ScyllaDB University LIVE, FREE Virtual Training Event | March 21
Register for Free
ScyllaDB Documentation Logo Documentation
  • Server
  • Cloud
  • Tools
    • ScyllaDB Manager
    • ScyllaDB Monitoring Stack
    • ScyllaDB Operator
  • Drivers
    • CQL Drivers
    • DynamoDB Drivers
  • Resources
    • ScyllaDB University
    • Community Forum
    • Tutorials
Download
ScyllaDB Docs ScyllaDB Enterprise ScyllaDB for Administrators Procedures Scylla Configuration Procedures Advanced Internode (RPC) Compression

Caution

You're viewing documentation for a previous version. Switch to the latest stable version.

Advanced Internode (RPC) Compression¶

Available with the Premium plan

Internode (RPC) compression controls whether traffic between nodes is compressed. If enabled, it reduces network bandwidth usage.

To further reduce network traffic, you can configure ScyllaDB Enterprise to use ZSTD-based compression and shared dictionary compression. You can enable one or both of these features to limit network throughput and reduce network transfer costs.

Enabling ZSTD-based Compression¶

ZSTD-based compression utilizes the ZSTD algorithm for RPC compression.

To enable ZSTD-based compression:

  1. Set internode_compression_enable_advanced to true.

  2. Set internode_compression_zstd_max_cpu_fraction to a non-zero value in the range [0, 1], where:

    • 0 - The node will never use ZSTD for RPC compression.

    • 1 - The node will always use ZSTD for RPC compression (for all messages, regardless of CPU consumption).

A good rule of thumb is to start from 0.05. As a result, the node will spend not more than 5% of its total CPU on RPC ZSTD compression.

Note that enabling ZSTD increases CPU usage. We recommend monitoring metrics to ensure additional CPU consumption does not disrupt the workload. If ZSTD impacts performance, try setting internode_compression_zstd_max_cpu_fraction to a lower value.

Enabling Shared Dictionary Compression¶

Shared dictionary compression allows you to limit network throughput and reduce network transfer costs.

If enabled, the message-by-message compression is replaced with a more efficient compression based on a dictionary trained on one node and shared with other nodes. The dictionary is periodically re-trained on the node’s RPC traffic and then distributed across the cluster.

To enable shared dictionaries:

  1. Set internode_compression_enable_advanced to true.

  2. Configure the rpc_dict_training_when parameter. In typical scenarios, you should set it to when_leader. As a result, the Raft leader node will train and publish new dictionaries.

internode_compression_enable_advanced: true
rpc_dict_training_when: when_leader

Warning

Enabling shared dictionary training might leak unencrypted data to disk.

Trained dictionaries contain randomly chosen samples of data transferred between nodes. The data samples are persisted in the Raft log, which is not encrypted. As a result, some data from otherwise encrypted tables might be stored on disk unencrypted.

Reference¶

See the Inter-node settings section in Configuration Parameters for a complete list of internode compression options.

Was this page helpful?

PREVIOUS
Rolling Restart Procedure
NEXT
Scylla Maintenance Procedures
  • Create an issue

