Merge pull request #99 from EpicGames/de/move-namespace-field

Keep Namespace out of CacheKey and store it on request level

10 files changed, 327 insertions, 199 deletions

diff --git a/zenserver-test/zenserver-test.cpp b/zenserver-test/zenserver-test.cpp
index 0f4858bd5..a6e89e702 100644
--- a/zenserver-test/zenserver-test.cpp
+++ b/zenserver-test/zenserver-test.cpp
@@ -1462,7 +1462,7 @@ TEST_CASE("zcache.rpc")
 		{
 			zen::IoHash KeyHash;
 			((uint32_t*)(KeyHash.Hash))[0] = Key;
-			const zen::CacheKey CacheKey   = zen::CacheKey::Create(Namespace, Bucket, KeyHash);
+			const zen::CacheKey CacheKey   = zen::CacheKey::Create(Bucket, KeyHash);
 			CbPackage			Package;
 			CbWriter			Writer;
 
@@ -1474,6 +1474,7 @@ TEST_CASE("zcache.rpc")
 				{
 					CachePolicy BatchDefaultPolicy = CachePolicy::Default;
 					Writer << "DefaultPolicy"sv << WriteToString<128>(BatchDefaultPolicy);
+					Writer << "Namespace"sv << Namespace;
 					Writer.BeginArray("Requests"sv);
 					{
 						AppendCacheRecord(Package, Writer, CacheKey, PayloadSize, BatchDefaultPolicy, CachePolicy::Default);
@@ -1505,7 +1506,10 @@ TEST_CASE("zcache.rpc")
 		bool						  Success;
 	};
 
-	auto GetCacheRecords = [](std::string_view BaseUri, std::span<zen::CacheKey> Keys, zen::CachePolicy Policy) -> GetCacheRecordResult {
+	auto GetCacheRecords = [](std::string_view		   BaseUri,
+							  std::string_view		   Namespace,
+							  std::span<zen::CacheKey> Keys,
+							  zen::CachePolicy		   Policy) -> GetCacheRecordResult {
 		using namespace zen;
 
 		CbObjectWriter Request;
@@ -1514,6 +1518,8 @@ TEST_CASE("zcache.rpc")
 		Request.BeginObject("Params"sv);
 		{
 			Request << "DefaultPolicy"sv << WriteToString<128>(Policy);
+			Request << "Namespace"sv << Namespace;
+
 			Request.BeginArray("Requests"sv);
 			for (const CacheKey& Key : Keys)
 			{
@@ -1563,9 +1569,7 @@ TEST_CASE("zcache.rpc")
 	auto LoadKey = [](zen::CbFieldView KeyView) -> zen::CacheKey {
 		if (zen::CbObjectView KeyObj = KeyView.AsObjectView())
 		{
-			return CacheKey::Create(KeyObj["Namespace"sv] ? KeyObj["Namespace"sv].AsString() : ""sv,
-									KeyObj["Bucket"sv].AsString(),
-									KeyObj["Hash"].AsHash());
+			return CacheKey::Create(KeyObj["Bucket"sv].AsString(), KeyObj["Hash"].AsHash());
 		}
 		return CacheKey::Empty;
 	};
@@ -1582,8 +1586,8 @@ TEST_CASE("zcache.rpc")
 		Inst.WaitUntilReady();
 
 		CachePolicy				   Policy = CachePolicy::Default;
-		std::vector<zen::CacheKey> Keys	  = PutCacheRecords(BaseUri, ""sv, "mastodon"sv, 128);
-		GetCacheRecordResult	   Result = GetCacheRecords(BaseUri, Keys, Policy);
+		std::vector<zen::CacheKey> Keys	  = PutCacheRecords(BaseUri, "ue4.ddc"sv, "mastodon"sv, 128);
+		GetCacheRecordResult	   Result = GetCacheRecords(BaseUri, "ue4.ddc"sv, Keys, Policy);
 
 		CHECK(Result.Records.size() == Keys.size());
 
@@ -1593,11 +1597,9 @@ TEST_CASE("zcache.rpc")
 
 			CbObjectView   RecordObj = RecordView.AsObjectView();
 			CbObjectView   KeyObj	 = RecordObj["Key"sv].AsObjectView();
-			const CacheKey Key		 = CacheKey::Create(KeyObj["Namespace"sv] ? KeyObj["Namespace"sv].AsString() : ""sv,
-												  KeyObj["Bucket"sv].AsString(),
-												  KeyObj["Hash"].AsHash());
-			IoHash AttachmentHash;
-			size_t NumValues = 0;
+			const CacheKey Key		 = CacheKey::Create(KeyObj["Bucket"sv].AsString(), KeyObj["Hash"].AsHash());
+			IoHash		   AttachmentHash;
+			size_t		   NumValues = 0;
 			for (CbFieldView Value : RecordObj["Values"sv])
 			{
 				AttachmentHash = Value.AsObjectView()["RawHash"sv].AsHash();
@@ -1623,16 +1625,16 @@ TEST_CASE("zcache.rpc")
 		Inst.WaitUntilReady();
 
 		CachePolicy				   Policy		= CachePolicy::Default;
-		std::vector<zen::CacheKey> ExistingKeys = PutCacheRecords(BaseUri, ""sv, "mastodon"sv, 128);
+		std::vector<zen::CacheKey> ExistingKeys = PutCacheRecords(BaseUri, "ue4.ddc"sv, "mastodon"sv, 128);
 		std::vector<zen::CacheKey> Keys;
 
 		for (const zen::CacheKey& Key : ExistingKeys)
 		{
 			Keys.push_back(Key);
-			Keys.push_back(CacheKey::Create("missing"sv, "missing"sv, IoHash::Zero));
+			Keys.push_back(CacheKey::Create("missing"sv, IoHash::Zero));
 		}
 
-		GetCacheRecordResult Result = GetCacheRecords(BaseUri, Keys, Policy);
+		GetCacheRecordResult Result = GetCacheRecords(BaseUri, "ue4.ddc"sv, Keys, Policy);
 
 		CHECK(Result.Records.size() == Keys.size());
 
@@ -1677,10 +1679,10 @@ TEST_CASE("zcache.rpc")
 		SpawnServer(UpstreamServer, UpstreamCfg);
 		SpawnServer(LocalServer, LocalCfg);
 
-		std::vector<zen::CacheKey> Keys = PutCacheRecords(UpstreamCfg.BaseUri, ""sv, "mastodon"sv, 4);
+		std::vector<zen::CacheKey> Keys = PutCacheRecords(UpstreamCfg.BaseUri, "ue4.ddc"sv, "mastodon"sv, 4);
 
 		CachePolicy			 Policy = CachePolicy::QueryLocal;
-		GetCacheRecordResult Result = GetCacheRecords(LocalCfg.BaseUri, Keys, Policy);
+		GetCacheRecordResult Result = GetCacheRecords(LocalCfg.BaseUri, "ue4.ddc"sv, Keys, Policy);
 
 		CHECK(Result.Records.size() == Keys.size());
 
@@ -1702,10 +1704,10 @@ TEST_CASE("zcache.rpc")
 		SpawnServer(UpstreamServer, UpstreamCfg);
 		SpawnServer(LocalServer, LocalCfg);
 
-		std::vector<zen::CacheKey> Keys = PutCacheRecords(UpstreamCfg.BaseUri, ""sv, "mastodon"sv, 4);
+		std::vector<zen::CacheKey> Keys = PutCacheRecords(UpstreamCfg.BaseUri, "ue4.ddc"sv, "mastodon"sv, 4);
 
 		CachePolicy			 Policy = (CachePolicy::QueryLocal | CachePolicy::QueryRemote);
-		GetCacheRecordResult Result = GetCacheRecords(LocalCfg.BaseUri, Keys, Policy);
+		GetCacheRecordResult Result = GetCacheRecords(LocalCfg.BaseUri, "ue4.ddc"sv, Keys, Policy);
 
 		CHECK(Result.Records.size() == Keys.size());
 
@@ -1736,7 +1738,7 @@ TEST_CASE("zcache.rpc.allpolicies")
 
 	std::string_view TestVersion   = "F72150A02AE34B57A9EC91D36BA1CE08"sv;
 	std::string_view TestBucket	   = "allpoliciestest"sv;
-	std::string_view TestNamespace = ""sv;
+	std::string_view TestNamespace = "ue4.ddc"sv;
 
 	// NumKeys = (2 Value vs Record)*(2 SkipData vs Default)*(2 ForceMiss vs Not)*(2 use local)
 	// *(2 use remote)*(2 UseValue Policy vs not)*(4 cases per type)
@@ -1838,7 +1840,7 @@ TEST_CASE("zcache.rpc.allpolicies")
 		IoHash	 KeyHash = KeyWriter.GetHash();
 		KeyData& KeyData = KeyDatas[KeyIndex];
 
-		KeyData.Key				 = CacheKey::Create(TestNamespace, TestBucket, KeyHash);
+		KeyData.Key				 = CacheKey::Create(TestBucket, KeyHash);
 		KeyData.KeyIndex		 = KeyIndex;
 		KeyData.GetRequestsData	 = (KeyIndex & (1 << 1)) == 0;
 		KeyData.UseValueAPI		 = (KeyIndex & (1 << 2)) != 0;
@@ -1937,6 +1939,7 @@ TEST_CASE("zcache.rpc.allpolicies")
 		{
 			CachePolicy BatchDefaultPolicy = CachePolicy::Default;
 			Writer << "DefaultPolicy"sv << WriteToString<128>(BatchDefaultPolicy);
+			Writer << "Namespace"sv << TestNamespace;
 			Writer.BeginArray("Requests"sv);
 			for (CachePutRequest& Request : PutRequests)
 			{
@@ -1992,6 +1995,7 @@ TEST_CASE("zcache.rpc.allpolicies")
 		{
 			CachePolicy BatchDefaultPolicy = CachePolicy::Default;
 			Writer << "DefaultPolicy"sv << WriteToString<128>(BatchDefaultPolicy);
+			Writer << "Namespace"sv << TestNamespace;
 			Writer.BeginArray("Requests"sv);
 			for (CachePutValueRequest& Request : PutValueRequests)
 			{
@@ -2047,6 +2051,7 @@ TEST_CASE("zcache.rpc.allpolicies")
 		{
 			CachePolicy BatchDefaultPolicy = CachePolicy::Default;
 			Writer << "DefaultPolicy"sv << WriteToString<128>(BatchDefaultPolicy);
+			Writer << "Namespace"sv << TestNamespace;
 			Writer.BeginArray("Requests"sv);
 			for (CacheGetRequest& Request : GetRequests)
 			{
@@ -2158,6 +2163,7 @@ TEST_CASE("zcache.rpc.allpolicies")
 		{
 			CachePolicy BatchDefaultPolicy = CachePolicy::Default;
 			Writer << "DefaultPolicy"sv << WriteToString<128>(BatchDefaultPolicy);
+			Writer << "Namespace"sv << TestNamespace;
 			Writer.BeginArray("Requests"sv);
 			for (CacheGetValueRequest& Request : GetValueRequests)
 			{
@@ -2252,6 +2258,7 @@ TEST_CASE("zcache.rpc.allpolicies")
 		{
 			CachePolicy BatchDefaultPolicy = CachePolicy::Default;
 			Writer << "DefaultPolicy"sv << WriteToString<128>(BatchDefaultPolicy);
+			Writer << "Namespace"sv << TestNamespace;
 			Writer.BeginArray("ChunkRequests"sv);
 			for (CacheGetChunkRequest& Request : ChunkRequests)
 			{
diff --git a/zenserver/cache/structuredcache.cpp b/zenserver/cache/structuredcache.cpp
index bc6f31dd3..135572d07 100644
--- a/zenserver/cache/structuredcache.cpp
+++ b/zenserver/cache/structuredcache.cpp
@@ -70,6 +70,7 @@ struct AttachmentCount
 
 struct PutRequestData
 {
+	std::string		  Namespace;
 	CacheKey		  Key;
 	CbObjectView	  RecordObject;
 	CacheRecordPolicy Policy;
@@ -244,30 +245,27 @@ namespace {
 		}
 	}
 
