Table of Contents

Replication Public API Reference

This document is the contract for the public Orleans.Lattice.Replication surface. It describes behaviour in caller-visible terms: what each public type is for, which members matter to callers, and where to find the operational detail. It does not name internal grains or implementation classes that are not public. For the how, follow the topic cross-references in each section.

Setup

Install the packages you need:

dotnet add package Orleans.Lattice.Replication
dotnet add package Orleans.Lattice.Replication.Grpc
dotnet add package Orleans.Lattice.Storage.AzureTable

Import the replication namespace:

using Orleans.Lattice.Replication;

Register replication on an Orleans silo, then bind a transport. The gRPC package is the canonical live-push and remote-snapshot binding. See Configuration for every option and named-options behaviour.

using Orleans.Lattice.Replication;
using Orleans.Lattice.Replication.Grpc;

siloBuilder.AddLatticeReplication(opts =>
{
    opts.ClusterId = "site-a";
    opts.ReplicatedTrees = new Dictionary<string, LatticeMergeMode>(StringComparer.Ordinal)
    {
        ["orders"] = LatticeMergeMode.LwwRegister,
    };
    opts.ReplicationPeers = new[] { "site-b" };
});

siloBuilder.Services.AddLatticeReplicationGrpc(grpc =>
{
    grpc.Peers["site-b"] = new Uri("https://site-b.example:5001");
});

On the receiving HTTP pipeline, map the gRPC endpoints with MapLatticeReplicationGrpc. The gRPC binding is a separate package with its own docs - see Orleans.Lattice.Replication.Grpc and Transport Security.

Registration and DI

Type Kind Purpose Key public members
LatticeReplicationServiceCollectionExtensions static class Registers replication services on an Orleans silo. AddLatticeReplication, ConfigureLatticeReplication, ReplicateLatticeSystemTrees, AddLatticeAutoSharedDictionary, AddLatticeReplicationHealthCheck, AddWalSaturationReceiverFlowControl, AddLatticeSagaParticipant
LatticeReplicationSecurityServiceCollectionExtensions static class Registers shared-secret sources and security options. AddLatticeReplicationSecrets, AddLatticeReplicationSecretsFromConfiguration, ConfigureLatticeReplicationSecurity

AddLatticeReplication wires the replication pipeline and default no-op transport. A production deployment replaces the transport by adding the gRPC binding or a custom IReplicationTransport. ConfigureLatticeReplication follows .NET named options: the overload without a tree name sets global defaults; the treeName overload overrides a single tree.

The gRPC transport and the Azure Table WAL backend ship as separate packages with their own API references - see Orleans.Lattice.Replication.Grpc (AddLatticeReplicationGrpc, MapLatticeReplicationGrpc, LatticeReplicationGrpcOptions) and Orleans.Lattice.Storage.AzureTable (AddAzureTableWalStorage, AzureTableWalStorageProvider, AzureTableWalStorageOptions).

Replication modes and configuration types

See Replication Modes and Replication Drivers.

Type Kind Purpose Key public members
LatticeReplicationOptions class Main replication options. Identity, tree opt-in, WAL, apply, ship, bootstrap, compression, wire-version, and remediation properties. See Configuration.
FallOffLogDecision readonly record struct Result of a receiver-side fall-off check: whether the receiver's per-origin high-water mark is older than the sender's oldest retained WAL entry, and whether a bootstrap was triggered or absorbed. FellOffLog, LocalHighWaterMark, BootstrapTriggered, Suppressed
OperatorReseedDecision readonly record struct Result of an operator snapshot request. Triggered, LastRequestedAt, RetryAfter

ReplicatedTrees is the static opt-in map from tree id to LatticeMergeMode. Trees not in the map do not ship unless runtime replication config is enabled (AddLatticeReplication(..., enableRuntimeConfig: true)), in which case a tree enabled at runtime through ILatticeReplicationConfigAuthority replicates too - see Runtime Replication Config. KeyFilter and KeyPrefixes narrow which keys the shipper emits from opted-in trees; snapshot exports do not apply them.

