Application Optimization: Caching and Block-Level Deduplication

Hi, I’m Thomas. Welcome to the lightboard session on application optimization. By using caching or block-level deduplication, application optimization can significantly reduce the bandwidth required between your locations. When a client downloads a file from a server, we cache the data that has been transferred between two edge devices. If a second client requests the same file, instead of transferring the entire file again, we can use the cached data. We send a block reference to the data in the cache, which the client uses to look up the requested file, and the file is then sent to the client.

This approach works regardless of how the clients access the file. For example, the file might be initially transferred by email, and the second request might come through HTTP, FTP, or Samba. The cache stores byte sequences rather than the files themselves, so whenever we see the same byte sequence, we replace it with a reference to its stored address.

This method also ensures that if a file is updated on the server-where part of the file remains the same but some parts are changed-we would still transfer a block reference to the unchanged data and transfer only the modified parts. This way, the client always receives the most up-to-date version of the file, and the changes are also stored in the cache. By doing so, we drastically reduce the amount of data that needs to be transferred between edge devices.