Changes between Version 2 and Version 3 of GENIMonitoring/Alerts

Timestamp:

05/12/15 16:23:11 (9 years ago)

Author:

cody@uky.edu

Comment:

--

GENIMonitoring/Alerts

@@ -3 +3 @@
 = GENI Monitoring Alerts =
 
-The GENI monitoring alerts system is based on the detection of events based on metric data that polled from remote systems.  As part of the polling process raw data is both recorded in a database and pushed to a queue.  The queue serves as a fanout interface for a one-to-many raw metric subscription service.
 
-[[Image(https://www.rabbitmq.com/img/tutorials/python-three-overall.png)]] 
+The GENI monitoring alerts system is based on the detection of events based on metric data that polled from remote systems.  Raw data is published to a queueing system, which allows multiple complex event queries to operate on the same data stream in parallel.  Output of complex queries can generate Nagios alerts, log results to a database, or both.        
+
+== Poll to raw metric stream ==
+As part of the polling process raw data is both recorded in a database and pushed to a queue.  The queue serves as a fanout interface for a one-to-many raw metric subscription service.
+
+[[Image(https://www.rabbitmq.com/img/tutorials/python-three-overall.png)]]* 
 
 In the previous figure ''P'' represents our polling agent, which publishes data to a queue exchange represented by ''X''.  Clients, designated as ''C1'' and ''C2'', subscribe to exchanges by binding their own queues to exchanges.  In the example, data published by ''P'' is replicated by ''X'' to client queues ''amq.gen-RQ6..'' for client ''C1'' and ''amq.gen-As8...'' for client ''C2''.     
 
+== Stream query of metric stream ==
 
-Alert data is obtained are based on a publish/subscribe queuing system that allows for pattern-based (matching) subscriptions. State transition and utilization will be emitted on this queue.  
+The publish/subscribe queuing system allows streams of raw metric data to be replicated between many processes in parallel.  This allows us to instantiate one or more complex event processing engines ''CEPE'' per replicated data stream and one or more queries inside of each CEPE.  We make use of the Esper [http://www.espertech.com/] CEPE.   
+
+==== Esper Complex Event Processing Engine ====
+Esper allows us to analyze large volumes of incoming messages or events, regardless of whether incoming messages are historical or real-time in nature. Esper filters and analyzes events in various ways, and respond to conditions of interest.  An example of the Esper CEPE architecture is shown in the figure below.
+
+[[Image(http://www.espertech.com/images/products_esp_cep.jpeg)]]** 
+
+Simply, ''CEPE queries'' are pattern-based (matching) subscriptions describing a possible future event. If the described event occurs, a described output is emitted from the CEPE. 
+
+==== Esper Queries ====
+
+In a typical database we query existing data based on some declarative language.  We can think of and Esper query like an upside down SQL, where if events occur in the future, results will be emitted.  The Using the ESPER query language, ''EPL'' (similar to SQL) complex events can are described.
 
 
+Consider the following EPL query: select count(*) from MyEvent(somefield = 10).win:time(3 min) having count(*) >= 5
 
 
-*Queue images are from RabbitMQ tutorials [https://www.rabbitmq.com/tutorials/tutorial-three-python.html]
+*Image from RabbitMQ tutorial [https://www.rabbitmq.com/tutorials/tutorial-three-python.html]
+*Image from Esper [http://www.espertech.com/]