PTS Jiahao is implementing a situation-aware application usi…
PTS Jiahao is implementing a situation-aware application using PTS. There are three sensor sources: camera, audio from a microphone, and smoke detector. The camera images are accumulated in Channel Ch1; samples from the microphone are periodically recorded in Channel Ch2; smoke detector sample levels are recorded in Channel Ch3. Jiahao’s application reads the most recent camera image; it then uses the timestamp associated with the camera image to get the closest (in time) samples from the other two channels. Here are the states of the channels at some point of time: Ch1 contains items with timestamps: 50, 100, 150, 200 Ch2 contains items with timestamps: 60, 120, 180 Ch3 contains items with timestamps: 30, 60, 90, 120, 150, 180, 210 Here are the APIs that PTS exposes to Jiahao: Get(ch, ts) returns the item with timestamp closest to ts Get(ch, “oldest”) returns the earliest timestamp Get(ch, “now”) returns the most recent timestamped item in a channel To use the Get primitive, one would write: = Get(ch1, ); //timestamp can be a specific value “ts”, “oldest”, or “now” a) [3 points] Please help Jiahao by filling in the timestamp fields in the following code snippet for accomplishing his desired outcome. = Get(ch1, ______); = Get(ch2, ______); = Get(ch3, ______);
Read DetailsRioVista The context for this question is the same as the pr…
RioVista The context for this question is the same as the previous question. A program using Vista and running on a system with the Rio file cache is trying to atomically update the variables foo and bar within a transaction, where both are within the specified data range. The initial value of each is set to TRUE. Within the transaction, foo is set to FALSE and later bar is set to FALSE. For each question, explain your choice using 1-2 succinct bullets. d) [2 points ] The system crashes just after setting the value of foo. It then crashes again during the recovery process. Does the second crash affect the contents of the persisted data after recovery?
Read DetailsRioVista [2 points] A system with a battery-backed RIO file…
RioVista [2 points] A system with a battery-backed RIO file cache is running Satya’s LRVM (not Vista). With a couple of succinct bullets, explain whether this system would be more performant than running LRVM on a traditional file system without the RIO file cache.
Read DetailsCDN [2 points] Consider a CDN with DNS-based routing to rout…
CDN [2 points] Consider a CDN with DNS-based routing to route client queries to proximal mirror sites, DHT-based object lookup, and eventual consistency to keep the mirrored content in sync. A news article is updated by the origin site from V1 to V2. (Answer True/False with justification. No credit without justification.) Two client queries may receive different versions of the news article .
Read DetailsIn animal models, reintroducing a high-fiber diet in later g…
In animal models, reintroducing a high-fiber diet in later generations is sufficient to fully restore microbial taxa that went extinct in earlier generations without the need for external reintroduction (e.g., transplantation).
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