From d8847913fae77ea3b9c9335a8314f7c8a5eb2bb9 Mon Sep 17 00:00:00 2001
From: Vishesh Jain <visheshj@twitter.com>
Date: Tue, 27 Aug 2019 21:12:52 +0530
Subject: [PATCH] 6607e486(airflow:master): [AIRFLOW-3160] Load latest_dagruns
 asynchronously, speed up front page load time #4005

---
 airflow/www/templates/airflow/dags.html      | 30 +++++++++++++++-----
 airflow/www/views.py                         | 20 +++++++++++++
 airflow/www_rbac/templates/airflow/dags.html | 30 +++++++++++++++-----
 airflow/www_rbac/views.py                    | 27 ++++++++++++++++++
 tests/core.py                                | 15 ++--------
 5 files changed, 96 insertions(+), 26 deletions(-)

diff --git a/airflow/www/templates/airflow/dags.html b/airflow/www/templates/airflow/dags.html
index 1a0ebc01f44ba..561aa8d783650 100644
--- a/airflow/www/templates/airflow/dags.html
+++ b/airflow/www/templates/airflow/dags.html
@@ -103,13 +103,11 @@ <h2>DAGs</h2>
 
                 <!-- Column 7: Last Run -->
                 <td class="text-nowrap latest_dag_run {{ dag.dag_id }}">
-                  {% set last_run = dag.get_last_dagrun(include_externally_triggered=True) %}
-                  {% if last_run and last_run.execution_date %}
-                    <a href="{{ url_for('airflow.graph', dag_id=dag.dag_id, execution_date=last_run.execution_date) }}">
-                      {{ last_run.execution_date.strftime("%Y-%m-%d %H:%M") }}
-                    </a>
-                    <span aria-hidden="true" id="statuses_info" title="Start Date: {{ last_run.start_date.strftime("%Y-%m-%d %H:%M") }}" class="glyphicon glyphicon-info-sign"></span>
-                  {% endif %}
+                  <div height="10" width="10" id='last-run-{{ dag.safe_dag_id }}' style="display: block;">
+                    <a></a>
+                    <img class="loading-last-run" width="15" src="{{ url_for("static", filename="loading.gif") }}">
+                    <span aria-hidden="true" id="statuses_info" title=" " class="glyphicon glyphicon-info-sign" style="display:none"></span>
+                  </div>
                 </td>
 
                 <!-- Column 8: Dag Runs -->
@@ -309,6 +307,24 @@ <h2>DAGs</h2>
           }
         });
       });
+      d3.json("{{ url_for('airflow.last_dagruns') }}", function(error, json) {
+        for(var safe_dag_id in json) {
+          dag_id = json[safe_dag_id].dag_id;
+          last_run = json[safe_dag_id].last_run;
+          g = d3.select('div#last-run-' + safe_dag_id)
+
+          g.selectAll('a')
+            .attr("href", "{{ url_for('airflow.graph') }}?dag_id=" + dag_id + "&execution_date=" + last_run)
+            .text(last_run);
+
+          g.selectAll('span')
+            .attr("data-original-title", "Start Date: " + last_run)
+            .style('display', null);
+
+          g.selectAll(".loading-last-run").remove();
+        }
+        d3.selectAll(".loading-last-run").remove();
+      });
       d3.json("{{ url_for('airflow.dag_stats') }}", function(error, json) {
         for(var dag_id in json) {
             states = json[dag_id];
diff --git a/airflow/www/views.py b/airflow/www/views.py
index 1596d86148cf3..e0b4097159ff4 100644
--- a/airflow/www/views.py
+++ b/airflow/www/views.py
@@ -668,6 +668,26 @@ def task_stats(self, session=None):
                 })
         return wwwutils.json_response(payload)
 
+    @expose('/last_dagruns')
+    @login_required
+    @provide_session
+    def last_dagruns(self, session=None):
+        DagRun = models.DagRun
+
+        dags_to_latest_runs = dict(session.query(
+            DagRun.dag_id, sqla.func.max(DagRun.execution_date).label('execution_date'))
+            .group_by(DagRun.dag_id).all())
+
+        payload = {}
+        for dag in dagbag.dags.values():
+            if dag.dag_id in dags_to_latest_runs and dags_to_latest_runs[dag.dag_id]:
+                payload[dag.safe_dag_id] = {
+                    'dag_id': dag.dag_id,
+                    'last_run': dags_to_latest_runs[dag.dag_id].strftime("%Y-%m-%d %H:%M")
+                }
+
+        return wwwutils.json_response(payload)
+
     @expose('/code')
     @login_required
     @provide_session
diff --git a/airflow/www_rbac/templates/airflow/dags.html b/airflow/www_rbac/templates/airflow/dags.html
index fb157b8b3062e..c1e32726451a3 100644
--- a/airflow/www_rbac/templates/airflow/dags.html
+++ b/airflow/www_rbac/templates/airflow/dags.html
@@ -103,13 +103,11 @@ <h2>DAGs</h2>
 
