feat: queue depth trend sparkline on dashboard

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - Failure rate sparkline per queue — a mini 12-bar chart in the Queues table shows the percentage of jobs that failed (vs. completed) in each of the last 12 hours; bars are red, sized proportionally to the failure rate (0–100 %), and include a tooltip with the hour label and exact percentage; empty hours render as a faint border-colored bar; queues with no activity in the last 12 hours show "—"
+- Queue depth trend — a "Queue Depth — Last 12 Hours" card on the dashboard shows estimated queue depth at 12 hourly snapshots; depth at time T is the count of jobs created before T that had not yet finished by T; bars are purple (distinct from the blue throughput and red failure rate charts); the card header shows current depth; empty state shown when no active jobs exist in the window
 
 ## [0.8.0] - 2026-05-20
 

README.md

@@ -33,7 +33,7 @@ SolidQueueWeb surfaces all of this in a browser UI available at any route you ch
 
 ## Features
 
-- **Dashboard** — stat cards showing counts for ready, scheduled, running, blocked, and failed jobs, plus queues, recurring tasks, and processes; "Done (1h)" and "Done (24h)" throughput cards; a "Throughput — Last 12 Hours" bar chart showing completed-job counts per hour (pure CSS, no charting library); auto-refreshes every 5 seconds
+- **Dashboard** — stat cards showing counts for ready, scheduled, running, blocked, and failed jobs, plus queues, recurring tasks, and processes; "Done (1h)" and "Done (24h)" throughput cards; a "Throughput — Last 12 Hours" bar chart (blue) and a "Queue Depth — Last 12 Hours" bar chart (purple) showing hourly snapshots of active job count; pure CSS, no charting library; auto-refreshes every 5 seconds
 - **Queues** — all queues sorted by name with size; oldest ready job latency (color-coded, with UTC timestamp tooltip); Done (24h) and Failed (24h) throughput counts; a mini 12-bar failure rate sparkline per queue showing failure % per hour over the last 12 hours; pause/resume controls
 - **Jobs** — filterable by status (ready, scheduled, claimed, blocked, failed) and by queue; search by job class name with dynamic auto-submit; time-based period filter (1 h / 24 h / 7 d); discard individual or all jobs; Turbo Frame navigation so only the table updates on filter or search; auto-refreshes every 10 seconds
 - **Failed jobs** — list of failed executions with error details; search by class name; filter by queue; time-based period filter; retry or discard individually or in bulk
@@ -112,7 +112,6 @@ No authentication is enforced by default. When the `authenticate` block returns
 Planned features, roughly ordered by priority:  
 
 **Observability**
-- Queue depth trend — historical queue size over time, not just the current snapshot
 - Slow job detection — flag jobs exceeding a configurable duration threshold
 
 **Operations**
@@ -125,6 +124,9 @@ Planned features, roughly ordered by priority:
 - Multi-database support — when Solid Queue runs on a separate database from the host app
 - Read replica support — route dashboard queries to a replica to avoid impacting the primary
 
+**Code quality**
+- Rails controller conventions — complete the 7-action refactor: `QueuesController#pause` / `#resume` → `Queues::PausesController#create` / `#destroy`; `Queues::JobsController#discard_all` → map to `#destroy` matching the pattern already applied to `JobsController`
+
 Pull requests for any of these are welcome. See [Contributing](#contributing) below.
 
 ## Contributing

app/assets/stylesheets/solid_queue_web/_11_throughput.css

@@ -90,4 +90,8 @@
 .sqd-mini-sparkline__bar--empty {
   background: var(--border);
   opacity: 0.5;
+}
+
+.sqd-sparkline__bar--depth {
+  background: var(--purple);
 }

app/controllers/solid_queue_web/blocked_jobs_controller.rb

@@ -0,0 +1,11 @@
+module SolidQueueWeb
+  class BlockedJobsController < ApplicationController
+    def destroy
+      jobs = SolidQueue::BlockedExecution.includes(:job).map(&:job)
+      SolidQueue::BlockedExecution.discard_all_from_jobs(jobs)
+      redirect_to root_path, notice: "#{jobs.size} blocked #{"job".pluralize(jobs.size)} discarded."
+    rescue => e
+      redirect_to root_path, alert: "Could not discard blocked jobs: #{e.message}"
+    end
+  end
+end

