Date post: | 01-Nov-2014 |
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State of Cassandra 2011
Jonathan Ellis Apache Chair CTO DataStax
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Job Trends from Indeed.com
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• Financial • Social Media • Advertising • Entertainment • Energy • E-tail • Health care • Government
Customer and Verticals
Why?
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Why?
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Why Cassandra?
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Why Cassandra?
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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
Tunable Consistency
Level
ANY
ONE
LOCAL_QUORUM
QUORUM
ALL
WRITE READ Level
ONE
LOCAL_QUORUM
QUORUM
ALL
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Generalizes Easily to Multi-DC
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0.7
• CREATE COLUMN FAMILY • Expiring columns (TTL) • Secondary (column) indexes • Efficient streaming
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0.8
• CQL • Counters • Automatic memtable tuning • New bulk load interface
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A performance retrospective
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Road to 1.0 October 8, 2011
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Theme: polish
• Repair • Compaction • Optimize reads for update-heavy workloads • CQL 1.1
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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
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Compression • Rows-per-block or blocks-per-row
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Read Performance: Compaction
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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
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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
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CQL
cqlsh> SELECT * FROM users WHERE state='UT' AND birth_date > 1970;! KEY | birth_date | full_name | state | bsanderson | 1975 | Brandon Sanderson | UT |
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CQL 1.1
• ALTER • Counter support • TTL support • Compound columns • Prepared statements
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Post-1.0 • Ease of use
• Ease of use
• Ease of use
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Post-1.0 features
• “Native” CQL transport • Triggers • Entity groups • Smarter range queries
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Brisk • Analytics for your
realtime data without ETL
• Widens scope of Cassandra’s applicability
• Also: Solandra
Questions
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Ques/ons?