3 Replies Latest reply: Dec 20, 2011 4:26 AM by Charles Lamb RSS

    Oracle NoSQL Database White Paper

    906230
      Hi all,
      I've just read Oracle NoSQL Database White Paper.
      I would like to know the following:
      1) Why should the number of partition be greater than the number of nodes? Is it because we can add more nodes after?
      2) Is "Katana" a major, minor or major and minor key? Why don’t we see any major or minor key in this example?
      3) For write operation: who propagates the operation to others nodes? Is it the client or the master node? In Implementation, I read the client does and in Architecture, I read the master does.
      Thanks
        • 1. Re: Oracle NoSQL Database White Paper
          Charles Lamb
          user962305 wrote:
          1) Why should the number of partition be greater than the number of nodes? Is it because we can add more nodes after?
          Yes, that's the reason. Note that dynamic expansion will not be available until a later release.
          2) Is "Katana" a major, minor or major and minor key? Why don’t we see any major or minor key in this example?
          Could you please give me the URL of the whitepaper and the page number you are referring to? I want to make sure I give you the correct answer.
          3) For write operation: who propagates the operation to others nodes? Is it the client or the master node? In Implementation, I read the client does and in Architecture, I read the master does.
          The answer is that both client and server can forward the request depending on the situation. If a node receives a request that it can not handle (e.g. due to a mastership change), then the node will forward the request to the current master. If a client is not able to contact a node (e.g. the node is down), then it will redirect the request to a different node in the replication group.

          Charles Lamb
          • 2. Re: Oracle NoSQL Database White Paper
            906230
            Hi Charles,

            You said
            Could you please give me the URL of the whitepaper and the page number you are referring to? I want to make sure I give you the correct answer.
            http://www.oracle.com/technetwork/database/nosqldb/learnmore/nosql-database-498041.pdf
            Page 8 Paragraph Architecture see image «Figure 3 : Request Processing »
            The answer is that both client and server can forward the request depending on the situation. If a node receives a request that it can not handle (e.g. due to >> a mastership change), then the node will forward the request to the current master. If a client is not able to contact a node (e.g. the node is down), then it >> will redirect the request to a different node in the replication group.
            For a write operation. Who initially propagates the operation to others nodes? The client can contact master node and master applies the operation. Will the same client propagates the write to all other nodes or will the master contact all replication nodes in his group?

            Thanks
            • 3. Re: Oracle NoSQL Database White Paper
              Charles Lamb
              user962305 wrote:
              http://www.oracle.com/technetwork/database/nosqldb/learnmore/nosql-database-498041.pdf
              Page 8 Paragraph Architecture see image «Figure 3 : Request Processing »
              In this example, there is only one component to the key ("Katana") so that is the master key. The Key factory method has several overloadings, one of which is just a single String (the major key).

              >
              The answer is that both client and server can forward the request depending on the situation. If a node receives a request that it can not handle (e.g. due to >> a mastership change), then the node will forward the request to the current master. If a client is not able to contact a node (e.g. the node is down), then it >> will redirect the request to a different node in the replication group.
              For a write operation. Who initially propagates the operation to others nodes? The client can contact master node and master applies the operation. Will the same client propagates the write to all other nodes or will the master contact all replication nodes in his group?
              Replication is always performed from the master, not the client. So any updates are sent from client to master and the master then propagates them to the clients. Reads, depending on the consistency level specified in the arguments to the API, may go directly from the client to any replica which can satisfy the request.

              Charles Lamb