On this page

  • Advanced Internode (RPC) Compression
    • Enabling ZSTD-based Compression
    • Enabling Shared Dictionary Compression
    • Reference
ScyllaDB Enterprise
  • 2024.2
    • 2024.2
    • 2024.1
    • 2023.1
    • 2022.2
  • Getting Started
    • Install ScyllaDB Enterprise
      • ScyllaDB Web Installer for Linux
      • Install ScyllaDB Without root Privileges
      • Air-gapped Server Installation
      • ScyllaDB Housekeeping and how to disable it
      • ScyllaDB Developer Mode
      • Launch ScyllaDB on AWS
      • Launch ScyllaDB on GCP
      • Launch ScyllaDB on Azure
    • Configure ScyllaDB
    • ScyllaDB Configuration Reference
    • ScyllaDB Requirements
      • System Requirements
      • OS Support by Linux Distributions and Version
      • Cloud Instance Recommendations
      • ScyllaDB in a Shared Environment
    • Migrate to ScyllaDB
      • Migration Process from Cassandra to Scylla
      • Scylla and Apache Cassandra Compatibility
      • Migration Tools Overview
    • Integration Solutions
      • Integrate Scylla with Spark
      • Integrate Scylla with KairosDB
      • Integrate ScyllaDB with Presto
      • Integrate Scylla with Elasticsearch
      • Integrate Scylla with Kubernetes
      • Integrate Scylla with the JanusGraph Graph Data System
      • Integrate Scylla with DataDog
      • Integrate Scylla with Kafka
      • Integrate Scylla with IOTA Chronicle
      • Integrate Scylla with Spring
      • Shard-Aware Kafka Connector for Scylla
      • Install Scylla with Ansible
      • Integrate Scylla with Databricks
      • Integrate Scylla with Jaeger Server
      • Integrate Scylla with MindsDB
    • Tutorials
  • ScyllaDB for Administrators
    • Administration Guide
    • Procedures
      • Cluster Management
      • Backup & Restore
      • Change Configuration
      • Maintenance
      • Best Practices
      • Benchmarking Scylla
      • Migrate from Cassandra to Scylla
      • Disable Housekeeping
    • Security
      • ScyllaDB Security Checklist
      • Enable Authentication
      • Enable and Disable Authentication Without Downtime
      • Creating a Custom Superuser
      • Generate a cqlshrc File
      • Reset Authenticator Password
      • Enable Authorization
      • Grant Authorization CQL Reference
      • Certificate-based Authentication
      • Role Based Access Control (RBAC)
      • ScyllaDB Auditing Guide
      • Encryption: Data in Transit Client to Node
      • Encryption: Data in Transit Node to Node
      • Generating a self-signed Certificate Chain Using openssl
      • Encryption at Rest
      • LDAP Authentication
      • LDAP Authorization (Role Management)
    • Admin Tools
      • Nodetool Reference
      • CQLSh
      • Admin REST API
      • Tracing
      • Scylla SStable
      • Scylla Types
      • SSTableLoader
      • cassandra-stress
      • SSTabledump
      • SSTableMetadata
      • Scylla Logs
      • Seastar Perftune
      • Virtual Tables
      • Reading mutation fragments
      • Maintenance socket
      • Maintenance mode
    • ScyllaDB Monitoring Stack
    • ScyllaDB Operator
    • ScyllaDB Manager
    • Upgrade Procedures
      • ScyllaDB Versioning
      • ScyllaDB Enterprise
      • ScyllaDB Open Source to ScyllaDB Enterprise
      • ScyllaDB Image
    • System Configuration
      • System Configuration Guide
      • scylla.yaml
      • ScyllaDB Snitches
    • Benchmarking ScyllaDB
    • ScyllaDB Diagnostic Tools
  • ScyllaDB for Developers
    • Develop with ScyllaDB
    • Tutorials and Example Projects
    • Learn to Use ScyllaDB
    • ScyllaDB Alternator
    • ScyllaDB Features
      • Lightweight Transactions
      • Global Secondary Indexes
      • Local Secondary Indexes
      • Materialized Views
      • Counters
      • Change Data Capture
      • Workload Attributes
      • Workload Prioritization
    • ScyllaDB Drivers
      • Scylla CQL Drivers
      • Scylla DynamoDB Drivers
  • CQL Reference
    • CQLSh: the CQL shell
    • Appendices
    • Compaction
    • Consistency Levels
    • Consistency Level Calculator
    • Data Definition
    • Data Manipulation
      • SELECT
      • INSERT
      • UPDATE
      • DELETE
      • BATCH
    • Data Types
    • Definitions
