diff --git a/app/assets/javascripts/discourse/templates/full-page-search.hbs b/app/assets/javascripts/discourse/templates/full-page-search.hbs
index 627be519f6d..3a72a706e78 100644
--- a/app/assets/javascripts/discourse/templates/full-page-search.hbs
+++ b/app/assets/javascripts/discourse/templates/full-page-search.hbs
@@ -125,6 +125,12 @@
               {{#if searchActive}}
                 <h3>{{i18n "search.no_results"}}</h3>
 
+                {{#if model.grouped_search_result.error}}
+                  <div class="warning">
+                    {{model.grouped_search_result.error}}
+                  </div>
+                {{/if}}
+
                 {{#if showSuggestion}}
                   <div class="no-results-suggestion">
                     {{i18n "search.cant_find"}}
diff --git a/app/assets/javascripts/discourse/widgets/search-menu.js.es6 b/app/assets/javascripts/discourse/widgets/search-menu.js.es6
index c963c187bf6..4792f02b6ff 100644
--- a/app/assets/javascripts/discourse/widgets/search-menu.js.es6
+++ b/app/assets/javascripts/discourse/widgets/search-menu.js.es6
@@ -1,3 +1,4 @@
+import { popupAjaxError } from "discourse/lib/ajax-error";
 import { searchForTerm, isValidSearchTerm } from "discourse/lib/search";
 import { createWidget } from "discourse/widgets/widget";
 import { h } from "virtual-dom";
@@ -78,6 +79,7 @@ const SearchHelper = {
             searchData.topicId = null;
           }
         })
+        .catch(popupAjaxError)
         .finally(() => {
           searchData.loading = false;
           widget.scheduleRerender();
diff --git a/app/assets/stylesheets/common/base/search.scss b/app/assets/stylesheets/common/base/search.scss
index 2d645b95952..9561a6b47d6 100644
--- a/app/assets/stylesheets/common/base/search.scss
+++ b/app/assets/stylesheets/common/base/search.scss
@@ -2,6 +2,12 @@
   display: flex;
   justify-content: space-between;
 
+  .warning {
+    background-color: $danger-medium;
+    padding: 5px 8px;
+    color: $secondary;
+  }
+
   .search-bar {
     display: flex;
     justify-content: space-between;
diff --git a/app/controllers/search_controller.rb b/app/controllers/search_controller.rb
index 6e12b367da8..82d8ac74bc0 100644
--- a/app/controllers/search_controller.rb
+++ b/app/controllers/search_controller.rb
@@ -6,6 +6,8 @@ class SearchController < ApplicationController
 
   skip_before_action :check_xhr, only: :show
 
+  before_action :cancel_overloaded_search, only: [:query]
+
   def self.valid_context_types
     %w{user topic category private_messages}
   end
@@ -44,10 +46,14 @@ class SearchController < ApplicationController
     search_args[:ip_address] = request.remote_ip
     search_args[:user_id] = current_user.id if current_user.present?
 
-    search = Search.new(@search_term, search_args)
-    result = search.execute
-
-    result.find_user_data(guardian) if result
+    if site_overloaded?
+      result = Search::GroupedSearchResults.new(search_args[:type_filter], @search_term, context, false, 0)
+      result.error = I18n.t("search.extreme_load_error")
+    else
+      search = Search.new(@search_term, search_args)
+      result = search.execute
+      result.find_user_data(guardian) if result
+    end
 
     serializer = serialize_data(result, GroupedSearchResultSerializer, result: result)
 
@@ -82,8 +88,12 @@ class SearchController < ApplicationController
     search_args[:user_id] = current_user.id if current_user.present?
     search_args[:restrict_to_archetype] = params[:restrict_to_archetype] if params[:restrict_to_archetype].present?
 
