fix(upload-journal): accept Amazon Aurora PostgreSQL (full_page_writes=off) #65
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Reference: QRun-IO/qbit-collaboration#65
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The retained upload journal's PostgreSQL 17 qualification (
PostgresJournalDatabase) refuses every call unlesscurrent_setting('full_page_writes')ison. Amazon Aurora PostgreSQL reportsfull_page_writes = off(measured on engine 17.9: context sighup, source default, not present in the cluster parameter group), so the journal cannot be used there.Rule implemented
to_regprocedure('aurora_version()') IS NOT NULL. It is true on Aurora, false on stock PostgreSQL 17, and never raises.full_page_writesqualifies when it ison, or when it isoffand that column is true (PostgresJournalDatabase.tornPagesPrevented).full_page_writes = offis still refused. On Aurora,synchronous_commit,fsync, recovery state, read-only state, isolation, time zone, lock timeout (1 to 5000 ms), server version, catalog, table and index checks are exactly as before. The refusal message is unchanged.Why it is safe on Aurora and not on stock PostgreSQL: stock PostgreSQL repairs a partly written page from the full page image in the write-ahead log, so
offcan lose committed rows after a crash. Aurora's storage layer does not write torn pages, and the parameter cannot be changed there.Known limit, documented in
docs/RETAINED-UPLOAD-JOURNAL.md: the detection is a name lookup, so a function namedaurora_version()on the search path of a stock server is reported as Aurora.Other places with the same assumption
full_page_writesis read in one place only,PostgresJournalDatabase.MySqlJournalDatabase(MySQL 8.4innodb_doublewrite, Aurora MySQL refused) and the H2WRITE_DELAY=0check are different backends and are not changed.Tests
PostgresJournalDatabaseTest(always runs, no database): the pure decision, and that the settings query detects Aurora only throughto_regprocedureas its last column.PostgresUploadJournalTest(opt-in with-DpostgresJournalTests=true, realpostgres:17container), three new cases: the settings query returns the detection column as the application role without aborting the transaction;full_page_writes = offis refused on stock PostgreSQL and accepted once Aurora is detected; Aurora withsynchronous_commitoff orfsyncoff is still refused.aurora_version()is created in the test database soto_regprocedureresolves, andfull_page_writes(andfsync) are turned off on the stock server withALTER SYSTEMand a reload. The container no longer passesfsync=onandfull_page_writes=onon the command line, because a command-line value cannot be changed by a reload; both are set toonwithALTER SYSTEMat start and before every test.Verification
Local, Windows 11, Java 21, Docker 29.9.2, commit
2837f41(cherry-pick ofc6edde7from therelease/1.1pull request; the two commits differ only inpom.xml, which neither changes):./mvnw -B verifyresults for this branch are added as a comment.Same change as the
release/1.1pull request, fordevelop, so the next1.2and later builds keep the rule.release/1.2is not changed by either pull request.Not merged, tagged or released by the author.
🤖 Generated with Claude Code
The PostgreSQL 17 journal qualification refused every call on Amazon Aurora PostgreSQL, which reports full_page_writes=off and does not expose the parameter in its cluster parameter group. - The settings query gains an eleventh column, to_regprocedure('aurora_version()') IS NOT NULL, which is true on Aurora, false on stock PostgreSQL 17 and never raises. - full_page_writes=off is accepted only when that column is true. Stock PostgreSQL with full_page_writes=off is still refused, and synchronous_commit, fsync, recovery, isolation, time zone and lock timeout are unchanged on Aurora. - The decision is the pure function tornPagesPrevented, covered by an always-on unit test. The opt-in real PostgreSQL 17 suite simulates Aurora with a function named aurora_version() and full_page_writes=off on the server. Co-Authored-By: Claude Fable 5.2 <noreply@anthropic.com>Verification of commit
2837f41(this pull request's head; cherry-pick ofc6edde7from #64).Local, Windows 11, Java 21, Docker 29.9.2:
./mvnw -B -DpostgresJournalTests=true verify, one run: 335 tests run, 0 failures, 0 errors, 11 skipped, Checkstyle 0 violations,All coverage checks have been met, BUILD SUCCESS. Within itPostgresUploadJournalTest(realpostgres:17container, includes the three Aurora cases) ran 15 tests with 0 failures, 0 errors, 0 skipped, andPostgresJournalDatabaseTestran 3 with 0 failures. The 11 skipped are the opt-inMySqlUploadJournalTest.Gitea Actions run 7339 (
build.yaml, push of this branch): completed, success, first attempt. Its log showsBuild kind: verify,Tests run: 335, Failures: 0, Errors: 0, Skipped: 26,BUILD SUCCESS. CI does not enablepostgresJournalTests.