Merge 549588f9ef into 8af1fa77f8

go.mod

@@ -7,7 +7,7 @@ require (
 	github.com/cloudnative-pg/api v1.30.0
 	github.com/cloudnative-pg/barman-cloud v0.5.2-0.20260709152604-43158c204df1
 	github.com/cloudnative-pg/cloudnative-pg v1.30.0
-	github.com/cloudnative-pg/cnpg-i v0.5.0
+	github.com/cloudnative-pg/cnpg-i v0.5.1-0.20260715125838-10dead49aded
 	github.com/cloudnative-pg/cnpg-i-machinery v0.4.2
 	github.com/cloudnative-pg/machinery v0.5.0
 	github.com/onsi/ginkgo/v2 v2.32.0

go.sum

@@ -24,8 +24,8 @@ github.com/cloudnative-pg/barman-cloud v0.5.2-0.20260709152604-43158c204df1 h1:+
 github.com/cloudnative-pg/barman-cloud v0.5.2-0.20260709152604-43158c204df1/go.mod h1:ZQLkdpk44FW5/BGWzABTOEcV9qPbwC+rbdscg2I8mBI=
 github.com/cloudnative-pg/cloudnative-pg v1.30.0 h1:fnhVq44xXx97MNiuvJsPrX1vSjYbgdyBK5MSGfdHdp0=
 github.com/cloudnative-pg/cloudnative-pg v1.30.0/go.mod h1:QkolwBOWZ+GvAiJt6KpDSymwkpf0K19/p4Q6MQlTM8U=
-github.com/cloudnative-pg/cnpg-i v0.5.0 h1:/TOzpNT6cwNgrpftTtrnLKdoHgMwd+88vZgXjlVgXeE=
-github.com/cloudnative-pg/cnpg-i v0.5.0/go.mod h1:7Gh4+UzhBpGhr4DreB1GN9wGYfvxwXCXZUyVt3zE/3I=
+github.com/cloudnative-pg/cnpg-i v0.5.1-0.20260715125838-10dead49aded h1:yutE8NcQ7HsQCmw2KDGoPcci/6mib2JK/CLWQ8mkBBQ=
+github.com/cloudnative-pg/cnpg-i v0.5.1-0.20260715125838-10dead49aded/go.mod h1:cdt+QK7+B/5cXXYQSnIE4H/fz7Oc8m60NlWN2HLptlE=
 github.com/cloudnative-pg/cnpg-i-machinery v0.4.2 h1:0reS9MtyLYINHXQ/MfxJ9jp39hhBf8e3Qdj+T5Nsq6I=
 github.com/cloudnative-pg/cnpg-i-machinery v0.4.2/go.mod h1:gvrKabgxXq0zGthXGucemDdsxakLEQDMxn43M4HLW30=
 github.com/cloudnative-pg/machinery v0.5.0 h1:hhTnkzn+AiN3NmbjCQ6RXj5rfqV3K6arzq6kdXAzcnQ=

internal/cnpgi/common/wal.go

@@ -27,6 +27,7 @@ import (
 	"path"
 	"time"
 
+	barmanapi "github.com/cloudnative-pg/barman-cloud/pkg/api"
 	"github.com/cloudnative-pg/barman-cloud/pkg/archiver"
 	barmanCommand "github.com/cloudnative-pg/barman-cloud/pkg/command"
 	barmanCredentials "github.com/cloudnative-pg/barman-cloud/pkg/credentials"
@@ -249,9 +250,11 @@ func (w WALServiceImplementation) Restore(
 		"Restoring WAL file",
 		"objectStore", objectStore.Name,
 		"serverName", serverName,
-		"walName", walName)
+		"walName", walName,
+		"mode", request.GetMode())
 	return &wal.WALRestoreResult{}, w.restoreFromBarmanObjectStore(
-		ctx, configuration.Cluster, &objectStore, serverName, walName, destinationPath)
+		ctx, configuration.Cluster, &objectStore, serverName, walName, destinationPath,
+		request.GetMode() == wal.WALRestoreRequest_MODE_REWIND)
 }
 
 // resolveRestoreObjectStore selects the object store and server name to use when
@@ -288,6 +291,7 @@ func (w WALServiceImplementation) restoreFromBarmanObjectStore(
 	serverName string,
 	walName string,
 	destinationPath string,
+	rewindMode bool,
 ) error {
 	contextLogger := log.FromContext(ctx)
 	startTime := time.Now()
@@ -331,8 +335,10 @@ func (w WALServiceImplementation) restoreFromBarmanObjectStore(
 		return nil
 	}
 
-	// We skip this step if streaming connection is not available
-	if isStreamingAvailable(cluster, w.InstanceName) {
+	// Step 2: return error if the end-of-wal-stream flag is set.
+	// We skip this step if the flag machinery does not apply to this invocation
+	useEndOfWALStreamFlag := shouldUseEndOfWALStreamFlag(cluster, w.InstanceName, rewindMode)
+	if useEndOfWALStreamFlag {
 		if err := checkEndOfWALStreamFlag(walRestorer); err != nil {
 			return err
 		}
@@ -340,10 +346,7 @@ func (w WALServiceImplementation) restoreFromBarmanObjectStore(
 
