Receive: Remove migration of legacy storage to multi-tsdb (thanos-io#8289)

This has been in since 0.13 (~5 years ago). This fixes issues caused when the default-tenant does not have any data and gets churned, resulting in the migration assuming that per-tenant directories are actually blocks, resulting in blocks not being queryable.

Signed-off-by: Aaron Walker <[email protected]>

Author: vCra

CHANGELOG.md

@@ -27,6 +27,7 @@ We use *breaking :warning:* to mark changes that are not backward compatible (re
 - [#8192](https://github.com/thanos-io/thanos/pull/8192) Sidecar: fix default get config timeout
 
 ### Removed
+- [#8289](https://github.com/thanos-io/thanos/pull/8289) Receive: *breaking :warning:* Removed migration of legacy-TSDB to multi-TSDB. Ensure you are running version >0.13
 
 ### Fixed
 - [#8199](https://github.com/thanos-io/thanos/pull/8199) Query: handle panics or nil pointer dereference in querier gracefully when query analyze returns nil

cmd/thanos/receive.go

@@ -210,10 +210,9 @@ func runReceive(
 		}
 	}
 
-	// TODO(brancz): remove after a couple of versions
-	// Migrate non-multi-tsdb capable storage to multi-tsdb disk layout.
-	if err := migrateLegacyStorage(logger, conf.dataDir, conf.defaultTenantID); err != nil {
-		return errors.Wrapf(err, "migrate legacy storage in %v to default tenant %v", conf.dataDir, conf.defaultTenantID)
+	// Create TSDB for the default tenant.
+	if err := createDefautTenantTSDB(logger, conf.dataDir, conf.defaultTenantID); err != nil {
+		return errors.Wrapf(err, "create default tenant tsdb in %v", conf.dataDir)
 	}
 
 	relabelContentYaml, err := conf.relabelConfigPath.Content()
@@ -796,38 +795,25 @@ func startTSDBAndUpload(g *run.Group,
 	return nil
 }
 
-func migrateLegacyStorage(logger log.Logger, dataDir, defaultTenantID string) error {
+func createDefautTenantTSDB(logger log.Logger, dataDir, defaultTenantID string) error {
 	defaultTenantDataDir := path.Join(dataDir, defaultTenantID)
 
 	if _, err := os.Stat(defaultTenantDataDir); !os.IsNotExist(err) {
-		level.Info(logger).Log("msg", "default tenant data dir already present, not attempting to migrate storage")
+		level.Info(logger).Log("msg", "default tenant data dir already present, will not create")
 		return nil
 	}
 
 	if _, err := os.Stat(dataDir); os.IsNotExist(err) {
-		level.Info(logger).Log("msg", "no existing storage found, no data migration attempted")
+		level.Info(logger).Log("msg", "no existing storage found, not creating default tenant data dir")
 		return nil
 	}
 
-	level.Info(logger).Log("msg", "found legacy storage, migrating to multi-tsdb layout with default tenant", "defaultTenantID", defaultTenantID)
-
-	files, err := os.ReadDir(dataDir)
-	if err != nil {
-		return errors.Wrapf(err, "read legacy data dir: %v", dataDir)
-	}
+	level.Info(logger).Log("msg", "default tenant data dir not found, creating", "defaultTenantID", defaultTenantID)
 
 	if err := os.MkdirAll(defaultTenantDataDir, 0750); err != nil {
 		return errors.Wrapf(err, "create default tenant data dir: %v", defaultTenantDataDir)
 	}
 
-	for _, f := range files {
-		from := path.Join(dataDir, f.Name())
-		to := path.Join(defaultTenantDataDir, f.Name())
-		if err := os.Rename(from, to); err != nil {
-			return errors.Wrapf(err, "migrate file from %v to %v", from, to)
-		}
-	}
-
 	return nil
 }