Episode #125 of the Stack Overflow podcast is here. We talk Tilde Club and mechanical keyboards. Listen now

Questions tagged [cassandra]

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.

Filter by
Sorted by
Tagged with
0
votes
0answers
14 views

Cannot Connect to Cassandra on GCE

I just started learning how to use Cassandra, but at the moment I am trying to troubleshoot a small problem with GCE and Cassandra. I am not able to connect to it at all. I am using this Deployment ...
0
votes
1answer
22 views

How to insert nested UDT types

I have all these case classes :- case class Role(id:UUID, roleName:String, description:Option[String], isVisible:Boolean, isDefault:...
1
vote
0answers
24 views

Cassandra not returning the row of the specified primary key

First of all, my table is structured like this: CREATE TABLE timeseries_data.test_data ( date timestamp PRIMARY KEY, data1 float, data2 float ) WITH bloom_filter_fp_chance = 0.01 AND ...
0
votes
2answers
5k views

how to import a huge csv file into Cassandra?

I am trying to import a csv file into Cassandra which is very long. These are food products: ingredients, nutrition, labels... It comes from Open Food Data. List information on food products: ...
0
votes
1answer
21 views

What happens if one DC goes down in Cassandra multi DC setup?

We have a Cassandra multi DC setup with 3 nodes in each DC, enabled with NetworkTopologyStrategy and RF 3. The java client interacts with Cassandra cluster using read and write consistency as ...
1
vote
0answers
11 views

compaction strategies and high performance storage

My apologies for this being a somewhat newbie question. However, my understanding of Cassandra is that is use three different compaction strategies: are these tunable, or is this area a black box, i....
2
votes
0answers
25 views

Querying a High Cardinality Field

I am designing a data model for our orders for our upcoming Cassandra migration. An order has an orderId (arcane UUID field) and an orderNumber (user-friendly number). A getOrder query can be done by ...
0
votes
0answers
17 views

Cassandra data modelling for IOT devices

We are building a micro service based IOT platform with a dashboard and views of various sensors etc. I have seen a few data modelling videos but I am not able to arrive at a good data model in ...
0
votes
0answers
57 views

Cassandra restore fails if sstableloader is used

Starting point: new cluster, DSE 6.7.4, C* 4.0.0.674 backed UP data, which was made by Opscenter snapshot backups to remote S3 bucket (1.5TB per each node) restoring data to new cluster needs to use ...
0
votes
0answers
10 views

Cassandara ec2 Number of Nodes and autoscale for increasing 70Gb of Data

I am beginner in Cassandra, I currently have 72 GBs of Data that is growing and i will have approximately 1gbs inserted into database daily. How can i decide number of nodes in the cluster and how ...
6
votes
2answers
5k 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
votes
1answer
127 views

Binary storage in Cassandra, HBase

I am looking at some implementations of Cassandra and HBase for medium-sized data sets (~1M resources) to be exposed to clients as graphs (via e.g. Tinkerpop). I would also like to store binaries in ...
0
votes
0answers
21 views

How to group by a field in a certain time range in Cassandra

I have a big Cassandra table with around 15 fields, and I wanted to create many materialized views to support all of my queries. The Primary Key on the base table is (CompanyName, ctime) where ctime ...
1
vote
1answer
195 views

Cassandra nodes are not equal

We have two nodes. Node1 was down for a long time. During this time Node2 raised 1 TB capacity when Node1 has 100 GB. We tried to repair Node1 with nodetool repair but nothing changed. After that we ...
1
vote
0answers
42 views

Cassandra slow read performance after migrating to new AWS instance class

Cluster of 3 cassandra nodes as a dev environment. Used to run in AWS on i3.2xlarge; migrated as a test to i3en.2xlarge to evaluate for later migrating production cluster to. When running cassandra-...
1
vote
1answer
783 views

Cassandra querying without full primary key

As far as I understand there are no secondary indices with multiple columns, only single columns. So how do I solve the index problem I'm having? This is my table: CREATE TABLE IF NOT EXISTS logstv....
1
vote
1answer
653 views

Python version issue on Cassandra 3.11.2

Searching around I found a lot of thread about this problem (coming from 2012) but I can't find an official solution: running cqlsh.bat File "C:\apache-cassandra-3.11.2\bin\\cqlsh.py", line 146 ...
1
vote
0answers
17 views

