feat(restore): introduce incremental restore (#7942)

This commit introduces incremental restore. It allows incremental
backups to be restored on top of a set of already restored backups.
In between two incremental restores, the cluster is in draining mode.

go.mod

@@ -18,7 +18,7 @@ require (
 	github.com/dgraph-io/dgo/v210 v210.0.0-20210407152819-261d1c2a6987
 	github.com/dgraph-io/gqlgen v0.13.2
 	github.com/dgraph-io/gqlparser/v2 v2.2.1
-	github.com/dgraph-io/graphql-transport-ws v0.0.0-20210223074046-e5b8b80bb4ed
+	github.com/dgraph-io/graphql-transport-ws v0.0.0-20210511143556-2cef522f1f15
 	github.com/dgraph-io/ristretto v0.1.1
 	github.com/dgraph-io/simdjson-go v0.3.0
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible
@@ -40,7 +40,6 @@ require (
 	github.com/google/uuid v1.0.0
 	github.com/gorilla/websocket v1.4.2
 	github.com/graph-gophers/graphql-go v0.0.0-20200309224638-dae41bde9ef9
-	github.com/graph-gophers/graphql-transport-ws v0.0.2 // indirect
 	github.com/hashicorp/vault/api v1.0.4
 	github.com/minio/minio-go/v6 v6.0.55
 	github.com/mitchellh/panicwrap v1.0.0

go.sum

@@ -130,8 +130,8 @@ github.com/dgraph-io/gqlgen v0.13.2/go.mod h1:iCOrOv9lngN7KAo+jMgvUPVDlYHdf7qDws
 github.com/dgraph-io/gqlparser/v2 v2.1.1/go.mod h1:MYS4jppjyx8b9tuUtjV7jU1UFZK6P9fvO8TsIsQtRKU=
 github.com/dgraph-io/gqlparser/v2 v2.2.1 h1:15msK9XEHOSrRqQO48UU+2ZTf1R1U8+tfL9H5D5/eQQ=
 github.com/dgraph-io/gqlparser/v2 v2.2.1/go.mod h1:MYS4jppjyx8b9tuUtjV7jU1UFZK6P9fvO8TsIsQtRKU=
-github.com/dgraph-io/graphql-transport-ws v0.0.0-20210223074046-e5b8b80bb4ed h1:pgGMBoTtFhR+xkyzINaToLYRurHn+6pxMYffIGmmEPc=
-github.com/dgraph-io/graphql-transport-ws v0.0.0-20210223074046-e5b8b80bb4ed/go.mod h1:7z3c/5w0sMYYZF5bHsrh8IH4fKwG5O5Y70cPH1ZLLRQ=
+github.com/dgraph-io/graphql-transport-ws v0.0.0-20210511143556-2cef522f1f15 h1:X2NRsgAtVUAp2nmTPCq+x+wTcRRrj74CEpy7E0Unsl4=
+github.com/dgraph-io/graphql-transport-ws v0.0.0-20210511143556-2cef522f1f15/go.mod h1:7z3c/5w0sMYYZF5bHsrh8IH4fKwG5O5Y70cPH1ZLLRQ=
 github.com/dgraph-io/ristretto v0.1.1 h1:6CWw5tJNgpegArSHpNHJKldNeq03FQCwYvfMVWajOK8=
 github.com/dgraph-io/ristretto v0.1.1/go.mod h1:S1GPSBCYCIhmVNfcth17y2zZtQT6wzkzgwUve0VDWWA=
 github.com/dgraph-io/simdjson-go v0.3.0 h1:h71LO7vR4LHMPUhuoGN8bqGm1VNfGOlAG8BI6iDUKw0=
@@ -281,13 +281,10 @@ github.com/gorilla/mux v1.6.2/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2z
 github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
 github.com/gorilla/websocket v0.0.0-20170926233335-4201258b820c/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
 github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
-github.com/gorilla/websocket v1.4.1/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0Ufc=
 github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/graph-gophers/graphql-go v0.0.0-20200309224638-dae41bde9ef9 h1:kLnsdud6Fl1/7ZX/5oD23cqYAzBfuZBhNkGr2NvuEsU=
 github.com/graph-gophers/graphql-go v0.0.0-20200309224638-dae41bde9ef9/go.mod h1:9CQHMSxwO4MprSdzoIEobiHpoLtHm77vfxsvsIN5Vuc=
-github.com/graph-gophers/graphql-transport-ws v0.0.2 h1:DbmSkbIGzj8SvHei6n8Mh9eLQin8PtA8xY9eCzjRpvo=
-github.com/graph-gophers/graphql-transport-ws v0.0.2/go.mod h1:5BVKvFzOd2BalVIBFfnfmHjpJi/MZ5rOj8G55mXvZ8g=
 github.com/grpc-ecosystem/go-grpc-middleware v1.0.0/go.mod h1:FiyG127CGDf3tlThmgyCl78X/SZQqEOJBCDaAfeWzPs=
 github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgfV/d3M/q6VIi02HzZEHgUlZvzk=
 github.com/grpc-ecosystem/grpc-gateway v1.4.1/go.mod h1:RSKVYQBd5MCa4OVpNdGskqpgL2+G+NZTnrVHpWWfpdw=

graphql/admin/endpoints_ee.go

@@ -71,6 +71,18 @@ const adminTypes = `
 		"""
 		backupNum: Int
 
+		"""
+		All the backups with num >= incrementalFrom will be restored.
+		"""
+		incrementalFrom: Int
+
+		"""
+		If isPartial is set to true then the cluster will be kept in draining mode after
+		restore. This makes sure that the db is not corrupted by any mutations or tablet
+		moves in between two restores.
+		"""
+		isPartial: Boolean
+
 		"""
 		Path to the key file needed to decrypt the backup. This file should be accessible
 		by all alphas in the group. The backup will be written using the encryption key

graphql/admin/restore.go

@@ -34,6 +34,8 @@ type restoreInput struct {
 	Location          string
 	BackupId          string
 	BackupNum         int
+	IncrementalFrom   int
+	IsPartial         bool
 	EncryptionKeyFile string
 	AccessKey         string
 	SecretKey         string
@@ -57,6 +59,8 @@ func resolveRestore(ctx context.Context, m schema.Mutation) (*resolve.Resolved,
 		Location:          input.Location,
 		BackupId:          input.BackupId,
 		BackupNum:         uint64(input.BackupNum),
+		IncrementalFrom:   uint64(input.IncrementalFrom),
+		IsPartial:         input.IsPartial,
 		EncryptionKeyFile: input.EncryptionKeyFile,
 		AccessKey:         input.AccessKey,
 		SecretKey:         input.SecretKey,

protos/pb.proto

@@ -319,6 +319,8 @@ message RestoreRequest {
   string vault_format = 15;
 
   uint64 backup_num = 16;
+  uint64 incremental_from = 17;
+  bool is_partial = 18;
 }
 
 message Proposal {