Viewing and Closing Opened Files and Locked Directories

Opened Files

A file handle is a number that the operating system assigns temporarily to a file when it is opened. The operating system uses the file handle internally when accessing the file. Once an application has modified and saved a file, the WAFS Agent retains the handle to the file while it is waiting to be uploaded or is in the process of uploading the file to the WAFS Server. This prevents simultaneous modification of the file across multiple Agents.

Locked Directories

When a user tries to open an application, save a file, or open a directory, there is usually more than one "file open" or "file close" operation performed. As a performance enhancement, when the first open occurs, the WAFS Agent tries to lock the parent directory. If the Agent obtains the lock, the Agent performs the open or close file operations locally. When these operations are performed locally, the Agent does not have to send communications messages to the Server and thereby reduces the effect of latency on the performance of the system.

Before the Agent releases the lock, the Agent combines all open operations together within one “burst” open operation and sends it to the Server. If the directory has already been locked by another Agent, none of the files in this directory can be opened until the locking Agent relinquishes the lock.

Effects of loss of communications

To ensure file coherency, the WAFS system must retain handles on files and the current set of directory locks when and Agent loses connection with the WAFS Server. Open file handles and locked directories can be viewed and manually closed at the WAFS Server via the Web interface. (The handle will be closed automatically when no longer needed.) Additionally, the opened file handles and directory locks will be automatically released based on a configurable timeout value.

The behavior during a loss of communications depends on the type of disconnection, defined as follows:

Opened file handles and locked directories by offline Agents are automatically closed after the time specified in the Editing Job Information page.

To view opened files and directories

  1. Do one of the following:

    The Job Administration Console appears.

  1. Click Opened Files/Directories. The Opened File List appears.

    web_openedfilelist.gif

    The Opened File List displays opened file handles and locked directories.

    The Since column displays the date and time the file was opened or the directory locked. If a file or directory was locked by an offline Agent, the name and IP address of the Agent is shown in red in the By column.

    web_jobadmin_openedfilelist.gif

  1. To close the file or directory manually, click Close.

  2. To change the amount of time to retain opened file handles for disconnected Agents, refer to Editing Job Information.