A Microsoft Fabric Livy session — FabricLivySession • fabricQueryR

A Livy session keeps Spark running while you submit several pieces of code Create one with fabric_livy_session(), call $wait() once it starts, use $run() to execute code, and call $close() when finished. Most users do not need to call this 'R6' class directly. These lifecycle methods do not have separate free-function wrappers

Format

An R6::R6Class generator

Value

The FabricLivySession 'R6' generator.

Public fields

id: Fabric session or high-concurrency acquisition ID
url: Session lifecycle URL
state: Latest service state
response: Latest raw service response
closed: Whether $close() completed
high_concurrency: Whether this is a high-concurrency session
session_id: Underlying Livy session ID for HC sessions
repl_id: Isolated REPL ID for HC sessions
verbose: Whether lifecycle messages are enabled

Methods

`FabricLivySession$new()`

Internal constructor used by fabric_livy_session()

Usage

FabricLivySession$new(
  livy_url,
  credential,
  payload,
  response = NULL,
  high_concurrency = FALSE,
  verbose = TRUE
)

Arguments

livy_url: Livy API base or collection URL
credential: Internal authentication credential
payload: Session creation request body
response: Existing session response when attaching
high_concurrency: Whether to acquire an HC session
verbose: Whether to emit lifecycle messages

Returns

A new session object

`FabricLivySession$print()`

Print a concise session summary

Usage

FabricLivySession$print(...)

Arguments

...: Unused

Returns

self, invisibly

`FabricLivySession$status()`

Return the latest session response

Usage

FabricLivySession$status(refresh = TRUE, deadline = NULL)

Arguments

refresh: Whether to retrieve current state from Fabric
deadline: Internal wall-clock deadline for the status request

Returns

The raw session response list

`FabricLivySession$wait()`

Wait until the session can accept statements

Usage

FabricLivySession$wait(timeout = 600, poll_interval = 3)

Arguments

timeout: Maximum wait in seconds
poll_interval: Polling interval in seconds

Returns

self, invisibly

`FabricLivySession$submit()`

Submit code without waiting for completion

Usage

FabricLivySession$submit(
  code,
  kind = c("spark", "pyspark", "sparkr", "sql"),
  source_id = NULL
)

Arguments

code: One string of Spark code
kind: Statement language
source_id: Optional caller-defined source identifier

Returns

A FabricLivyStatement

`FabricLivySession$run()`

Submit code, wait, and return its parsed result

Usage

FabricLivySession$run(
  code,
  kind = c("spark", "pyspark", "sparkr", "sql"),
  source_id = NULL,
  timeout = 600,
  poll_interval = 2
)

Arguments

code: One string of Spark code
kind: Statement language
source_id: Optional caller-defined source identifier
timeout: Maximum wait in seconds
poll_interval: Polling interval in seconds

Returns

A fabric_livy_statement_result list

`FabricLivySession$statements()`

List every statement in this execution context

Usage

FabricLivySession$statements()

Returns

The raw Livy statements response

`FabricLivySession$reset_timeout()`

Reset a regular session's inactivity timeout

Usage

FabricLivySession$reset_timeout()

Returns

self, invisibly

`FabricLivySession$close()`

Release this session or high-concurrency context

Usage

FabricLivySession$close(deadline = NULL)

Arguments

deadline: Internal wall-clock deadline for the cleanup request

Returns

TRUE when closed or FALSE when already closed, invisibly

Examples

if (FALSE) { # \dontrun{
# fabric_livy_session() creates this class for a discovered Lakehouse
workspace <- fabric_workspaces()[[1L]]
lakehouse <- fabric_lakehouses(workspace)[[1L]]
session <- fabric_livy_session(lakehouse)
inherits(session, "FabricLivySession")

# Wait before running code, and close the Spark session when finished
session$wait()
session$run("print(1 + 1)", kind = "pyspark")
session$close()
} # }