-	bool GetRpcRequestCacheKey(const CbObjectView& KeyView, CacheKey& Key)
+	std::optional<std::string> GetRpcRequestNamespace(const CbObjectView Params)
 	{
-		CbFieldView				   NamespaceField = KeyView["Namespace"sv];
-		std::optional<std::string> Namespace;
+		CbFieldView NamespaceField = Params["Namespace"sv];
 		if (!NamespaceField)
 		{
-			Namespace = ZenCacheStore::DefaultNamespace;
+			return std::string(ZenCacheStore::DefaultNamespace);
 		}
-		else
+
+		if (NamespaceField.HasError())
 		{
-			if (NamespaceField.HasError())
-			{
-				return false;
-			}
-			if (!NamespaceField.IsString())
-			{
-				return false;
-			}
-			Namespace = GetValidNamespaceName(NamespaceField.AsString());
+			return {};
 		}
-		if (!Namespace.has_value())
+		if (!NamespaceField.IsString())
 		{
-			return false;
+			return {};
 		}
+		return GetValidNamespaceName(NamespaceField.AsString());
+	}
+
+	bool GetRpcRequestCacheKey(const CbObjectView& KeyView, CacheKey& Key)
+	{
 		CbFieldView BucketField = KeyView["Bucket"sv];
 		if (BucketField.HasError())
 		{
@@ -292,7 +290,7 @@ namespace {
 			return false;
 		}
 		IoHash Hash = HashField.AsHash();
-		Key			= CacheKey::Create(*Namespace, *Bucket, Hash);
+		Key			= CacheKey::Create(*Bucket, Hash);
 		return true;
 	}
 
@@ -596,7 +594,7 @@ HttpStructuredCacheService::HandleGetCacheRecord(zen::HttpServerRequest& Request
 		metrics::OperationTiming::Scope $(m_UpstreamGetRequestTiming);
 
 		if (GetUpstreamCacheResult UpstreamResult =
-				m_UpstreamCache.GetCacheRecord({Ref.Namespace, Ref.BucketSegment, Ref.HashKey}, AcceptType);
+				m_UpstreamCache.GetCacheRecord(Ref.Namespace, {Ref.BucketSegment, Ref.HashKey}, AcceptType);
 			UpstreamResult.Success)
 		{
 			Success = true;
@@ -769,7 +767,7 @@ HttpStructuredCacheService::HandlePutCacheRecord(zen::HttpServerRequest& Request
 
 		if (EnumHasAllFlags(PolicyFromUrl, CachePolicy::StoreRemote))
 		{
-			m_UpstreamCache.EnqueueUpstream({.Type = ContentType, .Key = {Ref.Namespace, Ref.BucketSegment, Ref.HashKey}});
+			m_UpstreamCache.EnqueueUpstream({.Type = ContentType, .Namespace = Ref.Namespace, .Key = {Ref.BucketSegment, Ref.HashKey}});
 		}
 
 		Request.WriteResponse(HttpResponseCode::Created);
@@ -819,7 +817,8 @@ HttpStructuredCacheService::HandlePutCacheRecord(zen::HttpServerRequest& Request
 		if (EnumHasAllFlags(Policy, CachePolicy::StoreRemote) && !IsPartialRecord)
 		{
 			m_UpstreamCache.EnqueueUpstream({.Type			  = ZenContentType::kCbObject,
-											 .Key			  = {Ref.Namespace, Ref.BucketSegment, Ref.HashKey},
+											 .Namespace		  = Ref.Namespace,
+											 .Key			  = {Ref.BucketSegment, Ref.HashKey},
 											 .ValueContentIds = std::move(ValidAttachments)});
 		}
 
@@ -904,7 +903,8 @@ HttpStructuredCacheService::HandlePutCacheRecord(zen::HttpServerRequest& Request
 		if (EnumHasAllFlags(Policy, CachePolicy::StoreRemote) && !IsPartialRecord)
 		{
 			m_UpstreamCache.EnqueueUpstream({.Type			  = ZenContentType::kCbPackage,
-											 .Key			  = {Ref.Namespace, Ref.BucketSegment, Ref.HashKey},
+											 .Namespace		  = Ref.Namespace,
+											 .Key			  = {Ref.BucketSegment, Ref.HashKey},
 											 .ValueContentIds = std::move(ValidAttachments)});
 		}
 
@@ -946,7 +946,7 @@ HttpStructuredCacheService::HandleGetCacheValue(zen::HttpServerRequest& Request,
 
 		if (QueryUpstream)
 		{
-			if (auto UpstreamResult = m_UpstreamCache.GetCacheValue({Ref.Namespace, Ref.BucketSegment, Ref.HashKey}, Ref.ValueContentId);
+			if (auto UpstreamResult = m_UpstreamCache.GetCacheValue(Ref.Namespace, {Ref.BucketSegment, Ref.HashKey}, Ref.ValueContentId);
 				UpstreamResult.Success)
 			{
 				if (CompressedBuffer Compressed = CompressedBuffer::FromCompressed(SharedBuffer(UpstreamResult.Value)))
@@ -1124,8 +1124,13 @@ HttpStructuredCacheService::HandleRpcPutCacheRecords(zen::HttpServerRequest& Req
 
 	ZEN_ASSERT(BatchObject["Method"sv].AsString() == "PutCacheRecords"sv);
 
-	std::string_view PolicyText = Params["DefaultPolicy"].AsString();
-	DefaultPolicy				= !PolicyText.empty() ? ParseCachePolicy(PolicyText) : CachePolicy::Default;
+	std::string_view		   PolicyText = Params["DefaultPolicy"].AsString();
+	std::optional<std::string> Namespace  = GetRpcRequestNamespace(Params);
+	if (!Namespace)
+	{
+		return Request.WriteResponse(HttpResponseCode::BadRequest);
+	}
+	DefaultPolicy = !PolicyText.empty() ? ParseCachePolicy(PolicyText) : CachePolicy::Default;
 	std::vector<bool> Results;
 	for (CbFieldView RequestField : Params["Requests"sv])
 	{
@@ -1139,7 +1144,7 @@ HttpStructuredCacheService::HandleRpcPutCacheRecords(zen::HttpServerRequest& Req
 			return Request.WriteResponse(HttpResponseCode::BadRequest);
 		}
 		CacheRecordPolicy Policy = LoadCacheRecordPolicy(RequestObject["Policy"sv].AsObjectView(), DefaultPolicy);
-		PutRequestData	  PutRequest{std::move(Key), RecordObject, std::move(Policy)};
+		PutRequestData	  PutRequest{*Namespace, std::move(Key), RecordObject, std::move(Policy)};
 
 		PutResult Result = PutCacheRecord(PutRequest, &BatchRequest);
 
@@ -1203,7 +1208,7 @@ HttpStructuredCacheService::PutCacheRecord(PutRequestData& Request, const CbPack
 			else
 			{
 				ZEN_WARN("PUT - '{}/{}/{}' '{}' FAILED, attachment '{}' is not compressed",
-						 Request.Key.Namespace,
+						 Request.Namespace,
 						 Request.Key.Bucket,
 						 Request.Key.Hash,
 						 ToString(HttpContentType::kCbPackage),
@@ -1225,7 +1230,7 @@ HttpStructuredCacheService::PutCacheRecord(PutRequestData& Request, const CbPack
 	}
 
 	ZEN_DEBUG("PUT - '{}/{}/{}' {}, attachments '{}/{}/{}' (new/valid/total)",
-			  Request.Key.Namespace,
+			  Request.Namespace,
 			  Request.Key.Bucket,
 			  Request.Key.Hash,
 			  NiceBytes(TransferredSize),
@@ -1237,14 +1242,16 @@ HttpStructuredCacheService::PutCacheRecord(PutRequestData& Request, const CbPack
 	CacheValue.Value = IoBuffer(Record.GetSize());
 	Record.CopyTo(MutableMemoryView(CacheValue.Value.MutableData(), CacheValue.Value.GetSize()));
 	CacheValue.Value.SetContentType(ZenContentType::kCbObject);
-	m_CacheStore.Put(Request.Key.Namespace, Request.Key.Bucket, Request.Key.Hash, CacheValue);
+	m_CacheStore.Put(Request.Namespace, Request.Key.Bucket, Request.Key.Hash, CacheValue);
 
 	const bool IsPartialRecord = Count.Valid != Count.Total;
 
 	if (EnumHasAllFlags(Request.Policy.GetRecordPolicy(), CachePolicy::StoreRemote) && !IsPartialRecord)
 	{
-		m_UpstreamCache.EnqueueUpstream(
-			{.Type = ZenContentType::kCbPackage, .Key = Request.Key, .ValueContentIds = std::move(ValidAttachments)});
+		m_UpstreamCache.EnqueueUpstream({.Type			  = ZenContentType::kCbPackage,
+										 .Namespace		  = Request.Namespace,
+										 .Key			  = Request.Key,
+										 .ValueContentIds = std::move(ValidAttachments)});
 	}
 	return PutResult::Success;
 }
@@ -1277,8 +1284,13 @@ HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& Htt
 		bool						  UsedUpstream = false;
 	};
 
-	std::string_view			   PolicyText	 = Params["DefaultPolicy"sv].AsString();
-	CachePolicy					   DefaultPolicy = !PolicyText.empty() ? ParseCachePolicy(PolicyText) : CachePolicy::Default;
+	std::string_view		   PolicyText	 = Params["DefaultPolicy"sv].AsString();
+	CachePolicy				   DefaultPolicy = !PolicyText.empty() ? ParseCachePolicy(PolicyText) : CachePolicy::Default;
+	std::optional<std::string> Namespace	 = GetRpcRequestNamespace(Params);
+	if (!Namespace)
+	{
+		return HttpRequest.WriteResponse(HttpResponseCode::BadRequest);
+	}
 	std::vector<RecordRequestData> Requests;
 	std::vector<size_t>			   UpstreamIndexes;
 	CbArrayView					   RequestsArray = Params["Requests"sv].AsArrayView();
@@ -1322,7 +1334,7 @@ HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& Htt
 		ZenCacheValue RecordCacheValue;
 
 		if (EnumHasAllFlags(Policy.GetRecordPolicy(), CachePolicy::QueryLocal) &&
-			m_CacheStore.Get(Key.Namespace, Key.Bucket, Key.Hash, RecordCacheValue))
+			m_CacheStore.Get(*Namespace, Key.Bucket, Key.Hash, RecordCacheValue))
 		{
 			Request.RecordCacheValue = std::move(RecordCacheValue.Value);
 			if (Request.RecordCacheValue.GetContentType() != ZenContentType::kCbObject)
@@ -1436,7 +1448,7 @@ HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& Htt
 			}
 		}
 
