July 2018

Documentation and dependency version updates.

June 2018

1.7.0 (2018-06-06)

Bug Fixes

• avoid calling fallback function twice (#198) (#201) (b561a43)

Features

• optional timeout (#200) (#202) (7611d6f)

Provide error to fallback function

1.6.0 (2018-05-24)

Features

• pass error as parameter to fallback function (#197) (ae6c1cc)

Full Webpack support

1.5.0 (2018-04-25)

Bug Fixes

• add full support for webpack and angular (#185) (a8cdad6)

Hystrix stats aggregation and circuit enable/disable

1.4.0 (2018-03-26)

Bug Fixes

• address sec vuln in marked coming from jsdoc (224c6ef)
• security issue related to electron version (#138) (4739c62)

Features

• add enable/disable for a circuit (#160) (016eba5)
• allow multiple circuits to aggregate stats (#140) (ba71840)

Maintenance release

This release addresses an issue that may arise when a circuit is in the halfOpen state and there is still heavy traffic.

1.3.1 (2017-12-14)

Bug Fixes

• build on windows10 due browserify limitations (#112) (dee4a9a)
• halfOpen state does not reject and doesn't trigger a later re-try. (#120 (04df6f7)

Health Checks and Bug Fixes

1.3.0 (2017-10-16)

Bug Fixes

• ensure breaker.fire() returns rejected promise when fallback fails (fbedb07)
• ensure fallback event always fires (27c3f8b)
• JSDoc now available for semaphore-locked event (6f6c9bd)

Features

• Add health check function to a circuit breaker (#76) (0e39faa)

Installation

$ npm install --save opossum

https://www.npmjs.com/package/opossum

Rolling percentile latency, bug fixes, timeout codes

1.1.0 (2017-06-06)

Bug Fixes

• don't let circuits get stuck half open (5e1171c)
• fix logic around pendingClose (4d89ae4)

Features

• add ETIMEDOUT error code for timeout error (#64) (5df9f65)
• addition of rolling percentile latency's. GH-ISSUE #38 (ce7b50d)
• remove fidelity promises. (3f5827a)

Streaming Hystrix Data

1.0.0 (2017-04-06)

Bug Fixes

• do not fire failure event on short circuit (ab87350)
• make Status an EventEmitter (8aad11a)
• remove default maxFailures option (be65d3b)

Features

• add a group option. GH-Issue #43 (3052f23)
• Add an example on how to use the Hystrix Metrics (fd8246a)
• Addition of Hystrix Mertrics Stream. GH-ISSUE #39 (2d44df6)
• circuit status now contains a rolling window (#34) (05c0a2f)
• prefer an error percentage threshold (245d47b)

Now with more cache

Caching and the Beginning of Rolling Stats

This release introduces caching to a circuit. It's simple. Just provide { cache: true } in your options when creating the circuit, and the circuit will cache the first successful response it gets, and always use that. You can clear the cached value by calling circuit.clearCache(). This may be useful in situations where up-to-the-millisecond values are not required. For example, a badge icon that displays a message count may choose to cache the value, and only update it once every 5 seconds.

// The circuit will cache the message count
const circuit = circuitBreaker( getMessageCount, { cache: true } );

// reset the cache every 5 seconds
const interval = setInterval( () => circuit.clearCache, 5000 );

Rolling stats have also been introduced in this release. This replaces the existing cumulative behavior of a circuit's status, in favor of snapshots every X milliseconds, where X defaults to 10000, e.g. 10 seconds. This allows for rolling average calculations on important statistics for Hystrix dashboard, and is in pursuit of
#32 (but does not complete it).

Bug Fixes

• circuit should emit failure event on fallback (f2594d8)
• include the error when emitting the 'fallback event' (40eb2eb)
• promise should reject when action throws (58dab98)
• typo copy past duplicated property (54a27b9)

Features

• add basic rolling stats to a circuit (8fb9561)
• Add caching capability to circuits (6c3144f)
• Add caching capability to circuits (0b717f6)
• Applying code review (6a0f7ff)
• Applying code review (8445a24)
• circuits now have a name based on the action (f08d46e)