Change feed

See Change Feed.

Type Kind Purpose Key public members
IChangeFeed interface Cursor-driven, pull-based read of locally-authored WAL entries for a tree. Subscribe(string, HybridLogicalClock, bool, CancellationToken), Subscribe(string, ChangeFeedCursor, bool, CancellationToken), GetCurrentCursorAsync
ChangeFeedCursor readonly struct Per-partition offset cursor for lossless WAL consumption. Initial, constructor from offsets, GetOffsetForPartition, PartitionOffsets

The feed is for locally-authored writes. Entries installed by inbound apply are visible in local state but are not re-emitted through this feed; consumers that need to observe receiver-side installs should decorate IReplicationApplier. The HybridLogicalClock overload is a source-compatible shim: the default implementation ignores its cursor and reads every partition from the start, so resume with the ChangeFeedCursor overload.

Transport and wire envelope

See Transport, Orleans.Lattice.Replication.Grpc, and Wire Format.

Type Kind Purpose Key public members
IReplicationTransport interface Sends a batch to a peer cluster and returns the receiver ack. SendAsync(ReplicationBatch, CancellationToken)
ReplicationBatch readonly record struct Logical outbound batch routing metadata plus payload. TargetClusterId, TreeName, OriginClusterId, Payload, Envelope, EncodedEnvelope
ReplicationBatchEnvelope readonly record struct Decoded transport envelope. WireVersion, TreeName, OriginClusterId, Entries; the CurrentVersion and CurrentMinorVersion constants
ReplicationBatchEncodedEnvelope readonly record struct Pre-encoded envelope used by transport implementations. Header (an EncodedBatchHeader), EncodedEntries (the pre-encoded entry segments)
ReplicationAck readonly record struct Receiver acknowledgement and hints. Accepted, HighestAppliedHlc, BlockedAtHlc, the flow-control hints SuggestedBatchSize / PauseForMs, and the capability hints SupportedWireVersion, AdvertisedDictionaryIds, AdvertisedDictionaries
EncodedBatchHeader readonly record struct Fixed 32-byte wire framing header. Magic, WireVersion, OriginClusterIdHash, EntryCount, BatchSequence, AtomicBatchSpanCount, Mode, Compression, and the in-process DictionaryId (carried in the compressed tail, not the fixed header)

A transport must be idempotent at the batch boundary: sender retries can redeliver a batch, and the receiver deduplicates by exact (origin, hlc, key, op) record identity. The gRPC binding that implements this seam (LatticeReplicationGrpcOptions and the registration helpers) is documented in Orleans.Lattice.Replication.Grpc.

Replication apply

See Replication Apply and Deltas.

Type Kind Purpose Key public members
IReplicationApplier interface Applies inbound WAL records to the local tree. ApplyAsync, ApplyBatchAsync
ApplyResult readonly record struct Apply outcome and high-water-mark visibility. Applied, HighWaterMark, Deferred (the batch was held back by an inbound receive fence and must be retried)
IReplicationLocalVcSeeder interface Rebuilds a tree's local vector clock from the vector-clock slots on its values after an intra-cluster snapshot restore, so inbound dependency checks do not run against a zeroed vector. A no-op for a non-replicated tree. SeedFromTreeAsync(string, CancellationToken) returning LocalVcSeedReport
LocalVcSeedReport readonly record struct Observable result of local version-vector seeding. TreeName, Frontier, EntriesScanned, SeedApplied

ApplyAsync preserves the source cluster HLC and origin id. ApplyBatchAsync is the preferred batch seam because implementations can collapse high-water-mark updates and drain causal buffers once per batch. Its default interface implementation applies each entry through ApplyAsync in order and aggregates the results - Applied when any entry applied, the pointwise-maximum HighWaterMark, and Deferred when any entry was deferred - so a custom applier that implements only ApplyAsync still has a receive-fence deferral re-shipped by the sender rather than acknowledged past.

