Class: SparkConnect::StreamingQuery

Inherits:
Object
  • Object
show all
Defined in:
lib/spark_connect/streaming.rb

Overview

A handle to a running streaming query. Returned by DataStreamWriter#start. Mirrors PySpark’s ‘StreamingQuery`.

Constant Summary collapse

Proto = 
SparkConnect::Proto
Cmd = 
Proto::StreamingQueryCommand

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(session, instance_id, name) ⇒ StreamingQuery

Returns a new instance of StreamingQuery.

Parameters:



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# File 'lib/spark_connect/streaming.rb', line 218

def initialize(session, instance_id, name)
  @session = session
  @instance_id = instance_id
  @id = instance_id.id
  @run_id = instance_id.run_id
  @name = name.nil? || name.empty? ? nil : name
end

Instance Attribute Details

#id ⇒ String (readonly)

Returns the stable query id (survives restarts from a checkpoint).

Returns:

  • (String) —

    the stable query id (survives restarts from a checkpoint).



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# File 'lib/spark_connect/streaming.rb', line 209

def id
  @id
end

#name ⇒ String? (readonly)

Returns the query name, if one was set.

Returns:

  • (String, nil) —

    the query name, if one was set.



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# File 'lib/spark_connect/streaming.rb', line 213

def name
  @name
end

#run_id ⇒ String (readonly)

Returns the run id (unique per start).

Returns:

  • (String) —

    the run id (unique per start).



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# File 'lib/spark_connect/streaming.rb', line 211

def run_id
  @run_id
end

Instance Method Details

#active? ⇒ Boolean

Returns whether the query is still running.

Returns:

  • (Boolean) —

    whether the query is still running.



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# File 'lib/spark_connect/streaming.rb', line 239

def active?
  status["isActive"]
end

#await_termination(timeout_ms = nil) ⇒ Boolean

Block until the query terminates, or until ‘timeout_ms` elapses.

Parameters:

  • timeout_ms (Integer, nil) (defaults to: nil)

Returns:

  • (Boolean) —

    whether the query has terminated.



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# File 'lib/spark_connect/streaming.rb', line 257

def await_termination(timeout_ms = nil)
  ac = Cmd::AwaitTerminationCommand.new
  ac.timeout_ms = timeout_ms if timeout_ms
  command(await_termination: ac).await_termination.terminated
end

#exception ⇒ String?

Returns the query’s exception message, if it has failed.

Returns:

  • (String, nil) —

    the query’s exception message, if it has failed.



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# File 'lib/spark_connect/streaming.rb', line 277

def exception
  result = command(exception: true).exception
  result.exception_message && result.exception_message.empty? ? nil : result.exception_message
end

#explain(extended: false) ⇒ String

Returns the query’s execution plan.

Returns:

  • (String) —

    the query’s execution plan.



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# File 'lib/spark_connect/streaming.rb', line 283

def explain(extended: false)
  command(explain: Cmd::ExplainCommand.new(extended: extended)).explain.result
end

#last_progress ⇒ Hash?

Returns the most recent progress object, if any.

Returns:

  • (Hash, nil) —

    the most recent progress object, if any.



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# File 'lib/spark_connect/streaming.rb', line 249

def last_progress
  command(last_progress: true).recent_progress.recent_progress_json.map { |j| JSON.parse(j) }.last
end

#process_all_available ⇒ void

This method returns an undefined value.

Process all available data, then return (useful for tests with bounded sources).



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# File 'lib/spark_connect/streaming.rb', line 265

def process_all_available
  command(process_all_available: true)
  nil
end

#recent_progress ⇒ Array<Hash>

Returns parsed JSON progress objects for recent micro-batches.

Returns:

  • (Array<Hash>) —

    parsed JSON progress objects for recent micro-batches.



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# File 'lib/spark_connect/streaming.rb', line 244

def recent_progress
  command(recent_progress: true).recent_progress.recent_progress_json.map { |j| JSON.parse(j) }
end

#status ⇒ Hash

Returns the current status (‘message`, `is_data_available`, `is_trigger_active`, `is_active`).

Returns:

  • (Hash) —

    the current status (‘message`, `is_data_available`, `is_trigger_active`, `is_active`).



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# File 'lib/spark_connect/streaming.rb', line 228

def status
  s = command(status: true).status
  {
    "message" => s.status_message,
    "isDataAvailable" => s.is_data_available,
    "isTriggerActive" => s.is_trigger_active,
    "isActive" => s.is_active,
  }
end

#stop ⇒ Object

Stop the query. @return [void]



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# File 'lib/spark_connect/streaming.rb', line 271

def stop
  command(stop: true)
  nil
end

#to_s ⇒ Object Also known as: inspect 



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# File 'lib/spark_connect/streaming.rb', line 287

def to_s
  "#<SparkConnect::StreamingQuery id=#{@id} name=#{@name.inspect}>"
end