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.

learn more… | top users | synonyms

1
vote
1answer
24 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 ...
1
vote
1answer
91 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 ...
0
votes
1answer
94 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 ...
0
votes
1answer
98 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 ...
2
votes
0answers
31 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
votes
0answers
39 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
votes
0answers
270 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 ...
1
vote
0answers
23 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, ...
1
vote
0answers
38 views

What kind of database is Cassandra DB?

I was taking some courses to understand better the way Cassandra works (at academy.datastax.com) and by what I gathered it came to me that it is a Key Value Database because of the way it stores data ...
0
votes
0answers
17 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 ...
0
votes
0answers
40 views

Cassandra Database limitation

why Cassandra is limited to 65535 records only when stored in batch and loop is encounters 20000 only? I have inserted 20,000 customers but it shows an error like too many values for built statement, ...
0
votes
0answers
9 views

Running Cassandra on Encypted filesystem

Looking for pointers for running Cassandra on a Linux File system encrypted by open source tools. Will this satisfy "data-at-rest" encryption ? Is the encryption transparent to Cassandra DB ...
0
votes
0answers
32 views

Cassandra - save file

I'm new with Cassandra, and even more - I never have such task for habitual RDMS systems, like MariaDB or Oracle. So, how can I store file in to Cassandra's table? Preferably using Python-driver, but ...
0
votes
0answers
19 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) ...
0
votes
0answers
33 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] ...
0
votes
0answers
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 ...
0
votes
0answers
54 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 ...
0
votes
0answers
75 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 ...
0
votes
0answers
28 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 ...
0
votes
0answers
78 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 ...
0
votes
0answers
383 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 ...