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3 Replies Latest reply: Apr 30, 2013 8:22 AM by 894334 RSS

Error while configuring KVStore

894334 Newbie
Currently Being Moderated
Hi,

I am trying to install Oracle NoSQL release 2.0.26. I have created just two storage nodes for the time being. While I am trying to create a topology, I see an error -
"Can't build an initial topology with 0 shards. Please increase the number or capacity of storage nodes"

Can anyone tell me what this error is.

Thanks.
  • 1. Re: Error while configuring KVStore
    Bogdan Coman Journeyer
    Currently Being Moderated
    Hi,
    I am trying to install Oracle NoSQL release 2.0.26. I have created just two storage nodes for the time being. While I am trying to create a topology, I see an error -
    "Can't build an initial topology with 0 shards. Please increase the number or capacity of storage nodes"

    Can anyone tell me what this error is.
    That error says that each KVStore has to contain at least one shard. The more shards your store contains, the better your store is at servicing write requests.

    Every Storage Node hosts one or more Replication Nodes. Replication Nodes are organized into shards. A shard contains a single Replication Node which is responsible for performing database writes, and which copies those writes to the other Replication Nodes in the shard. This is called the master node. All other Replication Nodes in the shard are used to service read-only operations. These are called the replicas. Production KVStores should contain multiple shards. At installation time you provide information that allows Oracle NoSQL Database to automatically decide how many shards the store should contain. The more shards that your store contains, the better your write performance is because the store contains more nodes that are responsible for servicing write requests.

    Please let me know if you have any more questions. You can find some basic instructions for installing a simple multi-node system with 1 shard replicated across 3 hosts at http://docs.oracle.com/cd/NOSQL/html/quickstart.html

    Related documentation:
    Identify the Target Number of Shards - http://docs.oracle.com/cd/NOSQL/html/AdminGuide/store-config.html#num-rep-group
    The KVStore - http://docs.oracle.com/cd/NOSQL/html/GettingStartedGuide/introduction.html#kvstore

    Thanks,
    Bogdan
  • 2. Re: Error while configuring KVStore
    Linda Lee Journeyer
    Currently Being Moderated
    In addition to the information that Bogdan supplied, the most likely issue is that you have specified a replication factor of 3, and you only have two storage nodes. NoSQL DB will not place more than one Replication Node from the same shard on a single Storage Node, because that would make the shard vulnerable to storage node failure.

    Edited by: Linda Lee on Apr 22, 2013 4:26 PM
    We will try to make that error message more explicit, to provide a better hint as to what the problem is.
  • 3. Re: Error while configuring KVStore
    894334 Newbie
    Currently Being Moderated
    Thanks Linda Lee and Bogdan. When I created the third storage node, everything worked fine.
    Thank you so much for the help!

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