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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.

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Is there a way to prevent TTL from getting updated on an upsert?

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 ...
JGleason's user avatar
  • 141
3 votes
0 answers
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Data modelling for dynamic grouping of rows in Cassandra

I have a feed of game events with a schema like; { "gameId": text, "playerId": text, "eventId": text, "ts": bigint, "metrics": map<...
eimaj's user avatar
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3 votes
0 answers
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Cassandra - High Number of Dropped Mutations (Specific Table on a specific Node in the cluster)

History Leading to this issue: My Compression strategy in Production was LZ4 Compression. But I modified it to Deflate For compression change, we had to use nodetool Upgradesstables to forcefully ...
Hiteshdua1's user avatar
3 votes
0 answers
166 views

Securing a Cassandra Cluster

We've managed to set up a Cassandra 2.2.6 cluster of two physical nodes (nodetool sees both of them, so I'm quite certain the cluster is indeed active). My steps to create the cluster were (this ...
Ray's user avatar
  • 131
3 votes
0 answers
487 views

Is it good practice to have multiple keyspaces in Cassandra?

I've Cassandra configured on Amazon EC2 having 3 nodes(instances) in single cluster. Now what I want to do is give some space on Cassandra to my clients by creating separate keyspace for each in a ...
Alok Patel's user avatar
2 votes
1 answer
26 views

How does replication work when there are multiple racks in a DC?

I would like to understand how Replication Factor works when having the following scenario: We have a set of total of 18 disks, each one related to 1 Cassandra node, and all distributed in 3 Racks ...
LilRose's user avatar
  • 21
2 votes
1 answer
184 views

How do I backup data of Cassandra nodes running in Docker?

I hope to receive some tips and assistance. I have three virtual machines running Ubuntu 22.04, and each one has Cassandra deployed via docker-compose, forming a cluster. My current task is to ...
Dmitriy's user avatar
  • 21
2 votes
0 answers
91 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 ...
Prashant Pandey's user avatar
2 votes
0 answers
1k views

Repair running too slow

Last week I asked a question that was answered below... I need to improve the question I asked earlier (in quotes below) and give a little more context. The answer below did help the repair ...
marshall's user avatar
2 votes
0 answers
211 views

Cassandra's nodetool snapshot renders node unresponsive

I have noticed that using nodetool snapshot on a Cassandra node causes heavy load (100% on two cores) for around 10-30 seconds. The snapshots are around 1GB in size. During that time connections to ...
Hugo G's user avatar
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2 votes
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301 views

What are the implications of using quite large partitions (rows) in Cassandra?

I am looking to store data in Cassandra, due to the fact that I have many writes that need to perform well, and all my reads can be done based on primary key. While doing the data modeling, however, I ...
Mark's user avatar
  • 462
2 votes
0 answers
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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 = ...
Praful Bagai's user avatar
2 votes
0 answers
101 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 ...
Mehdi TAZI's user avatar
2 votes
0 answers
323 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 ...
Wynand Pieterse's user avatar
2 votes
1 answer
394 views

Setting up a 3-node cluster, getting exception "Unable to gossip with any peers"

Getting Gossip error when trying to setup 3 node cluster. Node-1: Private IP: 10.10.0.1 Public IP: public_ip_1 Node-2: Private IP: 10.10.0.2 Public IP: public_ip_2 Node-3: Private IP: 10.10.0.3 ...
Ranjeet Ranjan's user avatar
2 votes
1 answer
62 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 ...
muninn's user avatar
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1 vote
1 answer
26 views

Querying Cassandra from SQL server with where clause issue

I'm facing a strange issue where I have a SQL server connected to Cassandra to pull time series data. I'm using the 'DataStax C/C++ Driver for Apache Cassandra' and have connected via a 'linked' ...
Thomas Gross's user avatar
1 vote
3 answers
37 views

Which Python 2.7.x version is compatible with both Cassandra 3.11 and 4.1?

