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Questions tagged [cassandra]

Apache Cassandra is an open source distributed database management system. It is designed to handle very large amounts of data spread out across many commodity servers while providing a highly available service with no single point of failure. It is a NoSQL solution.

3
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1answer
6k views

Why I got NoHostAvailable:?

if I run this simple query: SELECT * from myapp.latests WHERE organization_id = 1 and user_id = 1; I get error: NoHostAvailable: Running nodetool status results into: Datacenter: eu-central ======...
2
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1answer
2k views

Upgrading Cassandra from 1.1.0 to latest

I have a single node cassandra database running since 2 years now... never had any issues with it, but I would like to upgrade it to the latest cassandra (2.1.2 at the time I write those lines), of ...
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2answers
155 views

Handling read conflict in cassandra?

Say we have three nodes(simple replica no sharding) i.e. N1,N2 and N3 with replication factor as 3. As read and write request can go to any node, Say Request write request(to update the same ...
75
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5answers
34k views

Which database could handle storage of billions/trillions of records?

We are looking at developing a tool to capture and analyze netflow data, of which we gather tremendous amounts of. Each day we capture about ~1.4 billion flow records which would look like this in ...
16
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5answers
4k views

Infrastructure for Highly Concurrent, High Write DB

My requirements are: 3000 Connections 70-85% Write vs Read Currently, we are maxing out a High-CPU, Extra Large Instance at 700 connections. All 8 cores are maxed. We think it's the number of ...
11
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2answers
3k views

What are the penalties of using many (thousands) of column families or keyspaces in Cassandra?

I am in the process of evaluating the best design for our Cassandra installation. There is not so much information out there on the Internet about using the first two levels of access that Cassandra ...
2
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1answer
635 views

Mongo CP, Cassandra AP?

I have read lot of articles on net but still confused why Mongo CP, Cassandra AP, RDBMS CA ? Will explain my understanding and query along with that . Mongo Consider a scenario where I have ...
0
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1answer
2k views

A good dataset to experiment NoSQL databases [closed]

I need to do some experiments in HBase and Cassandra and to do that I need an adequate dataset. The dataset I'm looking for has to be large enough (i.e. more than 2GB) and the data in it has to be ...
0
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1answer
46 views

Replica model in Cassandra vs Mongo?

Say in Mongo we have one primary and two replica node(simple replica no sharding). Read and write request will be handled only primary node and replica will just backup the data in case of failover. ...