Keep executions for each specific exception (#34352)

* Keep executions for each specific declaration

Fixes #34337

ActiveJob used the global executions counter to control the number of
times a job should be retried. The problem with this approach was that
in case a job raised different exceptions during its executions they
weren't retried the number of times defined by their `attemps` number.

**Example:**

Having the following job:
```ruby
class BuggyJob < ActiveJob::Base
  retry_on CustomException, attemps: 3
  retry_on OtherException, attempts: 3
end
```
If the job raised `CustomException` in the first two executions and then
it raised `OtherException`, the job wasn't retried anymore because the
global executions counter was already indicating 3 attempts.

With this patch each `retry_on` declaration has its specific counter so
that the first two executions that raise `CustomException` don't affect
the retries count that future exceptions may have.

* Revert "clarifies documentation around the attempts arugment to retry_on"

This reverts commit 86aa8f8c5631f77ed9a208e5107003c01512133e.

1 files changed, 9 insertions, 0 deletions

diff --git a/activejob/lib/active_job/core.rb b/activejob/lib/active_job/core.rb
index 698153636b..4ab62f89b0 100644
--- a/activejob/lib/active_job/core.rb
+++ b/activejob/lib/active_job/core.rb
@@ -28,6 +28,12 @@ module ActiveJob
     # Number of times this job has been executed (which increments on every retry, like after an exception).
     attr_accessor :executions
 
+    # Hash that contains the number of times this job handled errors for each specific retry_on declaration.
+    # Keys are the string representation of the exceptions listed in the retry_on declaration,
+    # while its associated value holds the number of executions where the corresponding retry_on
+    # declaration handled one of its listed exceptions.
+    attr_accessor :exception_executions
+
     # I18n.locale to be used during the job.
     attr_accessor :locale
 
@@ -75,6 +81,7 @@ module ActiveJob
       @queue_name = self.class.queue_name
       @priority   = self.class.priority
       @executions = 0
+      @exception_executions = Hash.new(0)
     end
 
     # Returns a hash with the job data that can safely be passed to the
@@ -88,6 +95,7 @@ module ActiveJob
         "priority"   => priority,
         "arguments"  => serialize_arguments_if_needed(arguments),
         "executions" => executions,
+        "exception_executions" => exception_executions,
         "locale"     => I18n.locale.to_s,
         "timezone"   => Time.zone.try(:name)
       }
@@ -126,6 +134,7 @@ module ActiveJob
       self.priority             = job_data["priority"]
       self.serialized_arguments = job_data["arguments"]
       self.executions           = job_data["executions"]
+      self.exception_executions = job_data["exception_executions"]
       self.locale               = job_data["locale"] || I18n.locale.to_s
       self.timezone             = job_data["timezone"] || Time.zone.try(:name)
     end