Cassandra Reference

Quick reference for Apache Cassandra.

Ports

Port	Protocol	Purpose
9042	CQL	Native client connections (TLS configured via client_encryption_options)
7000	TCP	Inter-node communication (TLS configured via server_encryption_options)
7199	JMX	JMX monitoring

Deprecated Ports

• Port 9142 (native_transport_port_ssl) was deprecated in Cassandra 4.x and removed in 5.0. TLS is now configured on the standard 9042 port.
• Port 7001 (ssl_storage_port) is deprecated. Internode TLS is configured on the standard 7000 port.

Directories

Directory	Purpose
/var/lib/cassandra/data	SSTable data
/var/lib/cassandra/commitlog	Commit log
/var/lib/cassandra/saved_caches	Key/row cache
/var/lib/cassandra/hints	Hinted handoff
/etc/cassandra/	Configuration
/var/log/cassandra/	Logs

Configuration Files

File	Purpose
cassandra.yaml	Main configuration
cassandra-env.sh	Environment variables
jvm11-server.options	JVM settings
cassandra-rackdc.properties	DC/rack configuration
logback.xml	Logging configuration

Consistency Levels

Level	Description
ANY	One response (including hints)
ONE	One replica
TWO	Two replicas
THREE	Three replicas
QUORUM	Majority of replicas
LOCAL_QUORUM	Majority in local DC
EACH_QUORUM	Majority in each DC
ALL	All replicas
LOCAL_ONE	One in local DC
SERIAL	Serial consistency (LWT)
LOCAL_SERIAL	Local serial (LWT)

Common nodetool Commands

nodetool status              # Cluster status
nodetool info                # Node info
nodetool tpstats             # Thread pools
nodetool tablestats ks       # Table stats
nodetool compactionstats     # Compaction status
nodetool repair -pr ks       # Primary range repair
nodetool flush ks            # Flush memtables
nodetool drain               # Prepare for shutdown
nodetool snapshot            # Create backup
nodetool describecluster     # Cluster info

CQL Quick Reference

-- Keyspace
CREATE KEYSPACE ks WITH replication = {
    'class': 'NetworkTopologyStrategy', 'dc1': 3
};

-- Table
CREATE TABLE ks.users (
    user_id UUID PRIMARY KEY,
    name TEXT
);

-- CRUD
INSERT INTO ks.users (user_id, name) VALUES (uuid(), 'John');
SELECT * FROM ks.users WHERE user_id = ?;
UPDATE ks.users SET name = 'Jane' WHERE user_id = ?;
DELETE FROM ks.users WHERE user_id = ?;

Data Types

Type	Description
UUID	128-bit unique identifier
TIMEUUID	Time-based UUID
TEXT	UTF-8 string
INT	32-bit integer
BIGINT	64-bit integer
FLOAT	32-bit floating point
DOUBLE	64-bit floating point
BOOLEAN	true/false
TIMESTAMP	Date and time
DATE	Date only
BLOB	Binary data
LIST<T>	Ordered collection
SET<T>	Unique collection
MAP<K,V>	Key-value pairs

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Apache Cassandra Project Resources

Official Resources

Resource	URL
Project Website	cassandra.apache.org
Documentation	cassandra.apache.org/doc/latest/
Downloads	cassandra.apache.org/download/

Source Code and Development

Resource	URL
GitHub Repository	github.com/apache/cassandra
GitHub Mirror (read-only)	github.com/apache/cassandra
ASF GitBox	gitbox.apache.org/repos/asf/cassandra.git

Issue Tracking and Enhancement Proposals

Resource	URL
JIRA Issue Tracker	issues.apache.org/jira/browse/CASSANDRA
CEP Wiki (Enhancement Proposals)	cwiki.apache.org/confluence/display/CASSANDRA/CEP
Cassandra Wiki	cwiki.apache.org/confluence/display/CASSANDRA

Community

Resource	URL
ASF Slack (#cassandra)	s.apache.org/slack-invite (then join #cassandra)
Stack Overflow	stackoverflow.com/questions/tagged/cassandra

Mailing Lists

List	Purpose	Subscribe
user@cassandra.apache.org	User questions and discussions	Subscribe
dev@cassandra.apache.org	Development discussions	Subscribe
commits@cassandra.apache.org	Commit notifications	Subscribe

Blogs and News

Resource	URL
Apache Cassandra Blog	cassandra.apache.org/blog/
Planet Cassandra	planetcassandra.org

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Next Steps

• CQL Reference - Full CQL guide
• Configuration - Configuration details
• nodetool - Command reference