    • Global Secondary Indexes
    • Expiring Data with Time to Live (TTL)
    • Functions
    • Wasm support for user-defined functions
    • JSON Support
    • Materialized Views
    • Non-Reserved CQL Keywords
    • Reserved CQL Keywords
    • DESCRIBE SCHEMA
    • Service Levels
    • ScyllaDB CQL Extensions
  • ScyllaDB Architecture
    • Data Distribution with Tablets
    • ScyllaDB Ring Architecture
    • ScyllaDB Fault Tolerance
    • Consistency Level Console Demo
    • ScyllaDB Anti-Entropy
      • Scylla Hinted Handoff
      • Scylla Read Repair
      • Scylla Repair
    • SSTable
      • ScyllaDB SSTable - 2.x
      • ScyllaDB SSTable - 3.x
    • Compaction Strategies
    • Raft Consensus Algorithm in ScyllaDB
  • Troubleshooting ScyllaDB
    • Errors and Support
      • Report a Scylla problem
      • Error Messages
      • Change Log Level
    • ScyllaDB Startup
      • Ownership Problems
      • Scylla will not Start
      • Scylla Python Script broken
    • Upgrade
      • Inaccessible configuration files after ScyllaDB upgrade
    • Cluster and Node
      • Handling Node Failures
      • Failure to Add, Remove, or Replace a Node
      • Failed Decommission Problem
      • Cluster Timeouts
      • Node Joined With No Data
      • SocketTimeoutException
      • NullPointerException
      • Failed Schema Sync
    • Data Modeling
      • Scylla Large Partitions Table
      • Scylla Large Rows and Cells Table
      • Large Partitions Hunting
      • Failure to Update the Schema
    • Data Storage and SSTables
      • Space Utilization Increasing
      • Disk Space is not Reclaimed
      • SSTable Corruption Problem
      • Pointless Compactions
      • Limiting Compaction
    • CQL
      • Time Range Query Fails
      • COPY FROM Fails
      • CQL Connection Table
    • ScyllaDB Monitor and Manager
      • Manager and Monitoring integration
      • Manager lists healthy nodes as down
  • Knowledge Base
    • Upgrading from experimental CDC
    • Compaction
    • Consistency in ScyllaDB
    • Counting all rows in a table is slow
    • CQL Query Does Not Display Entire Result Set
    • When CQLSh query returns partial results with followed by “More”
    • Run Scylla and supporting services as a custom user:group
    • Customizing CPUSET
    • Decoding Stack Traces
    • Snapshots and Disk Utilization
    • DPDK mode
    • Debug your database with Flame Graphs
    • Efficient Tombstone Garbage Collection in ICS
    • How to Change gc_grace_seconds for a Table
    • Gossip in Scylla
    • Increase Permission Cache to Avoid Non-paged Queries
    • How does Scylla LWT Differ from Apache Cassandra ?
    • Map CPUs to Scylla Shards
    • Scylla Memory Usage
    • NTP Configuration for Scylla
    • Updating the Mode in perftune.yaml After a ScyllaDB Upgrade
    • POSIX networking for Scylla
    • Scylla consistency quiz for administrators
    • Recreate RAID devices
    • How to Safely Increase the Replication Factor
    • Scylla and Spark integration
    • Increase Scylla resource limits over systemd
    • Scylla Seed Nodes
    • How to Set up a Swap Space
    • Scylla Snapshots
    • Scylla payload sent duplicated static columns
    • Stopping a local repair
    • System Limits
    • How to flush old tombstones from a table
    • Time to Live (TTL) and Compaction
    • Scylla Nodes are Unresponsive
    • Update a Primary Key
    • Using the perf utility with Scylla
    • Configure Scylla Networking with Multiple NIC/IP Combinations
  • Reference
    • AWS Images
    • Azure Images
    • GCP Images
    • Configuration Parameters
    • Glossary
    • Limits
    • ScyllaDB Enterprise vs. Open Source Matrix
    • API Reference (BETA)
    • Metrics (BETA)
  • ScyllaDB University
  • ScyllaDB FAQ
  • Contribute to ScyllaDB
  • Alternator: DynamoDB API in Scylla
    • Getting Started With ScyllaDB Alternator
    • ScyllaDB Alternator for DynamoDB users
    • Alternator-specific APIs
Docs Tutorials University Contact Us About Us
© 2025, ScyllaDB. All rights reserved. | Terms of Service | Privacy Policy | ScyllaDB, and ScyllaDB Cloud, are registered trademarks of ScyllaDB, Inc.
Last updated on 12 May 2025.
Powered by Sphinx 7.4.7 & ScyllaDB Theme 1.8.6