Merge pull request #22127 from vespa-engine/jonmv/retain-reentrancy

Preserve reentrancy

18 files changed, 116 insertions, 93 deletions

diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/ApplicationController.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/ApplicationController.java
index 5b61996083f..3be5345b377 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/ApplicationController.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/ApplicationController.java
@@ -13,6 +13,7 @@ import com.yahoo.config.provision.TenantName;
 import com.yahoo.config.provision.zone.ZoneId;
 import com.yahoo.log.LogLevel;
 import com.yahoo.text.Text;
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.athenz.api.AthenzDomain;
 import com.yahoo.vespa.athenz.api.AthenzIdentity;
 import com.yahoo.vespa.athenz.api.AthenzPrincipal;
@@ -402,7 +403,7 @@ public class ApplicationController {
      * @throws IllegalArgumentException if the application already exists
      */
     public Application createApplication(TenantAndApplicationId id, Credentials credentials) {
-        try (Lock lock = lock(id)) {
+        try (Mutex lock = lock(id)) {
             if (getApplication(id).isPresent())
                 throw new IllegalArgumentException("Could not create '" + id + "': Application already exists");
             if (getApplication(dashToUnderscore(id)).isPresent()) // VESPA-1945
@@ -456,7 +457,7 @@ public class ApplicationController {
         ZoneId zone = job.type().zone(controller.system());
         DeploymentId deployment = new DeploymentId(job.application(), zone);
 
-        try (Lock deploymentLock = lockForDeployment(job.application(), zone)) {
+        try (Mutex deploymentLock = lockForDeployment(job.application(), zone)) {
             Set<ContainerEndpoint> containerEndpoints;
             Optional<EndpointCertificateMetadata> endpointCertificateMetadata;
 
@@ -470,7 +471,7 @@ public class ApplicationController {
             RevisionId revision = run.versions().sourceRevision().filter(__ -> deploySourceVersions).orElse(run.versions().targetRevision());
             ApplicationPackage applicationPackage = new ApplicationPackage(applicationStore.get(deployment, revision));
 
-            try (Lock lock = lock(applicationId)) {
+            try (Mutex lock = lock(applicationId)) {
                 LockedApplication application = new LockedApplication(requireApplication(applicationId), lock);
                 Instance instance = application.get().require(job.application().instance());
 
@@ -742,7 +743,7 @@ public class ApplicationController {
      * @param action Function which acts on the locked application.
      */
     public void lockApplicationIfPresent(TenantAndApplicationId applicationId, Consumer<LockedApplication> action) {
-        try (Lock lock = lock(applicationId)) {
+        try (Mutex lock = lock(applicationId)) {
             getApplication(applicationId).map(application -> new LockedApplication(application, lock)).ifPresent(action);
         }
     }
@@ -755,7 +756,7 @@ public class ApplicationController {
      * @throws IllegalArgumentException when application does not exist.
      */
     public void lockApplicationOrThrow(TenantAndApplicationId applicationId, Consumer<LockedApplication> action) {
-        try (Lock lock = lock(applicationId)) {
+        try (Mutex lock = lock(applicationId)) {
             action.accept(new LockedApplication(requireApplication(applicationId), lock));
         }
     }
@@ -828,14 +829,14 @@ public class ApplicationController {
      * Any operation which stores an application need to first acquire this lock, then read, modify
      * and store the application, and finally release (close) the lock.
      */
-    Lock lock(TenantAndApplicationId application) {
+    Mutex lock(TenantAndApplicationId application) {
         return curator.lock(application);
     }
 
     /**
      * Returns a lock which provides exclusive rights to deploying this application to the given zone.
      */
-    private Lock lockForDeployment(ApplicationId application, ZoneId zone) {
+    private Mutex lockForDeployment(ApplicationId application, ZoneId zone) {
         return curator.lockForDeployment(application, zone);
     }
 
