The JusDB Database Engineering Blog

Redis Sentinel and Redis Cluster both provide HA, but teams regularly choose the wrong one. Sentinel is simpler and covers 95% of use cases; Cluster is required for horizontal scale. Here's when to choose each.

Aerospike 7.0 delivers 1 million writes per second with sub-millisecond latency using its Hybrid Memory Storage architecture. Learn when Aerospike beats Redis and Cassandra, and how to configure it for production.

FoundationDB powers Apple iCloud and Snowflake's metadata layer with ACID transactions across distributed nodes. Learn how its ordered key-value core, layer architecture, and simulation testing deliver unmatched reliability.

Redis Streams and Kafka both handle millions of events per second, but they solve different problems. Compare latency, retention, delivery guarantees, and operational overhead to choose the right architecture.

Design DynamoDB access patterns with composite keys, sparse GSIs, paginated queries, transactions, and evidence-based capacity planning.

Manage Elasticsearch indexes with ILM policies, correct shard sizing, and force merge for historical indices. Covers hot/warm/delete phases and cluster health monitoring.

Use Redis Streams for event sourcing and message queues. Covers XADD, XREADGROUP, consumer groups, XAUTOCLAIM for stale messages, and Python producer/consumer examples.

DynamoDB and MongoDB are the two most common NoSQL choices, but cost structures, query flexibility, and operational overhead differ dramatically depending on your access patterns.

MongoDB 8.0 brings significant replication improvements including faster elections, durable oplog writes, and changes to write concern behavior. Here's what changed and how to take advantage of it.

MongoDB indexes fragment over time as documents are inserted, updated, and deleted. Here's how to detect fragmentation, measure its performance impact, and rebuild indexes safely.

Day-to-day MongoDB replica set operations: adding/removing members, triggering elections, diagnosing replication lag, and managing oplog size.

An honest comparison of MongoDB and PostgreSQL in 2026 — document model vs relational model, JSONB as a document store, ACID transaction trade-offs, horizontal scaling, licensing, and migration paths.