microsoft/semantic-kernel · error · ServiceResponseException

Could not upsert messages.

Error message

Could not upsert messages.

What it means

Raised by RedisMemoryStore.upsert() when self._database.hset(...) throws any Exception. ServiceResponseException with literal message 'Could not upsert messages.' and the original chained via `from e`. The collection-existence check has already passed; this is a write-time failure on the hash.

Solutions

1. Inspect the chained exception (e) for the exact Redis error (e.g. WRONGTYPE, OOM).
2. If WRONGTYPE, delete the offending key or use a different collection so the key prefix is clean.
3. Retry with backoff for transient connection/OOM errors.
4. Verify self._vector_type matches the record embedding dtype before serializing.

Example fix

// before
key = await store.upsert('mycol', record)
// after
try:
    key = await store.upsert('mycol', record)
except ServiceResponseException as e:
    raise RuntimeError(f'upsert failed: {e.__cause__}') from e

try:
    key = await store.upsert(collection_name, record)
except ServiceResponseException as e:
    cause = e.__cause__
    # WRONGTYPE -> clean key; OOM/connection -> retry

When it happens

Trigger: Calling upsert() on an existing index where hset fails: connection drop mid-write, wrong data type already stored at the key (e.g. a string where a hash is expected), memory pressure / OOM, or serialize_record_to_redis producing an invalid mapping.

Common situations: Key collision where a non-hash value was written out-of-band; Redis maxmemory eviction policy rejecting writes; transient network reset; serialization of an embedding with the wrong numpy dtype.

Related errors

• Batch upsert failed
• Failed to create collection
• Upsert failed
• Collection does not exist, cannot insert.
• Collection ' ' does not exist

AI-assisted analysis of microsoft/semantic-kernel@c028a0c7dc (2026-08-13). Data as JSON: /api/errors/1f838d47362e0bbd. Report an issue: GitHub.

Appendix: source

Thrown at python/semantic_kernel/connectors/memory_stores/redis/redis_memory_store.py:221

        Returns:
            str: Redis key associated with the upserted memory record
        """
        if not await self.does_collection_exist(collection_name):
            raise ServiceResourceNotFoundError(f'Collection "{collection_name}" does not exist')

        # Typical Redis key structure: collection_name:{some identifier}
        record._key = get_redis_key(collection_name, record._id)

        # Overwrites previous data or inserts new key if not present
        # Index registers any hash matching its schema and prefixed with collection_name:
        try:
            self._database.hset(
                record._key,
                mapping=serialize_record_to_redis(record, self._vector_type),
            )
            return record._key
        except Exception as e:
            raise ServiceResponseException("Could not upsert messages.") from e

    async def upsert_batch(self, collection_name: str, records: list[MemoryRecord]) -> list[str]:
        """Upserts a group of memory records into the data store.

        Does not guarantee that the collection exists.
            * If the record already exists, it will be updated.
            * If the record does not exist, it will be created.

        Note: if the records do not have the same dimensionality configured for the collection,
        they will not be detected to belong to the collection in Redis.

        Args:
            collection_name (str): Name for a collection of embeddings
            records (List[MemoryRecord]): List of memory records to upsert

        Returns:
            List[str]: Redis keys associated with the upserted memory records
        """

View on GitHub (pinned to c028a0c7dc)