2/17
- Collin is continuing with Map-Reduce implementation
- Unclear if rules-based code will provide full benefit
- Seems like most "faults" arise "synchronously" so far in his case, so he could handle them by propagating them rather than having to poll for failures.
TODO(stutsman): Move Survey of DCFT Systems up to Section 2; start writing up the Replica Manager in the paper draft- Concise, but complete description
- No need to give reasons for details (segments have ordering constraints, don't explain why)
- Eventually section will want several other short examples
- Some from in and out of RAMCloud
- John will do write up of the ServerList
- Interesting point to try to work in: based on Sparrow feedback
- Everyone starts without handling faults
- The hope is that adding fault-handling is a matter of adding try/catch.
- Turns out it has resulted in complete rework for a us a few times.
- Another point: want to avoid rules-based programming whenever possible
- It's less efficient, and it is hard
- That's one reason why it's great that it is easy to intermix with threaded/imperative code
- In several places in RAMCloud we contain fault-handling complexity within a subsystem and then the rest of the code that interacts with the system is easy
2/10 Meeting - Conversation about Actors
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- Several observations are in order here. Firstly, the behavior of an actor can be history sensitive. Secondly, there is no presumed sequentiality in the actions an actor performs since, mathematically, each of its actions is a function of the actor's behavior and the incoming communication.
- The shared variables approach does not provide any mechanism for abstraction and information hiding.. For instance, there must be predetermined protocols so tat one process can determine if another has written the results 'it needs into the relevant variables.
- Buffered asynchronous communication affords us efficiency 'in execution by pipelining the actions to be performed.
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