TOOLS-4309 Fail with a specific error on the upgradeDowngradeViewlessTimeseries oplog entry - #1094
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TOOLS-4309 Fail with a specific error on the upgradeDowngradeViewlessTimeseries oplog entry#1094mattb-mdb wants to merge 1 commit into
mattb-mdb wants to merge 1 commit into
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…Timeseries oplog entry SERVER-114505 adds an oplog-only upgradeDowngradeViewlessTimeseries command, emitted during setFCV transitions across 8.x <-> 9.0 to convert timeseries collections between their viewful and viewless forms. Because knownCommands is a closed allowlist, mongorestore --oplogReplay aborted on it with a generic "unknown oplog command name" error. Neither one-line mitigation is correct. Allowlisting the entry lets it fall through to ApplyOp, but filterUUIDs strips ui unless --preserveUUID is set and the server handler tripwire-asserts that the UUID is present. Ignoring the entry skips the conversion, leaving the collection in a form that does not match the namespaces used by the oplog entries after it. Instead, intercept the command before the allowlist check and fail with a diagnostic naming the conversion and pointing at --oplogLimit. Also adds TestTimeseriesDumpConcurrentWithSetFCV, which resolves an open question from the investigation: a mongodump whose read is interrupted by the conversion fails with the server's InterruptedDueToTimeseriesUpgradeDowngrade error rather than silently producing a truncated dump.
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SERVER-114505 adds an oplog-only upgradeDowngradeViewlessTimeseries command, emitted during setFCV transitions across 8.x ↔ 9.0 to convert timeseries collections between their viewful and viewless forms. Because knownCommands is a closed allowlist, mongorestore --oplogReplay aborted on it with a generic unknown oplog command name error.
Changes
mongorestore/oplog.go — intercept the command ahead of the allowlist check and fail with a diagnostic that names the conversion, gives the timestamp, and points at --oplogLimit.
The entry is deliberately neither applied nor skipped. Allowlisting it would trip a server-side assertion (filterUUIDs strips ui unless --preserveUUID is set, and the handler asserts the UUID is present); ignoring it would leave the collection in a form that doesn't match the namespaces used by later oplog entries. Refusing the replay is the correct outcome.
Tests
TestOplogRestoreViewlessTimeseriesConversion (mongorestore/oplog_test.go) — builds a synthetic oplog with an insert followed by the conversion entry, in both the upgrade and downgrade (skipViewCreation) forms, and asserts the specific error. Also asserts the pre-conversion insert was applied, proving replay stops at the conversion. Synthetic, so it runs on any server version.
TestTimeseriesDumpConcurrentWithSetFCV (mongodump/mongodump_test.go) — resolves an open question from the investigation: a mongodump that overlaps a setFCV. Blocks the dump's getMore with the failCommand failpoint, runs setFCV 9.0 → 8.0 underneath it, and asserts the dump either contains every measurement or fails outright — never a silent truncation. Against 9.0.0-rc0 the server aborts the read with InterruptedDueToTimeseriesUpgradeDowngrade, so this is a hard error rather than data loss, and needs no tools-side change. Requires enableTestCommands=1 (CI has it); skips below 9.0 / FCV 9.0.