - Group Replication Recovery
  - Link Status Unknown
- Group replication Status:
  - Online
  - Group Replication Recovering
  - Offline/Error
  - Unknown/Plugin Not Available

Note

The topology graph displays semi-synchronous links only if both source and replica use the semi-sync plugins.

Group replication topologies are displayed differently. For example, the following is a three-node group:

Figure 29.2 Group Replication Single Group Topology

Example of an online, replication group. The group has two secondary members and one primary member.

While the following shows normal communication between two groups:

Figure 29.3 Group Replication Multiple Group Topology

Example of two groups with a primary group member in one group, replicating to a secondary group member in the other group.

NDB Cluster topologies contain all the cluster components, Management node, API node, and data node, and uses color to display their states. Each layer is identified by host or process information. Further information can be seen by hovering the cursor over any of the elements.

Figure 29.4 NDB Cluster Topology

Example of an NDB Cluster topology, showing the Management, NDB, and Data nodes.

NDB Management Node:

Figure 29.5 NDB Cluster Topology - Management Node

NDB API Node:

Figure 29.6 NDB Cluster Topology - API Node

Figure 29.7 NDB Cluster Topology - Data Node