• Processing time • the time of the local clock where an event is being processed • a processing-time window wouldn’t account for game activity while the train is in the tunnel • results depend on aren’t deterministic • Event time • the time when an event actually happened • an event-time window would give you the extra life • results are deterministic and independent of the processing speed

different things • last 5 sec • last 10 events • last 1h every 10 min • last user session Window operators 2 Vasiliki Kalavri | Boston University 2020 object MaxSensorReadings { def main(args: 0)))
 .keyBy(_.id) .timeWindow(Time.minutes(1)) .max("temp")
 } } 3 Example: Window sensor readings Vasiliki Kalavri | Boston University 2020 In the DataStream API, you can use the or IngestionTime Vasiliki Kalavri | Boston University 2020 Window operators can be applied on a keyed or a non-keyed stream: • Window operators on keyed windows are evaluated in parallel • Non-keyed

DStream. 23 / 79 Window Operations (1/3) ▶ Spark provides a set of transformations that apply to a over a sliding window of data. ▶ A window is defined by two parameters: window length and slide interval interval. ▶ A tumbling window effect can be achieved by making slide interval = window length 24 / 79 Window Operations (2/3) ▶ window(windowLength, slideInterval) • Returns a new DStream which is computed based on windowed batches. ▶ countByWindow(windowLength, slideInterval) • Returns a sliding window count of elements in the stream. ▶ reduceByWindow(func, windowLength, slideInterval) • Returns

removable media . . . . . . . . . . . . . . . . . . . . . . . . . 24 1.8.5 Resizing the machine’s window . . . . . . . . . . . . . . . . . . . . . . 24 1.8.6 Saving the state of the machine . . . . . Configure VM window menu entries . . . . . . . . . . . . . . . . . . . . 184 9.19.5 Configure VM window status bar entries . . . . . . . . . . . . . . . . . 187 9.19.6 Configure VM window visual modes shows you how VirtualBox, installed on a Mac computer, is running Windows 7 in a virtual machine window: In this User Manual, we’ll begin simply with a quick introduction to virtualization and how to

removable media . . . . . . . . . . . . . . . . . . . . . . . . . 24 1.8.5 Resizing the machine’s window . . . . . . . . . . . . . . . . . . . . . . 24 1.8.6 Saving the state of the machine . . . . . Configure VM window menu entries . . . . . . . . . . . . . . . . . . . . 184 9.19.5 Configure VM window status bar entries . . . . . . . . . . . . . . . . . 187 9.19.6 Configure VM window visual modes shows you how VirtualBox, installed on a Mac computer, is running Windows 7 in a virtual machine window: In this User Manual, we’ll begin simply with a quick introduction to virtualization and how to

removable media . . . . . . . . . . . . . . . . . . . . . . . . . 24 1.8.5 Resizing the machine’s window . . . . . . . . . . . . . . . . . . . . . . 24 1.8.6 Saving the state of the machine . . . . . Configure VM window menu entries . . . . . . . . . . . . . . . . . . . . 199 9.20.5 Configure VM window status bar entries . . . . . . . . . . . . . . . . . 202 9.20.6 Configure VM window visual modes shows you how VirtualBox, installed on a Mac computer, is running Windows 8 in a virtual machine window: In this User Manual, we’ll begin simply with a quick introduction to virtualization and how to

removable media . . . . . . . . . . . . . . . . . . . . . . . . . 24 1.8.5 Resizing the machine’s window . . . . . . . . . . . . . . . . . . . . . . 24 1.8.6 Saving the state of the machine . . . . . Configure VM window menu entries . . . . . . . . . . . . . . . . . . . . 199 9.20.5 Configure VM window status bar entries . . . . . . . . . . . . . . . . . 202 9.20.6 Configure VM window visual modes shows you how VirtualBox, installed on a Mac computer, is running Windows 8 in a virtual machine window: In this User Manual, we’ll begin simply with a quick introduction to virtualization and how to

removable media . . . . . . . . . . . . . . . . . . . . . . . . . 24 1.8.5 Resizing the machine’s window . . . . . . . . . . . . . . . . . . . . . . 24 1.8.6 Saving the state of the machine . . . . . Configure VM window menu entries . . . . . . . . . . . . . . . . . . . . 212 9.20.5 Configure VM window status bar entries . . . . . . . . . . . . . . . . . 215 9.20.6 Configure VM window visual modes shows you how VirtualBox, installed on a Mac computer, is running Windows 8 in a virtual machine window: In this User Manual, we’ll begin simply with a quick introduction to virtualization and how to

removable media . . . . . . . . . . . . . . . . . . . . . . . . . 24 1.8.5 Resizing the machine’s window . . . . . . . . . . . . . . . . . . . . . . 24 1.8.6 Saving the state of the machine . . . . . Configure VM window menu entries . . . . . . . . . . . . . . . . . . . . 212 9.20.5 Configure VM window status bar entries . . . . . . . . . . . . . . . . . 215 9.20.6 Configure VM window visual modes shows you how VirtualBox, installed on a Mac computer, is running Windows 8 in a virtual machine window: In this User Manual, we’ll begin simply with a quick introduction to virtualization and how to

removable media . . . . . . . . . . . . . . . . . . . . . . . . . 24 1.8.5 Resizing the machine’s window . . . . . . . . . . . . . . . . . . . . . . 24 1.8.6 Saving the state of the machine . . . . . Configure VM window menu entries . . . . . . . . . . . . . . . . . . . . 212 9.20.5 Configure VM window status bar entries . . . . . . . . . . . . . . . . . 215 9.20.6 Configure VM window visual modes shows you how VirtualBox, installed on a Mac computer, is running Windows 8 in a virtual machine window: In this User Manual, we’ll begin simply with a quick introduction to virtualization and how to