I'm upgrading Cassandra from 3.11 to 4.1. One of the requirements is the latest python 2.7 updates. I want to upgrade Cassandra with no downtime, so I need to know which python 2.7 update is ...
user avatar
1 vote
1 answer
63 views

Apache Cassandra node restarts randomly

I have a cluster of 11 nodes, Apache Cassandra version 3.11.4, where certain nodes are restarted at random times. Nodes characteristics: CPU(s): 32 Model name: Intel(R) Xeon(R) Silver 4110 CPU @ 2....
Midas Salimgali's user avatar
1 vote
2 answers
38 views

If a snapshot is cloned to a new node, will the data be replicated to the rest of the nodes in the cluster?

I have restored cassandra snapshot in one node in a new cluster which consists of 6 nodes. Will it replicate to the remaining nodes? Or do we need to copy the snapshot to remaining nodes (as done in ...
Prasad's user avatar
  • 31
1 vote
2 answers
32 views

How do I migrate from a JBOD configuration to a single-volume setup?

Need some help with something I couldn't find a solution online. I have CassandraDB running on a server. This server has 3 mounted volumes /data1, /data2 and /data3. In my scylla.yaml file, I've ...
Mujeer Ahmed's user avatar
1 vote
1 answer
186 views

Not a able to decommission the old datacenter

I am using cassandra 4.1 with Java 11. I have added the new data center and modified all my keyspaces including system_auth, system_traces, and system_distributed to replicate to new data center. Now ...
Vijayraj M's user avatar
1 vote
2 answers
49 views

Will there be any data loss from adding a new DC?

In multi dc setup; Let's say dc1 has 9 nodes and we added a new data center dc2 with 6 nodes. We then ran nodetool rebuild on the 6 nodes using a source of dc1. Will there be any data loss?
S.R's user avatar
  • 11
1 vote
2 answers
137 views

Is there a way to recreate lost SSTable index and other component files?

In Cassandra, in addition to the main sstable file, which ends with big-Data.db, there appear to be 7 other files, namely: big-CompressionInfo.db big-Digest.crc32 big-TOC.txt big-Summary.db big-...
ranban282's user avatar
1 vote
1 answer
100 views

How to reduce Backpressure rejection while receiving WRITES and increase throughput limit of cluster

After we rebuild a down node we could see some other nodes are going down and its prompting "Backpressure rejection while receiving WRITES". Nodes are behaving as down and its continuing for ...
Cassandra Thrift's user avatar
1 vote
1 answer
120 views

nodetool rebuild returned "Unable to find sufficient sources for streaming range"

We are migrating self hosted cassandra 3.11.6 to self hosted cassandra with k8ssandra-operator using cassandra 3.11.7. At some point of the migration we had to stop it due to other unrelated incident. ...
Mazurkim's user avatar
1 vote
1 answer
260 views

Is Cassandra 4.1 not compatible with Ubuntu 20.04?

I can't make connection into my nodecluster, my nodetool status is currenty refused, i am using Cassandra 4.1 but not working trying edit in cassandra.yaml for localhost using 127.0.0.1 also edit my ...
BlossomX's user avatar
1 vote
1 answer
305 views

How do I model a Cassandra table that stores friends of a user?

Recently I started to learn Cassandra. I needed to design the database for my web application. So, I prepared conceptual data model as well as application workflow, and currently I’m stuck on ...
Jacobino's user avatar
1 vote
1 answer
189 views

Cannot run nodetool commands after enabling JMX authentication in DSE

I would like to use these two pages to enable DSE Unified Authentication and realize a secure environment. I have tried to configure it but it does not work. How is it as a symptom. When I type ...
Youjie's user avatar
  • 41
1 vote
1 answer
81 views

Cassandra can't start with an old backup of /var/lib/cassandra

I have an old Cassandra backup of /var/lib/cassandra on an external drive and I want to setup a new database with this backup. I install the same Cassandra version as then and in the yaml file I ...
Vasilis_Dimitrakopoulos's user avatar
1 vote
1 answer
124 views

