Tag: Outbox
All the articles with the tag "Outbox".
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[JPA + Spring Mastery 08] Transaction Split Patterns — Saga / Outbox / REQUIRES_NEW, from academic origins to a 9-scenario EXP-09b measurement
The maxim *don't call external APIs inside a transaction* is well known; the *how* is rarely treated honestly. This article goes from PROPAGATION's seven semantics to 2PC (XA)'s limits, to Garcia-Molina's 1987 Sagas paper, Pat Helland's CIDR 2005 Data on the Outside, and Vogels's ACM Queue 2008 Eventually Consistent — then through Toss SLASH24's SAGA, 29CM and Ridi's Outbox in production — and lands on the EXP-09b 9-scenario measurement matrix (patterns A/B/C × OFF/DB_FAIL/EXT_FAIL). Payments to Saga, notifications to Outbox, cache only to plain split — academic + production + measurement, in three layers.
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External API Calls Inside Transactions — Reproducing Pool Exhaustion and Comparing Simple Split, Saga, and Outbox by Measurement
I reproduced HikariCP pool exhaustion caused by external API calls inside transactions in a Spring + raw JDBC environment, then compared three remedies — Simple Split, Saga, and Outbox — across 60 workers × 9 chaos scenarios. I caught the moment Simple Split breaks consistency as 60 mismatched records, watched Saga's three-tier safety net trigger in sequence, and saw how Outbox's 72ms ACK and 93-second average completion split the same dataset into opposite conclusions depending on which metric you read.