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An Asynchronous Message Delivery Service for iGaDs (intelligent Guards against Disasters) Yi-Zong Ou Institute of Information Science Academia Sinica, R.O.C (Taiwan) C. M. Huang, C. T. Hu, E. T. H. Chu, C. S. Shih, J. W. S. Liu esIoT-2013 Taichung,Taiwan July 3-5th Imagine that… Earthquake 7.0 3 A Future Scenario Alert xmlns: … Sender: Central Weather Bureau Status: Actual MsgType: Alert Scope: Public Info Category: Geo Event: Earthquake Urgency: Immediate Severity: Strong Certainty: Observed Description: A strong earthquake measuring 7.3 occurred in … Parameters: Magnitude, depth, … Areas: Polygons specifying affected areas Resources: … … Common Alert Protocol ITU-T Recommendation X 1303 (07/2007) A common format that supports Broadcast of messages of all types to all public alert systems Message exchange between emergency information systems Aggregation and correlation of warnings from multiple sources End-to-end authentication and validation Automatic reports by sensor systems to analysis centers Automatic processing by smart devices and applications Standard-Based Alert Delivery Authenticated message senders Integrated Public Alert and Warning System http://www.fema.gov/emergency/ipaws/ipaws_cap_mg.pdf Pushing Alert Messages CMAS CMAS Happening now: Guide for CAP-EAS implementation published by EAS industry Weekly testing since December 2011 CMAS 7 iGaDs in Smart Homes and Buildings iGad (AlertType == Earthquake) AND (Magnitude >= 7.3) OR iGaD AND (Severity >= 3) AND (AlertType == Tornado) (OutsideAirPressure * THRESHOLD_RATIO < InsideAirPressure) CAP-aware elevator controller CAP-aware entry access controller CAP-aware building management system (AlertType == Earthquake) AND (Magnitude>= 7.3) OR (AlertType == Tornado) AND (Severity >= 4) 8 iGaD demo prototypes Modem Alert message buffer Signature validation XML parser CAP Message Processor Affected areas Location filter Device location Alert type & information Resources Alert records Rule processor Activation parameters and rules Rule engine Local data Device interfaces Configuration files Device Controller [1] Cyber-physical elements of enhanced disaster prepared smart environment,” by Liu, Chu and Shih, IEEE Computer [2] Ubiquitous smart devices and applications for disaster preparedness,” by Liao, et al, 9 IEEE UIC-ATC 2012 iGaDs and Qpid CAP message Authorized alert sender Broadcast pathways ?xmlns version = “1.0” <alert xmlns = … … <event>Earthquake</event> <urgency>Immediate</urgency> <severity>Strong</severity> … <parameter> <valueName>Magnitude </valueName> <value>7.3</value> </parameter> … PuSH PuSH IP Network Message processor iGaD Action activation rule evaluation Device interface iGaD PuSH To diverse devices: Gas regulator, door or windows controller…… iGaD PubSubHubbub (PuSH) A server-to-server web-hook-based Pub/Sub protocol as an extension to Atom and RSS (topic: feed URL). The subscriber subscribes to the Topic URL from the Topic URL's declared Hub(s). Publisher Announce new alert Ping Data Push Subscribe notification Alert PuSH subscribers Information Message Hub Fetch data Subscriber Notifications Update! 11 Qpid Apache Qpid™ is a cross-platform Enterprise Messaging system which implements the Advanced Message Queuing Protocol (AMQP) Reliable delivery service Feasible use to restore network during disaster. Messages with routing key Exchange Bindings Queues Priority queues Decreasing Priority Earth -quake Debris Tsunami Flow 12 PQ Node Notification to local subscribers Hub Requests from publishers PubSubHubbub Data Bridge Down stream data Up stream data Cached data Messages from other Qpids Exchange Priority Queues Messages to other Qpids Bindings Decreasing Priority 13 PQ Node – Down stream Requests from publishers Notifications to local subscribers Hub Data PubSubHubbub Data Update Monitor (DUM) Work item (Earthquake) Call DataBridgeNotifyDataUpdate( Highest Topic,RelativeDeadline, ...); Priority Data Transfer Service (DTS) Data Bridge data Data Exchange High Priority Queues Low Bindings Route to other Qpids Decreasing Priority 14 PQ Node – Up stream Notifications to local subscribers Hub PubSubHubbub Data Retrieval Service (DRS) Work item Messages from other Qpids Data Priority Queues Cached Data High Incoming Data Monitor (IDM) Register long pollsLow Data Bridge Route to other Exchange Qpids Bindings Decreasing Priority 15 Summary and Future work Our work provides: Asynchronous prioritized messaging delivery service Web-based Publish/Subscribe alert messages to iGaDs via Internet We will investigate: How responsive a network of nodes built from PuSH, data bridge and Qpid? How system resources of each node are allocated to tasks that move data within the node? 16 Thank you very much! This work is supported by the Academia Sinica, Republic of China (Taiwan) Open Information Systems for Disaster Management project. Why PuSH on Qpid? Pub/Sub for Qpid needs subscribers to stay connection (session) with the Qpid broker. If the connection terminated, there is no way that Qpid can push notification to Subscribers PuSH can push notification via callback URL. Subscriber does not need to stay connection with hub. 18 Why design priority queues in data bridge ? There is no priority among queues in a Qpid broker. Prioritized messages only exist in single queue. Retrieve messages from a priority queue is only ordered by priority. Impossible to change the algorithm (ex: 5high, 3low avoid starvation) to retrieve messages. No prioritized message delivery between two brokers. Hence, we design to send messages in the order of priority before entering a Qpid broker. 19