---
title: "Cache Notes"
description: "Brief notes on caching"
keywords: ["cache", "notes"]
category: "performance"
tags: ["caching"]
---

# Cache Notes

## Overview

Caching stores data closer to where it is needed. Use caching to reduce latency and database load. Common tools include Redis and Memcached. Consider TTL settings carefully. Caching is important for performance. Every application should use some form of caching. Without caching, applications are slow. Caching makes things faster. There are many types of caching available.

## Types of Caches

There are different types of caches. Application caches store data in memory. Distributed caches share data across instances. CDN caches store static assets at the edge. Browser caches store resources locally. Each type of cache has its own use case. You should pick the right cache for your needs. Some caches are faster than others. Some caches are more reliable than others.

## Tips

Keep cache keys short and descriptive. Monitor hit rates to ensure the cache is effective. Invalidate entries on writes to prevent stale data. Use LRU eviction when memory is limited. Avoid caching sensitive data without encryption. Consider using a distributed cache for multi-instance deployments. Set appropriate TTL values based on data volatility. Test cache behavior under load to identify bottlenecks early.

## Common Problems

Cache stampede happens when many requests hit the database at once. Stale data happens when the cache is not invalidated. Memory pressure happens when the cache is too large. Cold start happens when the cache is empty. These are all common problems. You should be aware of these problems. There are solutions for each of these problems. The solutions depend on your specific situation.

## Summary

Caching is a fundamental technique. Use it wisely. Monitor it carefully. Invalidate it properly. Choose the right eviction policy. Consider your data access patterns. Think about consistency requirements. Plan for cache failures.
