Real-Time processing of files, particularly in multi-directional synchronization jobs, can be very complex in the logic used for the processing. This topic discusses some issues to be aware of and explains how the product handles certain situations.

Advanced Open File Support

Understanding how Advanced Open File Support impacts Real-Time Monitors is an important topic. This section will provide detailed information about this processing.

Without Advanced Open File Support

When a Real-Time Monitor without Advanced Open File Support encounters an open source file, the file will not be copied. Instead the file will be queued for retry. These retries will be managed internally by the Real-Time Monitor. When the file is closed, the Real-Time Monitor will process the file on the next retry.

With Advanced Open File Support

Prior to SureSync 6.0, when Advanced Open File Support was turned on, the synchronization engine would copy the open source file every time a save was performed. That might sound like a good idea on the surface but it can result in a ton of data transfer. For example, many programs have automatic save functions that will saves files every 5-10 minutes. Access databases are also terrible in this regard because a single record change will result in a synchronization occurring. If many people are making changes to the database, this file can be copied many times with no real benefit. Balancing bandwidth consumption and processing time with the need to have the files synchronized is important to achieving optimal performance.

SureSync 6.0 handles open and locked files much more intelligently. When an open source file is encountered, SureSync will queue the file to be copied. However, it will not perform a copy using Advanced Open File Support right away. Instead, the Real-Time Monitor will try the file for the first hour not using Advanced Open File Support. If the file is still open on the source, it will not be copied and will be queued again. When the file has been open for more than an hour, the file will be processed using Advanced Open File Support.

Open Destination Files

Open destination files is another area which must be discussed to have a clear understanding of how SureSync processes files in a Real-Time Monitor. If a user opens a file, makes a change and saves the file then SureSync will queue the file and start processing the change. If the file is found open on one or more of the destinations, the copy to that path is queued to be retried again later. SureSync will continue retrying that file copy at 5 minute intervals until the destination file copy is closed.

To help you identify these files, the SureSync Job Log will make an entry in the SureSync Job Log which informs you that the file has been queued for retries due to an open destination file. Once SureSync has been able to successfully copy the file, it will make another entry in the log stating that the file was replaced after x number of retries.

Renaming & Moving Directory Structures

SureSync's Real-Time Monitors support the renaming of files and folders which eliminates the overhead of deleting the old files from the destinations and adding the files in the new location back that many synchronization tools deal with. This rename functionality is powerful and efficient but you must be aware of some potential issues that can occur if users have files open on destinations.

For this to make sense, lets consider an example. Assume that you're renaming a directory named SalesData to Sales. This folder contains thousands of folders and files used by sales people in multiple offices. If you rename this folder on one side during the business day, odds are good a user will have a file open on one or more of the destinations. This can result in the folder structure rename occurring but some files being left behind in the old structure because they are in use. Windows will not allow a file to be moved when it is in use. If the user closes the file without making any changes, SureSync will cleanup the old location. However, if the user changes the file, SureSync has no choice but to replicate that change back in the old location or the file change would be lost. This can result in two sets of folders, the old which contains just the changed files which were open and the new which contains the entire renamed structure. This results in the need to do some additional cleanup moving later.

To avoid this situation, it is strongly recommended to perform renames and moves of large, frequently used directory structures during the off hours when people are not accessing the files. This ensures a clean move with no need for additional cleanup.