nodetool import

Imports SSTables from an external directory into a table.

---

Synopsis

nodetool [connection_options] import [options] <keyspace> <table> <directory>...

See connection options for connection options.

Description

nodetool import loads SSTables from an external directory into a Cassandra table. Unlike refresh, which requires files to be in the data directory, import can load from any location and optionally moves or copies files.

Available in Cassandra 4.0+.

---

Arguments

Argument	Description
keyspace	Target keyspace
table	Target table
directory	One or more directories containing SSTables to import

---

Options

Option	Description
-c, --no-invalidate-caches	Skip row cache invalidation
-cd, --copy-data	Copy files instead of moving
-e, --extended-verify	Extended verification of SSTables
-k, --keep-level	Keep original SSTable level (for LCS)
-l, --keep-repaired	Keep repaired status
-niv, --no-index-validation	Skip index component validation
-q, --quick	Quick import (less verification)
-ri, --require-index-components	Require index components to be present
-t, --no-tokens	Skip token verification
-v, --no-verify	Skip SSTable verification

---

Examples

Basic Import

nodetool import my_keyspace my_table /path/to/sstables/

Import with Copy (Keep Original)

nodetool import -cd my_keyspace my_table /backup/sstables/

Quick Import (Less Verification)

nodetool import -q my_keyspace my_table /path/to/sstables/

Import Keeping LCS Levels

nodetool import -k my_keyspace my_table /path/to/sstables/

Extended Verification Import

nodetool import -e my_keyspace my_table /path/to/sstables/

---

Import vs Refresh vs SSTableLoader

Feature	import	refresh	sstableloader
External directory	Yes	No	Yes
Move/copy files	Yes	No	Streams
Token verification	Optional	No	Yes
Different topology	No	No	Yes
Speed	Fast	Fast	Slower

---

Workflow: Restore from Backup

# 1. Extract backup to a directory
tar -xzf backup.tar.gz -C /tmp/restore/

# 2. Import SSTables
nodetool import my_keyspace my_table /tmp/restore/my_keyspace/my_table/

# 3. Verify
nodetool tablestats my_keyspace.my_table

---

Workflow: Bulk Load

# 1. Generate SSTables externally (e.g., from Spark)
# Files are in /data/generated/my_keyspace/my_table/

# 2. Import to each node
nodetool import my_keyspace my_table /data/generated/my_keyspace/my_table/

# 3. Repair for consistency
nodetool repair my_keyspace my_table

---

Directory Requirements

The source directory should contain SSTable files:

/path/to/sstables/
├── nb-1-big-Data.db
├── nb-1-big-Index.db
├── nb-1-big-Filter.db
├── nb-1-big-Statistics.db
├── nb-1-big-Summary.db
├── nb-1-big-TOC.txt
└── nb-1-big-CompressionInfo.db

---

Token Verification

By default, import verifies tokens belong to this node:

# Normal import (verifies tokens)
nodetool import my_keyspace my_table /path/

# Skip token verification (use carefully)
nodetool import -t my_keyspace my_table /path/

Token Verification

Skipping token verification (-t) may import data that doesn't belong to this node. Only use when certain about data placement.

---

File Handling

Default (Move)

By default, files are moved from source to data directory:

nodetool import my_keyspace my_table /tmp/sstables/
# Files moved from /tmp/sstables/ to data directory
# Source directory will be empty after import

Copy Mode

Use -cd to copy instead of move:

nodetool import -cd my_keyspace my_table /backup/sstables/
# Files copied, originals remain in /backup/sstables/

---

Common Issues

Permission Denied

# Ensure Cassandra can read source directory
chmod -R 755 /path/to/sstables/
chown -R cassandra:cassandra /path/to/sstables/

Invalid SSTable

ERROR: SSTable is not valid

Try with verification options:

# Extended verification to see details
nodetool import -e my_keyspace my_table /path/

# Or skip verification (risky)
nodetool import -c my_keyspace my_table /path/

Token Range Mismatch

ERROR: Token ... is not owned by this node

Either:

• Import to the correct node
• Use -v to skip verification (if certain data is correct)
• Use sstableloader for different topologies

---

Post-Import Steps

# 1. Verify import
nodetool tablestats my_keyspace.my_table

# 2. Check data is queryable
cqlsh -e "SELECT COUNT(*) FROM my_keyspace.my_table;"

# 3. Run repair for consistency (recommended for bulk loads)
nodetool repair -pr my_keyspace my_table

---

Best Practices

Import Guidelines

1. Use copy mode for backups - Keep original files with -cd
2. Verify first - Use extended verification for critical data
3. Check token ownership - Ensure SSTables belong to this node
4. Run repair after - Ensure consistency across replicas
5. Monitor space - Ensure sufficient disk for imported data

---

Related Commands

Command	Relationship
refresh	Load SSTables from data directory
snapshot	Create backups
tablestats	Verify after import
repair	Run after bulk imports