app/controllers/solid_queue_web/dashboard_controller.rb

@@ -1,44 +1,7 @@
 module SolidQueueWeb
   class DashboardController < ApplicationController
     def index
-      @stats = {
-        ready:     SolidQueue::ReadyExecution.count,
-        scheduled: SolidQueue::ScheduledExecution.count,
-        claimed:   SolidQueue::ClaimedExecution.count,
-        failed:    SolidQueue::FailedExecution.count,
-        blocked:   SolidQueue::BlockedExecution.count,
-        queues:    SolidQueue::Job.select(:queue_name).distinct.count,
-        processes: SolidQueue::Process.count,
-        recurring: SolidQueue::RecurringTask.count
-      }
-
-      now = Time.current
-      finished_times = SolidQueue::Job.where(finished_at: 24.hours.ago..now).pluck(:finished_at)
-      @throughput = {
-        completed_1h:  finished_times.count { |t| t >= 1.hour.ago },
-        completed_24h: finished_times.size
-      }
-      @sparkline = 12.times.map do |i|
-        from = (12 - i).hours.ago
-        to   = i == 11 ? now : (11 - i).hours.ago
-        finished_times.count { |t| t >= from && t < to }
-      end
-    end
-
-    def retry_all_failed
-      jobs = SolidQueue::FailedExecution.includes(:job).map(&:job)
-      SolidQueue::FailedExecution.retry_all(jobs)
-      redirect_to root_path, notice: "#{jobs.size} failed #{"job".pluralize(jobs.size)} queued for retry."
-    rescue => e
-      redirect_to root_path, alert: "Could not retry failed jobs: #{e.message}"
-    end
-
-    def discard_all_blocked
-      jobs = SolidQueue::BlockedExecution.includes(:job).map(&:job)
-      SolidQueue::BlockedExecution.discard_all_from_jobs(jobs)
-      redirect_to root_path, notice: "#{jobs.size} blocked #{"job".pluralize(jobs.size)} discarded."
-    rescue => e
-      redirect_to root_path, alert: "Could not discard blocked jobs: #{e.message}"
+      @stats = DashboardStats.new
     end
   end
 end

app/services/solid_queue_web/dashboard_stats.rb

@@ -0,0 +1,44 @@
+module SolidQueueWeb
+  class DashboardStats
+    attr_reader :counts, :throughput, :sparkline, :depth_sparkline
+
+    def initialize
+      @now = Time.current
+      compute
+    end
+
+    private
+
+    def compute
+      @counts = {
+        ready:     SolidQueue::ReadyExecution.count,
+        scheduled: SolidQueue::ScheduledExecution.count,
+        claimed:   SolidQueue::ClaimedExecution.count,
+        failed:    SolidQueue::FailedExecution.count,
+        blocked:   SolidQueue::BlockedExecution.count,
+        queues:    SolidQueue::Job.select(:queue_name).distinct.count,
+        processes: SolidQueue::Process.count,
+        recurring: SolidQueue::RecurringTask.count
+      }
+
+      finished_times = SolidQueue::Job.where(finished_at: 24.hours.ago..@now).pluck(:finished_at)
+      @throughput = {
+        completed_1h:  finished_times.count { |t| t >= 1.hour.ago },
+        completed_24h: finished_times.size
+      }
+      @sparkline = 12.times.map do |i|
+        from = (12 - i).hours.ago
+        to   = i == 11 ? @now : (11 - i).hours.ago
+        finished_times.count { |t| t >= from && t < to }
+      end
+
+      job_timestamps = SolidQueue::Job
+        .where("created_at >= ? OR finished_at IS NULL", 72.hours.ago)
+        .pluck(:created_at, :finished_at)
+      @depth_sparkline = 12.times.map do |i|
+        t = i == 11 ? @now : (12 - i).hours.ago
+        job_timestamps.count { |created, finished| created <= t && (finished.nil? || finished > t) }
+      end
+    end
+  end
+end

