Oracle NoSQL Storage Nodes

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What are the guidelines for creating Oracle NoSQL Database Storage Node (SN), can we create multiple storage nodes on the same machine? If so what are the trades off? I looked at the product documentation, but it's not clear

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Anand Chandak On

So digging deeper here's what was found :

It is recommended that Storage Nodes (SNs) be allocated one per node in the cluster for availability and performance reasons. If you believe that a given node has the I/O and CPU resources to host multiple Replication Nodes, the Storage Node's capacity parameter can be set to a value greater than one, and the system will know that multiple RNs may be hosted at this SN. This way, the system can: ensure that each Replication Node in a shard is hosted on a different Storage Node, reducing a shard's vulnerability to failure dynamically divide up memory and other hardware resources among the Replication Nodes ensure that the master Replication Nodes, which are the ones which service write operations in a store, are distributed evenly among the Storage Nodes both at startup, and after any failovers. If more than one SN is hosted on the same node, multiple SNs are lost if that node fails, and data may become inaccessible.

You can set the capacity parameter for a Storage Node in several ways:

  • When using the makebootconfig command
  • List item with the change-policy command
  • List item with the plan change-params command.

Also, in very limited situations, such as for early prototyping and experimentation, it can be useful to create multiple SNs on the same node. On a single machine, a Storage Node is uniquely identified by its root directory (KVROOT) plus a configuration file name, which defaults to "config.xml." This means you can create multiple SNs as by creating a unique KVROOT directory for each SN. Usually, these would be on different nodes, but it's also possible to have them on a single node.