Cassandra multi data centre cluster configuration [closed]

We are decided to use "cassandra" as a database and now want to go with cluster with two datacenters DC1 & DC2. This DC2 is for backup purpose and it is replica of DC1. Initially we are expecting ...
3
votes
0answers
68 views

Can Cassandra prevent TTL from updating on upsert of table

I have a Cassandra table that is like this... CREATE TABLE IF NOT EXISTS analytics.data( id double, data text, PRIMARY KEY(id, data) ) WITH default_time_to_live = 120 AND gc_grace_seconds ...
0
votes
0answers
35 views

What is the best compaction strategy for overwritable/mutable/upsert-able data?

Suppose I have a Cassandra table like this: CREATE TABLE keyspace.last_modified ( category text, subcategory text, id text, created_at bigint, PRIMARY KEY ((category, subcategory, ...
0
votes
1answer
27 views

Stopping N number of nodes of a Cassandra cluster running on a single machine using bash script

I have set up a Multi-Node cassandra (3.11) cluster (with N nodes) in a single Ubuntu machine. I have written a bash script which Creates N copies of conf folder Configures the cassandra yaml file ...
2
votes
1answer
302 views

Cassandra multi-DC:write on LOCAL and read from any DC

We use a multi-data center (DC) cassandra cluster. During write on to the cluster, I want only LOCAL DC to perform writes on its nodes as we are already routing the write requests to the desired DC ...
1
vote
1answer
727 views

Copy/move data from one cassandra server to another

I'm in the midst of replacing a kubernetes stack (to more specific: moving it from a locally hosted cluster to an AKS cluster in Azure), and as a result have to re-create all of my services, including ...
0
votes
1answer
163 views

how to disable delete in replication Cassandra datastax

my previous scenario i used Sql server one instance in amazon for live and the second in local network for archiving by disable delete in replication can i do this in Cassandra or what best ...
1
vote
2answers
531 views

Correct way to perform backup of Cassandra/Scylladb

What's the correct(advisable) method to backup a cassandra or scylladb so that we can restore it on development environment with ease?
2
votes
2answers
60 views

Allocate space in Cassandra

We run a Cassandra cluster with 2 DC, 3 nodes each (2 RF). The state of the cluster is quite bad (never repaired) and the disks were getting full so we added additional nodes which after the bootstrap ...
2
votes
2answers
240 views

Cassandra in a Public Cloud - Which Snitch?

I am planning on deploying Cassandra in a public cloud (like Amazon AWS). The cluster will span multiple zones and regions. The cluster will also require logical DC separation within a given region. ...
2
votes
2answers
281 views

Cassandra query performs differently at different times

I am using apache-cassandra-2.0.12 in production, with network topology strategy and ReplicationFactor : 3 in a cluster with 2 DC’s each contains 4 nodes While analyzing the response time for the ...
2
votes
1answer
410 views

What may be the consequences of deleting the system keyspace?

I have a Cassandra cluster composed of 2 nodes. One node could not start Cassandra yesterday. I deleted the system keyspace directory and I started the node again. The node is running after system ...
1
vote
2answers
148 views

Does Cassandra CQL provide a command to generate an execution plan?

In Oracle and other DBs you can generate an execution plan for SQL. Is this possible for Cassandra? I want to determine if it is possible to measure the relative complexity of several CQL statements ...
1
vote
1answer
71 views

User Grant in cassandra DB

I would like a user abc to access only a single keyspace and no other keyspaces in the Database. How can I achieve so?
1
vote
0answers
103 views

Why getting Error accessing Cassandra with DataStax ODBC Driver?

We are using Cassandra 2.2.11, and trying to configure DataStax ODBC driver. We are getting the following error message: SQLSTATE: HY000[DataStax][CassandraODBC] (10) Error while executing a query ...
0
votes
1answer
10 views

Show cassandra help documentation in terminal instead of browser

I've just started playing around with Cassandra through the cqlsh cli. When using the help command for the topics the documentation opens in the browser. Is there a way to show the documentation in ...
1
vote
0answers
102 views

Cassandra pool warning displaying continuously

I am using the Cassandra driver for python in Spyder. I am trying to fetch some data from Cassandra table. Here is my code: from cassandra.cluster import Cluster cluster=Cluster(['some_ip']) session=...
15
votes
1answer
539 views

Is it safe to add a new node to a Cassandra cluster while a repair is running?

