D-ECS-DS-23 · Question #43
XOR chunks are used to reconstruct secondary copy.
The question as presented appears incomplete - the correct answer field is blank, and only one distractor (D) is visible. Here's what I can explain based on what's provided: The core concept being tested is the distinction between data reconstruction and normal read operations…
Question
XOR chunks are used to reconstruct secondary copy.
Options
- D
- Load balancer routes read request to one of the sites available.
Explanation
The question as presented appears incomplete - the correct answer field is blank, and only one distractor (D) is visible. Here's what I can explain based on what's provided:
The core concept being tested is the distinction between data reconstruction and normal read operations in distributed or replicated storage systems. XOR-based chunk reconstruction is a recovery mechanism: when a data segment is lost or unavailable, the system uses XOR parity across remaining chunks to mathematically rebuild the missing piece - this is the foundation of RAID-5/6 parity and erasure coding.
Why D is a distractor: Load balancer routing a read request to "one of the sites available" describes a normal, healthy-state read in an active-active replication setup - not reconstruction. If data is simply available at multiple sites, no XOR math is needed; the load balancer just picks one.
The key distinction to remember: XOR reconstruction kicks in when a copy is missing or degraded (failure/recovery path), while load balancing operates when copies are healthy and accessible (normal I/O path). They serve opposite scenarios.
Memory tip: Think "XOR = eXtra Operation Required" - you only do the extra math when something is broken. If everything is fine, a load balancer handles it with no reconstruction needed.
Note: The question may be missing answer choices. If you have the full option set, share it and I can give a more precise breakdown.
Topics
Community Discussion
No community discussion yet for this question.