Service Unavailable

HTTP Error 503. The service is unavailable.

I am getting 503 error in every 30 mins time. I have to ask from hosting people to restart the application pool. They said this application scripts needs to optimize. But I am just using DNN 6.

Why is this happening? Please any body can advise to fix this? Hosting people are saying that this is not a server issue and it is the application issue.

Please let me know what should I do?

Hello, I did make the step by step everything you guys write here but the app pool was down again. Already created a store proceed to clean the tables every 30 minutes to try to solve the problem, I put a post here with the error, but i get no help, nor even from the Arvixe or DNN.

Service Unavailable - Arvixe - DotNetNuke v.6.2.4 Community Edition

My post: http://www.dotnetnuke.com/Resources/Forums/forumid/198/postid/475466/scope/posts.aspx#475466

Store Procedure

USE [BD]
GO
/****** Object:  StoredProcedure [dbo].[sp_cleanSearch]    Script Date: 21-12-2012 16:28:43 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[sp_cleanSearch]
AS
truncate table SearchItemWordPosition;
DELETE SearchItemWord;
DELETE SearchWord;
DELETE SearchItem;

Many thanks in advance.

HS