Add PGHero for more insights into the DB (#15073)

* Add PGHero for more insights into the DB

Andrew Kane's Ruby gems will continue being added until morale improves!

* Add linux x86_64 protobuf

* Fix discrepancy between Gemfile and Gemfile.lock

No idea how this happened, but it happened when merging `main` back into
this branch.

Co-authored-by: Dan Uber <dan@forem.com>

Gemfile

@@ -69,7 +69,9 @@ gem "omniauth-twitter", "~> 1.4" # OmniAuth strategy for Twitter
 gem "parallel", "~> 1.21" # Run any kind of code in parallel processes
 gem "patron", "~> 0.13.3" # HTTP client library based on libcurl, used with GitHub OAuth client
 gem "pg", "~> 1.2" # Pg is the Ruby interface to the PostgreSQL RDBMS
+gem "pg_query", ">= 0.9.0" # Allows PGHero to analyze queries
 gem "pg_search", "~> 2.3.5" # PgSearch builds Active Record named scopes that take advantage of PostgreSQL's full text search
+gem "pghero", "~> 2.8" # Dashboard for Postgres
 gem "puma", "~> 5.5.2" # Puma is a simple, fast, threaded, and highly concurrent HTTP 1.1 server
 gem "pundit", "~> 2.1" # Object oriented authorization for Rails applications
 gem "pusher", "~> 2.0" # Ruby library for Pusher Channels HTTP API

Gemfile.lock

@@ -334,6 +334,9 @@ GEM
       multi_json (>= 1.11.0)
     globalid (0.5.2)
       activesupport (>= 5.0)
+    google-protobuf (3.18.1)
+    google-protobuf (3.18.1-universal-darwin)
+    google-protobuf (3.18.1-x86_64-linux)
     guard (2.18.0)
       formatador (>= 0.2.4)
       listen (>= 2.7, < 4.0)
@@ -539,9 +542,13 @@ GEM
       ast (~> 2.4.1)
     patron (0.13.3)
     pg (1.2.3)
+    pg_query (2.1.1)
+      google-protobuf (>= 3.17.1)
     pg_search (2.3.5)
       activerecord (>= 5.2)
       activesupport (>= 5.2)
+    pghero (2.8.1)
+      activerecord (>= 5)
     pry (0.14.1)
       coderay (~> 1.1)
       method_source (~> 1.0)
@@ -967,7 +974,9 @@ DEPENDENCIES
   parallel (~> 1.21)
   patron (~> 0.13.3)
   pg (~> 1.2)
+  pg_query (>= 0.9.0)
   pg_search (~> 2.3.5)
+  pghero (~> 2.8)
   pry (~> 0.14)
   pry-rails (~> 0.3)
   puma (~> 5.5.2)

app/workers/capture_query_stats_worker.rb

@@ -0,0 +1,9 @@
+class CaptureQueryStatsWorker
+  include Sidekiq::Worker
+
+  def perform
+    return unless ENV["PG_HERO_CAPTURE_QUERY_STATS"] == "true"
+
+    PgHero.capture_query_stats
+  end
+end

config/routes/admin.rb

@@ -9,6 +9,7 @@ namespace :admin do
                                  { rack_protection: { except: %i[authenticity_token form_token json_csrf
                                                                  remote_token http_origin session_hijacking] } })
     mount flipper_ui, at: "feature_flags"
+    mount PgHero::Engine, at: "pghero"
   end
   resources :invitations, only: %i[index new create destroy]
   resources :organization_memberships, only: %i[update destroy create]

config/schedule.yml

@@ -140,3 +140,7 @@ push_notifications_cleanup:
   description: "Cleans up Push Notifications from Redis (runs every 8 hours on the 20th minute after the hour)"
   cron: "20 */8 * * *"
   class: "PushNotifications::CleanupWorker"
+capture_query_stats:
+  description: "Collects Postgres query stats for PGHero (runs every 5 minutes)"
+  cron: "*/5 * * * *"
+  class: "CaptureQueryStatsWorker"

db/migrate/20211013153230_create_pghero_query_stats.rb

@@ -0,0 +1,15 @@
+class CreatePgheroQueryStats < ActiveRecord::Migration[6.1]
+  def change
+    create_table :pghero_query_stats do |t|
+      t.text :database
+      t.text :user
+      t.text :query
+      t.integer :query_hash, limit: 8
+      t.float :total_time
+      t.integer :calls, limit: 8
+      t.timestamp :captured_at
+    end
+
+    add_index :pghero_query_stats, [:database, :captured_at]
+  end
+end

db/schema.rb

@@ -839,6 +839,17 @@ ActiveRecord::Schema.define(version: 2021_10_19_151431) do
     t.index ["slug"], name: "index_pages_on_slug", unique: true
   end
 
+  create_table "pghero_query_stats", force: :cascade do |t|
+    t.bigint "calls"
+    t.datetime "captured_at"
+    t.text "database"
+    t.text "query"
+    t.bigint "query_hash"
+    t.float "total_time"
+    t.text "user"
+    t.index ["database", "captured_at"], name: "index_pghero_query_stats_on_database_and_captured_at"
+  end
+
   create_table "podcast_episode_appearances", force: :cascade do |t|
     t.boolean "approved", default: false, null: false
     t.datetime "created_at", precision: 6, null: false