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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Add new data center to Cassandra with replication factor of 1
I want to add a backup data center on a cloud provider. Assume I have DC1, DC2, DC3 in the cluster and I want DC4 have every piece of data in the cluster with replication of 1. Is this achievable ...
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How should I store nested JSON object inside the Cassandra?
This is the first time I am working with Cassandra and I have a data structure like following, want to save it inside the Cassandra:
{"user_id": "123",
"user_cards": {
...
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I am on version 3.11.13 and want to upgrade to version 4.1.0
I Would like to what is the upgrade path from 3.11.13 to which next version I should upgrade to finally be on 4.1.0
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Corrupt empty row found in unfiltered partition
I have a Cassandra cluster consisting of 15 nodes.
The Cassandra version is 3.7.0
I am constantly getting an error message in the log messages of almost all nodes.
The recurring error message is ...
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I am unable to complete the "Exercise 6 - Node"
I am unable to complete the
"Exercise 6 - Node" from DS201: Foundations of Apache Cassandra™ and DataStax Enterprise
From "Exercise 6 - Node", I followed all the steps provided.
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Cassandra node failes to reconnect to the cluster on Kubernetes with Istio
I am intending to create a multidatacenter Cassandra cluster with two datacenters distributed between two Kubernetes clusters. The cluster interconnection is configured by the means of Istio ...
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New table ID and directory was used instead of using exist one after upgrade from 3.11.13 to 4.0.7
After I upgrade Cassandra from 3.11.13 to 4.0.7 in a 3 node Cassandra cluster. Most of tables in the keyspace used the existing table IDs and directories. But one table of this keyspace didn't use the ...
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How much data per Apache Cassandra node?
I have a 3 node Cassandra 4.0beta3 cluster that is filling up and I need to know when I should add a couple more nodes. How much data is safe to keep on one node?
The nodes have 7.2T of disk each (log ...
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Is Apache Cassandra Quickstart broken?
I'm following the steps in the current (2023-03-13) Cassandra quickstart:
STEP 1: GET CASSANDRA USING DOCKER
docker pull cassandra:latest
STEP 2: START CASSANDRA
docker network create cassandra
...
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Nodetool compact with -s option not giving expected result
We are using Cassandra version 3.11.5 and team was using "nodetool compact" command for compaction which had created very big sstable of 250 GB.
This time we have ran "nodetool compact -...
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Upgrading Cassandra from 3.11.8 to 4.1.0 and am getting errors in debug.log/system.log that I can't work out what they mean
I am trying to upgrade my 3 node Cassandra cluster from version 3.11.8 to 4.1.0.
The steps I have taken are:-
Do a nodetool drain on the old 3.11.8 version
Stop the old version
Download and put in ...
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What is the difference between nodetool commands "garbagecollect" vs "compact"?
What is the difference between working procedure of below 2 commands. How differently these are working
nodetool garbagecollect
and
nodetool compact -s
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Is it okay to use DataStax's fork of open-source Cassandra on GitHub?
Cassandra's release cycle is quite slow. From the user's point of view, there is a desire to quickly introduce and use more innovative features.
If you look at Github Datastax cassandra, the latest ...
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How do I upgrade a DataStax Enterprise cluster to 6.8.25 with OpsCenter Lifecycle Manager?
What are the steps (or all the commands) to upgrade (just the 6.8.25 fix, I have 6.18.16 version now) all nodes in cluster with LifeCycle Manager?
I've found this but it refers to 6.5 version of DSE:
...
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Cassandra 3 - Import and Exporting Blobs Fail with "'str' object has no attribute 'decode'" Error
I'm trying to test copying a table into a csv, and then importing the data int he csv into a table.
Table:
CREATE TABLE keyspace_n.collection_n (
id1 text,
id2 int,
id3 text,
appname text,
coll blob,
...
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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<...
