Content tagged with "java"
Upgraded AWS JDBC Wrapper from 2.6.4 to 3.2.0 and re-tested Blue/Green Switchover on both PostgreSQL and MySQL. MySQL's connection failure turned out to be timing-dependent (0–1 failures). Summarizes 3.x migration guidance.
Tested Blue/Green Switchover on Aurora MySQL and compared with PostgreSQL. IN_PROGRESS phase was only 3s (vs 12s for PG), but the BG plugin may have 0–1 connection errors (timing-dependent). HikariCP's stale writer problem is engine-agnostic. Plain JDBC stayed on old host for 31s after recovery.
Compared downtime during Blue/Green Switchover across Plain JDBC, HikariCP with retry, and AWS JDBC Driver BG plugin. The plugin recorded 0 failures in 400 queries during testing. HikariCP kept connecting to the old writer — a critical pitfall.
aws-advanced-jdbc-wrapper 2.6.4 brings in slf4j-api 1.7.36 as a transitive dependency, conflicting with HikariCP 6.x which requires SLF4J 2.x. Exclude 1.7 and explicitly declare slf4j-api 2.0.
All connections are dropped during Blue/Green Switchover, but HikariCP may reconnect to the old writer via DNS cache. Write queries fail with read-only transaction errors. Same behavior on both PostgreSQL and MySQL.