-		const auto OnCacheRecordGetComplete = [this, &ParseValues](CacheRecordGetCompleteParams&& Params) {
+		const auto OnCacheRecordGetComplete = [this, Namespace, &ParseValues](CacheRecordGetCompleteParams&& Params) {
 			if (!Params.Record)
 			{
 				return;
@@ -1453,7 +1465,7 @@ HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& Htt
 				Request.RecordObject = ObjectBuffer;
 				if (EnumHasAllFlags(Request.DownstreamPolicy.GetRecordPolicy(), CachePolicy::StoreLocal))
 				{
-					m_CacheStore.Put(Key.Namespace, Key.Bucket, Key.Hash, {.Value = {Request.RecordCacheValue}});
+					m_CacheStore.Put(*Namespace, Key.Bucket, Key.Hash, {.Value = {Request.RecordCacheValue}});
 				}
 				ParseValues(Request);
 				Request.UsedUpstream = true;
@@ -1493,7 +1505,7 @@ HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& Htt
 						{
 							ZEN_DEBUG("Uncompressed value '{}' from upstream cache record '{}/{}/{}'",
 									  Value.ContentId,
-									  Key.Namespace,
+									  *Namespace,
 									  Key.Bucket,
 									  Key.Hash);
 						}
@@ -1510,7 +1522,7 @@ HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& Htt
 			}
 		};
 
-		m_UpstreamCache.GetCacheRecords(UpstreamRequests, std::move(OnCacheRecordGetComplete));
+		m_UpstreamCache.GetCacheRecords(*Namespace, UpstreamRequests, std::move(OnCacheRecordGetComplete));
 	}
 
 	CbPackage	   ResponsePackage;
@@ -1533,7 +1545,7 @@ HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& Htt
 			}
 
 			ZEN_DEBUG("HIT - '{}/{}/{}' {}{}{}",
-					  Key.Namespace,
+					  *Namespace,
 					  Key.Bucket,
 					  Key.Hash,
 					  NiceBytes(Request.RecordCacheValue.Size()),
@@ -1549,11 +1561,11 @@ HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& Htt
 			if (!EnumHasAnyFlags(Request.DownstreamPolicy.GetRecordPolicy(), CachePolicy::Query))
 			{
 				// If they requested no query, do not record this as a miss
-				ZEN_DEBUG("DISABLEDQUERY - '{}/{}/{}'", Key.Namespace, Key.Bucket, Key.Hash);
+				ZEN_DEBUG("DISABLEDQUERY - '{}/{}/{}'", *Namespace, Key.Bucket, Key.Hash);
 			}
 			else
 			{
-				ZEN_DEBUG("MISS - '{}/{}/{}' {}", Key.Namespace, Key.Bucket, Key.Hash, Request.RecordObject ? ""sv : "(PARTIAL)"sv);
+				ZEN_DEBUG("MISS - '{}/{}/{}' {}", *Namespace, Key.Bucket, Key.Hash, Request.RecordObject ? ""sv : "(PARTIAL)"sv);
 				m_CacheStats.MissCount++;
 			}
 		}
@@ -1579,8 +1591,13 @@ HttpStructuredCacheService::HandleRpcPutCacheValues(zen::HttpServerRequest& Requ
 
 	ZEN_ASSERT(BatchObject["Method"sv].AsString() == "PutCacheValues"sv);
 
-	std::string_view  PolicyText	= Params["DefaultPolicy"].AsString();
-	CachePolicy		  DefaultPolicy = !PolicyText.empty() ? ParseCachePolicy(PolicyText) : CachePolicy::Default;
+	std::string_view		   PolicyText	 = Params["DefaultPolicy"].AsString();
+	CachePolicy				   DefaultPolicy = !PolicyText.empty() ? ParseCachePolicy(PolicyText) : CachePolicy::Default;
+	std::optional<std::string> Namespace	 = GetRpcRequestNamespace(Params);
+	if (!Namespace)
+	{
+		return Request.WriteResponse(HttpResponseCode::BadRequest);
+	}
 	std::vector<bool> Results;
 	for (CbFieldView RequestField : Params["Requests"sv])
 	{
@@ -1615,21 +1632,21 @@ HttpStructuredCacheService::HandleRpcPutCacheValues(zen::HttpServerRequest& Requ
 				{
 					IoBuffer Value = Chunk.GetCompressed().Flatten().AsIoBuffer();
 					Value.SetContentType(ZenContentType::kCompressedBinary);
-					m_CacheStore.Put(Key.Namespace, Key.Bucket, Key.Hash, {.Value = Value});
+					m_CacheStore.Put(*Namespace, Key.Bucket, Key.Hash, {.Value = Value});
 					TransferredSize = Chunk.GetCompressedSize();
 				}
 				Succeeded = true;
 			}
 			else
 			{
-				ZEN_WARN("PUTCACHEVALUES - '{}/{}/{}/{}' FAILED, value is not compressed", Key.Namespace, Key.Bucket, Key.Hash, RawHash);
+				ZEN_WARN("PUTCACHEVALUES - '{}/{}/{}/{}' FAILED, value is not compressed", *Namespace, Key.Bucket, Key.Hash, RawHash);
 				return Request.WriteResponse(HttpResponseCode::BadRequest);
 			}
 		}
 		else if (EnumHasAllFlags(Policy, CachePolicy::QueryLocal))
 		{
 			ZenCacheValue ExistingValue;
-			if (m_CacheStore.Get(Key.Namespace, Key.Bucket, Key.Hash, ExistingValue) &&
+			if (m_CacheStore.Get(*Namespace, Key.Bucket, Key.Hash, ExistingValue) &&
 				IsCompressedBinary(ExistingValue.Value.GetContentType()))
 			{
 				Succeeded = true;
@@ -1640,11 +1657,11 @@ HttpStructuredCacheService::HandleRpcPutCacheValues(zen::HttpServerRequest& Requ
 
 		if (Succeeded && EnumHasAllFlags(Policy, CachePolicy::StoreRemote))
 		{
-			m_UpstreamCache.EnqueueUpstream({.Type = ZenContentType::kCompressedBinary, .Key = Key});
+			m_UpstreamCache.EnqueueUpstream({.Type = ZenContentType::kCompressedBinary, .Namespace = *Namespace, .Key = Key});
 		}
 		Results.push_back(Succeeded);
 		ZEN_DEBUG("PUTCACHEVALUES - '{}/{}/{}' {}, '{}'",
-				  Key.Namespace,
+				  *Namespace,
 				  Key.Bucket,
 				  Key.Hash,
 				  NiceBytes(TransferredSize),
@@ -1679,9 +1696,15 @@ HttpStructuredCacheService::HandleRpcGetCacheValues(zen::HttpServerRequest& Http
 {
 	ZEN_TRACE_CPU("Z$::RpcGetCacheValues");
 
-	CbObjectView	 Params		   = RpcRequest["Params"sv].AsObjectView();
-	std::string_view PolicyText	   = Params["DefaultPolicy"sv].AsString();
-	CachePolicy		 DefaultPolicy = !PolicyText.empty() ? ParseCachePolicy(PolicyText) : CachePolicy::Default;
+	CbObjectView			   Params		 = RpcRequest["Params"sv].AsObjectView();
+	std::string_view		   PolicyText	 = Params["DefaultPolicy"sv].AsString();
+	CachePolicy				   DefaultPolicy = !PolicyText.empty() ? ParseCachePolicy(PolicyText) : CachePolicy::Default;
+	std::optional<std::string> Namespace	 = GetRpcRequestNamespace(Params);
+	if (!Namespace)
+	{
+		return HttpRequest.WriteResponse(HttpResponseCode::BadRequest);
+	}
+
 	struct RequestData
 	{
 		CacheKey		 Key;
@@ -1717,7 +1740,7 @@ HttpStructuredCacheService::HandleRpcGetCacheValues(zen::HttpServerRequest& Http
 		ZenCacheValue CacheValue;
 		if (EnumHasAllFlags(Policy, CachePolicy::QueryLocal))
 		{
-			if (m_CacheStore.Get(Key.Namespace, Key.Bucket, Key.Hash, CacheValue) && IsCompressedBinary(CacheValue.Value.GetContentType()))
+			if (m_CacheStore.Get(*Namespace, Key.Bucket, Key.Hash, CacheValue) && IsCompressedBinary(CacheValue.Value.GetContentType()))
 			{
 				Result = CompressedBuffer::FromCompressed(SharedBuffer(CacheValue.Value));
 			}
@@ -1725,7 +1748,7 @@ HttpStructuredCacheService::HandleRpcGetCacheValues(zen::HttpServerRequest& Http
 		if (Result)
 		{
 			ZEN_DEBUG("GETCACHEVALUES HIT - '{}/{}/{}' {} ({}) in {}",
-					  Key.Namespace,
+					  *Namespace,
 					  Key.Bucket,
 					  Key.Hash,
 					  NiceBytes(Result.GetCompressed().GetSize()),
@@ -1740,12 +1763,12 @@ HttpStructuredCacheService::HandleRpcGetCacheValues(zen::HttpServerRequest& Http
 		else if (!EnumHasAnyFlags(Policy, CachePolicy::Query))
 		{
 			// If they requested no query, do not record this as a miss
-			ZEN_DEBUG("GETCACHEVALUES DISABLEDQUERY - '{}/{}/{}'", Key.Namespace, Key.Bucket, Key.Hash);
+			ZEN_DEBUG("GETCACHEVALUES DISABLEDQUERY - '{}/{}/{}'", *Namespace, Key.Bucket, Key.Hash);
 		}
 		else
 		{
 			ZEN_DEBUG("GETCACHEVALUES MISS - '{}/{}/{}' ({}) in {}",
-					  Key.Namespace,
+					  *Namespace,
 					  Key.Bucket,
 					  Key.Hash,
 					  "LOCAL"sv,
@@ -1763,13 +1786,14 @@ HttpStructuredCacheService::HandleRpcGetCacheValues(zen::HttpServerRequest& Http
 		for (size_t Index : RemoteRequestIndexes)
 		{
 			RequestData& Request = Requests[Index];
-			RequestedRecordsData.push_back({{Request.Key.Namespace, Request.Key.Bucket, Request.Key.Hash}});
+			RequestedRecordsData.push_back({Request.Key.Bucket, Request.Key.Hash});
 			CacheChunkRequests.push_back(&RequestedRecordsData.back());
 		}
 		Stopwatch Timer;
 		m_UpstreamCache.GetCacheValues(
+			*Namespace,
 			CacheChunkRequests,
-			[this, &RequestedRecordsData, &Requests, &RemoteRequestIndexes, &Timer](CacheValueGetCompleteParams&& Params) {
+			[this, Namespace, &RequestedRecordsData, &Requests, &RemoteRequestIndexes, &Timer](CacheValueGetCompleteParams&& Params) {
 				CacheChunkRequest& ChunkRequest = Params.Request;
 				if (Params.Value)
 				{
@@ -1783,9 +1807,9 @@ HttpStructuredCacheService::HandleRpcGetCacheValues(zen::HttpServerRequest& Http
 						// that we copy data from upstream even when SkipData and !StoreLocal are true means that it is too expensive
 						// for us to keep the data only on the upstream server.
 						// if (EnumHasAllFlags(Policy, CachePolicy::StoreLocal))
-						m_CacheStore.Put(Request.Key.Namespace, Request.Key.Bucket, Request.Key.Hash, ZenCacheValue{Params.Value});
+						m_CacheStore.Put(*Namespace, Request.Key.Bucket, Request.Key.Hash, ZenCacheValue{Params.Value});
 						ZEN_DEBUG("GETCACHEVALUES HIT - '{}/{}/{}' {} ({}) in {}",
-								  ChunkRequest.Key.Namespace,
+								  *Namespace,
 								  ChunkRequest.Key.Bucket,
 								  ChunkRequest.Key.Hash,
 								  NiceBytes(Request.Result.GetCompressed().GetSize()),
@@ -1797,7 +1821,7 @@ HttpStructuredCacheService::HandleRpcGetCacheValues(zen::HttpServerRequest& Http
 					}
 				}
 				ZEN_DEBUG("GETCACHEVALUES MISS - '{}/{}/{}' ({}) in {}",
-						  ChunkRequest.Key.Namespace,
+						  *Namespace,
 						  ChunkRequest.Key.Bucket,
 						  ChunkRequest.Key.Hash,
 						  "UPSTREAM"sv,
@@ -1888,6 +1912,7 @@ HttpStructuredCacheService::HandleRpcGetCacheChunks(zen::HttpServerRequest& Http
 
