bump inst-jobs to 0.15.18

includes the following two commits:
- a9b242c2c5
- 4a078d0ea0

closes CNVS-48730
closes USERS-479
flag=none

test plan: jobs still query and pop work correctly

Change-Id: I7ec8d4228232578852507694f7b4334b1536623f
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/232729
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>

Gemfile.d/app.rb

@@ -74,7 +74,7 @@ gem 'inst_statsd', '2.1.6'
   gem 'statsd-ruby', '1.4.0', require: false
   gem 'aroi', '0.0.7', require: false
   gem 'dogstatsd-ruby', '4.7.0'
-gem 'inst-jobs', '0.15.16'
+gem 'inst-jobs', '0.15.18'
   gem 'fugit', '1.3.3', require: false
     gem 'et-orbi', '1.2.2', require: false
 gem 'inst-jobs-autoscaling', '1.0.5'

db/migrate/20200330230722_add_id_to_get_delayed_jobs_index.rb

@@ -0,0 +1,43 @@
+#
+# Copyright (C) 2020 - present Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+
+class AddIdToGetDelayedJobsIndex < ActiveRecord::Migration[4.2]
+  tag :postdeploy
+  disable_ddl_transaction!
+
+  def connection
+    Delayed::Job.connection
+  end
+
+  def up
+    rename_index :delayed_jobs, "get_delayed_jobs_index", "get_delayed_jobs_index_old"
+    add_index :delayed_jobs, [:priority, :run_at, :id],
+      algorithm: :concurrently,
+      where: "queue = 'canvas_queue' AND locked_at IS NULL AND next_in_strand",
+      name: "get_delayed_jobs_index"
+    remove_index :delayed_jobs, name: "get_delayed_jobs_index_old"
+  end
+
+  def down
+    rename_index :delayed_jobs, "get_delayed_jobs_index", "get_delayed_jobs_index_old"
+    add_index :delayed_jobs, [:priority, :run_at],
+      algorithm: :concurrently,
+      where: "queue = 'canvas_queue' AND locked_at IS NULL AND next_in_strand",
+      name: "get_delayed_jobs_index"
+    remove_index :delayed_jobs, name: "get_delayed_jobs_index_old"
+  end
+end