The JusDB Database Engineering Blog

A top-down playbook for high-performance MongoDB: measure with the profiler and explain(), model for access patterns, index by the ESR rule, keep the working set in the WiredTiger cache, pool connections, and scale reads with secondaries and sharding — with flow diagrams for each layer.

Complete MongoDB guide covering document modeling, aggregation pipelines, sharding, replication, and Atlas deployment. Learn when MongoDB is the right choice for your application.

Navigate the open source database landscape. Compare MySQL, PostgreSQL, MongoDB, Redis, and Cassandra with detailed feature analysis and selection criteria.

Compare ScyllaDB and Apache Cassandra — throughput, latency, operational complexity, and when to switch

Choose the right Cassandra compaction strategy for your workload — STCS for write-heavy, LCS for read-heavy, TWCS for time-series

Model Cassandra from access patterns, distribute and bound partitions, and operate time-series TTL and compaction without relying on dangerous shortcuts.

Compare Redis RDB snapshots and AOF logging — durability trade-offs, performance impact, and recovery scenarios

Configure Redis Cluster for horizontal scaling — hash slots, replication, failover, and client-side routing

Master MongoDB aggregation pipeline stages — $lookup, $group, $facet, explain plans, and index optimization

Design MongoDB sharded clusters — choose shard keys, manage chunk balancing, and avoid hot shards in production

MongoDB's Slot-Based Execution (SBE) engine introduced a plan cache memory leak affecting certain MongoDB versions — here's how to detect, mitigate, and fix it.

A critical bug in MongoDB 8.0 (SERVER-97368) affects TTL index behavior — causing documents to persist beyond expiration or delete prematurely. Here's how to detect and mitigate it.