1. Data Processing

2. Polling vs. Interrupts Polling Similar to voting (hence “polling”) Cycle through all clients to see if they have requests Interrupts Similar to students raising hands Clients interrupt server and make a request

3. Real-time vs. Batch Processing Real-time processing No waiting Handle things in “real-time” as they happen Example: Air traffic control Batch processing Wait for a period of time for events to queue up Handle all the events in one batch Example: Updating all computers overnight

4. Variations and Combinations Polling & Real-time processing Polling & Batch-processing Interrupts & Real-time processing Interrupts & Batch-processing

5. Assignment Grading Example Polling with Real-time processing 1. Teacher asks each student if they are done 2. Teacher grades student’s assignment immediately after he/she turns it in Polling with Batch-processing 1. Teacher asks each student if they are done 2. Teacher grades all submitted assignments in one sitting Interrupts with Real-time processing 1. Student turns in assignment to teacher whenever 2. Teacher grades assignment immediately Interrupts with Batch-processing 1. Student turns in assignment to teacher whenever 2. Teacher grades all submitted assignments in one sitting

6. 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