# Advanced Internode (RPC) Compression

ScyllaDB Cloud uses advanced internode (RPC) compression to reduce the amount
of data transferred between nodes in a cluster.

Internode compression is used for operations such as replication, repair,
streaming, and coordination between nodes. These can otherwise generate
significant network traffic, especially in multi-node or multi–data center
deployments.

Compression substantially reduces the total cost of ownership (TCO) by
lowering intrazonal network costs.

## Compression Mechanism

Internode compression reduces the size of data exchanged between nodes by
applying compression before transmission and decompression on receipt. This
improves network efficiency and can reduce latency in bandwidth-constrained
environments.

ScyllaDB Cloud uses **Zstandard (ZSTD)**-based compression, a modern algorithm
that provides a strong balance between compression ratio and CPU overhead. This
allows data to be compressed effectively while maintaining high throughput and
low latency.

In addition, compression is enhanced using dictionary-based techniques, which
improve efficiency for repeating data patterns commonly found in database
workloads.

## Behavior in ScyllaDB Cloud

ZSTD-based internode compression is:

* **Enabled for all clusters and service tiers**
* **Applied automatically to internode (RPC) traffic**
* **Fully managed by the platform**

No configuration or user action is required.

This behavior ensures efficient use of network resources and contributes to
overall cluster performance without requiring manual tuning.

#### NOTE
Some dictionary training data may be encrypted using
[storage-level encryption](https://cloud.docs.scylladb.com/stable/security/storage-level-encryption.md)
instead of [database-level encryption](https://cloud.docs.scylladb.com/stable/security/database-level-encryption.md).