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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I have cassandra - do I need redis too? [closed]

I'm reading data from kafka and persisting it into cassandra. Each piece of data contains many properties (varying list). Of these properties I need to make available a small subset for repeated read ...
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11 views

How to connect Cassandra database with Chicago Boss Application?

My cassandra database is on a VMware server. The problem is that I don't find any database adapter which can help me in connecting my cassandra database with my chicago boss(a web framework in Erlang) ...
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23 views

What is the graveyard compaction in cassandra?

Cassandra noob here. While going through the documentation etc, I'm repetitevely finding references to graveyard compaction (and occasionally tombstones), example: $ cassandra-cli [default@unknown] ...
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1answer
23 views

How Wide-columns databases achieve dynamic columns on the storage layout? [closed]

As known, in relational databases, when adding a new column, data must be reallocated (http://stackoverflow.com/questions/463677/alter-table-without-locking-the-table) to maintain a single row ...
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18 views

Update a Record in Cassandra

I'm having the following query while updating a particular record. I've a user Column Family CF as follow:- class User(Model): user_id = UUID(default=uuid.uuid4,primary_key= True) date = ...
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14 views

Cassandra- Data modelling for UserProfilie [closed]

I've a user model, having attributes as follow:- class User(Model): user_id = columns.Integer(primary_key=True) username = columns.Text() email = columns.Text() fname = columns.Text() ...
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96 views

Modeling Graph Data in Cassandra DB

I want to use Apache Cassandra to store a large amount of graph data according to a property graph model. The model contains the following entities: Vertices: Contains a map of key/value pairs ...
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1answer
72 views

What is the Cassandra setting for coordinator timeouts for schema change queries?

In my testing, I've found that the write_request_timeout_in_ms setting does not have any bearing on the timeouts for CREATE TABLE or ALTER TABLE statements in CQL. For instance, I have it set to ...
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25 views

Cassandra: memtable_offheap_space_in_mb and memtable_cleanup_threshold

I use C* v2.1.2 do write only workload (into one column family) and experiment with offheap-objects memtable space. I set parameters to: memtable_offheap_space_in_mb = 51200 # 50Gb ...
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1answer
62 views

Database migration for Large Data Set from MySQL to NoSQL

I have an existing APP that has N types of products that is normalized with MySQL. Each types of products have over 500K skus, and one of them are in the in 2M currently. We are currently tracking on ...
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1answer
152 views

Cassandra row ordering best practice

I have a column family that store articles. I'll need to get those articles from the most recent to the oldest, getting them from Country, and of course the ability to limit the number of fetched ...
2
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1answer
115 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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6 views

Middle of Node replace

I had to replace a dead node, now I have two other nodes that are down. Can I shutdown the entire cluster in the middle of replace node process? If I resume do I have remove the JVM_OPTS=$JVM_OPTS ...
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38 views

Data modeling question on Cassandra DB

I'm trying to save events of a month for a user to my Cassandra DB instance. Each month the data will expire and will be removed. The data I try to model will contain user id, date of event and event ...
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33 views

Cassandra Deployement Architecture

I'm new to Cassandra. I have the responsibility to design a basic deployment architecture for a use case. I'd like to know if my solution is correct, and get advice and recommendations from you. Here ...
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49 views

Cassandra CL quorum giving inconsistent values

How is this even possible? cqlsh:keyspace> consistency Current consistency level is QUORUM. select * from email_idx where email='xxx@yyy.com'; email------------------- | user_id ...
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1answer
441 views

Do you have to run nodetool repair on every node?

Do you have to run nodetool repair on every node in a cluster, or do you only need to run it on one node, and from there Cassandra will take care of the rest?
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25 views

cassandra:request didn't complete with rpc_timeout

cassandra:request didn't complete with rpc_timeout.I Have set up a cassandra server of only one node and import 60 lacs record.but when we run select query it show error of rpc_timeout over 10000 ...
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43 views

How to apply updates in a “Fan out on write” architecture?

If I copy certain writes to different tables for faster read performance on certain queries(fan out on write), how should I design updates? Since the data is spread over different tables, I'm trying ...
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1answer
105 views

Date model for commenting system stored in a key-value NoSQL DB?

I'm trying to leverage Cassandra's strong support for time series data to build a commenting system. So far I'm thinking that each row would be a particular topic, and each comment would be a new ...
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1answer
1k views

Small startup: Cassandra + Hadoop or ElasticSearch

To give some context, I am from a small start up (4 team members) and we work in the education space. We've developed an e-learning platform that several schools are already using. We currently have ...
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1answer
63 views

Keeping rows ordered by counter value

I'm storing linked words in a Cassandra v2 cluster and I'm having a hard time doing efficient reads. I'm trying to fetch the top X rows with the highest counter value. Cassandra doesn't store the ...
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285 views

Cassandra cluster on Windows Machine

I am new to Cassandra, and have been trying to create a cluster using DevOps. When I add a node , I get the following error: Error provisioning cluster: Unable to SSH to some of the hosts ...
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1answer
379 views

Allow filtering not working as expected

I'm having issues with getting ALLOW FILTERING to work. In our Cassandra 1.2 database, we have a table like this: CREATE TABLE some_table partition_key text, other_key text, non_key ...
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1answer
393 views

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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130 views

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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1answer
368 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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388 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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1answer
81 views

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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1answer
100 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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1answer
818 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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1answer
71 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
3k 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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185 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
4k 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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1answer
2k 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 & ...
2
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1answer
5k 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, ...
12
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1answer
226 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
2k 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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5answers
10k 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 ...
6
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1answer
3k 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 ...
2
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1answer
181 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 ...
2
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0answers
250 views

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 ...
2
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1answer
160 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
229 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
466 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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1answer
314 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
896 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
2k 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 ...