 	ZEN_TRACE_CPU("Z$::RpcGetCacheChunks");
 
+	std::string						Namespace;
 	std::vector<CacheKeyRequest>	RecordKeys;		 // Data about a Record necessary to identify it to the upstream
 	std::vector<RecordBody>			Records;		 // Scratch-space data about a Record when fulfilling RecordRequests
 	std::vector<CacheChunkRequest>	RequestKeys;	 // Data about a ChunkRequest necessary to identify it to the upstream
@@ -1897,27 +1922,28 @@ HttpStructuredCacheService::HandleRpcGetCacheChunks(zen::HttpServerRequest& Http
 	std::vector<CacheChunkRequest*> UpstreamChunks;	 // ChunkRequests that we need to send to the upstream
 
 	// Parse requests from the CompactBinary body of the RpcRequest and divide it into RecordRequests and ValueRequests
-	if (!ParseGetCacheChunksRequest(RecordKeys, Records, RequestKeys, Requests, RecordRequests, ValueRequests, RpcRequest))
+	if (!ParseGetCacheChunksRequest(Namespace, RecordKeys, Records, RequestKeys, Requests, RecordRequests, ValueRequests, RpcRequest))
 	{
 		return HttpRequest.WriteResponse(HttpResponseCode::BadRequest);
 	}
 
 	// For each Record request, load the Record if necessary to find the Chunk's ContentId, load its Payloads if we
 	// have it locally, and otherwise append a request for the payload to UpstreamChunks
-	GetLocalCacheRecords(RecordKeys, Records, RecordRequests, UpstreamChunks);
+	GetLocalCacheRecords(Namespace, RecordKeys, Records, RecordRequests, UpstreamChunks);
 
 	// For each Value request, load the Value if we have it locally and otherwise append a request for the payload to UpstreamChunks
-	GetLocalCacheValues(ValueRequests, UpstreamChunks);
+	GetLocalCacheValues(Namespace, ValueRequests, UpstreamChunks);
 
 	// Call GetCacheChunks on the upstream for any payloads we do not have locally
-	GetUpstreamCacheChunks(UpstreamChunks, RequestKeys, Requests);
+	GetUpstreamCacheChunks(Namespace, UpstreamChunks, RequestKeys, Requests);
 
 	// Send the payload and descriptive data about each chunk to the client
-	WriteGetCacheChunksResponse(Requests, HttpRequest);
+	WriteGetCacheChunksResponse(Namespace, Requests, HttpRequest);
 }
 
 bool
-HttpStructuredCacheService::ParseGetCacheChunksRequest(std::vector<CacheKeyRequest>&			  RecordKeys,
+HttpStructuredCacheService::ParseGetCacheChunksRequest(std::string&								  Namespace,
+													   std::vector<CacheKeyRequest>&			  RecordKeys,
 													   std::vector<cache::detail::RecordBody>&	  Records,
 													   std::vector<CacheChunkRequest>&			  RequestKeys,
 													   std::vector<cache::detail::ChunkRequest>&  Requests,
@@ -1929,11 +1955,20 @@ HttpStructuredCacheService::ParseGetCacheChunksRequest(std::vector<CacheKeyReque
 
 	ZEN_ASSERT(RpcRequest["Method"sv].AsString() == "GetCacheChunks"sv);
 
-	CbObjectView	 Params				= RpcRequest["Params"sv].AsObjectView();
-	std::string_view DefaultPolicyText	= Params["DefaultPolicy"sv].AsString();
-	CachePolicy		 DefaultPolicy		= !DefaultPolicyText.empty() ? ParseCachePolicy(DefaultPolicyText) : CachePolicy::Default;
-	CbArrayView		 ChunkRequestsArray = Params["ChunkRequests"sv].AsArrayView();
-	size_t			 NumRequests		= static_cast<size_t>(ChunkRequestsArray.Num());
+	CbObjectView	 Params			   = RpcRequest["Params"sv].AsObjectView();
+	std::string_view DefaultPolicyText = Params["DefaultPolicy"sv].AsString();
+	CachePolicy		 DefaultPolicy	   = !DefaultPolicyText.empty() ? ParseCachePolicy(DefaultPolicyText) : CachePolicy::Default;
+
+	std::optional<std::string> NamespaceText = GetRpcRequestNamespace(Params);
+	if (!NamespaceText)
+	{
+		ZEN_WARN("GetCacheChunks: Invalid namespace in ChunkRequest.");
+		return false;
+	}
+	Namespace = *NamespaceText;
+
+	CbArrayView ChunkRequestsArray = Params["ChunkRequests"sv].AsArrayView();
+	size_t		NumRequests		   = static_cast<size_t>(ChunkRequestsArray.Num());
 
 	// Note that these reservations allow us to take pointers to the elements while populating them. If the reservation is removed,
 	// we will need to change the pointers to indexes to handle reallocations.
@@ -1996,11 +2031,9 @@ HttpStructuredCacheService::ParseGetCacheChunksRequest(std::vector<CacheKeyReque
 			}
 			else
 			{
-				ZEN_WARN("GetCacheChunks: Keys in ChunkRequest are not sorted: {}/{}/{} came after {}/{}/{}.",
-						 RequestKey.Key.Namespace,
+				ZEN_WARN("GetCacheChunks: Keys in ChunkRequest are not sorted: {}/{} came after {}/{}.",
 						 RequestKey.Key.Bucket,
 						 RequestKey.Key.Hash,
-						 PreviousRecordKey->Key.Namespace,
 						 PreviousRecordKey->Key.Bucket,
 						 PreviousRecordKey->Key.Hash);
 				return false;
@@ -2022,7 +2055,8 @@ HttpStructuredCacheService::ParseGetCacheChunksRequest(std::vector<CacheKeyReque
 }
 
 void
-HttpStructuredCacheService::GetLocalCacheRecords(std::vector<CacheKeyRequest>&				RecordKeys,
+HttpStructuredCacheService::GetLocalCacheRecords(std::string_view							Namespace,
+												 std::vector<CacheKeyRequest>&				RecordKeys,
 												 std::vector<cache::detail::RecordBody>&	Records,
 												 std::vector<cache::detail::ChunkRequest*>& RecordRequests,
 												 std::vector<CacheChunkRequest*>&			OutUpstreamChunks)
@@ -2041,7 +2075,7 @@ HttpStructuredCacheService::GetLocalCacheRecords(std::vector<CacheKeyRequest>&
 			if (!Record.Exists && EnumHasAllFlags(Record.DownstreamPolicy, CachePolicy::QueryLocal))
 			{
 				ZenCacheValue CacheValue;
-				if (m_CacheStore.Get(RecordKey.Key.Namespace, RecordKey.Key.Bucket, RecordKey.Key.Hash, CacheValue))
+				if (m_CacheStore.Get(Namespace, RecordKey.Key.Bucket, RecordKey.Key.Hash, CacheValue))
 				{
 					Record.Exists	  = true;
 					Record.CacheValue = std::move(CacheValue.Value);
@@ -2058,7 +2092,7 @@ HttpStructuredCacheService::GetLocalCacheRecords(std::vector<CacheKeyRequest>&
 
 	if (!UpstreamRecordRequests.empty())
 	{
-		const auto OnCacheRecordGetComplete = [this, &RecordKeys, &Records](CacheRecordGetCompleteParams&& Params) {
+		const auto OnCacheRecordGetComplete = [this, Namespace, &RecordKeys, &Records](CacheRecordGetCompleteParams&& Params) {
 			if (!Params.Record)
 			{
 				return;
@@ -2076,10 +2110,10 @@ HttpStructuredCacheService::GetLocalCacheRecords(std::vector<CacheKeyRequest>&
 
 			if (EnumHasAllFlags(Record.DownstreamPolicy, CachePolicy::StoreLocal))
 			{
-				m_CacheStore.Put(Key.Namespace, Key.Bucket, Key.Hash, {.Value = Record.CacheValue});
+				m_CacheStore.Put(Namespace, Key.Bucket, Key.Hash, {.Value = Record.CacheValue});
 			}
 		};
-		m_UpstreamCache.GetCacheRecords(UpstreamRecordRequests, std::move(OnCacheRecordGetComplete));
+		m_UpstreamCache.GetCacheRecords(Namespace, UpstreamRecordRequests, std::move(OnCacheRecordGetComplete));
 	}
 
 	std::vector<CacheChunkRequest*> UpstreamPayloadRequests;
@@ -2163,7 +2197,8 @@ HttpStructuredCacheService::GetLocalCacheRecords(std::vector<CacheKeyRequest>&
 }
 
 void
-HttpStructuredCacheService::GetLocalCacheValues(std::vector<cache::detail::ChunkRequest*>& ValueRequests,
+HttpStructuredCacheService::GetLocalCacheValues(std::string_view						   Namespace,
+												std::vector<cache::detail::ChunkRequest*>& ValueRequests,
 												std::vector<CacheChunkRequest*>&		   OutUpstreamChunks)
 {
 	using namespace cache::detail;
@@ -2173,7 +2208,7 @@ HttpStructuredCacheService::GetLocalCacheValues(std::vector<cache::detail::Chunk
 		if (!Request->Exists && EnumHasAllFlags(Request->DownstreamPolicy, CachePolicy::QueryLocal))
 		{
 			ZenCacheValue CacheValue;
-			if (m_CacheStore.Get(Request->Key->Key.Namespace, Request->Key->Key.Bucket, Request->Key->Key.Hash, CacheValue))
+			if (m_CacheStore.Get(Namespace, Request->Key->Key.Bucket, Request->Key->Key.Hash, CacheValue))
 			{
 				if (IsCompressedBinary(CacheValue.Value.GetContentType()))
 				{
@@ -2207,7 +2242,8 @@ HttpStructuredCacheService::GetLocalCacheValues(std::vector<cache::detail::Chunk
 }
 
 void
-HttpStructuredCacheService::GetUpstreamCacheChunks(std::vector<CacheChunkRequest*>&			 UpstreamChunks,
+HttpStructuredCacheService::GetUpstreamCacheChunks(std::string_view							 Namespace,
+												   std::vector<CacheChunkRequest*>&			 UpstreamChunks,
 												   std::vector<CacheChunkRequest>&			 RequestKeys,
 												   std::vector<cache::detail::ChunkRequest>& Requests)
 {
@@ -2215,7 +2251,7 @@ HttpStructuredCacheService::GetUpstreamCacheChunks(std::vector<CacheChunkRequest
 
 	if (!UpstreamChunks.empty())
 	{
-		const auto OnCacheValueGetComplete = [this, &RequestKeys, &Requests](CacheValueGetCompleteParams&& Params) {
+		const auto OnCacheValueGetComplete = [this, Namespace, &RequestKeys, &Requests](CacheValueGetCompleteParams&& Params) {
 			if (Params.RawHash == Params.RawHash.Zero)
 			{
 				return;
@@ -2242,7 +2278,7 @@ HttpStructuredCacheService::GetUpstreamCacheChunks(std::vector<CacheChunkRequest
 					}
 					else
 					{
-						m_CacheStore.Put(Key.Key.Namespace, Key.Key.Bucket, Key.Key.Hash, {.Value = Params.Value});
+						m_CacheStore.Put(Namespace, Key.Key.Bucket, Key.Key.Hash, {.Value = Params.Value});
 					}
 				}
 				if (!EnumHasAllFlags(Request.DownstreamPolicy, CachePolicy::SkipData))
@@ -2259,12 +2295,13 @@ HttpStructuredCacheService::GetUpstreamCacheChunks(std::vector<CacheChunkRequest
 			m_CacheStats.UpstreamHitCount++;
 		};
 