-    search = Search.new(params[:term], search_args)
-    result = search.execute
+    if site_overloaded?
+      result = GroupedSearchResults.new(search_args["type_filter"], params[:term], context, false, 0)
+    else
+      search = Search.new(params[:term], search_args)
+      result = search.execute
+    end
     render_serialized(result, GroupedSearchResultSerializer, result: result)
   end
 
@@ -118,6 +128,18 @@ class SearchController < ApplicationController
 
   protected
 
+  def site_overloaded?
+    (queue_time = request.env['REQUEST_QUEUE_SECONDS']) &&
+      (GlobalSetting.disable_search_queue_threshold > 0) &&
+      (queue_time > GlobalSetting.disable_search_queue_threshold)
+  end
+
+  def cancel_overloaded_search
+    if site_overloaded?
+      render_json_error I18n.t("search.extreme_load_error"), status: 409
+    end
+  end
+
   def lookup_search_context
 
     return if params[:skip_context] == "true"
diff --git a/app/serializers/grouped_search_result_serializer.rb b/app/serializers/grouped_search_result_serializer.rb
index 15d2436cc7d..653ac70ac84 100644
--- a/app/serializers/grouped_search_result_serializer.rb
+++ b/app/serializers/grouped_search_result_serializer.rb
@@ -6,7 +6,7 @@ class GroupedSearchResultSerializer < ApplicationSerializer
   has_many :categories, serializer: BasicCategorySerializer
   has_many :tags, serializer: TagSerializer
   has_many :groups, serializer: BasicGroupSerializer
-  attributes :more_posts, :more_users, :more_categories, :term, :search_log_id, :more_full_page_results, :can_create_topic
+  attributes :more_posts, :more_users, :more_categories, :term, :search_log_id, :more_full_page_results, :can_create_topic, :error
 
   def search_log_id
     object.search_log_id
diff --git a/config/discourse_defaults.conf b/config/discourse_defaults.conf
index e66ed464b20..4f409f574e8 100644
--- a/config/discourse_defaults.conf
+++ b/config/discourse_defaults.conf
@@ -224,6 +224,9 @@ force_anonymous_min_queue_seconds = 1
 # only trigger anon if we see more than N requests for this path in last 10 seconds
 force_anonymous_min_per_10_seconds = 3
 
+# disable search if app server is queueing for longer than this (in seconds)
+disable_search_queue_threshold = 1
+
 # maximum number of posts rebaked across the cluster in the periodical job
 # rebake process is very expensive, on multisite we have to make sure we never
 # flood the queue
diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index 9c231b987b5..c3ba80e7d78 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -2096,6 +2096,7 @@ en:
         value: "SSO secret"
 
   search:
+    extreme_load_error: "Site is under extreme load, search is disabled, try again later"
     within_post: "#%{post_number} by %{username}"
     types:
       category: "Categories"
diff --git a/lib/search/grouped_search_results.rb b/lib/search/grouped_search_results.rb
index 1cd6dae587e..23a605f2cfe 100644
--- a/lib/search/grouped_search_results.rb
+++ b/lib/search/grouped_search_results.rb
@@ -24,7 +24,8 @@ class Search
       :term,
       :search_context,
       :include_blurbs,
-      :more_full_page_results
+      :more_full_page_results,
+      :error
     )
 
     attr_accessor :search_log_id
@@ -40,6 +41,11 @@ class Search
       @users = []
       @tags = []
       @groups = []
+      @error = nil
+    end
+
+    def error=(error)
+      @error = error
     end
 
     def find_user_data(guardian)
diff --git a/spec/requests/search_controller_spec.rb b/spec/requests/search_controller_spec.rb
index 0b69e391914..f583be479f7 100644
--- a/spec/requests/search_controller_spec.rb
+++ b/spec/requests/search_controller_spec.rb
@@ -3,6 +3,21 @@
 require 'rails_helper'
 
 describe SearchController do
+
+  fab!(:awesome_post) do
+    SearchIndexer.enable
+    Fabricate(:post, raw: 'this is my really awesome post')
+  end
+
+  fab!(:user) do
+    Fabricate(:user)
+  end
+
+  fab!(:user_post) do
+    SearchIndexer.enable
+    Fabricate(:post, raw: "#{user.username} is a cool person")
+  end
+
   context "integration" do
     before do
       SearchIndexer.enable
@@ -18,6 +33,49 @@ describe SearchController do
       $redis.flushall
     end
 
