State of Cassandra, 2011
- 1. State of Cassandra 2011 Jonathan Ellis Apache Chair CTO DataStax
- 2. Job Trends from Indeed.com 2
- 3. Customer and Verticals • Financial • Social Media • Advertising • Entertainment • Energy • E-tail • Health care • Government 3
- 4. Why? Why? 4 4
- 5. 5
- 7. Better technology • Multi-master, multi-DC • Linearly scalable • Larger-than-memory datasets • Best-in-class performance (not just writes!) • Fully durable • Integrated caching • Tuneable consistency 7
- 8. Tunable Consistency WRITE READ Level Level ANY ONE ONE LOCAL_QUORUM LOCAL_QUORUM QUORUM QUORUM ALL ALL
- 9. Generalizes Easily to Multi-DC 9
- 10. 0.7 • CREATE COLUMN FAMILY • Expiring columns (TTL) • Secondary (column) indexes • Efficient streaming 1 0
- 11. 0.8 • CQL • Counters • Automatic memtable tuning • New bulk load interface 1 1
- 12. A performance retrospective 1 2
- 13. October 8, 2011 Road to 1.0 13
- 14. Theme: polish • Repair • Compaction • Optimize reads for update-heavy workloads • CQL 1.1 1 4
- 15. Repair • Consistency is checked per-ColumnFamily but data is transferred per-Keyspace • Merkle trees requests are sent en masse, but may not execute start at the same time 1 5
- 16. Compression • Rows-per-block or blocks-per-row 1 6
- 17. Read Performance: Compaction 1 7
- 18. Level-based Compaction • SSTables are non-overlapping within a level • Bounds the number that can contain a given row L2: 1000 MB L1: 100 MB L0: newly flushed 1 8
- 19. Read performance: maxtimestamp • Sort sstables by maximum (client-provided) timestamp • Only merge sstables until we have the columns request • Allows pre-merging highly fragmented rows without waiting for compaction 1 9
- 20. CQL cqlsh> SELECT * FROM users WHERE state='UT' AND birth_date > 1970;! KEY | birth_date | full_name | state | bsanderson | 1975 | Brandon Sanderson | UT | 2 0
- 21. CQL 1.1 • ALTER • Counter support • TTL support • Compound columns • Prepared statements 2 1
- 22. Post-1.0 • Ease of use • Ease of use • Ease of use 2 2
- 23. Post-1.0 features • “Native” CQL transport • Triggers • Entity groups • Smarter range queries 2 3
- 24. Brisk • Analytics for your realtime data without ETL • Widens scope of Cassandra’s applicability • Also: Solandra 2 4
- 25. Questions Ques/ons? 25 25