高手幫忙-503 Service Temporarily Unavailable

求助各位高手幫忙.
我的網站一天長時間出現這個問題
完全不知道發生甚麼事.
問網絡商,只是回覆這個you still see the "503 Service Temporarily Unavailable error", this mean your website is overloaded in terms of traffic during peak hours. Please consider to use dedicated server if keep seeing the 503 error.

但再出現問題時,又他們看到運作正常,說沒問題
難道我在玩嗎?真的有問題才問的呀.
問多少遍都解決不了.
請問為什麼會出現這個的.
只是論壇才有問題.
這個情況困擾了我2周了.
我的網站不能長期這樣.
完全尋求無門.
希望各位幫忙.

論壇出現的句子:

Service Temporarily Unavailable
The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.

Additionally, a 503 Service Temporarily Unavailable error was encountered while trying to use an ErrorDocument to handle the request.

资源占用太大，让你升级独立主机呢