+    context "when overloaded" do
+
+      before do
+        global_setting :disable_search_queue_threshold, 0.2
+      end
+
+      let! :start_time do
+        freeze_time
+        Time.now
+      end
+
+      let! :current_time do
+        freeze_time 0.3.seconds.from_now
+      end
+
+      it "errors on #query" do
+
+        get "/search/query.json", headers: {
+          "HTTP_X_REQUEST_START" => "t=#{start_time.to_f}"
+        }, params: {
+          term: "hi there", include_blurb: true
+        }
+
+        expect(response.status).to eq(409)
+      end
+
+      it "no results and error on #index" do
+        get "/search.json", headers: {
+          "HTTP_X_REQUEST_START" => "t=#{start_time.to_f}"
+        }, params: {
+          q: "awesome"
+        }
+
+        expect(response.status).to eq(200)
+
+        data = JSON.parse(response.body)
+
+        expect(data["posts"]).to be_empty
+        expect(data["grouped_search_result"]["error"]).not_to be_empty
+      end
+
+    end
+
     it "returns a 400 error if you search for null bytes" do
       term = "hello\0hello"
 
@@ -29,22 +87,21 @@ describe SearchController do
     end
 
     it "can search correctly" do
-      my_post = Fabricate(:post, raw: 'this is my really awesome post')
-
       get "/search/query.json", params: {
         term: 'awesome', include_blurb: true
       }
 
       expect(response.status).to eq(200)
+
       data = JSON.parse(response.body)
-      expect(data['posts'][0]['id']).to eq(my_post.id)
-      expect(data['posts'][0]['blurb']).to eq('this is my really awesome post')
-      expect(data['topics'][0]['id']).to eq(my_post.topic_id)
+
+      expect(data['posts'].length).to eq(1)
+      expect(data['posts'][0]['id']).to eq(awesome_post.id)
+      expect(data['posts'][0]['blurb']).to eq(awesome_post.raw)
+      expect(data['topics'][0]['id']).to eq(awesome_post.topic_id)
     end
 
     it 'performs the query with a type filter' do
-      user = Fabricate(:user)
-      my_post = Fabricate(:post, raw: "#{user.username} is a cool person")
 
       get "/search/query.json", params: {
         term: user.username, type_filter: 'topic'
@@ -53,7 +110,7 @@ describe SearchController do
       expect(response.status).to eq(200)
       data = JSON.parse(response.body)
 
-      expect(data['posts'][0]['id']).to eq(my_post.id)
+      expect(data['posts'][0]['id']).to eq(user_post.id)
       expect(data['users']).to be_blank
 
       get "/search/query.json", params: {
@@ -71,10 +128,8 @@ describe SearchController do
       it 'should not be restricted by minimum search term length' do
         SiteSetting.min_search_term_length = 20000
 
-        post = Fabricate(:post)
-
         get "/search/query.json", params: {
-          term: post.topic_id,
+          term: awesome_post.topic_id,
           type_filter: 'topic',
           search_for_id: true
         }
@@ -82,15 +137,13 @@ describe SearchController do
         expect(response.status).to eq(200)
         data = JSON.parse(response.body)
 
-        expect(data['topics'][0]['id']).to eq(post.topic_id)
+        expect(data['topics'][0]['id']).to eq(awesome_post.topic_id)
       end
 
       it "should return the right result" do
-        user = Fabricate(:user)
-        my_post = Fabricate(:post, raw: "#{user.username} is a cool person")
 
         get "/search/query.json", params: {
-          term: my_post.topic_id,
+          term: user_post.topic_id,
           type_filter: 'topic',
           search_for_id: true
         }
@@ -98,7 +151,7 @@ describe SearchController do
         expect(response.status).to eq(200)
         data = JSON.parse(response.body)
 
-        expect(data['topics'][0]['id']).to eq(my_post.topic_id)
+        expect(data['topics'][0]['id']).to eq(user_post.topic_id)
       end
     end
   end
@@ -174,7 +227,6 @@ describe SearchController do
     end
 
     context "with a user" do
-      fab!(:user) { Fabricate(:user) }
 
       it "raises an error if the user can't see the context" do
         get "/search/query.json", params: {
@@ -205,7 +257,7 @@ describe SearchController do
     end
 
     it "doesn't record the click for a different user" do
-      sign_in(Fabricate(:user))
+      sign_in(user)
 
       _, search_log_id = SearchLog.log(
         term: SecureRandom.hex,
@@ -225,7 +277,7 @@ describe SearchController do
     end
 
     it "records the click for a logged in user" do
-      user = sign_in(Fabricate(:user))
+      sign_in(user)
 
       _, search_log_id = SearchLog.log(
         term: SecureRandom.hex,