-		m_UpstreamCache.GetCacheValues(UpstreamChunks, std::move(OnCacheValueGetComplete));
+		m_UpstreamCache.GetCacheValues(Namespace, UpstreamChunks, std::move(OnCacheValueGetComplete));
 	}
 }
 
 void
-HttpStructuredCacheService::WriteGetCacheChunksResponse(std::vector<cache::detail::ChunkRequest>& Requests,
+HttpStructuredCacheService::WriteGetCacheChunksResponse(std::string_view						  Namespace,
+														std::vector<cache::detail::ChunkRequest>& Requests,
 														zen::HttpServerRequest&					  HttpRequest)
 {
 	using namespace cache::detail;
@@ -2290,7 +2327,7 @@ HttpStructuredCacheService::WriteGetCacheChunksResponse(std::vector<cache::detai
 				}
 
 				ZEN_DEBUG("HIT - '{}/{}/{}/{}' {} '{}' ({})",
-						  Request.Key->Key.Namespace,
+						  Namespace,
 						  Request.Key->Key.Bucket,
 						  Request.Key->Key.Hash,
 						  Request.Key->ValueId,
@@ -2301,19 +2338,11 @@ HttpStructuredCacheService::WriteGetCacheChunksResponse(std::vector<cache::detai
 			}
 			else if (!EnumHasAnyFlags(Request.DownstreamPolicy, CachePolicy::Query))
 			{
-				ZEN_DEBUG("SKIP - '{}/{}/{}/{}'",
-						  Request.Key->Key.Namespace,
-						  Request.Key->Key.Bucket,
-						  Request.Key->Key.Hash,
-						  Request.Key->ValueId);
+				ZEN_DEBUG("SKIP - '{}/{}/{}/{}'", Namespace, Request.Key->Key.Bucket, Request.Key->Key.Hash, Request.Key->ValueId);
 			}
 			else
 			{
-				ZEN_DEBUG("MISS - '{}/{}/{}/{}'",
-						  Request.Key->Key.Namespace,
-						  Request.Key->Key.Bucket,
-						  Request.Key->Key.Hash,
-						  Request.Key->ValueId);
+				ZEN_DEBUG("MISS - '{}/{}/{}/{}'", Namespace, Request.Key->Key.Bucket, Request.Key->Key.Hash, Request.Key->ValueId);
 				m_CacheStats.MissCount++;
 			}
 		}
@@ -2409,8 +2438,8 @@ TEST_CASE("z$service.parse.relative.Uri")
 	CHECK(LegacyValueContentIdRequest.ValueContentId == IoHash::FromHexString("56789abcdef12345678956789abcdef123456789"sv));
 
 	HttpRequestData V2DefaultNamespaceRequest;
-	CHECK(HttpRequestParseRelativeUri("default", V2DefaultNamespaceRequest));
-	CHECK(V2DefaultNamespaceRequest.Namespace == ZenCacheStore::DefaultNamespace);
+	CHECK(HttpRequestParseRelativeUri("ue4.ddc", V2DefaultNamespaceRequest));
+	CHECK(V2DefaultNamespaceRequest.Namespace == "ue4.ddc");
 	CHECK(!V2DefaultNamespaceRequest.Bucket.has_value());
 	CHECK(!V2DefaultNamespaceRequest.HashKey.has_value());
 	CHECK(!V2DefaultNamespaceRequest.ValueContentId.has_value());
@@ -2423,8 +2452,8 @@ TEST_CASE("z$service.parse.relative.Uri")
 	CHECK(!V2NamespaceRequest.ValueContentId.has_value());
 
 	HttpRequestData V2BucketRequestWithDefaultNamespace;
-	CHECK(HttpRequestParseRelativeUri("default/test", V2BucketRequestWithDefaultNamespace));
-	CHECK(V2BucketRequestWithDefaultNamespace.Namespace == ZenCacheStore::DefaultNamespace);
+	CHECK(HttpRequestParseRelativeUri("ue4.ddc/test", V2BucketRequestWithDefaultNamespace));
+	CHECK(V2BucketRequestWithDefaultNamespace.Namespace == "ue4.ddc");
 	CHECK(V2BucketRequestWithDefaultNamespace.Bucket == "test"sv);
 	CHECK(!V2BucketRequestWithDefaultNamespace.HashKey.has_value());
 	CHECK(!V2BucketRequestWithDefaultNamespace.ValueContentId.has_value());
@@ -2437,7 +2466,7 @@ TEST_CASE("z$service.parse.relative.Uri")
 	CHECK(!V2BucketRequestWithNamespace.ValueContentId.has_value());
 
 	HttpRequestData V2HashKeyRequest;
-	CHECK(HttpRequestParseRelativeUri("default/test/0123456789abcdef12340123456789abcdef1234", V2HashKeyRequest));
+	CHECK(HttpRequestParseRelativeUri("test/0123456789abcdef12340123456789abcdef1234", V2HashKeyRequest));
 	CHECK(V2HashKeyRequest.Namespace == ZenCacheStore::DefaultNamespace);
 	CHECK(V2HashKeyRequest.Bucket == "test");
 	CHECK(V2HashKeyRequest.HashKey == IoHash::FromHexString("0123456789abcdef12340123456789abcdef1234"sv));
diff --git a/zenserver/cache/structuredcache.h b/zenserver/cache/structuredcache.h
index 5f248edd1..890a2ebab 100644
--- a/zenserver/cache/structuredcache.h
+++ b/zenserver/cache/structuredcache.h
@@ -118,7 +118,8 @@ private:
 	PutResult	 PutCacheRecord(PutRequestData& Request, const CbPackage* Package);
 
 	/** HandleRpcGetCacheChunks Helper: Parse the Body object into RecordValue Requests and Value Requests. */
-	bool ParseGetCacheChunksRequest(std::vector<CacheKeyRequest>&			   RecordKeys,
+	bool ParseGetCacheChunksRequest(std::string&							   Namespace,
+									std::vector<CacheKeyRequest>&			   RecordKeys,
 									std::vector<cache::detail::RecordBody>&	   Records,
 									std::vector<CacheChunkRequest>&			   RequestKeys,
 									std::vector<cache::detail::ChunkRequest>&  Requests,
@@ -126,18 +127,24 @@ private:
 									std::vector<cache::detail::ChunkRequest*>& ValueRequests,
 									CbObjectView							   RpcRequest);
 	/** HandleRpcGetCacheChunks Helper: Load records to get ContentId for RecordRequests, and load their payloads if they exist locally. */
-	void GetLocalCacheRecords(std::vector<CacheKeyRequest>&				 RecordKeys,
+	void GetLocalCacheRecords(std::string_view							 Namespace,
+							  std::vector<CacheKeyRequest>&				 RecordKeys,
 							  std::vector<cache::detail::RecordBody>&	 Records,
 							  std::vector<cache::detail::ChunkRequest*>& RecordRequests,
 							  std::vector<CacheChunkRequest*>&			 OutUpstreamChunks);
 	/** HandleRpcGetCacheChunks Helper: For ValueRequests, load their payloads if they exist locally. */
-	void GetLocalCacheValues(std::vector<cache::detail::ChunkRequest*>& ValueRequests, std::vector<CacheChunkRequest*>& OutUpstreamChunks);
+	void GetLocalCacheValues(std::string_view							Namespace,
+							 std::vector<cache::detail::ChunkRequest*>& ValueRequests,
+							 std::vector<CacheChunkRequest*>&			OutUpstreamChunks);
 	/** HandleRpcGetCacheChunks Helper: Load payloads from upstream that did not exist locally. */
-	void GetUpstreamCacheChunks(std::vector<CacheChunkRequest*>&		  UpstreamChunks,
+	void GetUpstreamCacheChunks(std::string_view						  Namespace,
+								std::vector<CacheChunkRequest*>&		  UpstreamChunks,
 								std::vector<CacheChunkRequest>&			  RequestKeys,
 								std::vector<cache::detail::ChunkRequest>& Requests);
 	/** HandleRpcGetCacheChunks Helper: Send response message containing all chunk results. */
-	void WriteGetCacheChunksResponse(std::vector<cache::detail::ChunkRequest>& Requests, zen::HttpServerRequest& HttpRequest);
+	void WriteGetCacheChunksResponse(std::string_view						   Namespace,
+									 std::vector<cache::detail::ChunkRequest>& Requests,
+									 zen::HttpServerRequest&				   HttpRequest);
 
 	spdlog::logger&			 Log() { return m_Log; }
 	spdlog::logger&			 m_Log;
diff --git a/zenserver/cache/structuredcachestore.cpp b/zenserver/cache/structuredcachestore.cpp
index 4edc13b4a..da948fd72 100644
--- a/zenserver/cache/structuredcachestore.cpp
+++ b/zenserver/cache/structuredcachestore.cpp
@@ -2128,6 +2128,8 @@ ZenCacheDiskLayer::TotalSize() const
 
 //////////////////////////// ZenCacheStore
 
+static constexpr std::string_view UE4DDCNamespaceName = "ue4.ddc";
+
 ZenCacheStore::ZenCacheStore(CasGc& Gc, std::filesystem::path BasePath) : GcStorage(Gc), GcContributor(Gc)
 {
 	CreateDirectories(BasePath);
@@ -2150,11 +2152,13 @@ ZenCacheStore::ZenCacheStore(CasGc& Gc, std::filesystem::path BasePath) : GcStor
 
 	ZEN_INFO("Found #{} namespaces in '{}' and #{} legacy buckets", Namespaces.size(), BasePath, LegacyBuckets.size());
 
-	if (std::find(Namespaces.begin(), Namespaces.end(), DefaultNamespace) == Namespaces.end())
+	if (std::find(Namespaces.begin(), Namespaces.end(), UE4DDCNamespaceName) == Namespaces.end())
 	{
-		ZEN_INFO("Moving #{} legacy buckets to anonymous namespace", LegacyBuckets.size());
+		// default (unspecified) and ue4-ddc namespace points to the same namespace instance
+
+		ZEN_INFO("Moving #{} legacy buckets to '{}' namespace", LegacyBuckets.size(), UE4DDCNamespaceName);
 
