Class: Webhookdb::LoggedWebhook::Resilient

Inherits:
Object
  • Object
show all
Defined in:
lib/webhookdb/logged_webhook/resilient.rb

Instance Method Summary collapse

Instance Method Details

#_dburl_log_kwargs(dburl) ⇒ Object 



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# File 'lib/webhookdb/logged_webhook/resilient.rb', line 44

def _dburl_log_kwargs(dburl)
  u = URI(dburl)
  return {fallback_database_host: u.host, fallback_database_name: u.path}
end

#database_urls ⇒ Object 



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# File 'lib/webhookdb/logged_webhook/resilient.rb', line 6

def database_urls = Webhookdb::LoggedWebhook.available_resilient_database_urls

#insert(kwargs) ⇒ Object 



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# File 'lib/webhookdb/logged_webhook/resilient.rb', line 8

def insert(kwargs)
  return Webhookdb::LoggedWebhook.dataset.insert(kwargs)
rescue Sequel::DatabaseError => e
  service_integration_opaque_id = kwargs.fetch(:service_integration_opaque_id)
  str_payload = JSON.dump(kwargs)
  self.database_urls.each do |url|
    next unless self.write_to(url, service_integration_opaque_id, str_payload)
    self.logger.warn "resilient_insert_handled", error: e, **self._dburl_log_kwargs(url)
    return true
  end
  self.logger.error "resilient_insert_unhandled", error: e, logged_webhook_kwargs: kwargs
  raise
end

#logger ⇒ Object 



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# File 'lib/webhookdb/logged_webhook/resilient.rb', line 4

def logger = Webhookdb::LoggedWebhook.logger

#replay ⇒ Object

  • For each (reachable) database:

  • Select 1 row, with a lock

  • Replay the webhook

  • On success, delete the row

  • On failure, process the next row



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# File 'lib/webhookdb/logged_webhook/resilient.rb', line 54

def replay
  tblname = Webhookdb::LoggedWebhook.resilient_table_name
  begin
    Webhookdb::LoggedWebhook.db.execute("SELECT 1=1")
  rescue Sequel::DatabaseError
    self.logger.debug("resilient_replay_primary_db_not_ready")
    return nil
  end
  replayed = 0
  self.database_urls.each do |url|
    Sequel.connect(url) do |rdb|
      has_more = true
      # Keep track of the last pk we've replayed, so we can grab the next available one.
      # Otherwise we can end up spinning on the same one, especially with other threads.
      seen_pk = 0
      while has_more
        # Each row must be processed in a transaction
        rdb.transaction do
          row = rdb.from(tblname).where { pk > seen_pk }.for_update.skip_locked.order(:pk).limit(1).first
          if row.nil?
            has_more = false
            break # The break only works for the transaction
          end
          pk = row.fetch(:pk)
          seen_pk = pk
          payload = JSON.parse(row.fetch(:json_payload))
          # We replay the webhook from a separate job
          # so it can be done idempotently/exclusively.
          lwh = Webhookdb::LoggedWebhook.create(payload)
          lwh.replay_async
          replayed += 1
          rdb.from(tblname).where(pk:).delete
        end
      end
    end
    return replayed
  rescue Sequel::DatabaseError
    self.logger.debug("resilient_replay_fallback_unavailable", **self._dburl_log_kwargs(url))
    return nil
  end
end

#write_to(dburl, service_integration_opaque_id, str_payload) ⇒ Object 



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# File 'lib/webhookdb/logged_webhook/resilient.rb', line 22

def write_to(dburl, service_integration_opaque_id, str_payload)
  tblname = Webhookdb::LoggedWebhook.resilient_table_name
  Sequel.connect(dburl, single_threaded: true) do |db|
    begin
      db.create_table?(tblname.to_sym) do
        primary_key :pk
        text :service_integration_opaque_id
        text :json_payload
      end
    rescue Sequel::UniqueConstraintViolation
      # We cannot avoid this race condition. If needed, we can optimize this, but it's a pain
      # so don't worry about it for now.
      nil
    end
    db.from(tblname).insert(service_integration_opaque_id:, json_payload: str_payload)
  end
  return true
rescue StandardError => e
  self.logger.debug "resilient_insert_failure", error: e, **self._dburl_log_kwargs(dburl)
  return false
end