https://github.com/komamitsu/phi-accrual-failure-detector

A port of Akka's Phi Accrual Failure Detector
https://github.com/komamitsu/phi-accrual-failure-detector

failure-detector java

Last synced: about 1 month ago
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A port of Akka's Phi Accrual Failure Detector

• Host: GitHub
• URL: https://github.com/komamitsu/phi-accrual-failure-detector
• Owner: komamitsu
• License: apache-2.0
• Created: 2015-09-20T13:57:04.000Z (almost 11 years ago)
• Default Branch: master
• Last Pushed: 2023-09-10T02:16:00.000Z (almost 3 years ago)
• Last Synced: 2026-01-14T04:57:26.905Z (6 months ago)
• Topics: failure-detector, java
• Language: Java
• Size: 72.3 KB
• Stars: 48
• Watchers: 3
• Forks: 6
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.txt

Awesome Lists containing this project

• awesome-java - Phi Accrual Failure Detector

README

          
# phi-accrual-failure-detector

A port of [Akka's Phi Accrual Failure Detector](https://github.com/akka/akka/blob/master/akka-remote/src/main/scala/akka/remote/PhiAccrualFailureDetector.scala).

Implementation of 'The Phi Accrual Failure Detector' by Hayashibara et al. as defined in [their paper](http://ddg.jaist.ac.jp/pub/HDY+04.pdf)

The suspicion level of failure is given by a value called φ (phi). The basic idea of the φ failure detector is to express the value of φ on a scale that is dynamically adjusted to reflect current network conditions. A configurable threshold is used to decide if φ is considered to be a failure.

The value of φ is calculated as:

    φ = -log10(1 - F(timeSinceLastHeartbeat)

where F is the cumulative distribution function of a normal distribution with mean and standard deviation estimated from historical heartbeat inter-arrival times.

## Install

### Gradle

    dependencies {

        compile 'org.komamitsu:phi-accrual-failure-detector:1.0.0'

    }

### Maven

    

        org.komamitsu

        phi-accrual-failure-detector

        1.0.0

    

 

 

## Usage

 

    PhiAccrualFailureDetector failureDetector = new PhiAccrualFailureDetector.Builder().build();

    System.out.println("The node is alive.");

    for (int i = 0; i < 5; i++) {

        failureDetector.heartbeat();

        System.out.println(failureDetector.phi());

        TimeUnit.SECONDS.sleep(1);

    }

    System.out.println("The node got crashed.");

    for (int i = 0; i < 5; i++) {

        System.out.println(failureDetector.phi());

        TimeUnit.SECONDS.sleep(1);

    }

    System.out.println("The node is up.");

    for (int i = 0; i < 5; i++) {

        failureDetector.heartbeat();

        System.out.println(failureDetector.phi());

        TimeUnit.SECONDS.sleep(1);

    }

    >>>

    The node is alive.

    0.07503303214093988

    0.04123372001754947

    0.02973367253880404

    0.024211164763365475

    0.0210350451959075

    The node got crashed.

    0.434230547557814

    2.026327722139659

    5.53345508216027

    12.239567237632542

    23.67083400864969

    The node is up.

    0.09372488186862751

    0.09191309083825062

    0.08979724362880628

    0.0875398030863105

    0.08525179892208078