-		std::filesystem::path DefaultNamespaceFolder = BasePath / fmt::format("{}{}", NamespaceDiskPrefix, DefaultNamespace);
+		std::filesystem::path DefaultNamespaceFolder = BasePath / fmt::format("{}{}", NamespaceDiskPrefix, UE4DDCNamespaceName);
 		CreateDirectories(DefaultNamespaceFolder);
 
 		// Move any non-namespace folders into the default namespace folder
@@ -2169,8 +2173,7 @@ ZenCacheStore::ZenCacheStore(CasGc& Gc, std::filesystem::path BasePath) : GcStor
 				ZEN_ERROR("Unable to move '{}' to '{}', reason '{}'", LegacyFolder, NewPath, Ec.message());
 			}
 		}
-
-		Namespaces.push_back(std::string(DefaultNamespace));
+		Namespaces.push_back(std::string(UE4DDCNamespaceName));
 	}
 
 	for (const std::string& NamespaceName : Namespaces)
@@ -2237,6 +2240,13 @@ ZenCacheStore::GetNamespace(std::string_view Namespace)
 	{
 		return It->second.get();
 	}
+	if (Namespace == DefaultNamespace)
+	{
+		if (auto It = m_Namespaces.find(std::string(UE4DDCNamespaceName)); It != m_Namespaces.end())
+		{
+			return It->second.get();
+		}
+	}
 	return nullptr;
 }
 
@@ -2249,6 +2259,10 @@ ZenCacheStore::IterateNamespaces(const std::function<void(std::string_view Names
 		Namespaces.reserve(m_Namespaces.size());
 		for (const auto& Entry : m_Namespaces)
 		{
+			if (Entry.first == DefaultNamespace)
+			{
+				continue;
+			}
 			Namespaces.push_back({Entry.first, *Entry.second});
 		}
 	}
diff --git a/zenserver/cache/structuredcachestore.h b/zenserver/cache/structuredcachestore.h
index 232e8b9a8..34b8d18f4 100644
--- a/zenserver/cache/structuredcachestore.h
+++ b/zenserver/cache/structuredcachestore.h
@@ -356,7 +356,8 @@ private:
 class ZenCacheStore final : public GcStorage, public GcContributor
 {
 public:
-	static constexpr std::string_view DefaultNamespace	  = "default";
+	static constexpr std::string_view DefaultNamespace =
+		"!default!";  // This is intentionally not a valid namespace name and will only be used for mapping when no namespace is given
 	static constexpr std::string_view NamespaceDiskPrefix = "ns_";
 
 	ZenCacheStore(CasGc& Gc, std::filesystem::path BasePath);
diff --git a/zenserver/upstream/upstreamcache.cpp b/zenserver/upstream/upstreamcache.cpp
index 52513abe9..98b4439c7 100644
--- a/zenserver/upstream/upstreamcache.cpp
+++ b/zenserver/upstream/upstreamcache.cpp
@@ -182,7 +182,7 @@ namespace detail {
 
 		virtual UpstreamEndpointStatus GetStatus() override { return m_Status.EndpointStatus(); }
 
-		virtual GetUpstreamCacheResult GetCacheRecord(CacheKey CacheKey, ZenContentType Type) override
+		virtual GetUpstreamCacheResult GetCacheRecord(std::string_view Namespace, const CacheKey& CacheKey, ZenContentType Type) override
 		{
 			ZEN_TRACE_CPU("Upstream::Horde::GetSingleCacheRecord");
 
@@ -191,11 +191,11 @@ namespace detail {
 				CloudCacheSession Session(m_Client);
 				CloudCacheResult  Result;
 
-				std::string_view BlobStoreNamespace = GetActualBlobStoreNamespace(Session, CacheKey.Namespace);
+				std::string_view BlobStoreNamespace = GetActualBlobStoreNamespace(Session, Namespace);
 
 				if (m_UseLegacyDdc && Type == ZenContentType::kBinary)
 				{
-					std::string_view DdcNamespace = GetActualDdcNamespace(Session, CacheKey.Namespace);
+					std::string_view DdcNamespace = GetActualDdcNamespace(Session, Namespace);
 					Result						  = Session.GetDerivedData(DdcNamespace, CacheKey.Bucket, CacheKey.Hash);
 				}
 				else if (Type == ZenContentType::kCompressedBinary)
@@ -299,7 +299,9 @@ namespace detail {
 			}
 		}
 
-		virtual GetUpstreamCacheResult GetCacheRecords(std::span<CacheKeyRequest*> Requests, OnCacheRecordGetComplete&& OnComplete) override
+		virtual GetUpstreamCacheResult GetCacheRecords(std::string_view			   Namespace,
+													   std::span<CacheKeyRequest*> Requests,
+													   OnCacheRecordGetComplete&&  OnComplete) override
 		{
 			ZEN_TRACE_CPU("Upstream::Horde::GetCacheRecords");
 
@@ -314,7 +316,7 @@ namespace detail {
 
 				if (!Result.Error)
 				{
-					std::string_view BlobStoreNamespace = GetActualBlobStoreNamespace(Session, CacheKey.Namespace);
+					std::string_view BlobStoreNamespace = GetActualBlobStoreNamespace(Session, Namespace);
 					CloudCacheResult RefResult =
 						Session.GetRef(BlobStoreNamespace, CacheKey.Bucket, CacheKey.Hash, ZenContentType::kCbObject);
 					AppendResult(RefResult, Result);
@@ -351,14 +353,14 @@ namespace detail {
 			return Result;
 		}
 
-		virtual GetUpstreamCacheResult GetCacheValue(const CacheKey& CacheKey, const IoHash& ValueContentId) override
+		virtual GetUpstreamCacheResult GetCacheValue(std::string_view Namespace, const CacheKey&, const IoHash& ValueContentId) override
 		{
 			ZEN_TRACE_CPU("Upstream::Horde::GetSingleCacheValue");
 
 			try
 			{
 				CloudCacheSession	   Session(m_Client);
-				std::string_view	   BlobStoreNamespace = GetActualBlobStoreNamespace(Session, CacheKey.Namespace);
+				std::string_view	   BlobStoreNamespace = GetActualBlobStoreNamespace(Session, Namespace);
 				const CloudCacheResult Result			  = Session.GetCompressedBlob(BlobStoreNamespace, ValueContentId);
 
 				m_Status.SetFromErrorCode(Result.ErrorCode, Result.Reason);
@@ -383,7 +385,8 @@ namespace detail {
 			}
 		}
 
-		virtual GetUpstreamCacheResult GetCacheValues(std::span<CacheChunkRequest*> CacheChunkRequests,
+		virtual GetUpstreamCacheResult GetCacheValues(std::string_view				Namespace,
+													  std::span<CacheChunkRequest*> CacheChunkRequests,
 													  OnCacheValueGetComplete&&		OnComplete) override final
 		{
 			ZEN_TRACE_CPU("Upstream::Horde::GetCacheValues");
@@ -399,7 +402,7 @@ namespace detail {
 				CompressedBuffer Compressed;
 				if (!Result.Error)
 				{
-					std::string_view	   BlobStoreNamespace = GetActualBlobStoreNamespace(Session, Request.Key.Namespace);
+					std::string_view	   BlobStoreNamespace = GetActualBlobStoreNamespace(Session, Namespace);
 					const CloudCacheResult BlobResult		  = Session.GetCompressedBlob(BlobStoreNamespace, Request.ChunkId);
 					Payload									  = BlobResult.Response;
 
@@ -446,7 +449,7 @@ namespace detail {
 					CloudCacheResult Result;
 					for (uint32_t Attempt = 0; Attempt < MaxAttempts && !Result.Success; Attempt++)
 					{
-						std::string_view BlobStoreNamespace = GetActualBlobStoreNamespace(Session, CacheRecord.Key.Namespace);
+						std::string_view BlobStoreNamespace = GetActualBlobStoreNamespace(Session, CacheRecord.Namespace);
 						if (m_UseLegacyDdc)
 						{
 							Result = Session.PutDerivedData(BlobStoreNamespace, CacheRecord.Key.Bucket, CacheRecord.Key.Hash, RecordValue);
@@ -484,6 +487,7 @@ namespace detail {
 
 					return PerformStructuredPut(
 						Session,
+						CacheRecord.Namespace,
 						CacheRecord.Key,
 						ReferencingObject.Save().GetBuffer().AsIoBuffer(),
 						MaxAttempts,
@@ -503,6 +507,7 @@ namespace detail {
 				{
 					return PerformStructuredPut(
 						Session,
+						CacheRecord.Namespace,
 						CacheRecord.Key,
 						RecordValue,
 						MaxAttempts,
@@ -548,6 +553,7 @@ namespace detail {
 
 		PutUpstreamCacheResult PerformStructuredPut(
 			CloudCacheSession&																				 Session,
+			std::string_view																				 Namespace,
 			const CacheKey&																					 Key,
 			IoBuffer																						 ObjectBuffer,
 			const int32_t																					 MaxAttempts,
@@ -556,7 +562,7 @@ namespace detail {
 			int64_t TotalBytes			= 0ull;
 			double	TotalElapsedSeconds = 0.0;
 
-			std::string_view BlobStoreNamespace = GetActualBlobStoreNamespace(Session, Key.Namespace);
+			std::string_view BlobStoreNamespace = GetActualBlobStoreNamespace(Session, Namespace);
 			const auto		 PutBlobs			= [&](std::span<IoHash> ValueContentIds, std::string& OutReason) -> bool {
 				for (const IoHash& ValueContentId : ValueContentIds)
 				{
@@ -738,14 +744,14 @@ namespace detail {
 
 		virtual UpstreamEndpointStatus GetStatus() override { return m_Status.EndpointStatus(); }
 
-		virtual GetUpstreamCacheResult GetCacheRecord(CacheKey CacheKey, ZenContentType Type) override
+		virtual GetUpstreamCacheResult GetCacheRecord(std::string_view Namespace, const CacheKey& CacheKey, ZenContentType Type) override
 		{
 			ZEN_TRACE_CPU("Upstream::Zen::GetSingleCacheRecord");
 
 			try
 			{
 				ZenStructuredCacheSession Session(*m_Client);
-				const ZenCacheResult	  Result = Session.GetCacheRecord(CacheKey.Bucket, CacheKey.Hash, Type);
+				const ZenCacheResult	  Result = Session.GetCacheRecord(Namespace, CacheKey.Bucket, CacheKey.Hash, Type);
 
 				m_Status.SetFromErrorCode(Result.ErrorCode, Result.Reason);
 
@@ -769,20 +775,24 @@ namespace detail {
 			}
 		}
 
-		virtual GetUpstreamCacheResult GetCacheRecords(std::span<CacheKeyRequest*> Requests, OnCacheRecordGetComplete&& OnComplete) override
+		virtual GetUpstreamCacheResult GetCacheRecords(std::string_view			   Namespace,
+													   std::span<CacheKeyRequest*> Requests,
+													   OnCacheRecordGetComplete&&  OnComplete) override
 		{
 			ZEN_TRACE_CPU("Upstream::Zen::GetCacheRecords");
 			ZEN_ASSERT(Requests.size() > 0);
 
 			CbObjectWriter BatchRequest;
 			BatchRequest << "Method"sv
-						 << "GetCacheRecords";
+						 << "GetCacheRecords"sv;
 
