We compared the cache consistency approach in Chubby with NFS, concluding that NFS offers much weaker semantics in terms of seeing different versions of files on different nodes. Perform a similar comparison between the cache consistency approaches adopted in Chubby and AFS.
What will be an ideal response?
In Chubby, clients cache data and, when a mutation occurs, this operation is blocked until all other cached entries are invalidated. Caches are also not updated directly but rather updates go through the server. This ensures deterministic results, that is clients either see valid data, or receive an error. In AFS, when a server receives a request to update a file, a callback is sent to every node with a cached copy and this invalidates this copy. On a subsequent open, a client checks the cached entry and, if marked invalid, it must retrieve a new copy from the server. These two schemes are very similar and both offer more deterministic guarantees than NFS. The key difference is that in AFS a callback message may be lost and this can result in clients accessing an old copy of the file.
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Answer the following statements true (T) or false (F)
1. it is possible to have a function that has no parameters 2. the parameters listed in the function declaration are considered global variables 3. variables that are declared outside of any function body or parameter list are considered global. 4. pow(2,3) is the same as pow(3,2). 5. Functions may have multiple return statements.
Every library item is saved as a(n) ____ file.
A. .lbi B. .lib C. .xml D. .htm
A(n) _________ should show the tables and their fields, data types, and relationships
A) extensible markup language B) database documenter C) database documentation D) entity relationship diagram
An example of a positive attitude is when you do not take time to listen to the entire customer problem
Indicate whether the statement is true or false