Replication Denodo 7.0 , Denodo 6.0 , Denodo 5.5 , Denodo 5.0
Virtual DataPort can operate within a replicated architecture to provide diverse levels of high availability via load balancing. Typically, load balancing architectures for DataPort operate as follows:
- An external load balancer system distributes the requests received among a pool of Virtual DataPort servers.
- The load balancer 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.
Denodo provides a ping script for the server health check operation. Depending on its configuration, the ping script can just check that the server is alive, or it can execute a simple query (for example “select * from dual()”). The script, as well as more detailed information on how to use it, can be found in the installation folder, under tools/db/denodo-db-tools.
In order to facilitate metadata replication among the servers in a cluster, Denodo provides a set of tools to manage those operations from the command line. Besides, the export script can receive the list of servers the form the cluster, replicating the metadata in all the servers with just one command. The scripts, as well as its usage details, can be found in the installation folder, under tools/db/denodo-db-tools.