Add the job size to start message logging

This would allow us to see how big jobs are in the log, perhaps
allowing us to set a sensible limit.

lib/gitlab/sidekiq_logging/structured_logger.rb

@@ -13,7 +13,7 @@ module Gitlab
         base_payload = parse_job(job)
         ActiveRecord::LogSubscriber.reset_runtime
 
-        Sidekiq.logger.info log_job_start(base_payload)
+        Sidekiq.logger.info log_job_start(job, base_payload)
 
         yield
 
@@ -40,13 +40,15 @@ module Gitlab
         output_payload.merge!(job.slice(*::Gitlab::Metrics::Subscribers::ActiveRecord::DB_COUNTERS))
       end
 
-      def log_job_start(payload)
+      def log_job_start(job, payload)
         payload['message'] = "#{base_message(payload)}: start"
         payload['job_status'] = 'start'
 
         scheduling_latency_s = ::Gitlab::InstrumentationHelper.queue_duration_for_job(payload)
         payload['scheduling_latency_s'] = scheduling_latency_s if scheduling_latency_s
 
+        payload['job_size_bytes'] = Sidekiq.dump_json(job).bytesize
+
         payload
       end
 

spec/lib/gitlab/sidekiq_logging/structured_logger_spec.rb

@@ -38,7 +38,8 @@ RSpec.describe Gitlab::SidekiqLogging::StructuredLogger do
         'pid' => Process.pid,
         'created_at' => created_at.to_f,
         'enqueued_at' => created_at.to_f,
-        'scheduling_latency_s' => scheduling_latency_s
+        'scheduling_latency_s' => scheduling_latency_s,
+        'job_size_bytes' => be > 0
       )
     end