M1: a subscription that dies while the session lives (outage longer than
the subscription lifetime but shorter than the session timeout) used to
end Healthy with fresh keep-alive stamps and frozen values. PublishError
BadNoSubscription / BadSubscriptionIdInvalid naming a tracked
subscription, or a tracked subscription whose SDK PublishingStopped
persists one more keep-alive window + 5 s across good keep-alives, now
declares it lost: Degraded, outage published once, and nothing advances
LastSuccessfulRead until the session is released, so the #527 watchdog
re-initialises and re-subscribes. Both detectors wire-tested.
M2: in-place recovery is bound to the session whose keep-alive recovered;
one overtaken by a re-initialise no longer re-arms the new session's
outage latch or degrades its health (ReadCoreAsync expectedSession).
L1 CAS health updates; L2 re-check before each recovery publish; L3 skip
CloseSession on a lost session; L4 SDK log forwarding rate-limited
(20/min); L5 per-driver SDK LoggerFactory disposed with the driver.
Wire test asserts the read stamp stays frozen while the server is down.
A bad keep-alive now degrades health (LastSuccessfulRead preserved) and,
once per outage, publishes BadNoCommunication (value retained) for every
subscribed ref plus a quality-only annotation on subscribed alarm
conditions. Good keep-alives and data/event notifications advance
LastSuccessfulRead, so an idle-but-alive subscription never looks dead
to the #527 watchdog. A keep-alive that recovers on the same session
re-reads the Bad refs and republishes them Good; a session that does not
come back is recovered by the watchdog's ShutdownAsync + InitializeAsync
+ re-subscribe.
Deletes the SessionReconnectHandler wiring (it retried forever in SDK
1.5.378, cloned subscriptions the driver never re-tracked and kept health
Healthy), OnReconnectComplete, TryRearmReconnect and the reconnect_*
counters (new keepalive_recovered). Teardown of a lost session skips
wire deletes and bounds CloseSession. SDK warnings reach the driver log.
Wire test reworked: restart => Bad, then watchdog-style reinit => Good.
- I-1: QuestDbConnection caps Npgsql Maximum Pool Size at 24 (DefaultMaxPoolSize)
when the connection string does not set it; an explicit value is kept. The
effective value is logged once at Information.
- M-1: QuestDbTagCatalog.EnsureAsync waits for the tag table's sequenced commits
and re-checks before inserting, so it no longer overwrites a provisioner row
(unit/description) that is committed but not yet applied. Integration test
reproduces the clobber against real QuestDB (falsified).
- M-3: the pre-1970 drop Warning is rate-limited per tag (once per 10 min);
DroppedPre1970 still counts every sample.
- M-5: QuestDbHistorianProvider is IAsyncDisposable/IDisposable and disposes the
shared Npgsql pool; Program.cs registers the provider through a factory and
every seam resolves it from the container, so DI disposes it at shutdown.
- M-8, M-9: docs fixes (HistoryUpdate transaction wording; folded duplicate
HistoryUpdate paragraph). Pool-size docs updated for the new default cap.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
AtTime conformance stamps are the requested time (M3; identical on SQL Server). The
QuestDB test fixture prunes idle pooled connections after 1 s: undisposed per-test data
sources exhausted QuestDB's 64-connection PG-wire limit in a full run.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
IHistorianDataSource.TimestampResolutionTicks (default 1; QuestDB 10). A drained tie
cluster now steps off T by the resolution, so a forward one-value-per-page read on a
microsecond backend no longer re-reads the same sample forever (C1). QuestDB AtTime
results carry the client's original request time (M3); regression for the NEXT seek
skipping a tombstone (M1). Conformance backend wires the real writer and updater.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
QuestDbHistorianDataSource serves Raw (LIMIT $n, no continuation, R8), AtTime
(chunked LIMIT 1 neighbour seeks, <=50 times per statement), Events and
Processed (one statement per node, bucket = (cast(ts AS LONG)*10 - start)/interval,
shared BucketPlan/AggregateEvaluator/AtTimeEvaluator). Every sample read filters
NOT deleted; every row goes through StoredSample.FromStored; RC2 long.MinValue
read repair. QuestDbConformanceBackend (seed/read-back) for the conformance suite;
writer/updater factories are T7 placeholders.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Two Sql.Common tests close review finding I-1: an Uncertain NEXT neighbour makes an AtTime
interpolation Uncertain, and an Uncertain (non-Bad) sample in a bucket makes the aggregate
Uncertain. Each falsified with the reviewer's surviving mutation.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
51 new test cases (34 methods) in Sql.Common.Tests covering AtTimeEvaluator, AggregateEvaluator
(hand-built tag-A bucket rows, ProcessedRead literals), BucketPlan, LiveWritePreparer and
HistoryUpdatePlanner (incl. resolutionTicks=10 truncate-before-dedup and the superseded-duplicate
outcome), plus EventContinuation, HistorianHealthCounters, ClampSeverity and StoredSample.FromStored.
Each was falsified by reverting the rule it pins (37 mutations, all red, all restored).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Moves the database-independent logic of the SQL Server historian backend into a new
shared library for the upcoming QuestDB backend (#666): status codes and bits, value/column
mapping, StoredSample + quality clamp, the AtTime and aggregate evaluators, BucketPlan,
LiveWritePreparer and HistoryUpdatePlanner (both with a resolutionTicks parameter, default 1),
tag-name rules, the bootstrap failure cache, health counters, alarm event ids, the event
continuation and severity clamp. The SQL Server backend now calls it; its T-SQL, TVP
builders, connection, bootstrapper and catalog stay.
