Add kafka-streams module: fraud detection topology tested with TopologyTestDriver

Similarity scoring, a 5-minute windowed count that alerts once, and a KTable blocklist join, with the Spring wiring on Spring Boot 4.1.1 and Kafka Streams 4.2.1. Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_01RjfyTgmERTWLqzafu34Cth
2026-10-14 06:44:56 +00:00
parent 5db56e70a0
commit 59fcdbe079
19 changed files with 520 additions and 0 deletions
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+c1,4700.0,3,crypto                       score=1.0000
+c1,3000.0,2,electronics                  score=1.0000
+c1,45.0,18,grocery                       score=-0.1185
+c1,120.0,13,electronics                  score=0.1387
+c1,2500.0,14,crypto                      score=0.2136
+threshold: 0.98
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+alerts <- c1 SIMILAR:1.0000:c1,4700.0,3,crypto
+alerts emitted: 1
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+alerts <- c9 VELOCITY:4 in 5m
+alerts emitted for 6 transactions in 2 minutes: 1
+alerts after one more transaction 10 minutes later: 0
+state store window 2026-10-14T10:00:00Z count=6
+state store window 2026-10-14T10:10:00Z count=1
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+before blocking, alerts: 0
+alerts <- c5 BLOCKED:reported stolen
+after the tombstone, alerts: 0
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+Topologies:
+   Sub-topology: 0
+    Source: KSTREAM-SOURCE-0000000000 (topics: [transactions])
+      --> KSTREAM-AGGREGATE-0000000005, KSTREAM-JOIN-0000000013, KSTREAM-MAPVALUES-0000000001
+    Processor: KSTREAM-AGGREGATE-0000000005 (stores: [txn-count-5m])
+      --> KTABLE-TOSTREAM-0000000006
+      <-- KSTREAM-SOURCE-0000000000
+    Processor: KSTREAM-MAPVALUES-0000000001 (stores: [])
+      --> score
+      <-- KSTREAM-SOURCE-0000000000
+    Processor: KTABLE-TOSTREAM-0000000006 (stores: [])
+      --> KSTREAM-FILTER-0000000007
+      <-- KSTREAM-AGGREGATE-0000000005
+    Processor: KSTREAM-FILTER-0000000007 (stores: [])
+      --> KSTREAM-MAP-0000000008
+      <-- KTABLE-TOSTREAM-0000000006
+    Processor: score (stores: [])
+      --> KSTREAM-FILTER-0000000003
+      <-- KSTREAM-MAPVALUES-0000000001
+    Processor: KSTREAM-FILTER-0000000003 (stores: [])
+      --> KSTREAM-SINK-0000000004
+      <-- score
+    Processor: KSTREAM-JOIN-0000000013 (stores: [blocked-cards-STATE-STORE-0000000010])
+      --> KSTREAM-SINK-0000000014
+      <-- KSTREAM-SOURCE-0000000000
+    Processor: KSTREAM-MAP-0000000008 (stores: [])
+      --> KSTREAM-SINK-0000000009
+      <-- KSTREAM-FILTER-0000000007
+    Source: KSTREAM-SOURCE-0000000011 (topics: [blocked-cards])
+      --> KTABLE-SOURCE-0000000012
+    Sink: KSTREAM-SINK-0000000004 (topic: alerts)
+      <-- KSTREAM-FILTER-0000000003
+    Sink: KSTREAM-SINK-0000000009 (topic: alerts)
+      <-- KSTREAM-MAP-0000000008
+    Sink: KSTREAM-SINK-0000000014 (topic: alerts)
+      <-- KSTREAM-JOIN-0000000013
+    Processor: KTABLE-SOURCE-0000000012 (stores: [blocked-cards-STATE-STORE-0000000010])
+      --> none
+      <-- KSTREAM-SOURCE-0000000011
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+StreamsBuilderFactoryBean present: true
+auto-startup: false
+running: false