Bootstrap and snapshots

See Snapshot Bootstrap, Auto-Bootstrap, and Automatic Drift Remediation.

Type Kind Purpose Key public members
ISnapshotProvider interface Exports a streaming as-of-HLC view of a tree. ExportAsync(string, HybridLogicalClock, CancellationToken), source-cluster overload, range-scoped overload
IBootstrapSnapshotSource interface Marker and specialization for bootstrap snapshot sources. Inherits ISnapshotProvider
ILatticeBootstrapCoordinator interface Drives receiver-side snapshot bootstrap. GetStateAsync, GetStatusAsync, BootstrapAsync
LatticeBootstrapState enum Bootstrap state-machine state. Idle, RequestingSnapshot, ApplyingSnapshot, IncrementalHandoff, LiveIncremental, Failed
BootstrapCoordinatorStatus readonly record struct Observable bootstrap phase and source cluster. Phase, SourceClusterId
SnapshotEntry readonly record struct One row in a snapshot stream. Key, value, timestamp, prepared/tombstone flags, transaction id, source-shard index, atomic-batch size/index, TTL expiry, delta, and merge-mode slots
SnapshotStream sealed class Async snapshot stream wrapper. TreeName, AsOfHlc, CausalStableFrontier, Entries
IRemoteSnapshotTransport interface Fetches snapshot metadata and stream items from a remote cluster. GetMetadataAsync, RequestSnapshotAsync
LatticeRemoteSnapshotService sealed class Public remote snapshot transport service. Implements IRemoteSnapshotTransport
RemoteSnapshotProvider sealed class Snapshot provider backed by a remote transport. Implements IBootstrapSnapshotSource
RemoteSnapshotMetadata readonly record struct Remote snapshot metadata response. TreeName, SourceClusterId, AsOfHlc, CausalStableFrontier
RemoteSnapshotMetadataRequest readonly record struct Remote metadata request. TreeName, SourceClusterId, FromAsOfHlc (a strict upper-bound filter; HybridLogicalClock.Zero disables it)
RemoteSnapshotStreamItem readonly record struct One item returned by remote snapshot streaming. Entry (one SnapshotEntry per streamed message)
LatticeBootstrapTransientFaultClassifier static class Default transient-fault classifier for the receiver-side bootstrap drain: timeouts, HTTP / socket / IO faults, retryable gRPC statuses (Unavailable, DeadlineExceeded, Aborted), and an expired Orleans enumeration session retry with bounded backoff; anything else pivots the bootstrap to Failed. IsTransient(Exception)

Bootstrap applies snapshot entries through the same public apply seam as incremental replication, then hands off to live shipping at the snapshot frontier.

Dead-letter queue

See Dead-Letter Queue.

Type Kind Purpose Key public members
ILatticeReplicationDeadLetters interface Lists, discards, and replays quarantined apply failures. ListAsync, CountAsync, DiscardAsync, ReplayAsync
DeadLetterEntry readonly record struct Retained failed apply entry. EntryId, Entry, FailureReason, RetryCount, EnqueuedAtTicks

Replay runs the parked entry through the canonical applier and removes it on any non-throwing, non-deferred return, whether or not the entry applied. A replay that an in-flight coordinated restore's receive fence defers leaves the entry parked, as does a thrown exception (see Replay semantics).

Operator, admin, and WAL introspection

See Auto-Bootstrap, WAL, and Observability.

Type Kind Purpose Key public members
ILatticeReplicationAdmin interface Operator-driven snapshot re-seed controls. RequestSnapshotAsync, ForceRequestSnapshotAsync
ILatticeWalIntrospection interface Sender-side view of retained WAL availability. GetOldestAvailableHlcAsync, GetOldestAvailableHlcByOriginAsync
ILatticeFallOffLogDetector interface Receiver-side check of the local per-origin high-water mark against a sender's oldest retained WAL entry; on fall-off it records the metric and, when AutoBootstrapOnFallOffLog is on, starts a bootstrap. CheckAndTriggerAsync returning FallOffLogDecision

The admin surface rate-limits routine re-seeds through OperatorReseedMinInterval; the force method bypasses that rate limit for disaster-recovery and scheduled re-seed scenarios.