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SELECT COUNT() returns ReadFailure after importing data from another cluster
I've cloned one cluster to another with these steps:
Copy table files on each source node from /var/lib/cassandra/data/keyspace/table/snapshots... to /location/snaps/
Run sstableloader on each ...
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Adding new nodes, nodetool rebuild returns "Unable to find sufficient sources for streaming range"
I have the cassandra 4.0.1 cluster with 3 nodes (datacenter1) and we have decided that we need to add the second datacenter (datacenter2), I have done all the steps described in this article
First of ...
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Importing data with sstableloader, getting streaming error "StreamReceiveException: java.lang.AssertionError"
I am using sstableloader to import data into Cassandra, and I'm getting the following error in one of the Cassandra nodes (one of the coordinator ).
I don't understand what the error is about. Is ...
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nodetool: Failed to connect to '127.0.0.1:7199' - ConnectException: 'Connection refused'
I tried to build a 6 nodes cassandra cluster with 2 DCs on AWS. I created EC2 with t2.micro on public subnet with public IP. The OS is Ubuntu 22.04. After install, I changed the listen_address to ...
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How do we monitor cross-datacenter replication latency?
We currently have a setup that consists of the following:
Cassandra 3.11.13
Datacenter 1 = 3 Cassandra nodes using LOCAL_QUORUM and replication factor 3
Datacenter 2 = 3 Cassandra nodes using ...
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Cannot open file /gc.log due to Permission denied
I just installed cassandra manually.
Encountered the following issue while starting.
Cannot open file /gc.log due to Permission denied.
How do I go about fixing this issues ?
Thanks
Siva
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Apache Cassandra 3.11.2 unable to start Centos 7
I am trying to start Apache Cassandra 3.11.2 on Centos 7 and I get error Exception:
ERROR [main] 2023-02-22 11:19:03,067 NativeLibraryLinux.java:64 - Failed to link the C library against JNA. Native ...
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Cassandra 3.11.2 startup returning ConfigurationException "Unable to find authenticator class 'com.datastax.bdp.cassandra.auth.PasswordAuthenticator'"
i am trying to start Apache Cassandra 3.11.2 on Centos 7 and i get error
Exception (org.apache.cassandra.exceptions.ConfigurationException) encountered during startup: Unable to find authenticator ...
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Which version of Stratio Lucene Index should we use with Cassandra 4.x?
We are using Stratio Lucene Indexer for V3.11.5 and currently planning to upgrade to V4.x.
As specific Cassandra Lucene index versions are targeted to specific Apache Cassandra versions.
https://...
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Is there a tool to get statistics about data in a Cassandra table?
I trying to find a way how to get some statistics info about data in a table (columns population, how many partitions,..).
For example in mariaDB there is possibility to execute ANALYZE TABLE it will ...
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Why would a new node be "Unable to gossip with other peers"?
Symptoms
A new node being added to a Cassandra cluster is unable to gossip with seed nodes.
Another symptom is when an existing which has been restarted is unable to gossip with other nodes in the ...
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What could cause intermittent gossip issues between nodes?
A Cassandra cluster which for the most part is operational would sometimes experience service disruptions particularly when one (or more) node is unable to gossip with other nodes in the cluster.
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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
...
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Switching from SimpleStrategy to NetworkTopologyStrategy, getting "ConfigurationException: Unknown data-center name"
We are trying to add new data centre as per the document https://docs.datastax.com/en/dse/6.8/dse-admin/datastax_enterprise/production/multiDCperWorkloadType.html. When we try to follow
steps 2
In ...
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Cassandra fully expired SSTables with timestamps in the future not getting deleted
I am struggling with a interesting problem of Cassandra nodes just using up more and more memory on disk for no apparent reason.
The schema is an append only data model of event data that should be ...
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Cassandra has stopped producing log files
I've recently taken up the role of managing a Cassandra Cluster that has been running in production for a few years. This is my first time working with Cassandra so I would appreciate any insights.
It ...
