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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MyRocks vs Cassandra data size

Both MyRocks (MySql) and Cassandra uses LSM architecture to store their data. So I have populated around 5 million rows in MySql with MyRocks as storage engine and also in Cassandra. In Cassandra it ...
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best way to retrieve data using multiple parameters in Cassandra?

I have created a table that contains the userid, the content that they posted on their newsfeed, the date of when they posted it, and a primary key(I am using nodejs) my first shot at retrieving the ...
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What things we should consider when configuring Cassandra Cluster?

I'm new to Cassandra, so wanted to understand what basic things we should consider when are we going to configure Cassandra cluster in on or multiple database centers? Thanks!
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578 views

Cassandra backup from all nodes or just one?

Cassandra is a distributed database, where each node is in sync with the other nodes from the same ring/cluster. When taking backups based on a snapshot, do I need to back up each node individually ...
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607 views

Cassandra writing (too?) large partitions

I have a Cassandra cluster running for quite some time now (months) and, as expected, it has been consuming large quantities of data every day. In the past few days the cluster has been having ...
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Cassandra - reinserting a node

I had to remove a cassandra dead node on a hurry (because an important script with a truncate query wouldn't work due to consistency level reasons -- any thoughts on that would be nice too). Anyway, ...
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Can I use result of one query inside other query in Cassandra

I need to delete all rows with given clustering column value. I don't have partition key so I don't have complete primary key. To delete record from Cassandra table we need to provide specific ...
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178 views

user based trace enable in Cassandra

i have created user and role in Cassandra and tracing is enabled. but sessions and event table does not capture user info. below tables gives information about what query has been executed and from ...
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password expire duration and maximum invalid login attempts

how to set password expire duration and maximum invalid login attempts for user under Cassandra DB ? for example user test tried to login with incorrect password 5 times , that should should get ...
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Is Cassandra's manual node addition/removal tasks tedious and practical in a large cluster?

I am evaluating using Cassandra as a large key-value store over about 500 commodity machines. AFAIK, Cassandra requires manual intervention during permanent machine failures (removing the deadnode, ...
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How can a Cassandra node see another node as down?

I'm running Cassandra on three nodes. Here's their nodetool status output: ubuntu@ip-10-0-8-8:~$ nodetool status Datacenter: us-east =================== Status=Up/Down |/ State=Normal/Leaving/Joining/...
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What is an efficient storage method to store Graph Data from GraphX (Spark)?

I generate graph data using Spark's GraphX library and I need an efficient way to store graph data. I have access to Apache Cassandra and ideally I want to store the graph data in there but the issue ...
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How to get information about the current cluster configurations with list of datacenters?

Is any way to get information about the current cluster configurations with a list of datacenters? I have tried to fetch this list from system.local using cqlsh with setting the consistency level ...
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Help in understanding Hinted Handoffs and Data replication in Cassandra

We have a 3 node Cassandra cluster with RF = 2. The read and write consistency is set to ONE. We are using Vnodes as well. Lets label these nodes as N1, N2 and N3. Let's say that N3 goes down. I was ...
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Cassandra cluster configuration

I have a cluster of 4 nodes in a data center dc1 Rack1. Now I have to create data center dc2 into same cluster. Will I need to reconfigure whole cluster or is there any way?
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How far does one table, one query go?

I'm doing a MySQL to Cassandra conversion. The fundamentals of the dataset are a master table of size ~10^7 rows to which several subsidiary tables are linked by foreign key. The subsidiary tables are ...
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635 views

Database latency vs throughput

I'm a bit confused by terms latency and throughput in case of databases. My understanding is that latency represents time needed to perform a single request (e.g. insert or select), while the ...
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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, ...
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Why doesn't nodetool work on my Cassandra Cluster?

I have never been able to get nodetool to operate correctly to give me information about my cluster. We have a simple 3-node cluster of Cassandra 3.11.1 nodes running under CentOS 7.3 -- using the ...
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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 ...
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849 views

Unable to get Cassandra in a Docker to talk to cluster

Trying to get Cassandra running in a docker using the official docker image. When I execute the below lines of code it starts then stops the docker without connecting to the cluster. I have checked ...
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Quorum read consistency in Cassandra

I'm new to distributed databases and there are a couple of things I couldn't figure out. We're developing an application and need to select the right database, this application needs strong ...
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831 views

Cassandra Consistency Level

I have 3 virtual Cassandra nodes cluster. Node1, Node2 & Node3. I have written a small python code to bulk load data into it. 1st time only 2 nodes out of three are available online, Node1 & ...
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Cassandra 3.11 commit logs nightmare

Clean installs of Cassandra 3.11 nodes are working fine for me for a few days, and then ‘nodetool flush’ and ‘nodetool compact’ are starting to throw exceptions. After this, restarts after a ‘nodetool ...
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Why does Cassandra recommend against creating an index on high-cardinality columns?