                 <!-- Column 7: Last Run -->
                 <td class="text-nowrap latest_dag_run {{ dag.dag_id }}">
-                  {% set last_run = dag.get_last_dagrun(include_externally_triggered=True) %}
-                  {% if last_run and last_run.execution_date %}
-                    <a href="{{ url_for('Airflow.graph', dag_id=dag.dag_id, execution_date=last_run.execution_date) }}">
-                      {{ last_run.execution_date.strftime("%Y-%m-%d %H:%M") }}
-                    </a>
-                    <span aria-hidden="true" id="statuses_info" title="Start Date: {{ last_run.start_date.strftime("%Y-%m-%d %H:%M") }}" class="glyphicon glyphicon-info-sign"></span>
-                  {% endif %}
+                  <div height="10" width="10" id='last-run-{{ dag.safe_dag_id }}' style="display: block;">
+                    <a></a>
+                    <img class="loading-last-run" width="15" src="{{ url_for("static", filename="loading.gif") }}">
+                    <span aria-hidden="true" id="statuses_info" title=" " class="glyphicon glyphicon-info-sign" style="display:none"></span>
+                  </div>
                 </td>
 
                 <!-- Column 8: Dag Runs -->
@@ -309,6 +307,24 @@ <h2>DAGs</h2>
           }
         });
       });
+      d3.json("{{ url_for('Airflow.last_dagruns') }}", function(error, json) {
+        for(var safe_dag_id in json) {
+          dag_id = json[safe_dag_id].dag_id;
+          last_run = json[safe_dag_id].last_run;
+          g = d3.select('div#last-run-' + safe_dag_id)
+
+          g.selectAll('a')
+            .attr("href", "{{ url_for('Airflow.graph') }}?dag_id=" + dag_id + "&execution_date=" + last_run)
+            .text(last_run);
+
+          g.selectAll('span')
+            .attr("data-original-title", "Start Date: " + last_run)
+            .style('display', null);
+
+          g.selectAll(".loading-last-run").remove();
+        }
+        d3.selectAll(".loading-last-run").remove();
+      });
       d3.json("{{ url_for('Airflow.dag_stats') }}", function(error, json) {
         for(var dag_id in json) {
             states = json[dag_id];
diff --git a/airflow/www_rbac/views.py b/airflow/www_rbac/views.py
index a69af7d53e8ee..3a8020fb2324c 100644
--- a/airflow/www_rbac/views.py
+++ b/airflow/www_rbac/views.py
@@ -410,6 +410,33 @@ def task_stats(self, session=None):
                     })
         return wwwutils.json_response(payload)
 
+    @expose('/last_dagruns')
+    @has_access
+    @provide_session
+    def last_dagruns(self, session=None):
+        DagRun = models.DagRun
+
+        filter_dag_ids = appbuilder.sm.get_accessible_dag_ids()
+
+        if not filter_dag_ids:
+            return
+
+        dags_to_latest_runs = dict(session.query(
+            DagRun.dag_id, sqla.func.max(DagRun.execution_date).label('execution_date'))
+            .group_by(DagRun.dag_id).all())
+
+        payload = {}
+        for dag in dagbag.dags.values():
+            dag_accessible = 'all_dags' in filter_dag_ids or dag.dag_id in filter_dag_ids
+            if (dag_accessible and dag.dag_id in dags_to_latest_runs and
+                    dags_to_latest_runs[dag.dag_id]):
+                payload[dag.safe_dag_id] = {
+                    'dag_id': dag.dag_id,
+                    'last_run': dags_to_latest_runs[dag.dag_id].strftime("%Y-%m-%d %H:%M")
+                }
+
+        return wwwutils.json_response(payload)
+
     @expose('/code')
     @has_dag_access(can_dag_read=True)
     @has_access
diff --git a/tests/core.py b/tests/core.py
index 07891003559d4..b0ee4da2ae736 100644
--- a/tests/core.py
+++ b/tests/core.py
@@ -1851,17 +1851,6 @@ def test_index(self):
         self.assertIn("DAGs", resp_html)
         self.assertIn("example_bash_operator", resp_html)
 
-        # The HTML should contain data for the last-run. A link to the specific run,
-        #  and the text of the date.
-        url = "/admin/airflow/graph?" + urlencode({
-            "dag_id": self.dag_python.dag_id,
-            "execution_date": self.dagrun_python.execution_date,
-        }).replace("&", "&amp;")
-        self.assertIn(url, resp_html)
-        self.assertIn(
-            self.dagrun_python.execution_date.strftime("%Y-%m-%d %H:%M"),
-            resp_html)
-
     def test_query(self):
         response = self.app.get('/admin/queryview/')
         self.assertIn("Ad Hoc Query", response.data.decode('utf-8'))
@@ -2005,7 +1994,9 @@ def test_dag_views(self):
         response = self.app.get(
             '/admin/airflow/task_stats')
         self.assertIn("example_bash_operator", response.data.decode('utf-8'))
-
+        response = self.app.get(
+            '/admin/airflow/last_dagruns')
+        self.assertIn("example_python_operator", response.data.decode('utf-8'))
         response = self.app.post("/admin/airflow/success", data=dict(
             task_id="print_the_context",
             dag_id="example_python_operator",