Wildly fluctuating bundle sizes - what's causing it?

I have it set up via

BuildPlayerWindow.RegisterBuildPlayerHandler

so that Addressables are built when the regular build button is pressed in the Unity build settings window. Overall this seems to work nicely, but recently I noticed a strange issue:

Sometimes, when I build, the produced bundles are 300 MB large. If I then do "Clean All" all in the groups window and rebuild again, they are only 150 MB. I still build via the regular player build button, but with my custom code calling:

Code (CSharp):

1. //AddressableAssetSettings.CleanPlayerContent();
2. //BuildCache.PurgeCache(true);
3. AddressableAssetSettings.BuildPlayerContent();
4. BuildPlayerWindow.DefaultBuildMethods.BuildPlayer(options);

I then go back to build setting window, untick the development box and rebuild. Now, the bundles are 300 MB again. As far as I know, the development/debug option has nothing to do with Addressables. Also, how could the release version be twice the size. When I clean manually and rebuild it seems to be fixed again.

Here are my results from the last compression test:



Of course the size will change if I change the compression override setting, but the point is, look at how it starts at the bottom with 300 MB, then I change no settings, only do a Clean All, rebuild and suddenly 147 MB. When switching to ETC it jumped back to 300, but after a clean went down to 147 again. Again when switching to ETC2 and so on.

For some reason, the fix cannot be reliably applied via code. My commented out code shows what I've tried, but this only works sometimes, so maybe it's got nothing to do with the cleaning per se, but only with building twice in a row.

Any idea where this could be coming from? I would report a bug, but of course the issue only happens in my multi-gigabyte project and I don't know the exact steps.

 

I guess there must be 2 bundles of the same asset on your local path. The old one and the new one, and both of which are getting copied to the Streaming Assets. Check the default local path location which should be Library\com.unity.addressables\aa\Android\Android unless you have changed it.

 

I've checked and inspected the contents of the APKs. Turns out, for whatever reason, the bundles are just much larger sometimes, but the number of bundles is the same.

 

Did you check your local build path? Default path - Library\com.unity.addressables\aa\Android\Android

Was there a single bundle for eg "shared_rooms_assets_all" when you built it for the 2nd time?

 

Yea, I looked at the library location and it mirrors exactly what went into the APK, both times. I also run "Clean Content" before each Addressables build, which deletes the files at the local build path before building new bundles.

I wish I could check the contents of the bundles to find out what es causing the large difference, but it feels like the large version could be without compression. I have LZ4 compression set on all groups, but I'll test how large the bundles become without compression. If that turns out to be the 320 MB instead of 170, it might be losing the compression settings in some cases.

 

Looking at your bundle names again, I guess it might be some other issue. I add hash to my filename because of which it creates a new filename every time I make a build because of which my load path contains both the old and the new files.

 

I use this third party script to inspect the contents of bundles:
https://github.com/faelenor/asset-bundle-analyzer

 

It's all difficult. The asset-bundle-analyzer tools seems nice, but it throws exceptions when I run it on my bundles. It only parses the first two bundles and then fails due to some encoding issue. It hasn't been updated in a few years, so probably not compatible with Unity 2021. Hm...

 

the script fails for me on 2 bundles, the unity generated shaders bundles, and my one custom bundle that contains only ScriptableObjects. I always have to delete or move those 2 bundles to get the script to work, but after that it's fine.

 

Thanks, those are good tips, but I'm not making much progress. I already deleted most of the bundles and also tried different versions of the tool, but I can't manage to inspect those bundles that actually have different sizes. So far I could only compare two bundles which are identical. Maybe that's part of the crux: the too large bundles are somehow broken and the analyze tool can't even parse them.

 

Thanks! 1.18.9 in Unity 2021.1.12

 

Do you have a public issue tracker link to it? I would like to keep an eye on it.