Creates first version of UI consisting of queue details and sidekiq s…

…tats:

- Adds route for UI to config
- Controller fetches metrics from service class
- Service class renamed and fetches data and manipulates it as needed
- View created using haml template to display information
- Adds descriptions of queues / metrics in locales en.yml

app/controllers/system_status_controller.rb

@@ -1,5 +1,10 @@
 # frozen_string_literal: true
 
 class SystemStatusController < ApplicationController
-  # service = SystemMetricsService.new
+  def index
+    system_metrics = GetSystemMetrics.new
+
+    @sidekiq_stats = system_metrics.fetch_sidekiq_stats
+    @queue_metrics = system_metrics.fetch_queue_management_metrics
+  end
 end

app/services/get_system_metrics.rb

@@ -2,51 +2,73 @@
 
 require 'sidekiq/api'
 
-class SystemMetricsService
+class GetSystemMetrics
   def initialize
     @queues = YAML.load_file('config/sidekiq.yml')[:queues]
+                  .reject { |queue_name| queue_name == 'very_long_update' }
     fetch_sidekiq_stats
   end
 
   def fetch_sidekiq_stats
     stats = Sidekiq::Stats.new
-
-    @processed_jobs_stat = stats.processed
-    @failed_jobs_stat = stats.failed # Failed Job Retention
-    @enqueued_jobs_stat = stats.enqueued
-    @scheduled_jobs_stat = stats.scheduled_size
-
-    # also allow stats from selected dates to be viewed
-    # using Stats::History
+    {
+      enqueued_jobs: stats.enqueued,
+      active_jobs: stats.processes_size
+    }
   end
 
-  # def fetch_system_health_metrics
-  # end
+  def fetch_queue_management_metrics
+    queues = []
+    paused_queues = []
+    all_operational = true
 
-  # def fetch_reliability_metrics
-  # end
+    @queues.each do |queue_name|
+      queue = Sidekiq::Queue.new(queue_name)
+      queues << get_queue_data(queue)
 
-  # def fetch_availability_metrics
-  # end
+      if queue.paused?
+        all_operational = false
+        paused_queues << queue_name
+      end
+    end
 
-  # def fetch_processing_efficiency_metrics
-  # end
+    {
+      queues:,
+      paused_queues:,
+      all_operational:
+    }
+  end
 
-  # def fetch_resource_utilization_metrics
-  # end
+  def get_queue_data(queue)
+    {
+      name: queue.name,
+      size: queue.size,
+      status: queue.size.zero? ? 'No pending jobs' : 'Pending jobs',
+      latency: convert_latency(queue.latency)
+    }
+  end
 
-  def fetch_queue_management_metrics
-    # Queue latency; how long jobs wait in the queue before processing
-    @queues.map do |queue_name|
-      queue = Sidekiq::Queue.new(queue_name)
-      {
-        name: queue.name,
-        size: queue.size,
-        latency: queue.latency
-      }
+  def convert_latency(seconds)
+    case seconds
+    when 0...60
+      "#{seconds.to_i} second#{'s' unless seconds == 1}"
+    when 60...3600
+      format_time(seconds, 60, 'minute', 'second')
+    when 3600...86400
+      format_time(seconds, 3600, 'hour', 'minute')
+    else
+      format_time(seconds, 86400, 'day', 'hour')
     end
   end
 
-  # def fetch_data_freshness_metrics
-  # end
+  def format_time(seconds, unit, main_unit_name, sub_unit_name)
+    main_unit = (seconds / unit).to_i
+    remaining_seconds = (seconds % unit).to_i
+    result = "#{main_unit} #{main_unit_name}#{'s' unless main_unit == 1}"
+    if remaining_seconds.positive?
+      sub_unit_value = (remaining_seconds / (unit / 60)).to_i
+      result += " #{sub_unit_value} #{sub_unit_name}#{'s' unless sub_unit_value == 1}"
+    end
+    result
+  end
 end

