Client protocol properties#

The following sections provide a reference for all properties related to the client protocol.

Spooling protocol properties#

The following properties are related to the Spooling protocol.

protocol.spooling.enabled#

  • Type: boolean

  • Default value: true

Enable the support for the client Spooling protocol. The protocol is used if client drivers and applications request usage, otherwise the direct protocol is used automatically.

protocol.spooling.shared-secret-key#

A required 256 bit, base64-encoded secret key used to secure spooled metadata exchanged with the client.

protocol.spooling.retrieval-mode#

  • Type: string

  • Default value: STORAGE

Determines how the client retrieves the segment. Following are possible values:

  • STORAGE - client accesses the storage directly with the pre-signed URI. Uses one client HTTP request per data segment.

  • COORDINATOR_STORAGE_REDIRECT - client first accesses the coordinator, which redirects the client to the storage with the pre-signed URI. Uses two client HTTP requests per data segment.

  • COORDINATOR_PROXY - client accesses the coordinator and gets data segment through it. Uses one client HTTP request per data segment, but requires a coordinator HTTP request to the storage.

  • WORKER_PROXY - client accesses the coordinator, which redirects to an available worker node. It fetches the data from the storage and provides it to the client. Uses two client HTTP requests, and requires a worker request to the storage.

protocol.spooling.encoding.json.enabled#

  • Type: boolean

  • Default value: true

Activate support for using uncompressed JSON encoding for spooled segments.

protocol.spooling.encoding.json+zstd.enabled#

  • Type: boolean

  • Default value: true

Activate support for using JSON encoding with Zstandard compression for spooled segments.

protocol.spooling.encoding.json+lz4.enabled#

  • Type: boolean

  • Default value: true

Activate support for using JSON encoding with LZ4 compression for spooled segments.

protocol.spooling.initial-segment-size#

Initial size of the spooled segments.

protocol.spooling.maximum-segment-size#

Maximum size for each spooled segment.

protocol.spooling.inlining.enabled#

  • Type: boolean

  • Default value: true

Allow spooled protocol to inline initial rows to decrease time to return the first row.

protocol.spooling.inlining.max-rows#

  • Type: integer

  • Default value: 1000

Maximum number of rows to inline per worker.

protocol.spooling.inlining.max-size#

Maximum size of rows to inline per worker.

Spooling file system properties#

The following properties are used to configure the object storage used with the Spooling protocol.

fs.azure.enabled#

  • Type: boolean

  • Default value: false

Activate Azure Storage file system support for spooling segments.

fs.s3.enabled#

  • Type: boolean

  • Default value: false

Activate S3 file system support for spooling segments.

fs.gcs.enabled#

  • Type: boolean

  • Default value: false

Activate Google Cloud Storage file system support for spooling segments.

fs.location#

The object storage location to use for spooling segments. Must be accessible by the coordinator and all workers. With the protocol.spooling.retrieval-mode retrieval modes STORAGE and COORDINATOR_STORAGE_REDIRECT the location must also be accessible by all clients. Valid location values vary by object storage type, and typically follow a pattern of scheme://bucketName/path/.

Examples:

  • s3://my-spooling-bucket/my-segments/

Caution

When using the same object storage for spooling from multiple Trino clusters, you must use separate locations for each cluster. For example:

  • s3://my-spooling-bucket/my-segments/cluster1

  • s3://my-spooling-bucket/my-segments/cluster2

fs.segment.ttl#

Maximum available time for the client to retrieve spooled segment before it expires and is pruned.

fs.segment.direct.ttl#

Maximum available time for the client to retrieve spooled segment using the pre-signed URI.

fs.segment.encryption#

  • Type: boolean

  • Default value: true

Encrypt segments with ephemeral keys using Server-Side Encryption with Customer key (SSE-C).

fs.segment.explicit-ack#

  • Type: boolean

  • Default value: true

Activate pruning of segments on client acknowledgment of a successful read of each segment.

fs.segment.pruning.enabled#

  • Type: boolean

  • Default value: true

Activate periodic pruning of expired segments.

fs.segment.pruning.interval#

Interval to prune expired segments.

fs.segment.pruning.batch-size#

  • Type: integer

  • Default value: 250

Number of expired segments to prune as a single batch operation.

Shared protocol properties#

The following properties are related to the Spooling protocol and the Direct protocol, formerly named the V1 protocol.

protocol.v1.prepared-statement-compression.length-threshold#

  • Type: integer

  • Default value: 2048

Prepared statements that are submitted to Trino for processing, and are longer than the value of this property, are compressed for transport via the HTTP header to improve handling, and to avoid failures due to hitting HTTP header size limits.

protocol.v1.prepared-statement-compression.min-gain#

Prepared statement compression is not applied if the size gain is less than the configured value. Smaller statements do not benefit from compression, and are left uncompressed.