nodetool version

Displays the Cassandra version running on the node.

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Synopsis

nodetool [connection_options] version

See connection options for connection options.

Description

nodetool version returns the release version of the Cassandra instance running on the connected node. This is essential for:

• Verifying deployment consistency across nodes
• Confirming successful upgrades
• Troubleshooting compatibility issues
• Documentation and audit purposes

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Output

Standard Output

ReleaseVersion: 4.1.3

The version follows semantic versioning: MAJOR.MINOR.PATCH

Component	Meaning
MAJOR	Significant changes, may include breaking changes
MINOR	New features, backward compatible
PATCH	Bug fixes, backward compatible

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Examples

Basic Usage

nodetool version

Output:

ReleaseVersion: 4.1.3

Cluster-Wide Version Check

#!/bin/bash
# Check versions across all nodes using SSH

for node in node1 node2 node3 node4 node5; do
    echo -n "$node: "
    ssh "$node" "nodetool version"
done

Output:

node1: ReleaseVersion: 4.1.3
node2: ReleaseVersion: 4.1.3
node3: ReleaseVersion: 4.1.3
node4: ReleaseVersion: 4.1.3
node5: ReleaseVersion: 4.1.3

Version Only (Scripting)

nodetool version | awk '{print $2}'

Output:

4.1.3

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When to Use

Pre-Upgrade Verification

Document current versions before upgrading:

pre_upgrade_versions.sh

#!/bin/bash
echo "=== Pre-Upgrade Versions ==="
for node in $(nodetool status | grep -E "^UN|^DN" | awk '{print $2}'); do
    version=$(ssh "$node" 'nodetool version' | awk '{print $2}')
    echo "$node: $version"
done > pre_upgrade_versions.txt

Post-Upgrade Verification

Confirm all nodes upgraded successfully:

post_upgrade_verify.sh

#!/bin/bash
echo "=== Post-Upgrade Verification ==="
expected="4.1.4"
for node in $(nodetool status | grep -E "^UN|^DN" | awk '{print $2}'); do
    actual=$(ssh "$node" 'nodetool version' | awk '{print $2}')
    if [ "$actual" = "$expected" ]; then
        echo "$node: $actual ✓"
    else
        echo "$node: $actual ✗ (expected $expected)"
    fi
done

Mixed Version Detection

Identify nodes running different versions:

detect_mixed_versions.sh

#!/bin/bash
# Collect all versions via SSH
nodetool status | grep -E "^UN|^DN" | awk '{print $2}' | while read node; do
    ssh "$node" 'nodetool version'
done | sort | uniq -c

Output showing mixed versions:

      3 ReleaseVersion: 4.1.3
      2 ReleaseVersion: 4.1.2

Compatibility Checking

Before connecting tools or drivers:

version=$(nodetool version | awk '{print $2}')
major=$(echo $version | cut -d. -f1)

if [ "$major" -ge 5 ]; then
    echo "Cassandra 5.x features available"
else
    echo "Running Cassandra 4.x"
fi

---

Version Compatibility

Major Version Features

Version	Key Features
5.0	Accord, Vector Search, Unified Compaction
4.1	Guardrails, Pluggable memtable
4.0	Virtual tables, Audit logging, Full query logging
3.11	Last 3.x release, LTS
3.0	Materialized views, SASI indexes

Upgrade Path Considerations

From	To	Notes
3.11.x	4.0.x	Supported direct upgrade
3.0.x	4.0.x	Upgrade to 3.11.x first
4.0.x	4.1.x	Supported direct upgrade
4.1.x	5.0.x	Supported direct upgrade

Mixed Versions

Running mixed versions should only be temporary during rolling upgrades. All nodes should run the same version in steady state.