Cursor and GC surface

Public cursor state is represented by ChangeFeedCursor (per-partition offsets for change-feed consumers) and by the core IWalCursorRegistry, into which each per-peer shipper reports its durable ship cursor and the blocked floor the receiver stamps on each ack; ILatticeWalIntrospection reports how far back the retained WAL reaches. WAL retention is controlled through LatticeReplicationOptions.WalRetention and MaintenanceGcInterval; the public contract is that consumers advance cursors and GC trims only what policy permits. See WAL.

Encoder and wire-version surface

See Wire Format.

Type Kind Purpose Key public members
IReplicationBatchEncoder interface Encodes and decodes replication batches. ContentType, CurrentWireVersion, Encode, Decode, and the default-implemented EncodeFraming / TryDecodeFraming
EncodedBatchHeader readonly record struct Fixed frame header. WriteTo, ReadFrom, HashClusterId, and the WireSize (32), MagicValue, and CurrentWireVersion (currently 5) constants
WireVersionNegotiation static class Computes an effective wire version from local and peer capabilities. Negotiate
WireVersionNegotiationResult readonly record struct Negotiation result. EffectiveWireVersion, DowngradeActive, PeerCapabilityKnown
WireVersionDownEncoder static class Down-stamps frames for older receivers. MinimumDownEncodableWireVersion, EnsureDownEncodable, PrepareHeader
ReplicationTypeAliases static class Centralises the stable olr.-prefixed Orleans serialization aliases of the replication wire types. None: every alias constant is internal, so the class exposes no public members

Use this surface when writing a transport or compatibility shim. Most application hosts only configure the related options in Configuration.

Metrics types

See Observability and Health Check.

Type Kind Purpose Key public members
LatticeReplicationMetrics static class Meter, counter, histogram, and tag names for replication telemetry. Public constants and instrument names
ReplicationPeerStats class Per-peer metrics accumulator. RecordBacklog, RecordInFlight, RecordSuccess, RecordError, RecordInboundSuccess, RecordInboundError, Snapshot
ReplicationPeerSnapshot readonly record struct Point-in-time per-peer telemetry. Tree, Peer, EntriesBehind, BytesBehind, ConsecutiveErrors, LastContactSeconds, Direction, InFlight
ReplicationContactDirection enum Direction tag for peer contact. Outbound, Inbound
WireVersionNegotiationState class Runtime wire-version telemetry state. Record, Snapshot
WireVersionNegotiationSnapshot readonly record struct Wire-version telemetry snapshot. Tree, Peer, NegotiatedVersion, DowngradeActive, PeerCapabilityKnown
LatticeReplicationHealthCheckOptions sealed class Health-check thresholds. EntriesBehind, LastContactSeconds, ConsecutiveErrors, UnhealthyAfter, InboundDegradedAfter, InboundCriticalAfter; the nested LongTier / DoubleTier threshold records; the matching Default* values (DefaultEntriesBehind, DefaultLastContactSeconds, DefaultConsecutiveErrors, DefaultUnhealthyAfter, DefaultInboundDegradedAfter, DefaultInboundCriticalAfter); DefaultName

Flow control

See Receiver Flow Control.

