Download from RemoteAssetCache fails when using Unity Accelerator with Unity 2019.4.36f1

Unity Engine
1

Unity version 2019.4.36f1
We started using Unity Accelerator for our Android builds.
The connection to the Unity Accelerator is successful.
We connect to the Unity Accelerator by adding additional arguments

-EnableCacheServer true -cacheServerNamespacePrefix abcdefgh
-cacheServerEndpoint ip_address:10080

EditorSettings.asset has the following settings related to the accelerator

EditorSettings:
  m_ObjectHideFlags: 0
  serializedVersion: 9
  m_ExternalVersionControlSupport: Visible Meta Files
  m_SerializationMode: 2
  m_LineEndingsForNewScripts: 1
  m_DefaultBehaviorMode: 0
  m_PrefabRegularEnvironment: {fileID: 0}
  m_PrefabUIEnvironment: {fileID: 0}
  m_SpritePackerMode: 2
  m_SpritePackerPaddingPower: 1
  m_EtcTextureCompressorBehavior: 0
  m_EtcTextureFastCompressor: 2
  m_EtcTextureNormalCompressor: 2
  m_EtcTextureBestCompressor: 5
  m_ProjectGenerationIncludedExtensions: txt;xml;fnt;cd;asmdef;asmref
  m_ProjectGenerationRootNamespace:
  m_CollabEditorSettings:
    inProgressEnabled: 1
  m_EnableTextureStreamingInEditMode: 1
  m_EnableTextureStreamingInPlayMode: 1
  m_AsyncShaderCompilation: 1
  m_EnterPlayModeOptionsEnabled: 0
  m_EnterPlayModeOptions: 3
  m_ShowLightmapResolutionOverlay: 1
  m_UseLegacyProbeSampleCount: 1
  m_AssetPipelineMode: 1
  m_CacheServerMode: 1
  m_CacheServerEndpoint: ip_address:10080
  m_CacheServerNamespacePrefix: abcdefgh
  m_CacheServerEnableDownload: 1
  m_CacheServerEnableUpload: 1

I can see from the logs that the upload is done successfully. I see a lot of messages in the log where the artifact uploads were successful. For example,

RemoteAssetCache - Upload - Artifact - success:true, namespace:abcdefg, key:51373f3cc1608b5316ace5594abe1996

RemoteAssetCache - Upload - Artifact - success:true, namespace:abcdefghmetadata, key:5adbc7377e70a0b917330624692181e5
RemoteAssetCache - Download - Metadata - success:false, namespace:abcdefghmetadata, key:748752f0aee9cb149b13dba1bbadbdd3
RemoteAssetCache - Upload - Metadata - success:true, namespace:abcdefghmetadata, key:748752f0aee9cb149b13dba1bbadbdd3
RemoteAssetCache - Download - Metadata - success:false, namespace:abcdefghmetadata, key:748752f0aee9cb149b13dba1bbadbdd3
RemoteAssetCache - Download - Metadata - success:false, namespace:abcdefghmetadata, key:6b186813b2bbfa905e33873cf5634d65

RemoteAssetCache - Download - Metadata - success:false, namespace:abcdefghmetadata, key:748752f0aee9cb149b13dba1bbadbdd3
RemoteAssetCache - Download - Metadata - success:false, namespace:abcdefghmetadata, key:6b186813b2bbfa905e33873cf5634d65
RemoteAssetCache - Download - Metadata - success:false, namespace:abcdefghmetadata, key:bb94652c2a72ab2bf5367a78bf46bf24
RemoteAssetCache - Download - Metadata - success:false, namespace:abcdefghmetadata, key:8f16cf53fffd700ecd70aa3571ed66ed
RemoteAssetCache - Download - Metadata - success:false, namespace:abcdefghmetadata, key:c1ff9da3ed0aa6329e14c1f88c438b9f
RemoteAssetCache - Download - Metadata - success:false, namespace:abcdefghmetadata, key:0dfbbf4a1295fe15f28382cd83f67e42

All the logs related to RemoteAssetCache - Download - Metadata have success:false but the uploads are successful. I have tried multiple builds and have also changed the cacheServerNamespacePrefix to a different value but still seeing this issue. Since the assets get imported every time instead of downloading from the Unity accelerator, the build time is high.

Any ideas on what might be the issue?

2

There seems to be some inconsistency in the namespace between abcdefg, and abcdefgh. Perhaps a typo in the configuration?

3 
RemoteAssetCache - Download - Metadata - success:false, namespace:abcdefghmetadata, key:748752f0aee9cb149b13dba1bbadbdd3
RemoteAssetCache - Upload - Metadata - success:true, namespace:abcdefghmetadata, key:748752f0aee9cb149b13dba1bbadbdd3

I think what this means is the client requested to download an asset with hash 748752f0aee9cb149b13dba1bbadbdd3, but the server does not have it cached yet, so the client downloaded/generated the asset itself, and then upload it to the server, hence the line “Upload - Metadata - success:true, namespace:abcdefghmetadata, key:748752f0aee9cb149b13dba1bbadbdd3” in the next line.

Next time a client request the file 748752f0aee9cb149b13dba1bbadbdd3 and if it’s still on the server, it should download successful

4

Hi. I also encountered this problem, have you solved it?