The Cassandra documentation states, Do not use an index in these situations: On high-cardinality columns because you then query a huge volume of records for a small number of results. See ...
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Which database system can break me free?

I am currently running a MySQL Database for logging and analyzing those logs. My current table schema looks like this: CREATE TABLE `mylogs` ( `transfer_id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT ...
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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 ...
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ALLOW FILTERING vs NOT; Cassandra Data Model Question

I have a toy Cassandra cluster running on some RaspberryPis at home. I am currently logging CryptoCoin data to it in hopes of learning more about Cassandra and as well as some other things along the ...
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Repair going very slow

We have a 32 node cluster with an average of approximately 150GB of data on each node. When running a full repair (not doing primary range) it is taking approximately 26 hours to complete. This seems ...
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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 ...
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Infrastructure for Highly Concurrent, High Write DB

My requirements are: 3000 Connections 70-85% Write vs Read Currently, we are maxing out a High-CPU, Extra Large Instance at 700 connections. All 8 cores are maxed. We think it's the number of ...
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ConnectException: 'Connection refused'

My node worked normally, and I could use nodetool status normally, but when I changed endpoint_snitch to Ec2Snitch I started getting the error: nodetool: Failed to connect to '127.0.0.1:7199' - ...
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Error while starting Cassandra 2.0.2 service

I am new to cassandra NoSQL database. When I tried to start cassandra I am getting bellow error. Command used to start. ./cassandra -f xss = -ea -javaagent:./../lib/jamm-0.2.5.jar -XX:+...
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Cassandra alters

I have cassandra table defined as: CREATE TABLE db.table ( value text, time timestamp, sid text, PRIMARY KEY (sid, time) ) WITH CLUSTERING ORDER BY (time ASC) AND ...
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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 ...
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How to set Cassandra volumes?

I have started a Cassandra server using Bitnami AMI, I have attached volumes to the EC2 instance, but how would I set Cassandra to use the attached volume?
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Cassandra nodetool repair parallelism: “parallel” versus “dc_parallel”

If I run nodetool repair --full I see settings like this: repairing keyspace some_keyspace with repair options (parallelism: parallel, primary range: false, incremental: false, job threads: 1, ...
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Do you have to run nodetool repair on every node?

Do you have to run nodetool repair on every node in a cluster, or do you only need to run it on one node, and from there Cassandra will take care of the rest?
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Why I get Cannot achieve consistency level ONE (Code 4096)? [duplicate]

Why I write to table, I get error: Cannot achieve consistency level ONE (Code 4096) What could be wrong? Here is my descriptions: DESCRIBE schools CREATE KEYSPACE schools WITH replication = {'...
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Upgrading Cassandra [duplicate]

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 ...
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“phpMyAdmin” for Cassandra

Is there a tool like phpMyAdmin for RDBMS-MySQL for a Cassandra DB? I know that there is less "runtime" config possible (column families can not be edited at runtime etc.). Nevertheless, it would be ...
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How to create multiple graphs with TitanDB (+Cassandra) in the same machine?

I'm experimenting with TitanDB (with Cassandra as storage) + Rexter. I've been reading the documentation during hours and trying to create multiple graph DBs on the same machine, but I didn't find ...
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Optimal database for large number of columns or rows

Problem 1: I have one file with 567 rows and 16,382 columns, most of which are floating point numbers. I have another file with 117,493 rows but only 3 columns. The contents deal with biology and ...
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1answer
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Why I got NoHostAvailable:?

if I run this simple query: SELECT * from myapp.latests WHERE organization_id = 1 and user_id = 1; I get error: NoHostAvailable: Running nodetool status results into: Datacenter: eu-central ======...
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Are most of the NoSQL databases key/value stores technically? [closed]

This video distinguishes between three (main) types of NoSQL databases: Key/Value store Tabular Document oriented Do these types differ in how they technically store their data or can they be ...
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Can Cassandra be used to increase database write rate?

I am developing a database for an analysis job that requires parsing terabytes of information into a database. My job is to create and populate a database and using it to answer analyst's questions. ...
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260 views

can I set a MAX Limit to a BIGINT cassandra's data type?

can I set a MAX Limit to a BIGINT cassandra data type? this is my first step in cassandra db. for example: bigint(10) just like in mysql?
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Which database could handle storage of billions/trillions of records?

We are looking at developing a tool to capture and analyze netflow data, of which we gather tremendous amounts of. Each day we capture about ~1.4 billion flow records which would look like this in ...
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578 views

Each node holds 50% of data on 2 nodes with replication_factor=1

Description: Linux OS, Cassandra 3.9, Using CCM to create 2 Nodes, Consistent Level = One replication = {'class': 'SimpleStrategy', 'replication_factor': '1'} Using writing script (* ) as below (...
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Querying Cassandra without a partition key

I read Cassandra's documentation on the internal steps it performs when querying data. It looks like Cassandra relies on the Partitioner and Replication Strategy to process queries. I am still ...