Retry N times with progressive backoffs before Fail

Logarithmic Backoffs

Rhod supports retying up to N times. By default it uses a logarithmic backoff:

backoff = Rhod::Backoffs::Logarithmic.new(1.3)
backoffs = []; 5.times { backoffs << backoff.next }; backoffs
# => [0.7570232465074598, 2.403267722339301, 3.444932048942182, 4.208673319629471, 4.811984719351674]

Rhod also comes with exponential, random and constant backoffs. You can also subclass Rhod::Backoffs::Backoff to create your own. See lib/rhod/backoffs/ for examples.

Example, open a remote reasource, fail once it has failed 10 times, with the default (logarithmic) backoff explictly stated:

require 'open-uri'
require 'rhod'

Rhod.create_profile(:retry_logarithmic, retries: 10, backoffs: :l)

Rhod.with_retry_logarithmic do
  open("http://google.com").read
end

Constant Backoffs

Example, open a remote reasource, fail once it has failed 10 times, waiting 0.2 seconds between attempts:

require 'open-uri'
require 'rhod'

Rhod.create_profile(:retry_constant, retries: 10, backoffs: 0.2)

Rhod.with_retry_constant do
  open("http://google.com").read
end

Exponetial Backoffs

Example, open a remote reasource, fail once it has failed 10 times, with an exponetially growing wait time between attempts:

require 'open-uri'
require 'rhod'

Rhod.create_profile(:retry_exponetially, retries: 10, backoffs: :^)

Rhod.with_retry_exponetially do
  open("http://google.com").read
end

Random Backoffs

Example, open a remote reasource, fail once it has failed 10 times, with a random wait between 1 and 5 seconds on each attempt

require 'open-uri'
require 'rhod'

Rhod.create_profile(:retry_randomly, retries: 10, backoffs: 'r1..5')

Rhod.with_retry_randomly do
  open("http://google.com").read
end