Type Kind Purpose Key public members
IReceiverFlowControlPolicy interface Maps receiver state to ack hints. EvaluateAsync
ReceiverFlowControlContext readonly record struct Input to a flow-control policy. TreeName, OriginClusterId, EntryCount, ApplyDurationMs
ReceiverFlowControlHint readonly record struct Suggested sender limits. SuggestedBatchSize, PauseForMs, None
NoOpReceiverFlowControlPolicy sealed class Policy that returns no hints. Instance, EvaluateAsync
WalSaturationReceiverFlowControlOptions sealed class Tunes how the throttled and saturated WAL states map to hints (a healthy WAL returns no hint). ThrottledBatchRatio, ThrottledPauseMs, SaturatedBatchSize, SaturatedPauseMs, and the matching DefaultThrottledBatchRatio, DefaultThrottledPauseMs, DefaultSaturatedBatchSize, DefaultSaturatedPauseMs constants
WalSaturationReceiverFlowControlPolicy sealed class Built-in WAL-saturation-aware policy. EvaluateAsync

Flow-control hints are advisory. The sender clamps its next batch size and pause to the ack it receives, but a receiver must still tolerate redelivery and retries.

Anti-entropy and remediation

See Automatic Drift Remediation, digest probes, Merkle walks, leaf re-replay, bootstrap fallback, and remediation guards.

Type Kind Purpose
IReplicationDigestProbeTransport interface Transport seam for the read-only peer RPCs: ProbeDigestAsync, ProbeMerkleWalkAsync, GetPeerHighWaterMarkAsync, plus the shipping-side ExchangeContentManifestAsync (payload elision) and PullCompressionDictionaryAsync. Every member except ProbeDigestAsync has a default implementation (an unavailable or not-supported response, or HybridLogicalClock.Zero for the watermark read), so a custom transport implements only what it can answer.
DigestProbeComparer static class Compares a local digest with a peer's digest probe response (Compare).
DigestProbeOutcome enum Digest comparison outcome: Match, Mismatch, VersionSkew, RemoteUnavailable.
DigestProbeRequest, DigestProbeResponse readonly record structs Digest probe request and response.
ContentManifestRequest, ContentManifestResponse, ContentManifestEntry readonly record structs Content-hash manifest exchange shapes used by payload elision.
MerkleWalkProbeRequest, MerkleWalkProbeResponse, MerkleWalkOutcome readonly record structs Merkle walk request, response, and outcome.
MerkleWalkAbortReason enum Reason a Merkle walk stopped before repair: None, DepthCapExceeded, ByteBudgetExceeded, RemoteUnavailable, VersionSkew.
PeerHighWaterMarkRequest, PeerHighWaterMarkResponse readonly record structs High-water-mark probe shapes.
LeafReReplayRange, LeafReReplayOutcome readonly record structs Targeted leaf replay range and result.
LeafReReplaySkipReason enum Reason targeted replay was skipped: None, Disabled, RangeEmpty, WalTrimmed.
BootstrapFallbackOutcome readonly record struct Result of snapshot fallback repair.
BootstrapFallbackSkipReason enum Reason snapshot fallback was skipped: None, Disabled, RangeEmpty, Empty.
RemediationGuard sealed class Budget and circuit-breaker guard for automatic repair.
RemediationDisabledReason enum Reason automatic remediation is disabled: OptOut, BudgetExhausted, CircuitOpen.

These types are public so custom transports and operators can integrate with the opt-in anti-entropy stack without depending on implementation details.

Compression-dictionary negotiation

See Compression and Wire Format.

Type Kind Purpose
SharedDictionaryNegotiation static class Computes dictionary negotiation decisions.
SharedDictionaryNegotiationResult readonly record struct One negotiation decision.
SharedDictionaryNegotiationState sealed class Tracks peer dictionary state.
SharedDictionaryNegotiationSnapshot readonly record struct Observable dictionary negotiation state.
AdvertisedCompressionDictionary readonly record struct Dictionary advertised by a peer.
CompressionDictionaryAdvertisement static class Builds the (id, fingerprint) set a receiver advertises on its acks.
CompressionDictionaryFingerprint static class Computes dictionary fingerprints.
CompressionDictionaryConvergence static class Pulls and installs the peer-advertised dictionaries the local provider does not hold (ConvergeAsync).
CompressionDictionaryPullRequest, CompressionDictionaryPullResponse readonly record structs Pull protocol for missing dictionaries.