app/views/solid_queue_web/dashboard/index.html.erb

@@ -3,61 +3,61 @@
 
 <div class="sqd-stats">
   <%= link_to jobs_path(status: "ready"), class: "sqd-stat sqd-stat--ready sqd-stat--link" do %>
-    <div class="sqd-stat__value"><%= @stats[:ready] %></div>
+    <div class="sqd-stat__value"><%= @stats.counts[:ready] %></div>
     <div class="sqd-stat__label">Ready</div>
   <% end %>
   <%= link_to jobs_path(status: "scheduled"), class: "sqd-stat sqd-stat--scheduled sqd-stat--link" do %>
-    <div class="sqd-stat__value"><%= @stats[:scheduled] %></div>
+    <div class="sqd-stat__value"><%= @stats.counts[:scheduled] %></div>
     <div class="sqd-stat__label">Scheduled</div>
   <% end %>
   <%= link_to jobs_path(status: "claimed"), class: "sqd-stat sqd-stat--claimed sqd-stat--link" do %>
-    <div class="sqd-stat__value"><%= @stats[:claimed] %></div>
+    <div class="sqd-stat__value"><%= @stats.counts[:claimed] %></div>
     <div class="sqd-stat__label">Running</div>
   <% end %>
   <%= link_to jobs_path(status: "blocked"), class: "sqd-stat sqd-stat--blocked sqd-stat--link" do %>
-    <div class="sqd-stat__value"><%= @stats[:blocked] %></div>
+    <div class="sqd-stat__value"><%= @stats.counts[:blocked] %></div>
     <div class="sqd-stat__label">Blocked</div>
   <% end %>
   <%= link_to failed_jobs_path, class: "sqd-stat sqd-stat--failed sqd-stat--link" do %>
-    <div class="sqd-stat__value"><%= @stats[:failed] %></div>
+    <div class="sqd-stat__value"><%= @stats.counts[:failed] %></div>
     <div class="sqd-stat__label">Failed</div>
   <% end %>
   <%= link_to queues_path, class: "sqd-stat sqd-stat--queues sqd-stat--link" do %>
-    <div class="sqd-stat__value"><%= @stats[:queues] %></div>
+    <div class="sqd-stat__value"><%= @stats.counts[:queues] %></div>
     <div class="sqd-stat__label">Queues</div>
   <% end %>
   <%= link_to recurring_tasks_path, class: "sqd-stat sqd-stat--recurring sqd-stat--link" do %>
-    <div class="sqd-stat__value"><%= @stats[:recurring] %></div>
+    <div class="sqd-stat__value"><%= @stats.counts[:recurring] %></div>
     <div class="sqd-stat__label">Recurring</div>
   <% end %>
   <%= link_to processes_path, class: "sqd-stat sqd-stat--processes sqd-stat--link" do %>
-    <div class="sqd-stat__value"><%= @stats[:processes] %></div>
+    <div class="sqd-stat__value"><%= @stats.counts[:processes] %></div>
     <div class="sqd-stat__label">Processes</div>
   <% end %>
   <%= link_to history_path(period: "1h"), class: "sqd-stat sqd-stat--done sqd-stat--link" do %>
-    <div class="sqd-stat__value"><%= @throughput[:completed_1h] %></div>
+    <div class="sqd-stat__value"><%= @stats.throughput[:completed_1h] %></div>
     <div class="sqd-stat__label">Done (1h)</div>
   <% end %>
   <%= link_to history_path(period: "24h"), class: "sqd-stat sqd-stat--done sqd-stat--link" do %>
-    <div class="sqd-stat__value"><%= @throughput[:completed_24h] %></div>
+    <div class="sqd-stat__value"><%= @stats.throughput[:completed_24h] %></div>
     <div class="sqd-stat__label">Done (24h)</div>
   <% end %>
 </div>
 
