https://github.com/aorwall/evactor

Complex event processor based on Akka
https://github.com/aorwall/evactor

akka scala

Last synced: 10 days ago
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Complex event processor based on Akka

• Host: GitHub
• URL: https://github.com/aorwall/evactor
• Owner: aorwall
• Created: 2011-09-14T17:52:25.000Z (about 13 years ago)
• Default Branch: master
• Last Pushed: 2013-10-11T14:52:33.000Z (about 11 years ago)
• Last Synced: 2024-10-10T23:33:36.472Z (27 days ago)
• Topics: akka, scala
• Language: Scala
• Homepage:
• Size: 1.79 MB
• Stars: 29
• Watchers: 7
• Forks: 10
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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README

        
Evactor

=====================

***Check out the [example](https://github.com/aorwall/evactor-twitter) module to get a better understanding on how all this works.***

This is an attempt to create a complex event processing implementation in Akka. The idea is that *processors* subscribe to *channels* to receive *events* published on the channels. The event processor can then process the events in some way and publish new events on other event channels. 

The project also houses a storage solution, based on Apache Cassandra, for auditing and statistics. An API exists for easy access to historic data.

Flow

---------------------

### Event

*TODO*

### Collector

A *collector* collects events from external event producers. 

### Processor

A processor is a component that performs operations on events. This could be to extract data, create new events based on aggregated events or examining a collection of events to find a particular pattern.

To receive events the processor subscribes to channels or to all events that flows through the system. When the processor creates a new event it can publish it to another channel.

### Channel

*TODO*

Configuration

---------------------

Everything is configured in the `application.conf` file.

### Collectors

*TODO*

### Processors

#### Routers

Handles routing in the system

##### Forwarder

Just forwarding an event to a different channel (and category)

###### Configuration

```text

forwarderName {

  type = forwarder

  subscriptions = [ {channel = "foo"} ]

  publication = { channel = "bar" }

}

```

##### Filter

Filtering out events that doesn't comply with a specified rule(expression)

###### Configuration

```text

filterName {

  type = filter

  subscriptions = [ {channel = "foo"} ]

  publication = { channel = "bar" } 

  expression = { mvel = "value > 0" }

  accept = false

}

```

#### Analysers

Analysing sequences of events and produces new events with the result 

##### Count analyser

Counts events within a specified time frame

###### Configuration

```text

filterName {

  type = countAnalyser

  subscriptions = [ {channel = "foo"} ]

  publication = { channel = "bar" } 

  categorize = true

  timeframe = 2 hours

}

```

##### Average analyser

Count average in a specified window (time or length)

###### Configuration

```text

averageAnalyserName {

  type = averageAnalyser

  subscriptions = [ {channel = "foo"} ]

  publication = { channel = "bar" }

  categorize = false

  expression = { static = "foo" }

  window = { time = 1 minute }

}

```

##### Regression analyser

Calculates the regression coefficient within a specified time frame

###### Configuration

```text

regressionName {

  type = regressionAnalyser

  subscriptions = [ {channel = "foo"} ]

  publication = { channel = "bar" } 

  categorize = true

  minSize = 25

  timeframe = 15 minutes

}

```

#### Alerter

Alerts when events that doesn't comply with a specified rule(expression) and informs when state is back to normal.

```text

  type = alerter

  subscriptions = [ {channel = "foo"} ]

  publication = { channel = "bar" } 

  categorize = false

  expression = { mvel = "true" }

```

#### Builders

*TODO*

#### Producers

Produces events to external consumers.

##### LogProducers

Writes events to log.

###### Configuration

```text

logger {

  type = logProducer

  subscriptions = [ {channel = "foo"} ]

  loglevel = INFO

}

```

#### Custom processor

It's possible to create a custom processor and use it in the configuration by specifying the class instead of *type*.

##### Configuration

```text

customProcessor {

  class = org.example.CustomProcessor

  subscriptions = [ {channel = "foo"} ]

  publication = { channel = "bar" } 

  arguments = ["foo", "bar"]

}

```

##### Example implementation

```scala

class SimpleProcessor (

    override val subscriptions: List[Subscription],

    val publication: Publication)

  extends Processor(subscriptions) with Publisher {

  def process(event: Event) {

    // do stuff

    publish(event)

  }

}

```

Storage

---------------------

*TODO*

API

---------------------

*TODO*

Build and deploy

---------------------

*TODO*

Licence

---------------------

Copyright 2012 Albert Örwall

Licensed under the Apache License, Version 2.0: http://www.apache.org/licenses/LICENSE-2.0