Compare Scenarios

Migration Step 1

Both scenarios define a migration step at this stage. Realtime Collaborative Editor: triggered by 'User-visible edit conflicts > 5% of sessions; poll interval '. Developer Tools Platform: triggered by 'First noisy neighbor incident where one tenant's CI burst de'.

Migration Step 2

Both scenarios define a migration step at this stage. Realtime Collaborative Editor: triggered by 'Data loss complaints from users editing simultaneously; conf'. Developer Tools Platform: triggered by 'Kafka publish failures rolling back pipeline completion tran'.

Migration Step 3

Developer Tools Platform has a defined migration; Realtime Collaborative Editor does not at this stage.

Server memory growing with active connections; file descriptor limits approached; new WebSocket connections refused

Tier 1: WebSocket Connection Ceiling: WebSocket server process connection limit or OS file descriptor ceiling. Recommended evolution: Increase file descriptor limits (ulimit); move to dedicated WebSocket server tier; implement connection multiplexing (multiple documents per connection where safe) .

Consecutive writes to the same document causing lock contention; write latency rising; auto-save batching queue depth increasing

Tier 2: Database Write Contention: High-frequency auto-save operations conflicting at the document row level; row-level locking under concurrent user edits . Recommended evolution: Move to operational transformation or CRDT-based conflict resolution; batch writes and resolve conflicts in-process before database commit; consider append-only event log for document operations .

Redis job queue depth > 1000 correlated with a single tenant identifier; other tenants reporting p99 job start time > 60 seconds; tenant-level queue metrics showing one tenant holding > 50% of in-flight worker slots

Tier 1: Job Queue Tenant Noisy Neighbor: Shared Redis queue with shared worker pool allowing one tenant to monopolize available capacity. Recommended evolution: Implement per-tenant queue lanes in Redis (separate key namespaces per tenant, e.g., jobs:{tenant_id}:{priority}); implement a weighted fair scheduler at the worker dispatch layer that reads from tenant queues in round-robin order with priority weighting; cap the number of concurrently executing jobs per tenant to the tenant's quota, not to the total available worker count .

DDL migration duration > 10s on pipeline_runs, jobs, or artifacts tables; migration deployment causing timeout errors for active CI pipeline API calls during the deployment window; pg_locks showing AccessExclusiveLock held by ALTER TABLE statement

Tier 2: PostgreSQL Schema Migration Lock: High-volume tables requiring locking DDL changes during deployments with concurrent tenant activity. Recommended evolution: Adopt zero-downtime migration patterns exclusively: add columns with nullable defaults first (no table lock in PostgreSQL 11+), then backfill, then add constraints via NOT VALID followed by VALIDATE CONSTRAINT in a separate transaction; use pg_repack for table rewrites; never run concurrent index creation without CONCURRENTLY on any table with > 1M rows .