Some offerings, such as FVP from PernixDataare embedded as a kernel extension to the hypervisor and so work in close co-operation with the hypervisor. Other policies may also trigger data write-back. The number of segments kept in the archive is such that the total size of all segments does not exceed the established size of the WAL archive.
Once the requested data is retrieved, it is typically copied into the cache, ready for the next access. Whereas, a Write-behind lets your application quickly update the cache and return.
Furthermore, application code is fully managed on the cache server, meaning that only a controlled subset of nodes will directly access the database resulting in more predictable load and security. One involves checking for a cache miss, then querying the database, populating the cache, and continuing application processing.
InvariantCulture, "Update dbo. The changes are persisted only if you shut down the node gracefully.
There are two basic writing approaches:  Write-through: write is done synchronously both to the cache and to the backing store. While the 1st segment's content is being copied, the 2nd segment is treated as an active WAL file and accepts all the updates coming from the application side.
Contributor s : Stan Gibilisco Share this item with your network: Write through is a storage method in which data is written into the cache and the corresponding main memory location at the same time.
Any attempt to do so would be a waste of resources. Prediction or explicit prefetching might also guess where future reads will come from and make requests ahead of time; if done correctly the latency is bypassed altogether.