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.

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Cassandra: maintenance

I am inexperienced with Cassandra, but I have some experience with SQL-based relational databases. I have been unable to find best practices information about how to maintain Cassandra once deployed. ...
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869 views

What is a good way to copy data from one Cassandra ColumnFamily to another on the same Keyspace (like SQL's INSERT INTO)?

Trying to find a way to easily transfer all the rows from a Cassandra ColumnFamily/Table to another. The COPY command, as I understand, is a good option. However, as it dumps all the data to .csv on ...
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DataStax OpsCenter - can't connect with agents [migrated]

I've installed DataStax OpsCenter (Apache Cassandra) and in OpsCenter, there is an error: "0 of 1 agents connected". When I click "fix", enter credentials and try to install nodes, i get error: ...
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180 views

How to create multiple graphs with TitanDB (+Cassandra) in the same machine?

I'm experimenting with TitanDB (with Cassandra as storage) + Rexter. I've been reading the documentation during hours and trying to create multiple graph DBs on the same machine, but I didn't find ...
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Adding Cassandra Node in OpenShift to Existing Cluster [migrated]

I have 3 cassandra nodes(S1,S2,S3) which are installed on CentOS 6. Two of them (S1,S2) are in datacenter A and one of them (S3) is in openshift. I am trying to make benchmark test with multiple node ...
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735 views

Cassandra: Request did not complete within rpc_timeout

i was working with Cassandra 1.2.4 probably, after restoring some key-space when i tried to query in a key-space it gave me Request did not complete within rpc_timeout so i checked system.log & ...
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Cassandra and cqlsh - “Cassandra unknown” and “CQL spec unknown” [migrated]

I just downloaded Cassandra 1.0.10 and Java 1.6.0_45 on Ubuntu. When I run the command cqlsh on terminal, I get the following output: Connected to Test Cluster at localhost:9160. [cqlsh 2.0.0 | ...
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1answer
50 views

How can I get nodetool without Cassandra

I have Cassandra pool across machines in LAN. I need nodetool on machine without Cassandra installed. How can I get it? Is the installing Cassandra and disabling db service is the best way?
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Cassandra: unstructured document storage?

I'm fairly new to NoSQL, but fairly experienced with SQL-based relational databases. We are evaluating Cassandra for one of our applications. I've seen where Cassandra is claimed to be able to store ...
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93 views

Cassendra schema design suggestion for chat archive

I have gone though this article and here is the schema I have got from it. This is helpful for my application for maintaining statuses of a user, but how can extend this to maintain one to one chat ...
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58 views

Cassandra with Hadoop

Cassandra uses Cassandra File System (CFS) and Hadoop uses Hadoop Distributed File System (HDFS) I'm already using Pig over HDFS and i would like to install Cassandra. Having additional servers for ...
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Upgrading Cassandra

my Cassandra version is 1.2.4 and i'm trying to upgrade it to 2.0.5 and i know that in the first part i have to upgrade it to 1.0.14 and after that try to upgrade it to the 2.0.5 , when I try to run ...
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5answers
6k 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 ...
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25 views

Restoring Cassandra fails

I try to restore a Cassandra table from snapshot , but when i try to see the result the query give me a rpc_timeout so i tried to see the log files java.lang.RuntimeException: ...
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1answer
65 views

Database software advice [closed]

I have this strange question. I'm building a service that stores information into one table. That table has 20 columns. My database will have many billion rows. Right now I'm using Cassandra, but it ...
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2answers
76 views

How does Apache Cassandra handle dynamic column set conflicts?

I know that each column in Apache Cassandra has a timestamp attached and that read conflicts for a single column is resolved deterministically by looking at timestamp or by comparing the value. Let's ...
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2answers
433 views

Is there any open source GUI tool to monitor cassandra? [closed]

I would like to monitor cassandra database as well as need to check the values in the database. Could any one suggest me best open source GUI tool ? Regards, Arun Raj.
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1answer
685 views

Cassandra - Query a column with collection type

I am pretty new to cassandra, so pardon me if this turns out to be a silly question. I have a table structure as below CREATE TABLE data_points ( id text PRIMARY KEY, created_at timestamp, ...
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How to organize fair cache in Cassandra Cluster for large number of customers using it?

Is there any recommendation of how to serve large number of customers with Cassandra? Imagine that all of them read rows (specific per customer) in Cassandra. If we have one big Column Family (CF) ...
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56 views

How to make cassandra reconize SSTable after reinstall?

I have 1 node Cassandra running datastax distribution. I reinstall Cassandra and updated cassandra.yaml data_file_directories. sudo apt-get --purge remove cassandra sudo apt-get install dsc20 But ...
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1answer
152 views

Cassandra multidatacenter configuration with 1 external ip

I'm trying to setup a multi-datacenter Cassandra cluster. The problem is that my datacenters have only 1 external IP (wan IP), I can setup port forwarding on the data centers switchs to access each ...
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2answers
817 views

Cassandra in multiple data center - EC2MultiRegionSnitch

I was reading article from : http://www.datastax.com/docs/1.0/cluster_architecture/replication#networktopologystrategy and I have a question about - EC2MultiRegionSnitch. I did not understand it well. ...
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1answer
172 views

Which database to use? [closed]

Hey there. I am looking for a free to use for commercial website database that should have these design features, in the given order: Auto-Sharding (getting more free space by adding more server ...
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1answer
2k views

What are the practical limitations on a column family in Cassandra?

In Cassandra, it's not recommended to have more than a few thousand column families, let's say 2,000 for the sake of argument. In cases where more than 2,000 types of data need to be persisted, one ...
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2answers
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Cassandra encryption at rest

I need to store some sensitive data in Cassandra and require it to be encrypted at rest. Is it likely Cassandra would function normally on top of a Linux encrypted file system (something like the open ...
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Strugling with updating a cassandra row in FluentCassandra

I have this problem with using Fluent Cassandra in a test application. All I want to do is set the IsOnline field to true inside the SignIn method, but I keep getting the exception supercolumn ...
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1answer
139 views

Cassandra upgrade/repair issues in migration

I wanted to migrate part of the column families in a cluster to a new cluster. I made a snapshot of the source cluster and copied the data, made a new cluster with the same name, same number of nodes ...
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2answers
206 views

Which database system can break me free?

I am currently running a MySQL Database for logging and analyzing those logs. My current table schema looks like this: CREATE TABLE `mylogs` ( `transfer_id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT ...
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2answers
389 views

How can I generate Cassandra data model from a MySQL schema?

Is there a tool for generating a Cassandra model from a MySQL database?
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287 views

Cassandra cqlsh browser queries possible only in bytes

I am using Cassandra database through cqlsh client on Linux. I can make only queries with values given as bytes, but I would like to search with the client like in SQL where everything is Strings. ...
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2answers
586 views

Commercial database systems versus open source database systems [closed]

Can anyone tell me what are the reasons for buying a commercial database system and not using an open-source free version? The reason for my question is that: Commercial systems cost upwards of ...
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1answer
2k views

What is different bettween Cassandra NoSQL data model and SQL data model

can any one tell. cassandra data model and sql data model how we can define row and column with cassandra data model?
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2answers
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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 ...
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5answers
1k 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 ...
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2answers
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“phpMyAdmin” for Cassandra

Is there a tool like phpMyAdmin for RDBMS-MySQL for a Cassandra DB? I know that there is less "runtime" config possible (column families can not be edited at runtime etc.). Nevertheless, it would be ...