microsoft/garnet · error · TsavoriteException

Consistent read context does not allow reads from address!

Error message

Consistent read context does not allow reads from address!

What it means

ConsistentReadContext provides sequential-read consistency by tracking read positions. ReadAtAddress reads a record at a specific logical address, which bypasses the consistent-read cursor/sequence tracking that guarantees you see a monotonic, coherent view of the store. Allowing address-based reads would break the consistency invariant, so both overloads throw.

Source

Thrown at libs/storage/Tsavorite/cs/src/core/ClientSession/ConsistentReadContext.cs:112

            TOutput output = default;
            return (Read(key, ref input, ref output, ref readOptions, userContext), output);
        }

        /// <inheritdoc/>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public Status Read(TKey key, ref TInput input, ref TOutput output, ref ReadOptions readOptions, out RecordMetadata recordMetadata, TContext userContext = default)
        {
            var hash = readOptions.KeyHash ?? GetKeyHash(key);
            Session.functions.PreSingleKeyConsistentRead(hash);
            var status = BasicContext.Read(key, ref input, ref output, ref readOptions, out recordMetadata, userContext);
            Session.functions.PostSingleKeyConsistentReadCallback();
            return status;
        }

        /// <inheritdoc/>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public Status ReadAtAddress(long address, ref TInput input, ref TOutput output, ref ReadOptions readOptions, out RecordMetadata recordMetadata, TContext userContext = default)
            => throw new TsavoriteException("Consistent read context does not allow reads from address!");

        /// <inheritdoc/>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public Status ReadAtAddress(long address, TKey key, ref TInput input, ref TOutput output, ref ReadOptions readOptions, out RecordMetadata recordMetadata, TContext userContext = default)
            => throw new TsavoriteException("Consistent read context does not allow reads from address!");

        /// <inheritdoc/>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ReadWithPrefetch<TBatch>(ref TBatch batch, TContext userContext = default)
            where TBatch : IReadArgBatch<TKey, TInput, TOutput>
#if NET9_0_OR_GREATER
            , allows ref struct
#endif
        {
            do
            {
                Thread.Yield();
                Session.functions.PreBatchKeyConsistentReadCallback(batch.Parameters);

View on GitHub (pinned to 951b0fc683)

Solutions

1. For address-based reads, use session.BasicContext.ReadAtAddress instead of ConsistentReadContext.ReadAtAddress.
2. If consistent reads are required, do not use ReadAtAddress — use key-based Read which respects the consistency cursor.
3. Create a separate session (without enableConsistentRead) for low-level address-based access.

Example fix

// before
var status = session.ConsistentReadContext.ReadAtAddress(addr, ref input, ref output, ref opts, out var meta);

// after
var status = session.BasicContext.ReadAtAddress(addr, ref input, ref output, ref opts, out var meta);

if (session.ConsistentReadContext is not null) throw new InvalidOperationException("Use BasicContext.ReadAtAddress for address-based reads; ConsistentReadContext disallows them.");

static bool CanReadAtAddress(ClientSession s) => !s.EnableConsistentRead;

When it happens

Trigger: Calling consistentContext.ReadAtAddress(address, ref input, ...) — the single-address overload — on a ConsistentReadContext obtained from a session with enableConsistentRead=true.

Common situations: Enabling consistent reads on a session but then attempting address-based reads (e.g. for recovery, replay, or low-level record access); porting BasicContext.ReadAtAddress code to a consistent-read session.

Related errors

• Transactional method call when BeginTransactional has not be
• BeginTransactional cannot be called twice (call EndTransacti
• Transactional consistent read context does not allow reads f
• TsavoriteLogAllocator does not support VerifyRecordFromDiskC
• TsavoriteLogAllocator Scan methods should not be used

AI-assisted analysis of microsoft/garnet@951b0fc683 (2026-08-13). Data as JSON: /api/errors/e4807184738a6927. Report an issue: GitHub.