app/views/system_status/index.html.haml

@@ -0,0 +1,66 @@
+.container.queues
+  .module
+    .section-header
+      %h3 Queues Overview
+    .notification
+      .container
+        - if @queue_metrics[:all_operational]
+          %p All Queues Operational
+        - else
+          %p All Queues Operational except:
+          .notifications
+            .notice
+              .container
+                - @queue_metrics[:paused_queues].each do |queue_name|
+                  %p= queue_name.humanize
+    %br/
+
+    %table.table.table--hoverable
+      %thead
+        %tr
+          %th Queue
+          %th Purpose
+          %th Status
+          %th 
+            .tooltip-trigger
+              = t("status.size")
+              %span.tooltip-indicator
+              .tooltip.dark
+                %p= t("status.size_doc")
+          %th 
+            .tooltip-trigger
+              = t("status.latency")
+              %span.tooltip-indicator
+              .tooltip.dark
+                %p= t("status.latency_doc")
+      %tbody
+        - @queue_metrics[:queues].each do |queue|
+          %tr{ class: queue[:size].zero? ? "table-row--success" : "table-row--warning" }
+            %td
+              .tooltip-trigger
+                = t("status.#{queue[:name]}")
+                %span.tooltip-indicator
+                .tooltip.dark
+                  %p= t("status.#{queue[:name]}_description")
+            %td= t("status.#{queue[:name]}_doc")
+            %td= queue[:status]
+            %td= queue[:size]
+            %td= queue[:latency]
+
+.container.sidekiq_stats
+  %br/
+  %h3 Sidekiq Stats
+  .stat-display
+    - @sidekiq_stats.each do |key, value|
+      .stat-display__stat.tooltip-trigger
+        .stat-display__value= value
+        %small= key.to_s.humanize
+
+        .tooltip.dark
+          - case key
+          - when :enqueued_jobs
+            %p= t("status.enqueued_jobs_doc")
+          - when :active_jobs
+            %p= t("status.active_jobs_doc")
+          - else
+            %p No additional info available

config/locales/en.yml

@@ -1294,6 +1294,34 @@ en:
         already_is_not: "%{username} is not a Special User!"
         demote_success: "%{username} is now just a user."
 
+  status:
+    active_jobs: Active jobs
+    active_jobs_doc: The number of currently processing jobs.
+    constant_update: Constant update
+    constant_update_description: Constant updates are independent of the main course stats, pulling in revision metadata, generating alerts, and doing other data and network-intensive tasks, for all current courses.
+    constant_update_doc: Handles transactional jobs like wiki edits and sending email. 
+    daily_update: Daily update
+    daily_update_description: This pulls in additional data and performs other tasks that do not need to be done many times per day.
+    daily_update_doc: Handles once-daily long-running data update tasks.
+    default: Default
+    default_description: Schedule course updates by sorting courses into queues depending on how long they run.
+    default_doc: Handles frequently-run tasks like adding courses to the update queues.
+    enqueued_jobs: Enqueued jobs
+    enqueued_jobs_doc: The number of currently enqueued jobs in all queues.
+    latency: Latency
+    latency_doc: The waiting time for jobs to start processing in the queue. High latency may indicate a busy system or processing delays.
+    long_update: Long update
+    long_update_description: Long updates process courses with more than 10,000 revisions.
+    long_update_doc: Handles updates for large courses.
+    medium_update: Medium update
+    medium_update_description: Medium updates process courses with fewer than 10,000 revisions.
+    medium_update_doc: Handles updates for typical-sized courses.
+    short_update: Short update
+    short_update_description: Short updates process courses with fewer than 1,000 revisions.
+    short_update_doc: Handles updates for small courses.
+    size: Size
+    size_doc: The number of jobs within a queue.
+
   # Suggestions source: https://en.wikipedia.org/wiki/Template:Grading_scheme
   suggestions:
     editing: Editing Suggestions

config/routes.rb

@@ -474,6 +474,8 @@
   get '/private_information' => 'about_this_site#private_information'
   get '/styleguide' => 'styleguide#index'
 
+  get '/status' => 'system_status#index'
+
   # Errors
   match '/404', to: 'errors#file_not_found', via: :all
   match '/422', to: 'errors#unprocessable', via: :all