Dictionary negotiation is opt-in and separate from the default dict-less Zstandard framing compression.

Topology and peer membership

See Replication Drivers.

Type Kind Purpose Key public members
IReplicationTopology interface Runtime source of peer cluster membership. CurrentPeers, Subscribe
PeerChanged readonly record struct Membership change notification. PeerClusterId, Kind
PeerChangeKind enum Kind of membership change. Added, Removed

The default topology projects LatticeReplicationOptions.ReplicationPeers. Register a custom singleton IReplicationTopology before replication setup to source membership from a service registry or configuration provider.

Security

See Transport Security.

Type Kind Purpose Key public members
ILatticeReplicationSecretSource interface Supplies shared secrets for peer authentication. GetOutboundSecretAsync, GetAcceptedSecretsAsync
ConfigurationBindingSecretSource sealed class Secret source backed by configuration. Constructor taking the bound IConfiguration section; GetOutboundSecretAsync, GetAcceptedSecretsAsync
LatticeReplicationAcceptedSecrets sealed class Accepted shared-secret set. Secrets, Version, Empty
LatticeReplicationSecurityOptions sealed class Shared-secret authentication options. RequireAuthentication, BindCredentialToOriginCluster, SecretRefreshInterval, ScanConfigurationForSecrets
LatticeReplicationEnvironmentVariables static class Environment-variable names for replication secrets. Prefix, Secret, AcceptedSecrets, PeerSecretPrefix, AllowSourceTreeSecrets
LatticeReplicationSharedSecret static class Shared-secret generation and validation helpers. MinimumLength, Generate, IsWellFormed, FixedTimeEquals

The gRPC binding requires HTTPS endpoints unless AllowPlaintextEndpoints is enabled. Shared-secret authentication is configured through the security extension methods above; origin binding (BindCredentialToOriginCluster) is on by default - see Configuration.

Cross-cluster saga participation

The saga service-provider interfaces let a host join the coordinated cross-cluster commit protocol that backs a fleet-wide restore. Register an implementation with AddLatticeSagaParticipant. See Coordinated restore.

Type Kind Purpose Key public members
ISagaParticipant interface Service-provider interface a host implements to take part in a cross-cluster saga: it votes on prepare, then applies or discards its staged work. PrepareAsync, CommitAsync, AbortAsync, GetStatusAsync
ISagaControlChannel interface Outbound control channel the coordinator uses to drive a named peer cluster through the saga phases. PrepareAsync, CommitAsync, AbortAsync, GetStatusAsync (each taking the target clusterId)
ISagaPeerAuthorizer interface Fail-closed gate deciding whether an inbound saga control request from a claimed origin cluster is accepted. IsAuthorizedAsync(string? originClusterId, CancellationToken)
ILatticeSagaControlHandler interface Server-side delegation seam for the inbound saga control channel. The gRPC saga service validates the request and enforces peer authorization, then delegates each imperative RPC to this handler. PrepareAsync, CommitAsync, AbortAsync, GetStatusAsync (each taking a SagaControlRequest)
NoParticipantSagaControlHandler sealed class The transport-only fallback handler the gRPC binding registers with TryAddSingleton. AddLatticeReplication registers its own durable handler - which routes each inbound saga call to the per-saga participant - with TryAddSingleton too, so on a silo that calls it before the gRPC binding (as the setup above does) the durable handler is the effective one and this class is never used. Holds no participant state: it reports SagaPhase.None for every saga and votes SagaVote.Abort on prepare, because a participant that cannot durably prepare must not let the coordinator commit. PrepareAsync, CommitAsync, AbortAsync, GetStatusAsync
SagaPhase enum The durable phase a participant reports for a saga. None = 0, Prepared = 1, Committed = 2, Aborted = 3
SagaVote enum A participant's prepare-phase vote. None = 0, Commit = 1, Abort = 2
SagaControlRequest readonly record struct The request every saga control call carries. SagaId, TargetTree, ManifestId, CoordinatorClusterId, SetId
SagaControlResponse readonly record struct A participant cluster's answer to a saga control call. SagaId, Phase, Vote, Detail
SagaParticipantPrepareResult readonly record struct An ISagaParticipant prepare vote. Vote, Detail
LatticeSystemTreeNames static class The reserved system-tree names the replication package owns. MembershipGroups, MembershipEdges, AuthPolicy, AuthAudit, ReplicationConfig, ReplicationConfigMapKey, BuildEnrolmentMap, BuildReplicationConfigEnrolmentMap

