Caching Flashcards
What are L1, L2, and L3 caches in computer hardware, and how do they differ?
L1 cache is the smallest and fastest, integrated into the CPU and stores frequently accessed data. L2 cache is larger but slower than L1, located on the CPU die or a separate chip. L3 cache is larger and slower than L2, often shared between CPU cores.
What is the role of the Translation Lookaside Buffer (TLB) in hardware caching?
The TLB stores recently used virtual-to-physical address translations, enabling the CPU to quickly translate memory addresses, reducing data access time.
What is the function of the page cache and file system caches at the operating system level?
Page cache, managed by the OS and residing in main memory, stores recently used disk blocks. File system caches like inode cache speed up file operations by reducing disk accesses.
How do web browsers and Content Delivery Networks (CDNs) utilize caching at the application front end?
Web browsers cache HTTP responses for faster data retrieval. CDNs cache static content like images and videos on edge servers to speed up content delivery.
What is the role of caching in load balancers and messaging infrastructure like Kafka?
Load balancers can cache responses to reduce back-end server load. Kafka caches messages on disk, allowing consumers to retrieve them at their own pace based on retention policy.
How do distributed caches like Redis and full-text search engines like Elastic Search use caching?
Redis stores key-value pairs in memory for high performance. Elastic Search indexes data for efficient document and log search.
What caching mechanisms are found within databases?
Databases use write-ahead logs (WAL), buffer pools to cache query results, materialized views for precomputed queries, transaction logs for recording updates, and replication logs for tracking database cluster state.
Why is caching data essential in system architecture?
Caching is crucial for optimizing system performance and reducing response time across various layers and applications in a computing system.
What is the significance of the L1 cache being integrated into the CPU?
The integration of L1 cache directly into the CPU minimizes latency, allowing for the fastest possible access to frequently used data and instructions, which enhances CPU performance.
How does the Translation Lookaside Buffer (TLB) improve CPU efficiency?
The TLB improves CPU efficiency by storing recent virtual-to-physical address translations, enabling quick memory address translation and reducing the time required for memory access.
Why is the page cache important in an operating system?
The page cache is important as it stores disk blocks in main memory, allowing the operating system to quickly serve data from memory rather than the slower process of reading from the disk.
What is the advantage of using Content Delivery Networks (CDNs) for caching?
CDNs enhance content delivery by caching static web assets like images and videos closer to the user, reducing latency and bandwidth usage, and improving load times for web pages.
How do load balancers utilize caching to improve system performance?
Load balancers use caching to store responses from back-end servers, allowing them to serve repeated requests more quickly and efficiently, thus reducing the load on back-end servers.
What is the purpose of caching messages in Kafka’s messaging infrastructure?
In Kafka, caching messages on disk allows for efficient message handling and retrieval, enabling consumers to process messages at their own pace and ensuring message availability over extended periods.
How does caching in Redis differ from traditional database operations?
Redis uses in-memory caching for key-value pairs, offering significantly faster read/write performance compared to traditional databases that rely more on disk-based storage.
In what ways do databases implement caching to enhance performance?
Databases implement caching through mechanisms like write-ahead logs for ensuring data integrity, buffer pools for storing frequently accessed data in memory, and materialized views for quick retrieval of complex query results.
Why is the L2 cache slower than the L1 cache?
The L2 cache is larger and typically located further from the CPU core compared to the L1 cache. This increased distance and size result in slightly higher latency, making L2 cache slower than L1.
How does an inode cache enhance file system performance?
The inode cache stores metadata about file system objects (like files and directories), enabling quicker access to this information and reducing the need for frequent disk reads, thus speeding up file system operations.
What role does caching play in HTTP response handling by web browsers?
When a web browser caches HTTP responses, it stores copies of frequently accessed web resources. This allows the browser to load these resources from the cache rather than fetching them again from the web server, speeding up web page loading.
How do databases use Write-Ahead Logs (WAL) for caching?
In databases, WALs are used to record changes before they are written to the main database. This ensures data integrity and allows for recovery in case of a system crash. The WAL also serves as a form of cache by allowing quick writes to a log, reducing immediate write load on the database.
What is the significance of shared L3 cache among CPU cores?
Shared L3 cache among CPU cores allows multiple cores to access a larger common cache. This facilitates efficient data sharing and reduces the need for data duplication across cores, enhancing overall CPU cache utilization.
How does caching in a full-text search engine like Elastic Search improve performance?
Elastic Search uses caching to store frequently accessed data and query results. This accelerates search operations by reducing the need to reprocess or reaccess data from the primary storage, leading to faster search response times.
What is the function of a buffer pool in a database system?
A buffer pool in a database system caches pages of data in memory. This allows quicker access to these pages, reducing disk I/O and improving database query performance.
How do Content Delivery Networks (CDNs) optimize caching based on geographic location?
CDNs cache content in multiple geographically distributed servers (edge servers). This ensures that content is delivered from the nearest server to the user, reducing latency and improving loading times for users in different locations.
What is CPU cache and what type of memory does it use?
CPU cache is the CPU’s internal memory designed to store copies of data and instructions from RAM that the CPU is likely to use frequently. It uses SRAM (Static RAM), which is faster than DRAM (Dynamic RAM) used in RAM modules because it doesn’t need to be constantly refreshed.
How does SRAM differ from DRAM in terms of operation and cost?
SRAM, used in CPU cache, doesn’t require constant refreshing, making it faster than DRAM. However, SRAM is more expensive to produce compared to DRAM.
Why is CPU cache important for computer performance?
CPU cache is crucial because it allows the CPU to access frequently used data quickly. If the needed data is in the cache, the CPU doesn’t have to wait for slower RAM, thus avoiding bottlenecks and enhancing overall computer performance.
What would happen if a computer did not have CPU cache?
Without CPU cache, a computer would be slower because the CPU would frequently have to wait for data from the slower RAM, creating a performance bottleneck.
How are the different levels of CPU cache (L1, L2, and L3) structured and functionally different?
L1 cache, the fastest and smallest, is located on the processor and runs at the processor’s speed. L2 cache is larger but slower than L1 and is used when data isn’t found in L1. L3 cache, larger than L2 but slower, is used when data isn’t in L2. L3 is shared across CPU cores, while L1 and L2 are dedicated to individual cores.
How has the location of the L2 cache evolved in modern CPUs compared to earlier computers?
In earlier computers, the L2 cache was located on a separate chip on the motherboard. In modern CPUs, it is integrated into the processor, which improves its speed and efficiency.
Why is the L3 cache referred to as ‘shared cache’?
The L3 cache is called ‘shared cache’ because it is shared between all the cores on a CPU. This contrasts with L1 and L2 caches, which are dedicated to individual CPU cores.
How do the sizes and speeds of L1, L2, and L3 caches compare?
The L1 cache is the smallest and fastest, L2 is larger but slower than L1, and L3 is the largest but the slowest among the three. Each level of cache is designed to balance speed and size to optimize CPU performance.
What is the role of CPU cache in reducing processing time?
The CPU cache reduces processing time by storing frequently accessed data and instructions close to the CPU. This proximity allows for quicker access compared to fetching data from slower main memory (RAM), thereby speeding up processing.
