Cassandra is a highly scalable, eventually consistent, distributed, structured row/column store.

36
votes
5answers
17k views

MySQL and NoSQL: Help me to choose the right one

There is a big database, 1,000,000,000 rows, called threads (these threads actually exist, I'm not making things harder just because of I enjoy it). Threads has only a few stuff in it, to make things ...
345
votes
6answers
111k views

Difference between partition key, composite key and clustering key in Cassandra?

I have been reading articles around the net to understand the differences between the following key types. But it just seems hard for me to grasp. Examples will definitely help make understanding ...
641
votes
6answers
275k views

MongoDB vs. Cassandra [closed]

I am evaluating what might be the best migration option.Currently, I am on a sharded MySQL (horizontal partition), with most of my data stored in JSON blobs. I do not have any complex SQL queries (...
33
votes
8answers
35k views

How to create auto increment IDs in Cassandra

We know that it is easy to create auto increment IDs in SQL databases, is there a good solution for it in Cassandra? The IDs should be for key or column name.
18
votes
4answers
8k views

cqlsh connection error: 'ref() does not take keyword arguments'

I've tried all the measures from this post and Cassandra doc. I've tried running all the versions of Cassandra including the latest release 3.7 from tarball and Debian package, but I keep getting ...
41
votes
3answers
31k views

Understand cassandra replication factor versus consistency level

I want to clarify very basic concept of replication factor and consistency level in Cassandra. Highly appreciate if someone can provide answer to below questions.RF- Replication FactorRC- Read ...
15
votes
1answer
22k views

Inner Join in cassandra CQL

How do I write subqueries/nested queries in cassandra. Is this facility is provided in CQL?Example I tried:cqlsh:testdb> select itemname from item where itemid=(select itemid from orders ...
71
votes
6answers
109k views

Cassandra port usage - how are the ports used?

When experimenting with Cassandra I've observed that Cassandra listens to the following ports:TCP *:8080TCP *:8888TCP *:57311TCP *:57312TCP 127.0.0.1:7000TCP 127.0.0.1:9160UDP 127.0.0.1:700...
17
votes
4answers
19k views

Cassandra cqlsh - how to show microseconds/milliseconds for timestamp columns?

I'm inserting into a Cassandra table with timestamp columns. The data I have comes with microsecond precision, so the time data string looks like this:2015-02-16T18:00:03.234+00:00However, in ...
6
votes
2answers
2k views

Is the IN relation in Cassandra bad for queries?

Given an example of the following select in CQL:SELECT * FROM tickets WHERE ID IN (1,2,3,4)Given ID is a partition key, is using IN relation better than doing multiple queries or is there no ...
3
votes
2answers
383 views

Issue while storing data from Spark-Streaming to Cassandra

SparkStreaming context reading a stream from RabbitMQ with an interval of 30 seconds. I want to modify the values of few columns of corresponding rows existing in cassandra and then want to store data ...
37
votes
6answers
23k views

cassandra - Saved cluster name Test Cluster !=configured name

How am I supposed to bot a new Cassandra node when I get this error?INFO [SSTableBatchOpen:1] 2014-02-25 01:51:17,132 SSTableReader.java (line 223) Opening /var/lib/cassandra/data/system/local/...
8
votes
5answers
13k views

TaskSchedulerImpl: Initial job has not accepted any resources;

Here is what I am trying to do.I have created two nodes of DataStax enterprise cluster,on top of which I have created a java program to get the count of one table (Cassandra database table).This ...
15
votes
4answers
37k views

MAX(), DISTINCT and group by in Cassandra

I am trying to remodel a SQL database Cassandra such that, I can find the Cassandra equivalent for the SQL queries. I use CQL 3 and Cassandra v1.2. I modeled the db design in cassandra so that it ...
16
votes
5answers
23k views

Can't connect to cassandra - NoHostAvailableException

I know there are several threads about the NoHostAvailableException but they simply don't provide a solution to my problem.I can't connect to Cassandra with the Datastax Java Cassandra Driver. I get ...

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