Remove CloudBlobAccess

I've noticed that a significant amount of time, both on my end and on our users' end, is wasted on making CloudBlobAccess work well. We need to be realistic here: there is no way to make CloudBlobAccess work well. Even though S3 buckets initially seem like a good match for storing CAS objects, their implementations are not powerful enough to make things work reliably. They don't provide the right consistency. Making them behave like an LRU cache is also expensive/inefficient. On top of that, there is no way to efficiently implement FindMissingBlobs(), which is almost certainly a requirement for having an efficient build cluster. Note that I am not against having a storage backend that uses cloud buckets. It's just that plainly mapping the CAS/AC key space on top of an S3 bucket is a bad idea. Using buckets as part of a more complex scheme (e.g., a LocalBlobAccess BlockList that can flush historical data into S3) may well be worth it. To phrase it differently: I am removing CloudBlobAccess, because my observation is that it causes us to work towards a local maximum, as opposed to aiming for a global maximum.
buildbarn · Sep 15, 2020 · 0efcb2a · 0efcb2a
1 parent 89343bc
commit 0efcb2a
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Showing 9 changed files with 24 additions and 537 deletions.
diff --git a/pkg/blobstore/cloud/BUILD.bazel b/pkg/blobstore/cloud/BUILD.bazel
diff --git a/pkg/blobstore/cloud/before_copy_func.go b/pkg/blobstore/cloud/before_copy_func.go
diff --git a/pkg/blobstore/cloud/cloud_blob_access.go b/pkg/blobstore/cloud/cloud_blob_access.go
diff --git a/pkg/blobstore/cloud/cloud_blob_access_test.go b/pkg/blobstore/cloud/cloud_blob_access_test.go
diff --git a/pkg/blobstore/cloud/s3_copy_mutator.go b/pkg/blobstore/cloud/s3_copy_mutator.go
diff --git a/pkg/blobstore/cloud/s3_copy_mutator_test.go b/pkg/blobstore/cloud/s3_copy_mutator_test.go
diff --git a/pkg/blobstore/configuration/BUILD.bazel b/pkg/blobstore/configuration/BUILD.bazel
@@ -18,7 +18,6 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//pkg/blobstore:go_default_library",
-        "//pkg/blobstore/cloud:go_default_library",
         "//pkg/blobstore/completenesschecking:go_default_library",
         "//pkg/blobstore/grpcclients:go_default_library",
         "//pkg/blobstore/local:go_default_library",
@@ -36,21 +35,11 @@ go_library(
         "//pkg/proto/configuration/blobstore:go_default_library",
         "//pkg/util:go_default_library",
         "@com_github_aws_aws_sdk_go//service/s3:go_default_library",
-        "@com_github_azure_azure_storage_blob_go//azblob:go_default_library",
         "@com_github_go_redis_redis_v8//:go_default_library",
         "@com_github_go_redis_redis_v8//redisext:go_default_library",
         "@com_github_golang_protobuf//ptypes:go_default_library_gen",
         "@com_github_google_uuid//:go_default_library",
-        "@com_google_cloud_go_storage//:go_default_library",
-        "@dev_gocloud//blob:go_default_library",
-        "@dev_gocloud//blob/azureblob:go_default_library",
-        "@dev_gocloud//blob/fileblob:go_default_library",
-        "@dev_gocloud//blob/gcsblob:go_default_library",
-        "@dev_gocloud//blob/memblob:go_default_library",
-        "@dev_gocloud//blob/s3blob:go_default_library",
-        "@dev_gocloud//gcp:go_default_library",
         "@org_golang_google_grpc//codes:go_default_library",
         "@org_golang_google_grpc//status:go_default_library",
-        "@org_golang_x_oauth2//google:go_default_library",
     ],
 )