Microsoft DP-700 Practice Test 27
Question 260
A source is connected and a default stream appears automatically. What should the operator understand?
- Use a supported Manage Fields transformation to select and rename output fields.
- Publish the modified Eventstream so destination changes take effect.
- Apply a Filter transformation before the critical-alarm destination.
- Use the generated default stream as the raw event flow before any derived transformations.
Explanation
Correct Answer
D:Every Eventstream source flow produces the default stream; a derived stream appears after supported operations are defined. Compare raw and transformed stream records.
Incorrect Answers
A:Field management shapes streaming events before delivery without changing the source producer.
B:Editing the stream canvas alone does not activate changes in the running eventstream.
C:A filter restricts events using explicit conditions while preserving the upstream raw stream for other outputs.
Question 261
A KQL analyst wants event counts in disjoint five-minute buckets. Which expression pattern fits?
- Use a sliding window of ten minutes with a two-minute slide.
- Use summarize count() by bin(event_time, 5m) in KQL.
- Make the foreachBatch write idempotent using batch identifiers or stable business keys.
- Increase the watermark delay to a justified arrival-lateness tolerance with a state-cost review.
Explanation
Correct Answer
B:Binning creates nonoverlapping time buckets for grouped event counts. Test records around a five-minute boundary.
Incorrect Answers
A:Sliding windows overlap, unlike tumbling windows, and allow each event to contribute to multiple windows.
C:Custom sinks can re-execute batches after failure; checkpointing alone does not make arbitrary external side effects exactly once.
D:An overly short watermark risks dropping valid late data from stateful results, while a longer delay retains more state.
Question 262
A stream processor needs overlapping ten-minute windows every two minutes. What window type is required?
- Filter invalid readings and summarize avg(temperature) by plant_id, bin(event_time, 1h).
- Use a sliding window of ten minutes with a two-minute slide.
- Define an event-time watermark based on acceptable source lateness.
- Increase the watermark delay to a justified arrival-lateness tolerance with a state-cost review.
Explanation
Correct Answer
B:Sliding windows overlap, unlike tumbling windows, and allow each event to contribute to multiple windows. Check an event's membership in consecutive windows.
Incorrect Answers
A:Filtering invalid values before grouped averaging yields interpretable per-plant, per-hour measures.
C:Watermarks bound old aggregation state while retaining events within the planned lateness tolerance.
D:An overly short watermark risks dropping valid late data from stateful results, while a longer delay retains more state.
Question 263
A Spark streaming aggregation retains huge state because late data is unbounded. What should be configured?
- Define an event-time watermark based on acceptable source lateness.
- Filter invalid readings and summarize avg(temperature) by plant_id, bin(event_time, 1h).
- Use a sliding window of ten minutes with a two-minute slide.
- Make the foreachBatch write idempotent using batch identifiers or stable business keys.
Explanation
Correct Answer
A:Watermarks bound old aggregation state while retaining events within the planned lateness tolerance. Measure state size and test delayed events.
Incorrect Answers
B:Filtering invalid values before grouped averaging yields interpretable per-plant, per-hour measures.
C:Sliding windows overlap, unlike tumbling windows, and allow each event to contribute to multiple windows.
D:Custom sinks can re-execute batches after failure; checkpointing alone does not make arbitrary external side effects exactly once.
Question 264
A monitoring query must identify the latest event for each device while retaining the associated payload. Which KQL pattern is suitable?
- Increase the watermark delay to a justified arrival-lateness tolerance with a state-cost review.
- Define an event-time watermark based on acceptable source lateness.
- Give each distinct streaming query its own durable checkpoint location.
- Use summarize arg_max(event_time, *) by device_id.
Explanation
Correct Answer
D:Arg_max selects a row corresponding to each group's maximum timestamp, unlike max() alone, which loses other row fields. Compare returned payloads with known latest timestamps.
Incorrect Answers
A:An overly short watermark risks dropping valid late data from stateful results, while a longer delay retains more state.
B:Watermarks bound old aggregation state while retaining events within the planned lateness tolerance.
C:Checkpoint metadata belongs to one query's offsets and state; sharing directories can corrupt recovery and duplicate results.
Question 265
A producer sometimes sends events 15 minutes late, but the Spark watermark is five minutes. What should the engineer reconsider?
- Filter invalid readings and summarize avg(temperature) by plant_id, bin(event_time, 1h).
- Use summarize count() by bin(event_time, 5m) in KQL.
- Use summarize arg_max(event_time, *) by device_id.
- Increase the watermark delay to a justified arrival-lateness tolerance with a state-cost review.
