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Diffstat (limited to 'activejob/lib/active_job/exceptions.rb')
| -rw-r--r-- | activejob/lib/active_job/exceptions.rb | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/activejob/lib/active_job/exceptions.rb b/activejob/lib/active_job/exceptions.rb new file mode 100644 index 0000000000..acbe0c4057 --- /dev/null +++ b/activejob/lib/active_job/exceptions.rb @@ -0,0 +1,122 @@ +require 'active_support/core_ext/numeric/time' + +module ActiveJob + # Provides behavior for retrying and discarding jobs on exceptions. + module Exceptions + extend ActiveSupport::Concern + + module ClassMethods + # Catch the exception and reschedule job for re-execution after so many seconds, for a specific number of attempts. + # If the exception keeps getting raised beyond the specified number of attempts, the exception is allowed to + # bubble up to the underlying queuing system, which may have its own retry mechanism or place it in a + # holding queue for inspection. + # + # You can also pass a block that'll be invoked if the retry attempts fail for custom logic rather than letting + # the exception bubble up. + # + # ==== Options + # * <tt>:wait</tt> - Re-enqueues the job with a delay specified either in seconds (default: 3 seconds), + # as a computing proc that the number of executions so far as an argument, or as a symbol reference of + # <tt>:exponentially_longer<>, which applies the wait algorithm of <tt>(executions ** 4) + 2</tt> + # (first wait 3s, then 18s, then 83s, etc) + # * <tt>:attempts</tt> - Re-enqueues the job the specified number of times (default: 5 attempts) + # * <tt>:queue</tt> - Re-enqueues the job on a different queue + # * <tt>:priority</tt> - Re-enqueues the job with a different priority + # + # ==== Examples + # + # class RemoteServiceJob < ActiveJob::Base + # retry_on CustomAppException # defaults to 3s wait, 5 attempts + # retry_on AnotherCustomAppException, wait: ->(executions) { executions * 2 } + # retry_on(YetAnotherCustomAppException) do |exception| + # ExceptionNotifier.caught(exception) + # end + # retry_on ActiveRecord::StatementInvalid, wait: 5.seconds, attempts: 3 + # retry_on Net::OpenTimeout, wait: :exponentially_longer, attempts: 10 + # + # def perform(*args) + # # Might raise CustomAppException, AnotherCustomAppException, or YetAnotherCustomAppException for something domain specific + # # Might raise ActiveRecord::StatementInvalid when a local db deadlock is detected + # # Might raise Net::OpenTimeout when the remote service is down + # end + # end + def retry_on(exception, wait: 3.seconds, attempts: 5, queue: nil, priority: nil) + rescue_from exception do |error| + if executions < attempts + logger.error "Retrying #{self.class} in #{wait} seconds, due to a #{exception}. The original exception was #{error.cause.inspect}." + retry_job wait: determine_delay(wait), queue: queue, priority: priority + else + if block_given? + yield exception + else + logger.error "Stopped retrying #{self.class} due to a #{exception}, which reoccurred on #{executions} attempts. The original exception was #{error.cause.inspect}." + raise error + end + end + end + end + + # Discard the job with no attempts to retry, if the exception is raised. This is useful when the subject of the job, + # like an Active Record, is no longer available, and the job is thus no longer relevant. + # + # ==== Example + # + # class SearchIndexingJob < ActiveJob::Base + # discard_on ActiveJob::DeserializationError + # + # def perform(record) + # # Will raise ActiveJob::DeserializationError if the record can't be deserialized + # end + # end + def discard_on(exception) + rescue_from exception do |error| + logger.error "Discarded #{self.class} due to a #{exception}. The original exception was #{error.cause.inspect}." + end + end + end + + # Reschedules the job to be re-executed. This is useful in combination + # with the +rescue_from+ option. When you rescue an exception from your job + # you can ask Active Job to retry performing your job. + # + # ==== Options + # * <tt>:wait</tt> - Enqueues the job with the specified delay in seconds + # * <tt>:wait_until</tt> - Enqueues the job at the time specified + # * <tt>:queue</tt> - Enqueues the job on the specified queue + # * <tt>:priority</tt> - Enqueues the job with the specified priority + # + # ==== Examples + # + # class SiteScraperJob < ActiveJob::Base + # rescue_from(ErrorLoadingSite) do + # retry_job queue: :low_priority + # end + # + # def perform(*args) + # # raise ErrorLoadingSite if cannot scrape + # end + # end + def retry_job(options = {}) + enqueue options + end + + private + def determine_delay(seconds_or_duration_or_algorithm) + case seconds_or_duration_or_algorithm + when :exponentially_longer + (executions ** 4) + 2 + when ActiveSupport::Duration + duration = seconds_or_duration_or_algorithm + duration.to_i + when Integer + seconds = seconds_or_duration_or_algorithm + seconds + when Proc + algorithm = seconds_or_duration_or_algorithm + algorithm.call(executions) + else + raise "Couldn't determine a delay based on #{seconds_or_duration_or_algorithm.inspect}" + end + end + end +end |