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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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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5answers
2k 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 ...
12
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1answer
320 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 ...
10
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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 ...
8
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2answers
10k 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 ...
8
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2answers
601 views

NoSQL : What is unstructured data?

we are currently running at the edge of resources with our mssql server based solution. We have now many traditional options regarding the next move to tackle the load: buy faster CPUs and IO ...
8
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1answer
4k 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
3k views

“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 ...
4
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2answers
266 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 ...
4
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2answers
3k 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?
4
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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 ...
4
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1answer
72 views

Cassandra one-to-many table design

I am new to Cassandra from 20 years of RDBMS, and over the last few days have been reading and watching everything I can get my hands on that applies to my situation. I'm sure this is a basic ...
4
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1answer
2k 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 (...
3
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1answer
15k 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, ...
3
votes
2answers
152 views

Cassandra cluster monitoring

We using Nagios for our servers monitoring. Each web-environment have 1 cluster as backend - Cassanra 2.0. Each cluster have 3-5 nodes. Question is: I want write a plugin for Nagios, for Cassandra's ...
3
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2answers
2k 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. ...
3
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2answers
8k 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.
2
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2answers
269 views

Migration from Cassandra 2.x to 3.x: schema_keyspaces table is gone. How do you query system keyspaces?

I just migrated from Cassandra 2.x to 3.x (specifically, 3.4). Now the system tables have completely changed, and these changes are not in the documentation. If you look at the current CQL docs for ...
2
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1answer
1k 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?
2
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2answers
2k 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 ...
2
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1answer
11 views

Cassandra nodetool repair scheduling and gc_grace_period

I am trying to devise a scheme with minimal repair frequency to not overload the system, and have a problem to understand how can I ensure that the data is not getting resurrected. I have a cassandra ...
2
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1answer
88 views

Why does Cassandra recommend against creating an index on high-cardinality columns?

The Cassandra documentation states, Do not use an index in these situations: On high-cardinality columns because you then query a huge volume of records for a small number of results. See ...
2
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1answer
272 views

How does the Cassandra distribute data?

I cannot find a detailed document on this anywhere, however, that being said, if anyone has an answer to my question, I would be extremely grateful. In regards to Cassandra's standard node ...
2
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1answer
203 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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1answer
18 views

DSE Cassandra decimal type

I generated solrschema with dsetool on a table name seriesdata (its key is composed by seriesmetadata_id, initialtime; two decimal field). These fields are defined as DecimalStrField but they are ...
2
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1answer
671 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 ...
2
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1answer
227 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 ...
2
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1answer
201 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 ...
2
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1answer
4k 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?
2
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0answers
17 views

Is there a configuration option that lets me limit the percent of a hard drive that Cassandra uses?

I'm doing some testing with a small hard disk and I'd like to basically stop Cassandra in its tracks if a write or compaction or any other service brings that usage of the disk above a certain ...
2
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1answer
72 views

Filter rows, but only select most recent row for each Id

I have some code that is processing a lot of tasks. These tasks are either connected to a user or an account. Each Task go through many statuses -> Queued, Started, Error, Postponed, Queued, Started, ...
2
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0answers
64 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 = ...
2
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0answers
53 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 ...
2
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0answers
287 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 ...
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2answers
1k 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 10....
1
vote
2answers
418 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 ...
1
vote
1answer
965 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 ...
1
vote
1answer
10 views

What's the advantage of the inet datatype in Cassandra vs a plain text string?

What is the inet datatype really for? The documentation refers to its usage having something to do with Python but I'm not much of a Python guy so that aspect is beyond me. Is there any advantage to ...
1
vote
1answer
25 views

Error after upgrading datastax to version 5

After upgrading to DataStax Enterprise version 5, the node does not come up, and I get this error in the log: Insufficient permissions on directory /hints Where is this directory located?
1
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1answer
22 views

sstableloader returns `java.lang.NumberFormatException: For input string: “Filter.db”`

I've been using the Java API to create an SSTable by following the instructions on this site. The program compiles and works fine; no errors. However when I try to load the table using the following ...
1
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1answer
23 views

Cassandra change replication factor hive datastore

I am trying to change replication factor of HiveMetaStore but I receive this message: cassandra@cqlsh:system> alter KEYSPACE HiveMetaStore with replication = {'class': '...
1
vote
1answer
25 views

How to predict new node allocation in a Cassandra cluster?

I have a 5-node Cassandra cluster. Each node has disk space of 5TB. The real usage for each node is around 2.5TB depending on allocations and compactions (some are around 2TB some around 2.8). I ...
1
vote
1answer
105 views

How to Query Properties of an Entity in Apache Cassandra

I am new to Apache Cassandra, and I would like to know how to create a table in which I can filter rows by non-key columns. In relational databases, I would simply create a table with an ID as a ...
1
vote
1answer
119 views

cassandra in memory tables

I am planning to use Cassandra in memory tables for my particular work load. THe problem is I am worried if the node fails then what will happen to the data in memory that was not flushed to disk ? ...
1
vote
1answer
386 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 ...
1
vote
1answer
4k 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 ...
1
vote
1answer
216 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
3k 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
3k 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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0answers
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Why restore a single node of a cluster?

We were reviewing the restore documentation for Cassandra here, and noted it made the following distinction between restoring a single node or an entire cluster: If restoring a single node, you ...