Apache Cassandra Developer Associate case studies
Apache Cassandra Developer Associate · Put your knowledge to work in context.
The Cassandra Developer Associate credential is an entry-level certification for software engineers who build applications on Apache Cassandra rather than administer clusters. It signals that you can model data around query patterns, write correct CQL, and use a client driver without fighting the database's distributed nature. The Apache Cassandra Developer Associate case studies are 5 cases and about 4,477 words.
1Choosing Consistency After Adding a Second Data Center
A retail platform runs Apache Cassandra 4.1 on 12 nodes: 6 in dc1 (the application data center) and 6 in dc2 (disaster recovery, added eight months ago). The keyspace uses NetworkTopologyStrategy with replication factor {'dc1': 3, 'dc2': 3}.
940 words, about 5 min2Bounding a Runaway Telemetry Partition
A mobility team runs a 6-node cluster (RF 3) holding vehicle telemetry: CREATE TABLE telemetry (vehicle id uuid, event time timestamp, lat double, lon double, speed int, PRIMARY KEY (vehicle id, event time)) WITH CLUSTERING ORDER BY (event time DESC); The fleet has 60,000 vehicles. Most ping every 30 s, but about 200 buses ping every 200 ms.
879 words, about 4 min3Secondary Index on a Low-Cardinality Status Column
An order service stores 400 million rows in orders (customer id uuid, order ts timestamp, status text, total decimal, PRIMARY KEY (customer id, order ts)) . status has 5 distinct values and about 4% of orders are PENDING.
879 words, about 4 min4Latency Above the Server, and a Counter That Drifts
A Java application uses DataStax driver 4.15 against a 9-node single-DC cluster with RF 3, reading and writing at LOCAL QUORUM. Application-side p99 write latency is 90 ms, but every node reports server-side write p99 of about 4 ms.
862 words, about 4 min5TTL, Tombstones and Compaction Backlog on a Metrics Table
A metrics platform writes about 20,000 rows/s into a time-series table with default time to live = 2592000 (30 days) and the default gc grace seconds. Compaction uses the default SizeTieredCompactionStrategy.
917 words, about 5 min