-<% max_val = [@sparkline.max, 1].max %>
+<% max_val = [@stats.sparkline.max, 1].max %>
 <div class="sqd-card" style="margin-bottom: 1rem;">
   <div class="sqd-card__header">
     <span class="sqd-card__title">Throughput &mdash; Last 12 Hours</span>
     <div class="sqd-throughput__summary">
-      <span>1h: <strong><%= @throughput[:completed_1h] %></strong></span>
-      <span>24h: <strong><%= @throughput[:completed_24h] %></strong></span>
+      <span>1h: <strong><%= @stats.throughput[:completed_1h] %></strong></span>
+      <span>24h: <strong><%= @stats.throughput[:completed_24h] %></strong></span>
     </div>
   </div>
-  <% if @throughput[:completed_24h] == 0 %>
+  <% if @stats.throughput[:completed_24h] == 0 %>
     <div class="sqd-sparkline__empty">No completed jobs in the last 24 hours</div>
   <% else %>
     <div class="sqd-sparkline" aria-label="Jobs completed per hour over the last 12 hours">
-      <% @sparkline.each_with_index do |count, i| %>
+      <% @stats.sparkline.each_with_index do |count, i| %>
         <% pct = (count.to_f / max_val * 100).round %>
         <% hour_start = (12 - i).hours.ago %>
         <% show_tick = [0, 3, 6, 9, 11].include?(i) %>
@@ -74,6 +74,36 @@
   <% end %>
 </div>
 
+<% current_depth = @stats.counts[:ready] + @stats.counts[:scheduled] + @stats.counts[:claimed] + @stats.counts[:blocked] + @stats.counts[:failed] %>
+<% max_depth = [@stats.depth_sparkline.max, 1].max %>
+<div class="sqd-card" style="margin-bottom: 1rem;">
+  <div class="sqd-card__header">
+    <span class="sqd-card__title">Queue Depth &mdash; Last 12 Hours</span>
+    <div class="sqd-throughput__summary">
+      <span>Now: <strong><%= current_depth %></strong></span>
+    </div>
+  </div>
+  <% if @stats.depth_sparkline.all?(&:zero?) %>
+    <div class="sqd-sparkline__empty">No active jobs in the last 12 hours</div>
+  <% else %>
+    <div class="sqd-sparkline" aria-label="Queue depth over the last 12 hours">
+      <% @stats.depth_sparkline.each_with_index do |depth, i| %>
+        <% pct = (depth.to_f / max_depth * 100).round %>
+        <% t = i == 11 ? Time.current : (12 - i).hours.ago %>
+        <% show_tick = [0, 3, 6, 9, 11].include?(i) %>
+        <div class="sqd-sparkline__col">
+          <div class="sqd-sparkline__bar-wrap">
+            <div class="sqd-sparkline__bar sqd-sparkline__bar--depth"
+                 style="height: <%= [pct, 3].max %>%"
+                 title="<%= i == 11 ? "now" : t.strftime("%-I%p").downcase %>: <%= depth %> <%= "job".pluralize(depth) %> in queue"></div>
+          </div>
+          <div class="sqd-sparkline__tick"><%= show_tick ? (i == 11 ? "now" : t.strftime("%-I%p").downcase) : "" %></div>
+        </div>
+      <% end %>
+    </div>
+  <% end %>
+</div>
+
 <div style="display:grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 1rem;">
   <div class="sqd-card">
     <div class="sqd-card__header">
@@ -88,37 +118,37 @@
     </div>
   </div>
 
-  <% if @stats[:failed] > 0 %>
+  <% if @stats.counts[:failed] > 0 %>
     <div class="sqd-card">
       <div class="sqd-card__header">
         <span class="sqd-card__title">Failed Jobs</span>
       </div>
       <div style="padding: 1rem; display: flex; flex-direction: column; gap: 0.5rem;">
         <p style="color: var(--danger); font-size: 13px;">
-          <%= pluralize(@stats[:failed], "failed job") %> need attention.
+          <%= pluralize(@stats.counts[:failed], "failed job") %> need attention.
         </p>
-        <%= button_to "Retry All Failed", retry_all_failed_path,
+        <%= button_to "Retry All Failed", retry_all_failed_jobs_path,
               method: :post,
               class: "sqd-btn sqd-btn--primary",
-              data: { confirm: "Retry all #{@stats[:failed]} failed #{"job".pluralize(@stats[:failed])}?" } %>
+              data: { confirm: "Retry all #{@stats.counts[:failed]} failed #{"job".pluralize(@stats.counts[:failed])}?" } %>
         <%= link_to "Review →", failed_jobs_path, class: "sqd-btn sqd-btn--muted" %>
       </div>
     </div>
   <% end %>
 