 			BatchRequest.BeginObject("Params"sv);
 			{
 				CachePolicy DefaultPolicy = Requests[0]->Policy.GetRecordPolicy();
 				BatchRequest << "DefaultPolicy"sv << WriteToString<128>(DefaultPolicy);
 
+				BatchRequest << "Namespace"sv << Namespace;
+
 				BatchRequest.BeginArray("Requests"sv);
 				for (CacheKeyRequest* Request : Requests)
 				{
@@ -791,7 +801,6 @@ namespace detail {
 						const CacheKey& Key = Request->Key;
 						BatchRequest.BeginObject("Key"sv);
 						{
-							BatchRequest << "Namespace"sv << Key.Namespace;
 							BatchRequest << "Bucket"sv << Key.Bucket;
 							BatchRequest << "Hash"sv << Key.Hash;
 						}
@@ -848,14 +857,16 @@ namespace detail {
 			return {.Error{.ErrorCode = Result.ErrorCode, .Reason = std::move(Result.Reason)}};
 		}
 
-		virtual GetUpstreamCacheResult GetCacheValue(const CacheKey& CacheKey, const IoHash& ValueContentId) override
+		virtual GetUpstreamCacheResult GetCacheValue(std::string_view Namespace,
+													 const CacheKey&  CacheKey,
+													 const IoHash&	  ValueContentId) override
 		{
 			ZEN_TRACE_CPU("Upstream::Zen::GetSingleCacheValue");
 
 			try
 			{
 				ZenStructuredCacheSession Session(*m_Client);
-				const ZenCacheResult	  Result = Session.GetCacheValue(CacheKey.Bucket, CacheKey.Hash, ValueContentId);
+				const ZenCacheResult	  Result = Session.GetCacheValue(Namespace, CacheKey.Bucket, CacheKey.Hash, ValueContentId);
 
 				m_Status.SetFromErrorCode(Result.ErrorCode, Result.Reason);
 
@@ -879,7 +890,8 @@ namespace detail {
 			}
 		}
 
-		virtual GetUpstreamCacheResult GetCacheValues(std::span<CacheChunkRequest*> CacheChunkRequests,
+		virtual GetUpstreamCacheResult GetCacheValues(std::string_view				Namespace,
+													  std::span<CacheChunkRequest*> CacheChunkRequests,
 													  OnCacheValueGetComplete&&		OnComplete) override final
 		{
 			ZEN_TRACE_CPU("Upstream::Zen::GetCacheValues");
@@ -887,12 +899,16 @@ namespace detail {
 
 			CbObjectWriter BatchRequest;
 			BatchRequest << "Method"sv
-						 << "GetCacheChunks";
+						 << "GetCacheChunks"sv;
+			BatchRequest << "Namespace"sv << Namespace;
 
 			BatchRequest.BeginObject("Params"sv);
 			{
 				CachePolicy DefaultPolicy = CacheChunkRequests[0]->Policy;
 				BatchRequest << "DefaultPolicy"sv << WriteToString<128>(DefaultPolicy).ToView();
+
+				BatchRequest << "Namespace"sv << Namespace;
+
 				BatchRequest.BeginArray("ChunkRequests"sv);
 				{
 					for (CacheChunkRequest* RequestPtr : CacheChunkRequests)
@@ -902,7 +918,6 @@ namespace detail {
 						BatchRequest.BeginObject();
 						{
 							BatchRequest.BeginObject("Key"sv);
-							BatchRequest << "Namespace"sv << Request.Key.Namespace;
 							BatchRequest << "Bucket"sv << Request.Key.Bucket;
 							BatchRequest << "Hash"sv << Request.Key.Hash;
 							BatchRequest.EndObject();
@@ -1042,7 +1057,11 @@ namespace detail {
 
 					for (uint32_t Attempt = 0; Attempt < MaxAttempts && !Result.Success; Attempt++)
 					{
-						Result = Session.PutCacheRecord(CacheRecord.Key.Bucket, CacheRecord.Key.Hash, PackagePayload, CacheRecord.Type);
+						Result = Session.PutCacheRecord(CacheRecord.Namespace,
+														CacheRecord.Key.Bucket,
+														CacheRecord.Key.Hash,
+														PackagePayload,
+														CacheRecord.Type);
 					}
 
 					m_Status.SetFromErrorCode(Result.ErrorCode, Result.Reason);
@@ -1061,12 +1080,14 @@ namespace detail {
 					CbPackage	   BatchPackage;
 					CbObjectWriter BatchWriter;
 					BatchWriter << "Method"sv
-								<< "PutCacheValues";
+								<< "PutCacheValues"sv;
 
 					BatchWriter.BeginObject("Params"sv);
 					{
 						// DefaultPolicy unspecified and expected to be Default
 
+						BatchWriter << "Namespace"sv << CacheRecord.Namespace;
+
 						BatchWriter.BeginArray("Requests"sv);
 						{
 							BatchWriter.BeginObject();
@@ -1074,7 +1095,6 @@ namespace detail {
 								const CacheKey& Key = CacheRecord.Key;
 								BatchWriter.BeginObject("Key"sv);
 								{
-									BatchWriter << "Namespace"sv << Key.Namespace;
 									BatchWriter << "Bucket"sv << Key.Bucket;
 									BatchWriter << "Hash"sv << Key.Hash;
 								}
@@ -1108,7 +1128,8 @@ namespace detail {
 						Result.Success = false;
 						for (uint32_t Attempt = 0; Attempt < MaxAttempts && !Result.Success; Attempt++)
 						{
-							Result = Session.PutCacheValue(CacheRecord.Key.Bucket,
+							Result = Session.PutCacheValue(CacheRecord.Namespace,
+														   CacheRecord.Key.Bucket,
 														   CacheRecord.Key.Hash,
 														   CacheRecord.ValueContentIds[Idx],
 														   Values[Idx]);
@@ -1131,7 +1152,11 @@ namespace detail {
 					Result.Success = false;
 					for (uint32_t Attempt = 0; Attempt < MaxAttempts && !Result.Success; Attempt++)
 					{
-						Result = Session.PutCacheRecord(CacheRecord.Key.Bucket, CacheRecord.Key.Hash, RecordValue, CacheRecord.Type);
+						Result = Session.PutCacheRecord(CacheRecord.Namespace,
+														CacheRecord.Key.Bucket,
+														CacheRecord.Key.Hash,
+														RecordValue,
+														CacheRecord.Type);
 					}
 
 					m_Status.SetFromErrorCode(Result.ErrorCode, Result.Reason);
@@ -1259,7 +1284,7 @@ public:
 		}
 	}
 
-	virtual GetUpstreamCacheResult GetCacheRecord(CacheKey CacheKey, ZenContentType Type) override
+	virtual GetUpstreamCacheResult GetCacheRecord(std::string_view Namespace, const CacheKey& CacheKey, ZenContentType Type) override
 	{
 		ZEN_TRACE_CPU("Upstream::GetCacheRecord");
 
@@ -1278,7 +1303,7 @@ public:
 				GetUpstreamCacheResult Result;
 				{
 					metrics::OperationTiming::Scope Scope(Stats.CacheGetRequestTiming);
-					Result = Endpoint->GetCacheRecord(CacheKey, Type);
+					Result = Endpoint->GetCacheRecord(Namespace, CacheKey, Type);
 				}
 
 				Stats.CacheGetCount.Increment(1);
@@ -1306,7 +1331,9 @@ public:
 		return {};
 	}
 
-	virtual void GetCacheRecords(std::span<CacheKeyRequest*> Requests, OnCacheRecordGetComplete&& OnComplete) override final
+	virtual void GetCacheRecords(std::string_view			 Namespace,
+								 std::span<CacheKeyRequest*> Requests,
+								 OnCacheRecordGetComplete&&	 OnComplete) override final
 	{
 		ZEN_TRACE_CPU("Upstream::GetCacheRecords");
 
@@ -1334,7 +1361,7 @@ public:
 				{
 					metrics::OperationTiming::Scope Scope(Stats.CacheGetRequestTiming);
 
-					Result = Endpoint->GetCacheRecords(RemainingKeys, [&](CacheRecordGetCompleteParams&& Params) {
+					Result = Endpoint->GetCacheRecords(Namespace, RemainingKeys, [&](CacheRecordGetCompleteParams&& Params) {
 						if (Params.Record)
 						{
 							OnComplete(std::forward<CacheRecordGetCompleteParams>(Params));
@@ -1371,7 +1398,9 @@ public:
 		}
 	}
 
-	virtual void GetCacheValues(std::span<CacheChunkRequest*> CacheChunkRequests, OnCacheValueGetComplete&& OnComplete) override final
+	virtual void GetCacheValues(std::string_view			  Namespace,
+								std::span<CacheChunkRequest*> CacheChunkRequests,
+								OnCacheValueGetComplete&&	  OnComplete) override final
 	{
 		ZEN_TRACE_CPU("Upstream::GetCacheValues");
 
@@ -1399,7 +1428,7 @@ public:
 				{
 					metrics::OperationTiming::Scope Scope(Endpoint->Stats().CacheGetRequestTiming);
 
-					Result = Endpoint->GetCacheValues(RemainingKeys, [&](CacheValueGetCompleteParams&& Params) {
+					Result = Endpoint->GetCacheValues(Namespace, RemainingKeys, [&](CacheValueGetCompleteParams&& Params) {
 						if (Params.RawHash != Params.RawHash.Zero)
 						{
 							OnComplete(std::forward<CacheValueGetCompleteParams>(Params));
@@ -1436,7 +1465,9 @@ public:
 		}
 	}
 
-	virtual GetUpstreamCacheResult GetCacheValue(const CacheKey& CacheKey, const IoHash& ValueContentId) override
+	virtual GetUpstreamCacheResult GetCacheValue(std::string_view Namespace,
+												 const CacheKey&  CacheKey,
+												 const IoHash&	  ValueContentId) override
 	{
 		ZEN_TRACE_CPU("Upstream::GetCacheValue");
 
@@ -1454,7 +1485,7 @@ public:
 
 				{
 					metrics::OperationTiming::Scope Scope(Stats.CacheGetRequestTiming);
-					Result = Endpoint->GetCacheValue(CacheKey, ValueContentId);
+					Result = Endpoint->GetCacheValue(Namespace, CacheKey, ValueContentId);
 				}
 
 				Stats.CacheGetCount.Increment(1);
@@ -1550,7 +1581,7 @@ private:
 		ZenCacheValue		  CacheValue;
 		std::vector<IoBuffer> Payloads;
 
-		if (!m_CacheStore.Get(CacheRecord.Key.Namespace, CacheRecord.Key.Bucket, CacheRecord.Key.Hash, CacheValue))
+		if (!m_CacheStore.Get(CacheRecord.Namespace, CacheRecord.Key.Bucket, CacheRecord.Key.Hash, CacheValue))
 		{
 			ZEN_WARN("process upstream FAILED, '{}/{}', cache record doesn't exist", CacheRecord.Key.Bucket, CacheRecord.Key.Hash);
 			return;
@@ -1565,7 +1596,7 @@ private:
 			else
 			{
 				ZEN_WARN("process upstream FAILED, '{}/{}/{}/{}', ValueContentId doesn't exist in CAS",
-						 CacheRecord.Key.Namespace,
+						 CacheRecord.Namespace,
 						 CacheRecord.Key.Bucket,
 						 CacheRecord.Key.Hash,
 						 ValueContentId);
diff --git a/zenserver/upstream/upstreamcache.h b/zenserver/upstream/upstreamcache.h
index 6f18b3119..13548efc8 100644
--- a/zenserver/upstream/upstreamcache.h
+++ b/zenserver/upstream/upstreamcache.h
@@ -32,6 +32,7 @@ struct ZenStructuredCacheClientOptions;
 struct UpstreamCacheRecord
 {
 	ZenContentType		Type = ZenContentType::kBinary;
+	std::string			Namespace;
 	CacheKey			Key;
 	std::vector<IoHash> ValueContentIds;
 };
@@ -163,12 +164,15 @@ public:
 	virtual UpstreamEndpointState  GetState()  = 0;
 	virtual UpstreamEndpointStatus GetStatus() = 0;
 
