We have a PHP Web application hosted on Windows Server 2016 using IIS and CGI Module. It connects to Azure MS-SQL database through ODBC Driver 17 for SQL Server. All of a sudden the application stopped connecting to the database throwing the error 08001. But when we did the application pool recycle it started working. Now it is happening intermittently and became a headache for us. It cant be a memory problem as it happened immediately after app pool recycle once. But again got corrected after one more app pool recycle. We don't know what is happening as none of the error logs give any clue. We've updated Drivers