Module: Kernel

Defined in:
lib/rescue_me.rb

Instance Method Summary collapse

Instance Method Details

#rescue_and_retry(max_attempts = 7, *temporary_exceptions) ⇒ Object

Reattempts to run code passed in to this block if a temporary exception occurs (e.g. Net::SMTPServerBusy), using an exponential back-off algorithm (e.g. retry immediately, then after 1, 2, 4, 8, 16, 32… sec).

max_attempts - the maximum number of attempts to make trying to run the
    block successfully before giving up
temporary_exceptions - temporary exceptions that are to be caught in your
    code. If no exceptions are provided will capture all Exceptions. You are
    strongly encouraged to provide arguments that capture temporary
    exceptional conditions that are likely to work upon a retry.



13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
 
# File 'lib/rescue_me.rb', line 13

def rescue_and_retry(max_attempts=7, *temporary_exceptions)
  retry_interval = 2 # A good initial start value. Tweak as needed.
  temporary_exceptions << StandardError if temporary_exceptions.empty?
  begin
    yield
  rescue *temporary_exceptions => e
    attempt = (attempt || 0) + 1
    message = "rescue_and_retry(#{attempt}/#{max_attempts}) " +
        "\"#{e.class}: #{e.message}\" in #{caller[1].sub(/.*\/(.*):in.*/,'\1')}"
    (defined? logger) ? logger.warn(message) : STDERR.puts(message)
    raise(e) if attempt >= max_attempts
    # Retry immediately before exponential waits (1, 2, 4, 16, ... sec)
    sleep retry_interval**(attempt - 2) if attempt >= 2
    retry
  end
end