Cassandra System.Log shows nodtool tpstats output

We have a Docker Cassandra container running 6.8.21. At times when the container is restarted the the Logs show the usual startup activities and all just works well post that. But on a few occasions ...
Sakiv's user avatar
  • 11
1 vote
1 answer
431 views

Disk space is not released after compaction

We have deleted some of the partionons of some tables in cassandra database. But after the delete space was not recliamed becuase of size-tiered compaction . Manualy compacted tables with -s options. ...
sunil kumar's user avatar
1 vote
0 answers
36 views

Tip on modeling Cassandra database schema time querry

I am working on modeling a database schema for Cassandra from existing relational schema, so in my database there are "events" (some events are scheduled events, some are recurring events) ...
Kurt Cobain's user avatar
1 vote
1 answer
167 views

Cassandra Table data modeling for a event system monitoring data

I have been working in a cassandra database to keep the real time data of an event/monitoring system that has quite a large number of events per hour(100k+) and I have hit a wall in a specific need: I ...
CromixPT's user avatar
1 vote
0 answers
301 views

Which NoSQL for storing images as 2D arrays (BLOBs)

I have large number of images that I need to access on per-pixel-basis in my app. The images are downloaded from web and are quite large (4k). Update is done several times a day (tousands of images), ...
Martin Perry's user avatar
1 vote
0 answers
62 views

Elassandra data modeling

In Cassandra, everyone always stresses how important data modeling is, and rightfully so. However, when using Elassandra, we have Elasticsearch baked in. How does should change how we think about ...
RyanQuey's user avatar
  • 153
1 vote
1 answer
155 views

Cassandra security - private IPs with some VPN solution or public IPs and open ports?

there are many different solutions to secure a cassandra cluster. One of them is to enter public IPs and open the 7000/9042 port on each sever. Another one is to have everything in a private network ...
mulesky's user avatar
  • 33
1 vote
1 answer
423 views

Cassandra query response time degradation

I am experimenting with Cassandra on 4 sites with 2 nodes on each one. Have small network latency between them. I always query the data in DC where I inserted it. I see very strange behavior: when I ...
Yuri Lansberg's user avatar
1 vote
0 answers
262 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 ...
yash's user avatar
  • 11
1 vote
0 answers
27 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....
ChrisAdkin's user avatar
1 vote
0 answers
173 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-...
user5416's user avatar
1 vote
0 answers
558 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 ...
Wellerson's user avatar
1 vote
0 answers
322 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=...
Osama Dar's user avatar
  • 111
1 vote
0 answers
674 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 ...
Valentin Bajrami's user avatar
1 vote
0 answers
169 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 ...
Bhupen Sinha's user avatar
1 vote
1 answer
2k 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 ...
Bhupen Sinha's user avatar
1 vote
0 answers
800 views

List Roles on cassandra getting NoHostAvailable on one DataCentre

I have a 2 DC cluster, 'main' and 'bi' with a replication factor of 3 and a NetworkTopologyStrategy. When I call LIST HOSTS; in cqlsh, my bi datacentre lists all the roles appropriately, but I get a ...
Nicholas's user avatar
  • 123
1 vote
0 answers
541 views

Increase timeout for cassandra native transport threads?

From the Cassandra documentation here native_transport_max_threads The maximum number of thread handling requests. Similar to rpc_max_threads, but this property differs as follows: The ...
Geotob's user avatar
  • 111
1 vote
0 answers
148 views

Is my schema for a Discussion forum using Cassandra optimum or has a scope for improvement?

I am designing a Discussion Forum for my app which has following primary objects: Image Video Text Audio The owner can start a discussion in context of any of the above object. Based on user ...
Ashutosh's user avatar
  • 111
1 vote
0 answers
78 views

Is it possible to have a partition to distribute transaction load horizontally in SQL Server 2016?

In Cassandra, you can have a partition key to align partitions to particular server nodes. My understanding is that you can distribute transactional responsibility horizontally in SQL Server 2016 (...
hawkeye's user avatar
  • 167