-  <% if @stats[:blocked] > 0 %>
+  <% if @stats.counts[:blocked] > 0 %>
     <div class="sqd-card">
       <div class="sqd-card__header">
         <span class="sqd-card__title">Blocked Jobs</span>
       </div>
       <div style="padding: 1rem; display: flex; flex-direction: column; gap: 0.5rem;">
         <p style="color: var(--warning); font-size: 13px;">
-          <%= pluralize(@stats[:blocked], "blocked job") %>.
+          <%= pluralize(@stats.counts[:blocked], "blocked job") %>.
         </p>
-        <%= button_to "Discard All Blocked", discard_all_blocked_path,
-              method: :post,
+        <%= button_to "Discard All Blocked", blocked_jobs_path,
+              method: :delete,
               class: "sqd-btn sqd-btn--danger",
-              data: { confirm: "Discard all #{@stats[:blocked]} blocked #{"job".pluralize(@stats[:blocked])}? This cannot be undone." } %>
+              data: { confirm: "Discard all #{@stats.counts[:blocked]} blocked #{"job".pluralize(@stats.counts[:blocked])}? This cannot be undone." } %>
         <%= link_to "Review →", jobs_path(status: "blocked"), class: "sqd-btn sqd-btn--muted" %>
       </div>
     </div>

config/routes.rb

@@ -1,7 +1,6 @@
 SolidQueueWeb::Engine.routes.draw do
   root to: "dashboard#index"
-  post "retry_all_failed",    to: "dashboard#retry_all_failed",    as: :retry_all_failed
-  post "discard_all_blocked", to: "dashboard#discard_all_blocked", as: :discard_all_blocked
+  resource :blocked_jobs, only: [:destroy]
 
   get "search", to: "search#index", as: :search
   get "history", to: "history#index", as: :history

spec/requests/solid_queue_web/blocked_jobs_spec.rb

@@ -0,0 +1,38 @@
+require "rails_helper"
+
+RSpec.describe "BlockedJobs", type: :request do
+  let!(:blocked_job) do
+    j = SolidQueue::Job.create!(
+      queue_name: "default", class_name: "TestJob",
+      arguments: {}.to_json, active_job_id: SecureRandom.uuid
+    )
+    j.ready_execution&.destroy
+    j.update!(concurrency_key: "TestJob/1")
+    allow_any_instance_of(SolidQueue::BlockedExecution).to receive(:set_expires_at)
+    SolidQueue::BlockedExecution.create!(
+      job: j, queue_name: j.queue_name, priority: j.priority, expires_at: 1.hour.from_now
+    )
+    j
+  end
+
+  describe "DELETE /jobs/blocked_jobs" do
+    it "discards all blocked jobs and redirects to the dashboard" do
+      delete "/jobs/blocked_jobs"
+      expect(response).to redirect_to("/jobs/")
+      follow_redirect!
+      expect(response.body).to include("discarded")
+    end
+
+    it "removes the blocked execution" do
+      expect { delete "/jobs/blocked_jobs" }.to change(SolidQueue::BlockedExecution, :count).by(-1)
+    end
+
+    it "handles failure gracefully" do
+      allow(SolidQueue::BlockedExecution).to receive(:discard_all_from_jobs).and_raise(RuntimeError, "boom")
+      delete "/jobs/blocked_jobs"
+      expect(response).to redirect_to("/jobs/")
+      follow_redirect!
+      expect(response.body).to include("Could not discard blocked jobs")
+    end
+  end
+end