I'm getting ready to expand an existing Cassandra cluster. I have repairs scheduled to run on a reoccurring basis. Do I need to disable repairs when adding a new node to a cluster, or can I ...
0
votes
1answer
64 views

Hints gc_grace and expirations

Have 3 node cluster. RF=3. Table with gc_grace_seconds = 120 secs. max_hints duration as default at 3 hours. inserted a row nodetool flush on all the 3 nodes bring down node 3 delete the inserted ...
0
votes
2answers
42 views

Cassandra Cluster storage

I want to try out Cassandra Cluster. My main question is about scalability. Every node in a Cassandra cluster has the same copy of data. So when I have in total 1 TB and have 5 nodes -> 5TB. This at ...
2
votes
1answer
36 views

Is there a way to change the compaction throughput via startup options in Cassandra?

We are currently running a Cassandra cluster in K8S containers as Stateful sets. We're considering exposing the config file but we would like to know if perhaps we can provide this value as a startup ...
2
votes
1answer
96 views

Apache Cassandra INSERT-only permissions

Looking at the Cassandra documentation, it appears that the smallest write-only permission on a table you can grant is MODIFY, which includes UPDATE, DELETE and TRUNCATE. Is there a proper way to ...
0
votes
1answer
20 views

cassandra nodes have diff value

I have 3 node cluster, problem is that for some rows , updatetime column have different value on 3 node: like : 1st node : updated_on | 2018-08-22 17:01:30+0530 2nd node : updated_on ...
1
vote
0answers
257 views

Error on cassandra-3.11.3-1.noarch centos7

I've a cluster consisting of 5 cassandra nodes. The cassandra version used is cassandra-3.11.3-1.noarch The keyspace strategy and is defined as follows: CREATE KEYSPACE my_keyspace WITH ...
0
votes
2answers
235 views

Handling read conflict in cassandra?

Say we have three nodes(simple replica no sharding) i.e. N1,N2 and N3 with replication factor as 3. As read and write request can go to any node, Say Request write request(to update the same ...
1
vote
1answer
321 views

How to deal with unbounded growth in cassandra shards

Let's say we have a website like youtube where we have a comment session per e video. Users want to be able to comment and to see the comments made by other users by comment creation time. This is ...
0
votes
1answer
33 views

Data replication in Cassandra

We have a 5 node cluster in Cassandra in which we have created a keyspace with RF=3. After creating a column-family(table) when we insert the data into the same, it is getting replicated in all the ...
1
vote
0answers
28 views

Kill client connection to Cassandra instance

Not able to go to find any documentation on how to kill a client connection to remote Cassandra I will instance .. as a DBA at the server end? Seems like an easy task but why no mention of this in ...
0
votes
0answers
85 views

OpsCenter missing in Datastax Cassandra for Windows

Following this guide within the Cassandra installer I should get OpsCenter too. But this screenshot https://www.datastax.com/wp-content/uploads/2012/01/dsc-win4.jpg doesn't match the current release (...
0
votes
1answer
27 views

SQL Join vs NoSQL Wide column

If we need to have 2 tables, one storing the author info(author_info), & another storing all the books info(book_info). author_info has authorId as it's primary key, whereas the book_info table ...
0
votes
0answers
927 views

dropping a table does not delete the directories on the disk

I am just testing the drop table command in Cassandra 3.11. The sequence is as follows: Load data worth 10gb drop the table on the node, nodetool flush nodetool clearsnapshot nodetool cleanup ...
0
votes
1answer
14 views

How these conflicting scenarios will work in cassandra when one of the mode crashes?

Say we have two nodes(simple replica no sharding) i.e. N1,N2 with replication factor as 2. I am using default Read and write consistency levels i.e. R and W are 1 which means it will read/write from/...
0
votes
1answer
60 views

Replica model in Cassandra vs Mongo?

Say in Mongo we have one primary and two replica node(simple replica no sharding). Read and write request will be handled only primary node and replica will just backup the data in case of failover. ...