SharePoint 2013 Site Collection | HTTP 404 error intermittently

Problem Description

Recently I came across a weird issue, a site collection in the SharePoint farm was giving HTTP 404 intermittently. My initial thought was maybe the whole web application had the issue but didn�t see this happening with any other site collections on the same web application. And I got this error only 1 out of 10 times. But another user seemed to have got it from the first try itself. It really baffled me for couple of hours. So I did an IIS reset and even restarted the SharePoint timer service on the SharePoint web front ends. That didn�t seem to help either.

Resolution

At some point, I realized that this was a site collection specific issue. This site collection had its own dedicated database. I had to detach and attach the content database of this site collection from the web application using Powershell(read dismount and mount)to resolve this issue.

Few weeks back I had done a detach/attach of the same content database from Central Administration. I think performing dismount and mount from Central Administration console led to this behavior. I still find this weird though.

P.S.: Please make a note of the Content DB name before you start this operation

Dismount-SPContentDatabase"<ContentDBName>"

Mount-SPContentDatabase"< ContentDBName >" -DatabaseServer"<DBServerNAme>" -WebApplicationhttp://SiteName