Questions tagged [cassandra]

Apache Cassandra is a highly scalable, eventually consistent, distributed, structured row store. Questions about Cassandra server administration should be asked on https://dba.stackexchange.com/questions/tagged/cassandra .

Apache Cassandra is a highly scalable, eventually consistent, distributed, structured row/column store. Cassandra brings together the distributed systems technologies from Dynamo and the data model from Google's . Like , Cassandra is eventually consistent. Like BigTable, Cassandra provides a ColumnFamily-based data model richer than typical key/value systems.

Cassandra's Dynamo-based cluster model provides linear scalability and fault tolerance on commodity hardware or cloud infrastructure. Its support for replicating across multiple data centers is best-in-class, providing low latency and the ability to survive entire data center outages.

Cassandra's data model offers the convenience of column indexes with the performance of log-structured updates and powerful built-in caching with the fastest write performance as compared to other database solutions and makes it a compelling option for big data processing. It provides linear scalability with the provision to add/remove nodes on the fly without downtime.

Cassandra was open-sourced by Facebook in 2008 and quickly became a top-level Apache project. Today, it's widely used by companies in many markets.

Official links:

Documentation

Useful Links:

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FileNotFoundException during compaction

All of my nodes are throwing a FileNotFoundException during compaction. As such, not a single compaction (auto, manual) can finish and my SSTable count is now in the thousands for a single CF (CQL3). nodetool compactionstats shows hundreds of…
PJ.
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I'm Unable to connect using python Cassandra-Driver

What might I be missing? I'm Unable to connect using python Cassandra-Driver however I seem to be able to connect fine when using the CQL module. cluster = Cluster( contact_points=['10.x.x.xx',], port=9160) session =…
EnergyGeek
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Cassandra adding disks / increase storage volume without adding new nodes

I have to increase storage volume in an cassandra cluster, the performance and throughput however is still more than enough. My first thoughts were to only add drives. Is it possible to increasing storage volume without adding new nodes? Is it…
Manuel
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How to DROP tables or column families in cassandra 2.0.5?

I am trying to drop a table/column family from my database but I am unable to do it. I have tried the following commands and their responses are: cqlsh:testreducedb> DROP_COLUMNFAMILY largest_time_total; Bad Request: line 1:0 no viable alternative…
Charlie Parker
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Adding a new node to existing node cassandra cluster

Starting from one host running Cassandra, I am trying to add a new node and form a cluster. I update the seeds list on both hosts and after restarting both nodes, I do nodetool status and see both nodes forming a cluster. However, I am seeing some…
Nitin Bhatt
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"Greater than" where-condition on timeuuid using Datastax C# Cassandra Driver

How do I make "greater than" or "less than" where-conditions in CQL queries on the timeuuid data type using the Datastax C# driver? I have a table in Cassandra for storing cookie history sorted by time stamp as timeuuid: CREATE TABLE cookie_history…
user628904
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Copy From CSV - COLUMN FAMILY NOT FOUND

I've spent the past two days checking the available answers on this site and a few other sites. I need help with the following (COPY FROM a CSV file) issue I'm encountering. I created the KEYSPACE and COLUMN FAMILY without any issues, but I receive…
Cary
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How does Cassandra rebalance when nodes go down?

Does anyone have experience with Cassandra when nodes go down or are unavailable? I am mostly interested in whether the cluster rebalances and what happens when the nodes come online, or are replaced by new machines.
yazz.com
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cassandra counters, atomic get and set

Does cassandra support an atomic get and set for a counter? I.e. create table c(id int, value counter, primary key (id)); update update c set value=value+1 where id=1; ok, now my counter is ready. But I want to be able to read a unique value from…
kostas.kougios
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Cassandra 2.0.3 client-to-server [TSocket reads 0 bytes] error

I want to enable authorization, authentication, Client/server encryption and internode encryption in Cassandra 2.0.3.. Unfortunately, this doesn't seem to be happening as all security configurations are working fine but when i enable "Client/server…
user1540371
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Cassandra not returning all matching columns with a "SELECT x WHERE y IN (z)" query

I have the following column family in Cassandra: CREATE TABLE item_index ( foo_id text, bar_id text, bar_metadata text, bar_url text, PRIMARY KEY (foo_id, bar_id) ) WITH bloom_filter_fp_chance=0.010000 AND caching='KEYS_ONLY' AND …
Zack
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How does "DROP TABLE IF EXISTS" work in Cassandra?

I'm trying to understand the syntax of DROP TABLE IF EXISTS in Cassandra. DROP TABLE IF EXISTS nonexistanttable; does not seem to work: $ ./cqlsh Connected to Test Cluster at localhost:9160. [cqlsh 4.1.1 | Cassandra 2.0.5 | CQL spec 3.1.1 | Thrift…
knorv
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Tuning write performance in cassandra

We have this typical scenario: 1 column family with less than 10 simple columns. When we get request from client we need to write 10 000 000 records of this column family in database and we are writing them in batches (1000 in one batch). This…
Ivan Longin
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How seed node works in Cassandra cluster

My understanding is : Seed node maintains all the nodes list in cluster. Lets say if we have to add a new node to the cluster, we have to enter the new node name in the seed list of seed server and then new node will be part of the ring. I am…
Brainchild
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SStablewriter for python cassandra

Is there a python variant of the SStable writers for cassandra? I found many java examples, http://amilaparanawithana.blogspot.com/2012/06/bulk-loading-external-data-to-cassandra.html Is this still something which is under consideration?
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