 	// Step 3: gather the WAL files names to restore. If the required file isn't a regular WAL, we download it directly.
 	var walFilesList []string
-	maxParallel := 1
-	if barmanConfiguration.Wal != nil && barmanConfiguration.Wal.MaxParallel > 1 {
-		maxParallel = barmanConfiguration.Wal.MaxParallel
-	}
+	maxParallel := maxWALFilesPerInvocation(barmanConfiguration, rewindMode)
 	if IsWALFile(walName) {
 		// If this is a regular WAL file, we try to prefetch
 		if walFilesList, err = gatherWALFilesToRestore(walName, maxParallel); err != nil {
@@ -365,9 +368,9 @@ func (w WALServiceImplementation) restoreFromBarmanObjectStore(
 		return classifyWALRestoreError(walStatus[0].WalName, walStatus[0].Err)
 	}
 
-	// We skip this step if streaming connection is not available
+	// We skip this step if the flag machinery does not apply to this invocation
 	endOfWALStream := isEndOfWALStream(walStatus)
-	if isStreamingAvailable(cluster, w.InstanceName) && endOfWALStream {
+	if useEndOfWALStreamFlag && endOfWALStream {
 		contextLogger.Info(
 			"Set end-of-wal-stream flag as one of the WAL files to be prefetched was not found")
 
@@ -415,6 +418,38 @@ func (w WALServiceImplementation) SetFirstRequired(
 	panic("implement me")
 }
 
+// maxWALFilesPerInvocation returns how many WAL files a single restore
+// invocation is allowed to fetch, the requested one included. Prefetching is
+// disabled when restoring on behalf of pg_rewind, which walks the WAL
+// backward: the following segments would never be requested, and past the end
+// of the timeline they do not even exist
+func maxWALFilesPerInvocation(barmanConfiguration *barmanapi.BarmanObjectStoreConfiguration, rewindMode bool) int {
+	if rewindMode {
+		return 1
+	}
+
+	if barmanConfiguration.Wal != nil && barmanConfiguration.Wal.MaxParallel > 1 {
+		return barmanConfiguration.Wal.MaxParallel
+	}
+
+	return 1
+}
+
+// shouldUseEndOfWALStreamFlag returns true when the end-of-wal-stream flag
+// machinery applies to the current invocation. The flag makes the following
+// invocation fail, so that PostgreSQL stops polling the WAL archive and
+// switches to streaming replication. It does not apply when no streaming
+// connection is available, nor when restoring on behalf of pg_rewind:
+// pg_rewind cannot fall back to streaming replication, and a stale flag would
+// make it abort on a segment that is available in the archive
+func shouldUseEndOfWALStreamFlag(cluster *cnpgv1.Cluster, podName string, rewindMode bool) bool {
+	if rewindMode {
+		return false
+	}
+
+	return isStreamingAvailable(cluster, podName)
+}
+
 // isStreamingAvailable checks if this pod can replicate via streaming connection.
 func isStreamingAvailable(cluster *cnpgv1.Cluster, podName string) bool {
 	if cluster == nil {

internal/cnpgi/common/wal_test.go

@@ -20,6 +20,7 @@ SPDX-License-Identifier: Apache-2.0
 package common
 
 import (
+	barmanapi "github.com/cloudnative-pg/barman-cloud/pkg/api"
 	cnpgv1 "github.com/cloudnative-pg/cloudnative-pg/api/v1"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
@@ -96,3 +97,47 @@ var _ = Describe("resolveRestoreObjectStore", func() {
 			"cluster-server", "cluster-store"),
 	)
 })
+
+var _ = Describe("maxWALFilesPerInvocation", func() {
+	configWithMaxParallel := func(maxParallel int) *barmanapi.BarmanObjectStoreConfiguration {
+		return &barmanapi.BarmanObjectStoreConfiguration{
+			Wal: &barmanapi.WalBackupConfiguration{MaxParallel: maxParallel},
+		}
+	}
+
+	DescribeTable(
+		"computes how many WAL files a single invocation may fetch",
+		func(cfg *barmanapi.BarmanObjectStoreConfiguration, rewindMode bool, want int) {
+			Expect(maxWALFilesPerInvocation(cfg, rewindMode)).To(Equal(want))
+		},
+
+		Entry("no WAL configuration", &barmanapi.BarmanObjectStoreConfiguration{}, false, 1),
+		Entry("parallel restore configured", configWithMaxParallel(8), false, 8),
+
+		// pg_rewind walks the timeline backwards: prefetching must stay off no
+		// matter what the object store configuration asks for
+		Entry("rewind mode overrides the configured parallelism", configWithMaxParallel(8), true, 1),
+	)
+})
+
+var _ = Describe("shouldUseEndOfWALStreamFlag", func() {
+	clusterWithPrimary := func(currentPrimary string) *cnpgv1.Cluster {
+		return &cnpgv1.Cluster{
+			Status: cnpgv1.ClusterStatus{CurrentPrimary: currentPrimary},
+		}
+	}
+
+	DescribeTable(
+		"decides whether the end-of-wal-stream flag machinery applies",
+		func(cluster *cnpgv1.Cluster, podName string, rewindMode bool, want bool) {
+			Expect(shouldUseEndOfWALStreamFlag(cluster, podName, rewindMode)).To(Equal(want))
+		},
+
+		Entry("replica with streaming available", clusterWithPrimary("cluster-1"), "cluster-2", false, true),
+		Entry("primary cannot stream from anyone", clusterWithPrimary("cluster-1"), "cluster-1", false, false),
+
+		// pg_rewind cannot fall back to streaming replication: the flag machinery
+		// must stay off even where a standby would use it
+		Entry("rewind mode wins over streaming availability", clusterWithPrimary("cluster-1"), "cluster-2", true, false),
+	)
+})