Compare Scenarios

Migration Step 1

Both scenarios define a migration step at this stage. Content Management Platform: triggered by 'Content read API p99 > 100ms during peak traffic; PostgreSQL'. Read-Heavy SaaS API: triggered by 'Connection pool exhaustion or p99 read latency > 200ms under'.

Migration Step 2

Both scenarios define a migration step at this stage. Content Management Platform: triggered by 'Full-text search p99 > 500ms; inability to implement faceted'. Read-Heavy SaaS API: triggered by 'Primary CPU > 70% during peak read hours'.

Migration Step 3

Content Management Platform has a defined migration; Read-Heavy SaaS API does not at this stage.

PostgreSQL pg_stat_statements showing > 10 distinct query patterns with high call counts from the content list API path; database queries per second growing linearly with API request rate for content list endpoints (should be sub-linear with proper batch fetching); p99 for content list API > 200ms during moderate traffic

Tier 1: N+1 Query Amplification: ORM-level N+1 patterns in content relationship traversal: author fetch, category fetch, related content fetch as independent queries per article. Recommended evolution: Audit every content API response with query logging enabled and count queries per request for each content type; implement eager loading for all included relationships (JOIN for 1:1, IN-clause batch for 1:N); validate that content list endpoints produce a fixed number of queries regardless of list size (O(1) queries, not O(N)); add a query count assertion to integration tests for content list endpoints to prevent regression .

PostgreSQL read replica CPU spike correlated exactly with publish events; Redis cache hit rate dropping to near 0% immediately after publish for popular content; content API p99 spiking from < 20ms to > 500ms during the 1–3 second window after a high-traffic content item is published

Tier 2: Cache Invalidation Thundering Herd: Cache key deletion on publish triggering simultaneous cache miss stampede for all concurrent readers of popular content. Recommended evolution: Implement cache-aside with probabilistic early expiration (PER): before the cache TTL expires, a fraction of reads proactively refresh the cache value while other reads continue serving the cached value; this eliminates the hard expiry boundary that causes simultaneous misses; alternatively, on publish, write the new content value directly into the cache key before invalidating the old one (update-in-place rather than delete-and-miss) to eliminate the invalidation gap .

p99 database latency rising; connection wait queue growing; requests timing out with "too many connections" or pool queue full errors

Tier 1: Connection Exhaustion: Database connection pool saturated or max_connections exceeded. Recommended evolution: Add PgBouncer connection pooler in transaction mode.

Database CPU > 80% sustained; read query p99 rising; cache miss rate stable but overall latency increasing

Tier 2: Read Throughput Ceiling: Single PostgreSQL primary saturated with read traffic. Recommended evolution: Add one or more streaming read replicas; implement lag-aware replica routing.