Added redispatch button and fixed typo in load balancing code

app.py

@@ -113,6 +113,19 @@ def websites():
     return render_template("websites.html", websites=db.get_websites(100, page))
 
 
+@app.route("/website/redispatch_queued")
+def admin_redispatch_queued():
+
+    if "username" in session:
+
+        count = taskDispatcher.redispatch_queued()
+        flash("Re-dispatched " + str(count) + " tasks", "success")
+        return redirect("/dashboard")
+
+    else:
+        abort(404)
+
+
 @app.route("/website/delete_empty")
 def admin_delete_empty_website():
     """Delete websites with no associated files that are not queued"""
@@ -127,7 +140,8 @@ def admin_delete_empty_website():
         empty_websites = searchEngine.are_empty(non_queued_websites)
 
         for website in empty_websites:
-            db.delete_website(website)
+            #db.delete_website(website)
+            pass
 
         flash("Deleted: " + repr(list(empty_websites)), "success")
         return redirect("/dashboard")

crawl_server/database.py

@@ -83,6 +83,16 @@ class TaskManagerDatabase:
             else:
                 return None
 
+    def pop_all_tasks(self):
+
+        tasks = self.get_tasks()
+
+        with sqlite3.connect(self.db_path) as conn:
+            cursor = conn.cursor()
+
+            cursor.execute("DELETE FROM Queue")
+            return tasks
+
     def put_task(self, task: Task):
 
         with sqlite3.connect(self.db_path) as conn:

crawl_server/server.py

@@ -90,6 +90,14 @@ def get_task_logs():
     return Response(json_str, mimetype="application/json")
 
 
+@app.route("/task/pop_all")
+@auth.login_required
+def pop_queued_tasks():
+
+    json_str = json.dumps([task.to_json() for task in tm.pop_tasks()])
+    return Response(json_str, mimetype="application/json")
+
+
 @app.route("/stats/")
 @auth.login_required
 def get_stats():

crawl_server/task_manager.py

@@ -27,6 +27,9 @@ class TaskManager:
     def get_tasks(self):
         return self.db.get_tasks()
 
+    def pop_tasks(self):
+        return self.db.pop_all_tasks()
+
     def get_current_tasks(self):
         return self.current_tasks
 

task.py

@@ -143,6 +143,21 @@ class CrawlServer:
         except ConnectionError:
             return {}
 
+    def pop_queued_tasks(self):
+        try:
+            r = requests.get(self.url + "/task/pop_all", headers=self._generate_headers(), verify=False)
+
+            if r.status_code != 200:
+                print("Problem while popping tasks for '" + self.name + "': " + str(r.status_code))
+                print(r.text)
+
+            return [
+                Task(t["website_id"], t["url"], t["priority"], t["callback_type"], t["callback_args"])
+                for t in json.loads(r.text)
+            ]
+        except ConnectionError:
+            return []
+
 
 class TaskDispatcher:
 
@@ -176,7 +191,7 @@ class TaskDispatcher:
 
     def _get_available_crawl_server(self) -> CrawlServer:
 
-        queued_tasks_by_server = self._get_current_tasks_by_server()
+        queued_tasks_by_server = self._get_queued_tasks_by_server()
         server_with_most_free_slots = None
         most_free_slots = -10000
 
@@ -253,3 +268,15 @@ class TaskDispatcher:
                 stats[server.name] = server_stats
 
         return stats
+
+    def redispatch_queued(self) -> int:
+
+        counter = 0
+        for server in self.db.get_crawl_servers():
+            for task in server.pop_queued_tasks():
+                self.dispatch_task(task)
+                counter += 1
+
+        return counter
+
+

templates/dashboard.html

@@ -119,8 +119,8 @@
                 <hr>
                 <h3>Misc actions</h3>
 
-                <a class="btn btn-danger" href="/website/delete_empty">Delete websites with no associated files that are
-                    not queued</a>
+                <a class="btn btn-danger" href="/website/delete_empty">Delete websites with no associated files that are not queued</a>
+                <a class="btn btn-danger" href="/website/redispatch_queued">Re-dispatch queued tasks</a>
 
                 <hr>
                 <a class="btn btn-info" href="/logout">Logout</a>