WAN Optimization Manager™ (WOM®) uses symmetric data deduplication to reduce the amount of bandwidth consumed across a WAN link for repeated data transfers. This feature is available only with a WOM license.
With data deduplication, the system performs pattern matching on the transmitted WAN data rather than caching. If any part of the transmitted data has already been sent, BIG-IP WOM replaces the previously transmitted data with references. As data flows through the pair, each WOM records the byte patterns and builds a synchronized dictionary. If an identical pattern of bytes traverses the WAN more than once, the BIG-IP WOM nearest the sender replaces the byte pattern with a reference to it, compressing the data. When the reference reaches the other side of the WAN, the remote BIG-IP WOM replaces the reference with the data, restoring the data to its original format.
Symmetric data deduplication provides the greatest benefit when transferring objects greater than 32K.
|Disk||Specifies that WOM uses the disk, in addition to memory, for storing
information used for optimization.
Note: If you enable data storage on the disk, you must then restart the datastor service from the command line using the command sequence bigstart restart datastor.
|Memory||Specifies that WOM uses only memory for storing information used for
Note: This setting can provide benefits for higher speed links.
Deduplication cache is the location to which WAN Optimization Manager™ (WOM®) copies data that it has previously transferred. The system creates a deduplication cache area for each pair of BIG-IP WOM systems that are set up to optimize traffic between them. Both systems keep the information in the deduplication cache synchronized between the endpoints on the two BIG-IP WOM systems. If the same or similar information is requested again, the system can send the optimized version of the data instead of sending it in its entirety.
The Remote Endpoints list screen identifies the deduplication cache as SDD (symmetric data deduplication) cache and displays the amounts apportioned to the listed endpoints.
The following factors determine the size of deduplication cache on BIG-IP® WOM®.
|BIG-IP WOM platform||Memory and disk sizes vary for different hardware platforms, and these specifications determine the maximum size that the system can reserve for deduplication cache.|
|Module provisioning||If more resources are provisioned for BIG-IP WOM, more can be used for deduplication cache.|
|Disk or memory mode||The size of deduplication cache varies significantly, depending on whether you are storing it on disk or in memory.|
|Number of remote endpoints||The total size of deduplication cache divided by the maximum number of remote endpoints yields the amount of deduplication cache that a WOM assigns to its local and remote endpoints.|
|Size of cache on remote endpoints||The local endpoint negotiates with each remote endpoint to determine the amount of cache available. For each pair of BIG-IP WOM systems, the smaller amount is used for both endpoints on that connection.|