C) Creating Symbolic Links aka Symlink

• A symbolic link (symlink) is a shortcut to a destination/folder/file with a name. Symlinks are commonly used when a website has http:// and https://

Example ) lrwxrwxrwx public -> secure

• In order to create a symlink for customer on our server you must check if the customer has the following in their hosting package.

• Otherwise you must create a ticket to Sys. Admins.

Before you create a symlink for a customer, you must backup the contents of the destination/folder/file etc!

The following is required when creating a symlink

• Secure Shell

• Secure Shell enabled/disabled (in WebsiteOS4).

• SSH Client

  • If Secure Shell is enabled they must have their Secure Shell Connection Information (i.e. username, password, host name).

  • If Secure Shell is disabled it must be enabled and have Secure Shell Connection Information (i.e. username, password, host name).

Creating a symlink using a SSH client

1. ln –s public/folder name_of_symlink

This will create the symlink called “name_of_symlink,” which actually is a shortcut to public/folder. Please note public/folder is simply the destination, it can be anything (i.e. public/photoalbum, public/nameofdirectory, etc). 

2. ls –ls | grep name_of_symlink

This indicates that “name_of_symlink’ destination is actually public/folder.

3. Cd name_of_symlink

This changes the directory to “name_of_symlink.”

4. ls –ls

This lists the contents in “name_of_symlink.”

Removing a symlink using a SSH client

• The following commands will remove the symlink from a customer’s domain.

• This is strictly for education purposes, as removal of a symlnk may cause disruption of the customer’s domain. Create a ticket to Sys Admins to request symlnk removal.

1. Rm name_of_link

This will remove the symlink called “name_of_symlink.”

2. Cd name_of_symlink

This indicates that “name_of_symlink’ should no longer exist.

14) Databases a) ms access (Microsoft Access)

• For the most part MS ACCESS databases suit web applications reasonably well on low traffic sites, however, high traffic sites may benefit from upgrading to a true multi-user database platform such as MS SQL or MySQL.

• For performance and reliability reasons, we strongly recommend the use of Microsoft SQL Server for the deployment of production-quality Web applications. Although Active Server Pages works with any ODBC-compliant database, it has been extensively tested and is designed to work with Microsoft SQL Server. ASP also supports Microsoft Access as a valid data source.

• Although the sample Web site and examples in this release use Microsoft Access, we recommend that Microsoft Access be used solely for development purposes and not for production.

• Microsoft Access was designed as a single-user desktop database, and not for server use. When multiple, concurrent users make requests of a Microsoft Access database, unpredictable results may occur. Microsoft has found the following line from the statement to be incorrect "Microsoft Access was designed as a single-user desktop database".

• Excerpt from the readme.txt (IIS) article, “We have found that sporadic performance issues occur when traffic intensive sites run on Microsoft Jet and IIS. We have ensured that our system is using the latest Microsoft Jet Components and Updates. We recommend that the native Jet OLE DB provider be used in place of the Access ODBC Driver.”  

• The following article outlines Microsoft’s recommendation to implement an SQL Server Database for use under IIS to accommodate for web, commerce, and transactional applications. http://support.microsoft.com/default.aspx?scid=kb;en-us;Q299973

• MS-Access 1997 not recommended on the Hostopia platform. The latest MDAC (version 2.7), which is currently installed on our system, is not compatible with Access 97 databases. You may find that customer’s database worked originally, however, once you write data to the database it will generate an error. In our clustered hosting environment, our main focus is security. In order for us to provide you with acceptable levels of security, our operating systems must be configured with current service packs and patches.

• FrontPage + MS ACCESS are not permitted on the Hostopia platform. Our system architecture does not allow modifications of MS ACCESS database though the FrontPage GUI. Both must be managed separately.

• In the best interest of our clients, our platform does not allow actions of one domain to affect the population of other domains residing on our system. Multiple domains to one specific MS Access database are prohibited on our system due to strict system security settings. If this functionality is required, we recommend the use of an MSSQL database.

MS Access Warning Messages

• Microsoft OLE DB Provider for ODBC Drivers error '80004005' [Microsoft][ODBC Microsoft Access Driver] Cannot update. Database or object is read-only.

  • Please ensure your database has the proper permissions set.

• Microsoft OLE DB Provider for ODBC Drivers error '80004005' [Microsoft][ODBC Microsoft Access Driver] General error Unable to open registry key 'Temporary (volatile) Jet DSN for process 0x4d4 Thread 0x748 DBC 0x84dbc84 Jet'.

  • The process, Thread and DCB numbers may vary

• Microsoft OLE DB Provider for ODBC Drivers error '80004005' [Microsoft][ODBC Microsoft Access Driver] Cannot open database '(unknown)'. It may not be a database that your application recognizes, or the file may be corrupt.

  • The latest MDAC (version 2.8), which is currently installed on our system, is not compatible with Access 97 databases.

  • You may find that your database worked originally; however, once you write data to the database it will throw this error.

  • In our clustered hosting environment, our main focus is security.

  • In order for us to maintain our strict security model, our operating systems must be updated with current service packs and patches.

  • If this is an Access 2000 database, it is likely that is it corrupted.

• Microsoft OLE DB Provider for ODBC Drivers error \'80040e4d\' [Microsoft][ODBC Microsoft Access Driver] Too many client tasks. /index.asp, line 134

  • This error is not generated by our systems.

  • This error is generated by the Access database engine. Indicating that it has reached its connection limit.

  • We can reset the connections, to temporarily fix the issue, but this will not guarantee that the error will not occur again.

  • Customers should consider switching to MSSQL or MYSQL, that do not have these limitations.

• Microsoft JET Database Engine error '80004005' Not a valid file name.

  • The MDB file you referenced in your connection string either doesn't exist, or might be malformed (e.g. maybe you just entered a folder name).

  • Response.Write your connection string to the screen and see exactly what it contains.