Explanation
Correct Answer
D:An overly short watermark risks dropping valid late data from stateful results, while a longer delay retains more state. Replay 15-minute-late events and monitor state size.
Incorrect Answers
A:Filtering invalid values before grouped averaging yields interpretable per-plant, per-hour measures.
B:Binning creates nonoverlapping time buckets for grouped event counts.
C:Arg_max selects a row corresponding to each group's maximum timestamp, unlike max() alone, which loses other row fields.
Question 266
A structured streaming job restarts and unexpectedly repeats output after using a shared checkpoint directory. What design is required?
- Give each distinct streaming query its own durable checkpoint location.
- Use summarize count() by bin(event_time, 5m) in KQL.
- Define an event-time watermark based on acceptable source lateness.
- Make the foreachBatch write idempotent using batch identifiers or stable business keys.
Explanation
Correct Answer
A:Checkpoint metadata belongs to one query's offsets and state; sharing directories can corrupt recovery and duplicate results. Restart two queries independently and verify offsets.
Incorrect Answers
B:Binning creates nonoverlapping time buckets for grouped event counts.
C:Watermarks bound old aggregation state while retaining events within the planned lateness tolerance.
D:Custom sinks can re-execute batches after failure; checkpointing alone does not make arbitrary external side effects exactly once.
Question 267
A KQL query must return hourly average temperature by plant while excluding null sensor values. What aggregation fits?
- Increase the watermark delay to a justified arrival-lateness tolerance with a state-cost review.
- Filter invalid readings and summarize avg(temperature) by plant_id, bin(event_time, 1h).
- Make the foreachBatch write idempotent using batch identifiers or stable business keys.
- Use a sliding window of ten minutes with a two-minute slide.
Explanation
Correct Answer
B:Filtering invalid values before grouped averaging yields interpretable per-plant, per-hour measures. Verify one known hourly sample by hand.
Incorrect Answers
A:An overly short watermark risks dropping valid late data from stateful results, while a longer delay retains more state.
C:Custom sinks can re-execute batches after failure; checkpointing alone does not make arbitrary external side effects exactly once.
D:Sliding windows overlap, unlike tumbling windows, and allow each event to contribute to multiple windows.
Question 268
A foreachBatch Spark sink writes to a nontransactional service and duplicates records after recovery. Which safeguard is needed?
- Make the foreachBatch write idempotent using batch identifiers or stable business keys.
- Increase the watermark delay to a justified arrival-lateness tolerance with a state-cost review.
- Use summarize count() by bin(event_time, 5m) in KQL.
- Define an event-time watermark based on acceptable source lateness.
Explanation
Correct Answer
A:Custom sinks can re-execute batches after failure; checkpointing alone does not make arbitrary external side effects exactly once. Replay a batch and compare target records.
Incorrect Answers
B:An overly short watermark risks dropping valid late data from stateful results, while a longer delay retains more state.
C:Binning creates nonoverlapping time buckets for grouped event counts.
D:Watermarks bound old aggregation state while retaining events within the planned lateness tolerance.
Question 269
A Copy activity repeats three times and ultimately succeeds, but the SLA misses its deadline. What run information helps explain delay?
- Use the unique pipeline run ID in the monitoring view.
- Inspect per-attempt retry counts, error reasons, and the duration contributed by retries.
- Review pipeline activity start/end times and success dependency configuration.
- Track concurrent run counts, queueing or activity durations, and capacity pressure over time.
Explanation
Correct Answer
B:A final success can hide repeated backoff and lost time; activity attempt history reveals why the total run was slow. Compare the retry timeline with a normal successful run.
Incorrect Answers
A:Run IDs distinguish executions of the same pipeline, including reruns using identical parameters.
C:Execution ordering is visible in the activity timeline and should match the intended dependency graph.
D:Peak load diagnosis needs a time series of execution and resource behavior, not one successful sample.
Question 270
A pipeline has been intermittently failing for weeks. Where can an engineer review status across multiple executions?
- Use the Fabric monitoring hub run history filtered for the pipeline.
- Review pipeline activity start/end times and success dependency configuration.
- Track concurrent run counts, queueing or activity durations, and capacity pressure over time.
- Follow the upstream/downstream run relationship to the specific child run.
Explanation
Correct Answer
A:Run history exposes success, failure, and duration patterns that a single editor execution cannot show. Plot failure timestamps by run ID.
Incorrect Answers
B:Execution ordering is visible in the activity timeline and should match the intended dependency graph.
C:Peak load diagnosis needs a time series of execution and resource behavior, not one successful sample.
D:Run hierarchy connects orchestration stages so the relevant child error is not lost in parent status.