If you are hosting an ASP.NET website on Windows Plesk Hosting, your website runs through an IIS Application Pool.
An Application Pool manages the processes required to run your website. If the Application Pool stops or becomes unresponsive, your website may temporarily show a 503 Service Unavailable error.
Dedicated vs. Shared Application Pool
The Application Pool type depends on your hosting plan:
Business Plans — Dedicated Application Pool
Customers with a Business Plan get a dedicated IIS Application Pool for their website.
This means your website has its own Application Pool, which you can manage directly from Plesk.
You can start, stop, or restart your dedicated Application Pool whenever required.
Other Hosting Plans — Shared Application Pool
Customers on plans other than the Business Plan use a shared Application Pool.
Since the Application Pool is shared with other websites, it cannot be independently managed or restarted from your Plesk account.
If you experience an Application Pool-related issue on a shared plan, please contact our Technical Support team.
How to Restart Your Application Pool
If you are on a Business Plan, you can manage your dedicated Application Pool directly from Plesk.
Step 1 — Log in to Plesk
Log in to your Plesk control panel.
Step 2 — Go to Hosting and DNS
Open your website and navigate to:
Hosting and DNS → Dedicated IIS Application Pool for Website
Open Dedicated IIS Application Pool for Website
Step 3 — Restart the Application Pool
From the Dedicated IIS Application Pool for Website section, you can manage your Application Pool.
If the Application Pool is stopped, start it again.
If your website is already running but experiencing a temporary issue, restarting the Application Pool can also help.