Tests: StatusCodeOracleTests, ValueWriterPrepareTests, the column half of SampleRowMapperTests
and ProcessedReadTests.Every_enum_member_is_either_served_or_refused move to the new
Sql.Common.Tests under the same names. SqlServer integration tests get mechanical renames
only. Test-name set across the three projects is identical to the baseline (160 tests).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- Historian.md: Empty samples always Bad (writer/updater/read clamp),
long-name refusal, 5 s bootstrap failure cache, AtTime after now, info-bit
masking, HistoryUpdate does NOT type-check (M-1 decision), DeleteRaw
needs both bounds, reverse Raw paging, the historian/historization metric
prefixes, and provisioning numeric-only lines qualified as Gateway.
- CLAUDE.md numeric-only lines qualified as Gateway backend.
- Stale 'sole historian' lines in DriverLifecycle, ServiceHosting and the
retired Wonderware stub; Client.CLI exit-code contract.
- ServerHistorianOptions: Endpoint/Backend XML docs untangled, Validate()
indented; Program.cs comments are backend-neutral; T10 week-test day count.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- I-1: an Empty sample is always Bad. The writer stores a non-Bad NaN/Inf as
Empty+BadOutOfRange and any other non-Bad Empty as BadNoData; the updater
refuses a non-Bad Empty with BadInvalidArgument; reads clamp a legacy
non-Bad Empty row to BadNoData (Raw and AtTime).
- Tag/source names over 400 chars are refused, never truncated: writer
per-tag failure, updater BadInvalidArgument, reads not-found, events none.
- HistorianInfoBits masks the historian bits before setting one.
- AtTime past now, stepped from the last sample => UncertainDataSubNormal.
- Bootstrapper: logger, 5 s negative cache, ClearPool + Warning when
sp_releaseapplock fails.
- Provider builds its shared state lazily (an invalid Schema no longer
throws at Resolve); Kinds is a FrozenSet; Gateway reuses the recorder's
DefaultSupportedKinds.
- Cleanup: SqlHistorianDataTypes in its own file (updater dup removed),
dead Invalidate and unused status consts deleted, named severity masks,
alarm writer brace.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Important 1: bucket offsets are now 100 ns ticks as bigint
(DATEDIFF_BIG(microsecond)*10 plus the sub-microsecond tick digits), so a
1601→9999 window no longer overflows (SQL 535) and nothing scales the interval
to nanoseconds in C#. Interval wider than the window clamps to one bucket and
the ceiling division cannot overflow. Exactness to the tick is unchanged.
Important 2 (spec §4 ruling d6afb394): a Bad previous neighbour means the time
is inside an outage — null value with that neighbour's Bad code, never
Uncertain. Usable previous + Bad next still holds the previous value Uncertain.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
SqlServerHistorianDataSource implements IHistorianDataSource over the T8 schema:
raw forward/reverse/point with the 0 = unbounded sentinel; AtTime in one statement
(TimeRow TVP + two OUTER APPLYs) with linear/stepped/no-prior rules and no
interpolation across a Bad neighbour or Empty outage marker; events with a
maxEvents+1 truncation probe and a non-null continuation point; processed
aggregates pushed down to T-SQL (SqlAggregateQueries) with nanosecond-exact
bucket edges, Calculated bits on every result, Uncertain on any non-Good input,
BadAggregateInvalidInputs for numeric aggregates over String/DateTime, a
100 000-bucket cap and HistoryAggregateNotSupportedException for the rest.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Serialize always writes v2 ("HV2\0" | ver 2 | id | tag | kind | payload | status u32 | ts).
TryDeserialize reads v2 by magic, falls back to the legacy exact-length layout (also when the
magic matches but v2 validation fails), else returns false - never throws.
FasterLogHistorizationOutbox: RecoverState and PeekBatchAsync both use TryDeserialize. An
unreadable record is indexed under a synthetic id (FIFO truncation passes it), skipped by peek,
counted once (UnreadableCount), and dropped by peek once it reaches the head so it can never
pin the outbox.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Since #516 a DriverConfig change is stop + respawn, so DriverSpawnPlan.ToApplyDelta
was always empty and the in-place path had no producer. #663 and #664 were both
latent bugs in it. This deletes it:
- host: ApplyChildDelta, _pendingDelta, HandleApplyResult and HandleDeltaApplied
- plan: DriverSpawnPlan.ToApplyDelta
- actor: the ApplyDelta, ApplyResult and DeltaApplied messages, the Connected
reinit handler and the mid-connect AdoptConfigDuringInit
- tests: the actor tests that drove the seam
IDriver.ReinitializeAsync and each driver's implementation and unit tests stay.
Comments and docs that cited AdoptConfigDuringInit as the reason a driver must
release prior state at init now cite the IDriver contract and overlapping
retries, which still apply.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
AdoptConfigDuringInit re-runs InitializeAsync(newConfig) and acks success, but
Calculation and Galaxy ignored the JSON there: Calculation kept its old tag
set, and Galaxy connected on its old endpoint. Calculation now rebuilds its tag
table from a config with a body (sharing AdoptConfig with ReinitializeAsync and
stopping any running timer scheduler first). Galaxy, which cannot hot-swap its
options, refuses a non-equivalent one the way ReinitializeAsync does. The actor
now sends DeltaApplied once the adopted init succeeds, so a dependency
consumer's mux interest is re-registered. Unreachable from deploys since #516.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Joseph Doherty