Data Processing
Polling vs. Interrupts
PollingSimilar to voting (hence “polling”)Cycle through all clients to see if they have
requestsInterrupts
Similar to students raising handsClients interrupt server and make a request
Real-time vs. Batch Processing
Real-time processingNo waitingHandle things in “real-time” as they happenExample: Air traffic control
Batch processingWait for a period of time for events to queue
upHandle all the events in one batchExample: Updating all computers overnight
Variations and Combinations
Polling & Real-time processingPolling & Batch-processingInterrupts & Real-time processingInterrupts & Batch-processing
Assignment Grading Example
Polling with Real-time processing1. Teacher asks each student if they are done2. Teacher grades student’s assignment immediately after
he/she turns it in
Polling with Batch-processing1. Teacher asks each student if they are done2. Teacher grades all submitted assignments in one sitting
Interrupts with Real-time processing1. Student turns in assignment to teacher whenever2. Teacher grades assignment immediately
Interrupts with Batch-processing1. Student turns in assignment to teacher whenever2. Teacher grades all submitted assignments in one sitting
Identify the proper system design for the following scenarios
Example: Homework – polling with batch processing
• Air traffic control• Printer system with multiple clients• Processing checks at a bank• Printing report cards for students• Library books being returned• Telephone call routing (e.g. main office)• Voting for SCA officers• College application reviews