Commit Graph
3 Commits
Author SHA1 Message Date
Claude b81af72bc3 Add spring-batch: jobs, steps, chunk processing and restartability on Boot 4.1
Companion code for "Spring Batch on Boot 4.1: Jobs, Steps, Chunk Processing and
Restartability". A productImportJob configured three ways by profile against a
poisoned CSV row, run as real java -jar processes (not just JUnit) so the
restart story is genuine: a chunk fails and rolls back, the process exits, a
brand-new JVM against the same file-based H2 database resumes at the exact
next unread row (READ_COUNT 20, not 60) and completes.

Findings the build pins:
- StepBuilder.chunk(int, PlatformTransactionManager) still compiles in Batch
  6.0.5 but returns the legacy SimpleStepBuilder; chunk(int) returns the new
  ChunkOrientedStepBuilder, and only the latter is used here.
- Two different ExecutionContext classes now exist in two different packages
  (infrastructure.item vs core.repository.persistence) with different shapes.
- spring-boot-starter-batch alone gives a resourceless JobRepository that
  forgets every JobInstance the moment the JVM exits; spring-boot-starter-
  batch-jdbc is what makes the restart demo possible at all, demonstrated by
  excluding BatchJdbcAutoConfiguration and watching a "restart" collide with
  the previous run's own data instead of resuming it.
- A migration-guide summary claiming CommandLineJobRunner was removed in 6.0
  is wrong -- javap against the real jar shows @Deprecated(forRemoval=true),
  not removed.
- RepeatStatus moved from core.repeat to infrastructure.repeat, caught by the
  compiler rather than by reading docs.

11 documentation chapters, 10 captured transcripts (unit tests, javap output,
and real two-JVM scenario runs), all regenerated by scripts/run-all.sh.

Fixed after push: three dead docs.spring.io links in the doc chapters
(readersAndWriters/* and chunk-oriented-processing/*.html paths moved when
Spring Batch 6 reorganized its reference docs; corrected to the current
readers-and-writers/*, processor.html and chunk-oriented-processing.html
paths, verified 200 via curl before committing).

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_019DXsJ1zpikbA1MQJN6RqFA
2026-09-13 06:37:46 +00:00
asmhatre 958b401f0f Spring Boot startup time: bean-by-bean diagnosis, and one directory per post
Adds spring-boot-startup-time/, the companion project for BLOG-618: a runnable
Spring Boot 4.1.1 application on JDK 25 that installs BufferingApplicationStartup
and FlightRecorderApplicationStartup behind a system property, and a /diag/startup
endpoint that computes step self time -- the number /actuator/startup does not give
you and the one that names the actual culprits.

Captured under docs/output/: the step tree sorted both ways, the same startup as JFR
events, a +5000-class experiment putting 0.11 ms per scanned class on the classpath
scan tax, the silent truncation a 2048-step buffer performs, and JDK 25 AOT cache
timings (6.93 s to 4.82 s). Post body and metadata live in post/.

Moves the existing Actuator project into actuator-in-production/ so the repository
holds one directory per article; the root README is now an index.
2026-09-05 00:17:37 +05:30
asmhatre 4b6cefa60a Spring Boot 4 Actuator in production: endpoints, security, custom health indicators
Companion repository for the ankurm.com article. Every transcript in docs/output/
was produced by running this project; scripts/run-all.sh regenerates all of them.

Verified against Spring Boot 4.1.1 / Framework 7.0.9 / Security 7.1.1 /
Micrometer 1.17.1 / kafka-clients 4.2.1 on Temurin JDK 25.0.4.1+1.
2026-09-04 10:40:04 +05:30