-	virtual GetUpstreamCacheResult GetCacheRecord(CacheKey CacheKey, ZenContentType Type)										= 0;
-	virtual GetUpstreamCacheResult GetCacheRecords(std::span<CacheKeyRequest*> Requests, OnCacheRecordGetComplete&& OnComplete) = 0;
+	virtual GetUpstreamCacheResult GetCacheRecord(std::string_view Namespace, const CacheKey& CacheKey, ZenContentType Type) = 0;
+	virtual GetUpstreamCacheResult GetCacheRecords(std::string_view			   Namespace,
+												   std::span<CacheKeyRequest*> Requests,
+												   OnCacheRecordGetComplete&&  OnComplete)									 = 0;
 
-	virtual GetUpstreamCacheResult GetCacheValue(const CacheKey& CacheKey, const IoHash& PayloadId) = 0;
-	virtual GetUpstreamCacheResult GetCacheValues(std::span<CacheChunkRequest*> CacheChunkRequests,
-												  OnCacheValueGetComplete&&		OnComplete)				= 0;
+	virtual GetUpstreamCacheResult GetCacheValue(std::string_view Namespace, const CacheKey& CacheKey, const IoHash& PayloadId) = 0;
+	virtual GetUpstreamCacheResult GetCacheValues(std::string_view				Namespace,
+												  std::span<CacheChunkRequest*> CacheChunkRequests,
+												  OnCacheValueGetComplete&&		OnComplete)											= 0;
 
 	virtual PutUpstreamCacheResult PutCacheRecord(const UpstreamCacheRecord& CacheRecord,
 												  IoBuffer					 RecordValue,
@@ -196,11 +200,15 @@ public:
 	virtual void RegisterEndpoint(std::unique_ptr<UpstreamEndpoint> Endpoint)  = 0;
 	virtual void IterateEndpoints(std::function<bool(UpstreamEndpoint&)>&& Fn) = 0;
 
-	virtual GetUpstreamCacheResult GetCacheRecord(CacheKey CacheKey, ZenContentType Type)										= 0;
-	virtual void				   GetCacheRecords(std::span<CacheKeyRequest*> Requests, OnCacheRecordGetComplete&& OnComplete) = 0;
+	virtual GetUpstreamCacheResult GetCacheRecord(std::string_view Namespace, const CacheKey& CacheKey, ZenContentType Type) = 0;
+	virtual void				   GetCacheRecords(std::string_view			   Namespace,
+												   std::span<CacheKeyRequest*> Requests,
+												   OnCacheRecordGetComplete&&  OnComplete)									 = 0;
 
-	virtual GetUpstreamCacheResult GetCacheValue(const CacheKey& CacheKey, const IoHash& ValueContentId)				= 0;
-	virtual void GetCacheValues(std::span<CacheChunkRequest*> CacheChunkRequests, OnCacheValueGetComplete&& OnComplete) = 0;
+	virtual GetUpstreamCacheResult GetCacheValue(std::string_view Namespace, const CacheKey& CacheKey, const IoHash& ValueContentId) = 0;
+	virtual void				   GetCacheValues(std::string_view				Namespace,
+												  std::span<CacheChunkRequest*> CacheChunkRequests,
+												  OnCacheValueGetComplete&&		OnComplete)												 = 0;
 
 	virtual void EnqueueUpstream(UpstreamCacheRecord CacheRecord) = 0;
 
diff --git a/zenserver/upstream/zen.cpp b/zenserver/upstream/zen.cpp
index 1ac4afe5c..efc75b5b4 100644
--- a/zenserver/upstream/zen.cpp
+++ b/zenserver/upstream/zen.cpp
@@ -408,10 +408,15 @@ ZenStructuredCacheSession::CheckHealth()
 }
 
 ZenCacheResult
-ZenStructuredCacheSession::GetCacheRecord(std::string_view BucketId, const IoHash& Key, ZenContentType Type)
+ZenStructuredCacheSession::GetCacheRecord(std::string_view Namespace, std::string_view BucketId, const IoHash& Key, ZenContentType Type)
 {
 	ExtendableStringBuilder<256> Uri;
-	Uri << m_Client.ServiceUrl() << "/z$/" << BucketId << "/" << Key.ToHexString();
+	Uri << m_Client.ServiceUrl() << "/z$/";
+	if (Namespace != ZenCacheStore::DefaultNamespace)
+	{
+		Uri << Namespace << "/";
+	}
+	Uri << BucketId << "/" << Key.ToHexString();
 
 	cpr::Session& Session = m_SessionState->GetSession();
 
@@ -432,10 +437,18 @@ ZenStructuredCacheSession::GetCacheRecord(std::string_view BucketId, const IoHas
 }
 
 ZenCacheResult
-ZenStructuredCacheSession::GetCacheValue(std::string_view BucketId, const IoHash& Key, const IoHash& ValueContentId)
+ZenStructuredCacheSession::GetCacheValue(std::string_view Namespace,
+										 std::string_view BucketId,
+										 const IoHash&	  Key,
+										 const IoHash&	  ValueContentId)
 {
 	ExtendableStringBuilder<256> Uri;
-	Uri << m_Client.ServiceUrl() << "/z$/" << BucketId << "/" << Key.ToHexString() << "/" << ValueContentId.ToHexString();
+	Uri << m_Client.ServiceUrl() << "/z$/";
+	if (Namespace != ZenCacheStore::DefaultNamespace)
+	{
+		Uri << Namespace << "/";
+	}
+	Uri << BucketId << "/" << Key.ToHexString() << "/" << ValueContentId.ToHexString();
 
 	cpr::Session& Session = m_SessionState->GetSession();
 
@@ -457,10 +470,19 @@ ZenStructuredCacheSession::GetCacheValue(std::string_view BucketId, const IoHash
 }
 
 ZenCacheResult
-ZenStructuredCacheSession::PutCacheRecord(std::string_view BucketId, const IoHash& Key, IoBuffer Value, ZenContentType Type)
+ZenStructuredCacheSession::PutCacheRecord(std::string_view Namespace,
+										  std::string_view BucketId,
+										  const IoHash&	   Key,
+										  IoBuffer		   Value,
+										  ZenContentType   Type)
 {
 	ExtendableStringBuilder<256> Uri;
-	Uri << m_Client.ServiceUrl() << "/z$/" << BucketId << "/" << Key.ToHexString();
+	Uri << m_Client.ServiceUrl() << "/z$/";
+	if (Namespace != ZenCacheStore::DefaultNamespace)
+	{
+		Uri << Namespace << "/";
+	}
+	Uri << BucketId << "/" << Key.ToHexString();
 
 	cpr::Session& Session = m_SessionState->GetSession();
 
@@ -485,10 +507,19 @@ ZenStructuredCacheSession::PutCacheRecord(std::string_view BucketId, const IoHas
 }
 
 ZenCacheResult
-ZenStructuredCacheSession::PutCacheValue(std::string_view BucketId, const IoHash& Key, const IoHash& ValueContentId, IoBuffer Payload)
+ZenStructuredCacheSession::PutCacheValue(std::string_view Namespace,
+										 std::string_view BucketId,
+										 const IoHash&	  Key,
+										 const IoHash&	  ValueContentId,
+										 IoBuffer		  Payload)
 {
 	ExtendableStringBuilder<256> Uri;
-	Uri << m_Client.ServiceUrl() << "/z$/" << BucketId << "/" << Key.ToHexString() << "/" << ValueContentId.ToHexString();
+	Uri << m_Client.ServiceUrl() << "/z$/";
+	if (Namespace != ZenCacheStore::DefaultNamespace)
+	{
+		Uri << Namespace << "/";
+	}
+	Uri << BucketId << "/" << Key.ToHexString() << "/" << ValueContentId.ToHexString();
 
 	cpr::Session& Session = m_SessionState->GetSession();
 
diff --git a/zenserver/upstream/zen.h b/zenserver/upstream/zen.h
index f70d9d06f..e8590f940 100644
--- a/zenserver/upstream/zen.h
+++ b/zenserver/upstream/zen.h
@@ -128,10 +128,18 @@ public:
 	~ZenStructuredCacheSession();
 
 	ZenCacheResult CheckHealth();
-	ZenCacheResult GetCacheRecord(std::string_view BucketId, const IoHash& Key, ZenContentType Type);
-	ZenCacheResult GetCacheValue(std::string_view BucketId, const IoHash& Key, const IoHash& ValueContentId);
-	ZenCacheResult PutCacheRecord(std::string_view BucketId, const IoHash& Key, IoBuffer Value, ZenContentType Type);
-	ZenCacheResult PutCacheValue(std::string_view BucketId, const IoHash& Key, const IoHash& ValueContentId, IoBuffer Payload);
+	ZenCacheResult GetCacheRecord(std::string_view Namespace, std::string_view BucketId, const IoHash& Key, ZenContentType Type);
+	ZenCacheResult GetCacheValue(std::string_view Namespace, std::string_view BucketId, const IoHash& Key, const IoHash& ValueContentId);
+	ZenCacheResult PutCacheRecord(std::string_view Namespace,
+								  std::string_view BucketId,
+								  const IoHash&	   Key,
+								  IoBuffer		   Value,
+								  ZenContentType   Type);
+	ZenCacheResult PutCacheValue(std::string_view Namespace,
+								 std::string_view BucketId,
+								 const IoHash&	  Key,
+								 const IoHash&	  ValueContentId,
+								 IoBuffer		  Payload);
 	ZenCacheResult InvokeRpc(const CbObjectView& Request);
 	ZenCacheResult InvokeRpc(const CbPackage& Package);
 
diff --git a/zenutil/include/zenutil/cache/cachekey.h b/zenutil/include/zenutil/cache/cachekey.h
index 427c99435..9adde8fc7 100644
--- a/zenutil/include/zenutil/cache/cachekey.h
+++ b/zenutil/include/zenutil/cache/cachekey.h
@@ -12,21 +12,13 @@ namespace zen {
 
 struct CacheKey
 {
-	std::string Namespace;
 	std::string Bucket;
 	IoHash		Hash;
 
-	static CacheKey Create(std::string_view Namespace, std::string_view Bucket, const IoHash& Hash)
-	{
-		return {.Namespace = ToLower(Namespace), .Bucket = ToLower(Bucket), .Hash = Hash};
-	}
+	static CacheKey Create(std::string_view Bucket, const IoHash& Hash) { return {.Bucket = ToLower(Bucket), .Hash = Hash}; }
 
 	auto operator<=>(const CacheKey& that) const
 	{
-		if (auto n = caseSensitiveCompareStrings(Namespace, that.Namespace); n != std::strong_ordering::equal)
-		{
-			return n;
-		}
 		if (auto b = caseSensitiveCompareStrings(Bucket, that.Bucket); b != std::strong_ordering::equal)
 		{
 			return b;