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Cassandra pod uses more heap memory than configured limit
I set up a Cassandra pod on Kubernetes. I noticed that the following environment variables are ignored by the image, since it goes way beyond 512M memory usage:
env:
- name: MAX_HEAP_SIZE
value: ...
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What is the best way to get rid of big STCS sstables?
What is the best possible way to get rid of the big sstables (hundreds of GB in size) created by STCS compaction?
Will it be sstablesplit or nodetool compact -s?
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Sample Cassandra database image for practice
Is there any sample cassandra database image with data available which can be downloaded and restored in personal system/vm for practice purpose.
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cassandra-stress shows low read ops when node down (blocked on firewall)
cassandra version: 3.11.13
openjdk version "1.8.0_342"
I did tests on small cluster 2 nodes, but also on a cluster with 6 nodes. Result is same.
I'm doing simple test
cassandra-stress read n=...
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Deletions getting omitted, data supposedly deleted returned in CQL queries
We are facing an issue on one of our production systems where after we delete the data
the data doesn't seem to get deleted. We have a Get call just after the delete call.
The data shows up.
Versions
...
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How is Cassandra data stored physically on disk?
I am learning cassandra architecture and was going through how write and read is done. What I learned is that on a write the MemTable(sorted by partition key) and commitLog(append only) are written ...
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Old SSTables not removed after running major compaction on TWCS table
I am in a new system where two different TTLs (30 days and 90 days) are being used with TWCS compaction. As a result, the team needs to do major compaction (STCS) every 40-50 days, which is affecting ...
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Why does Cassandra lose data when there is an outage on one node with RF=2?
Cassandra works in docker containers.
Cassandra version: 3.11.10.
Cassandra-driver-core: 3.10.2.
Cassandra restart policy: unless-stopped.
Cassandra cluster: 3 nodes.
Keyspace replication factor: {'...
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Agents not connecting to OpsCenter via STOMP, UI displays question marks in the STOMP column
The previous DBA created and connected a cluster (4 nodes) to DSE OpsCenter. It's almost perfect (nodes are connected and visible) except for the STOMP service.
In the OpsCenter -> Nodes -> ...
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How to upgrade Cassandra on GKE?
Is there any specific documentation on the GKE Cassandra upgrade process? Especially when we update the image on yaml file, what would be the post upgrade steps? Normally, when the upgrade happens on ...
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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 ...
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cqlsh COPY TO command errors as its trying to connect to multiple nodes and failing
I have forwarded a port to Cassandra pod and trying to back up the keyspace to CSV file. It's connecting successfully and backing up some records. However, it's trying to connect other nodes on the ...
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What can I do about "maximum memory usage reached (...), cannot allocate chunk of 1048576" in Cassandra?
I got this error:
maximum memory usage reached (536870912), cannot allocate chunk of 1048576.
I have increased the file cache to 1024, but I still get the error related to memory usage. What can I ...
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How can we improve the compaction time for STCS in Cassandra?
We are running STCS compaction nodewise. Until last month, it was taking around 3 days per node. This month took 11 days per node. No change or significant data insert/delete happened.
What are the ...
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Why is the load in nodetool status output much less than utilised disk space?
I have 3 node cluster and upon checking the nodetool status; Load is just less than 100 GB on all three nodes. The replication factor is two and percentage own is 65-70% for all three.
However when I ...
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How is 'storage space used' calculated in Astra?
I understand that a user is charged for 'storage space used' based on the monthly max usage, but how do things like a Replication Factor of 3 and the way compaction is configured play into the monthly ...
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How is Cassandra secondary index suitable for both low cardinality and unique columns?
I am "Still" reading a book on Cassandra where it says the following
Secondary indexes are best suited for low-cardinality columns, that is, columns that contain the same value for many ...
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Cassandra node was unable to process requests for a couple of minutes, log reported "Search Concurrency Factor is set to 1 for ReadStage"
Cassandra node was unable to process requests for couple of minutes, where we see this log "Search Concurrency Factor is set to 1 for ReadStage"
The application faced timeouts for a couple ...
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