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Detailed Version Information

For more comprehensive version and build details:

# Version only
nodetool version

# Full node information including version
nodetool info | head -10

Additional Version Details from info

nodetool info

Shows:

ID                     : 12345678-1234-1234-1234-123456789012
Gossip active          : true
Native Transport active: true
Load                   : 256.5 GiB
Generation No          : 1699876543
Uptime (seconds)       : 864000
Heap Memory (MB)       : 4096.00 / 8192.00
...

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Version Verification Script

#!/bin/bash
# check_cluster_versions.sh - Verify all nodes run expected version

EXPECTED_VERSION="${1:-}"

if [ -z "$EXPECTED_VERSION" ]; then
    echo "Usage: $0 <expected_version>"
    echo "Example: $0 4.1.3"
    exit 1
fi

echo "Checking cluster for version: $EXPECTED_VERSION"
echo "============================================="

# Get all nodes from local nodetool status
nodes=$(nodetool status | grep -E "^UN|^DN|^UJ|^UL" | awk '{print $2}')
mismatch=0
unreachable=0

for node in $nodes; do
    actual=$(ssh "$node" 'nodetool version' 2>/dev/null | awk '{print $2}')

    if [ -z "$actual" ]; then
        echo "$node: UNREACHABLE"
        ((unreachable++))
    elif [ "$actual" = "$EXPECTED_VERSION" ]; then
        echo "$node: $actual ✓"
    else
        echo "$node: $actual ✗ (expected $EXPECTED_VERSION)"
        ((mismatch++))
    fi
done

echo "============================================="
echo "Summary:"
echo "  Expected version: $EXPECTED_VERSION"
echo "  Version mismatches: $mismatch"
echo "  Unreachable nodes: $unreachable"

if [ $mismatch -gt 0 ] || [ $unreachable -gt 0 ]; then
    exit 1
fi
echo "All nodes running expected version"

---

Monitoring Integration

Prometheus/Metrics

# Export version as metric
version=$(nodetool version | awk '{print $2}')
echo "cassandra_version{version=\"$version\"} 1"

Health Check Script

#!/bin/bash
# Include version in health check output (run locally on each node)

health_check() {
    local version=$(nodetool version 2>/dev/null | awk '{print $2}')
    local status=$(nodetool status 2>/dev/null | grep "$(hostname -i)" | awk '{print $1}')

    echo "{\"node\": \"$(hostname)\", \"version\": \"$version\", \"status\": \"$status\"}"
}

health_check

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Troubleshooting

Cannot Connect to Node

nodetool version
# Error: Failed to connect to '127.0.0.1:7199'

Causes:

• Cassandra not running
• JMX not enabled
• Firewall blocking JMX port

Resolution:

# Check if Cassandra is running
pgrep -f CassandraDaemon

# Check JMX port
netstat -tlnp | grep 7199

# Check logs
tail /var/log/cassandra/system.log

Version Mismatch After Upgrade

If nodes show different versions after upgrade:

# Verify package version
dpkg -l | grep cassandra  # Debian/Ubuntu
rpm -qa | grep cassandra  # RHEL/CentOS

# Verify running version
nodetool version

# If mismatch, may need restart
systemctl restart cassandra

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Related Information

Version in Logs

Cassandra logs the version on startup:

grep -i "cassandra version" /var/log/cassandra/system.log | tail -1

Version in System Tables

-- CQL query for version
SELECT release_version FROM system.local;

Build Information

For detailed build info:

# Check build info in logs
grep -i "build" /var/log/cassandra/system.log | head -5

# Or from cassandra binary
cassandra -v

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Best Practices

Version Management Guidelines

1. Document versions - Maintain records of deployed versions
2. Verify after upgrades - Always check all nodes post-upgrade
3. Minimize mixed time - Complete rolling upgrades promptly
4. Monitor for drift - Include version in monitoring
5. Test compatibility - Verify driver/tool compatibility with version
6. Follow upgrade paths - Don't skip major versions

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Related Commands

Command	Relationship
info	Detailed node information
describecluster	Cluster-wide information
status	Cluster status overview
upgradesstables	Upgrade SSTable format