Cluster Architectures / Server Backup¶
Virtual DataPort can operate within a cluster architecture to provide high availability and load balancing.
Typically, clustering architectures for Virtual DataPort operate as follows:
- An external load-balancing system distributes the requests received among a pool of Virtual DataPort servers.
- The load-balancing system detects when a server is not responding (using the so-called “server health check”). In this case, the load is distributed among the remaining servers.
- The clustering system detects when the server is available again (using the “health check”) and adds it to the pool.
Virtual DataPort provides some features to make cluster architecture configuration easier:
- It provides a “Ping” script to check the status of Virtual DataPort servers. Although solutions provide their own default implementations for “health-checking” an application, the Ping script detects failure situations that would not be detected by other solutions.
- It provides a utility to automatically replicate the metadata and the configuration of a Virtual DataPort server into a pool of other Virtual DataPort servers. This utility can also be used to schedule backup copies of the metadata of a Server.
- “Safe shut down mode”: when entering this mode, the Server does not accept new connections and it will not shut down until all the current queries finish. This allows you to remove a Server from the cluster without affecting external clients.
The following sections describe how to:
- Install the Denodo Tools: a set of tools that help building a cluster with several Virtual DataPort servers (see section Denodo Tools).
- Use the Ping script (see section How to Check If a Virtual DataPort Server Is Alive)
- Replicate the metadata of a Virtual DataPort server, to a group of servers (see section Using the Import/Export Scripts for Backup And/or Replication).