Tenant isolation and runtime configuration authority

Type Kind Purpose Key public members
IReplicationTenantIsolationGate interface Evaluates whether an inbound replicated entry is admissible for the tenant its tree id names - the tenant must exist, be resident in this region, and be active - so a peer can never widen tenant or region scope. The replication package's default gate is inactive; the tenancy add-on supplies a real gate. IsActive, EvaluateAsync(string, CancellationToken) returning ReplicationTenantIsolationDecision
ReplicationTenantIsolationDecision enum The gate's verdict. Admit = 0, RejectUnknownTenant = 1, RejectOutOfRegion = 2, RejectSuspendedTenant = 3
ILatticeReplicationConfigAuthority interface The engine-level authoring seam for runtime per-tree replication config: authors enable / disable onto the sys-replication-config tree and reports the reconciled per-tree status (the runtime tree unioned with the static ReplicatedTrees map). It performs no authorization - the control facade authorizes first. Registered by AddLatticeReplication(..., enableRuntimeConfig: true). See Runtime configuration. EnableReplicationAsync, DisableReplicationAsync, GetTreeStatusAsync, GetAllTreeStatusesAsync
LatticeReplicationEnableResult, LatticeReplicationDisableResult readonly record structs Authority outcomes. TreeId, Mode, AlreadyEnabled, BootstrapRequested / TreeId, AlreadyDisabled
LatticeReplicationTreeStatus readonly record struct One tree's reconciled replication status. TreeId, Enabled, Mode, Ambiguous, Source
LatticeReplicationEnrollmentSource enum Which enrollment source puts a tree's status in force. Runtime = 0, Static = 1, RuntimeAndStatic = 2
LatticeReplicationConfigEntry sealed class One tree's CRDT config entry in the sys-replication-config OR-Map: a disable-wins enablement flag plus a multi-value merge-mode register, so concurrent divergent modes stay detectable. Enabled (RwFlag), Mode (MvRegister), IsEnabled, HasAmbiguousMode, Modes, IsBottom, TryGetMode, Enable, Disable, SetMode, MergeFrom, Clone, and the static EncodeMode / DecodeMode
ILatticeReplicationPreconditionValidator interface Validates the runtime preconditions a tree must meet to replicate under a merge mode (today: a flag mode requires a configured local replica id). Shared by the boot-time validation of statically declared trees and the runtime enable path. Validate(string, LatticeMergeMode) returning LatticeReplicationPreconditionResult
LatticeReplicationPreconditionResult readonly record struct A precondition verdict. IsSatisfied, FailureReason, Satisfied, Rejected(string)
LatticeReplicationModeChangeRejectedException exception Thrown when an enable would change the merge mode of an already-enabled tree, or the tree's mode is currently ambiguous. TreeId, RequestedMode, CurrentMode, CurrentModeAmbiguous
LatticeReplicationPreconditionFailedException exception Thrown when a replication precondition fails. TreeId, RequestedMode

Azure Table WAL durability

The durable Azure Table WAL backend ships as the separate Orleans.Lattice.Storage.AzureTable package. Use AddAzureTableWalStorage when the replication WAL must survive silo restarts and support production retention, bootstrap, and replay windows. Its public surface (AzureTableWalStorageProvider, AzureTableWalStorageOptions, and the retry policies) and configuration are documented in Orleans.Lattice.Storage.AzureTable - see its API Reference and Configuration. For the core WAL provider seam, see WAL and core WAL Storage Providers.