The T-Mesh technology supports multiple TCPWave DDI Management appliances serving the global DDI remotes.
The underlying database uses a write-set synchronous replication. The T-Mesh consists of a single floating HA master and multiple HA members. When the floating HA master fails, the next available member automatically assumes the role of a master without any human intervention. The franchise-critical DDI transactions do not impact when a single floating HA master or a HA member goes down. When a temporary network interruption occurs, the T-Mesh technology auto-recovers and the DDI management ecosystem synchronizes with a degree of transparency that the end-users see no impact. The T-Mesh cluster maintains a cache to expedite a member's recovery that has fallen out of sync. The remote DDI appliances design is to auto-sense the failure of their preferred DDI manager. The High Aavilability member failure will automatically prompt an election on the connected remotes to choose their next best DDI manager. The DDI administrator also has the UI ability to swing the DDI remotes from one management node to another without causing any service disruption. The design of the T-Mesh cluster technology is such that it operates with the end-users slightest configuration changes.
The T-Mesh cluster technology self-tunes its configurations every thirty minutes to deliver maximum performance. The TCPWave monitoring engine periodically monitors the health of the T-Mesh cluster. TCPWave recommends having three nodes in a T-Mesh.
While the T-Mesh technology eliminates the single points of
failure in an organization, it also provides the DDI administrators
with an easy-to-use user interface to maintain and monitor the
cluster. Joining a member or removing a member can be done easily
using the web interface.
You can perform configuration changes, update and upgrade, view remote's logs on the web interface, and restart the services on any DDI remote from the T-Mesh DDI controller. Internally, the T-Mesh cluster uses a delegate method that hands over the management activity of a given remote from one management node to another. Even though the action is initiated from one management node, the actual node that performs the appropriate action on the remote is the HA node directly connected to the remote using the T-Message Secure Tunnel. The management traffic is encrypted using SSL over a unique TCP port. The transport layer used in the T-Mesh ecosystem is encrypted using the highest degree. It is important to note that the nodes in the T-Mesh HA cluster need a proper clock discipline. The clock offset between the nodes of a T-Mesh ecosystem plays a significant factor in the overall stability.
The T-Mesh technology comes with a built-in conflict resolution logic. When two nodes have a dispute, the third node automatically acts as an arbitrator. The dispute resolution takes place in milliseconds. TCPWave recommends that all the nodes on the cluster be on the same network speed, hardware type, patch levels, etc. Since T-Mesh uses a replicated write-set to guarantee data consistency, a given write operation must be performed on all the nodes. Every DDI operation that uses the 1490 plus REST API calls gets processed within a few milliseconds on the performance-optimized database.