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/Controller.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/Controller.java
index be88aede1eb..52f1a5e0ab0 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/Controller.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/Controller.java
@@ -12,6 +12,7 @@ import com.yahoo.config.provision.SystemName;
 import com.yahoo.config.provision.zone.ZoneApi;
 import com.yahoo.container.jdisc.secretstore.SecretStore;
 import com.yahoo.jdisc.Metric;
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.curator.Lock;
 import com.yahoo.vespa.flags.FlagSource;
 import com.yahoo.vespa.hosted.controller.api.integration.ServiceRegistry;
@@ -197,7 +198,7 @@ public class Controller extends AbstractComponent {
 
     /** Remove confidence override for versions matching given filter */
     public void removeConfidenceOverride(Predicate<Version> filter) {
-        try (Lock lock = curator.lockConfidenceOverrides()) {
+        try (Mutex lock = curator.lockConfidenceOverrides()) {
             Map<Version, VespaVersion.Confidence> overrides = new LinkedHashMap<>(curator.readConfidenceOverrides());
             overrides.keySet().removeIf(filter);
             curator.writeConfidenceOverrides(overrides);
@@ -236,7 +237,7 @@ public class Controller extends AbstractComponent {
             throw new IllegalArgumentException("Cloud '" + cloudName + "' does not exist in this system");
         }
         Instant scheduledAt = clock.instant();
-        try (Lock lock = curator.lockOsVersions()) {
+        try (Mutex lock = curator.lockOsVersions()) {
             Map<CloudName, OsVersionTarget> targets = curator.readOsVersionTargets().stream()
                                                              .collect(Collectors.toMap(t -> t.osVersion().cloud(),
                                                                                        Function.identity()));
@@ -266,7 +267,7 @@ public class Controller extends AbstractComponent {
 
     /** Replace the current OS version status with a new one */
     public void updateOsVersionStatus(OsVersionStatus newStatus) {
-        try (Lock lock = curator.lockOsVersionStatus()) {
+        try (Mutex lock = curator.lockOsVersionStatus()) {
             OsVersionStatus currentStatus = curator.readOsVersionStatus();
             for (CloudName cloud : clouds()) {
                 Set<Version> newVersions = newStatus.versionsIn(cloud);
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/LockedApplication.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/LockedApplication.java
index 551327fd2e5..3e822415e96 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/LockedApplication.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/LockedApplication.java
@@ -4,6 +4,7 @@ package com.yahoo.vespa.hosted.controller;
 import com.yahoo.config.application.api.DeploymentSpec;
 import com.yahoo.config.application.api.ValidationOverrides;
 import com.yahoo.config.provision.InstanceName;
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.curator.Lock;
 import com.yahoo.vespa.hosted.controller.api.integration.organization.IssueId;
 import com.yahoo.vespa.hosted.controller.api.integration.organization.User;
@@ -30,7 +31,7 @@ import java.util.function.UnaryOperator;
  */
 public class LockedApplication {
 
-    private final Lock lock;
+    private final Mutex lock;
     private final TenantAndApplicationId id;
     private final Instant createdAt;
     private final DeploymentSpec deploymentSpec;
@@ -51,7 +52,7 @@ public class LockedApplication {
      * @param application The application to lock.
      * @param lock The lock for the application.
      */
-    LockedApplication(Application application, Lock lock) {
+    LockedApplication(Application application, Mutex lock) {
         this(Objects.requireNonNull(lock, "lock cannot be null"), application.id(), application.createdAt(),
              application.deploymentSpec(), application.validationOverrides(),
              application.deploymentIssueId(), application.ownershipIssueId(),
@@ -59,7 +60,7 @@ public class LockedApplication {
              application.projectId(), application.instances(), application.revisions());
     }
 
-    private LockedApplication(Lock lock, TenantAndApplicationId id, Instant createdAt, DeploymentSpec deploymentSpec,
+    private LockedApplication(Mutex lock, TenantAndApplicationId id, Instant createdAt, DeploymentSpec deploymentSpec,
                               ValidationOverrides validationOverrides,
                               Optional<IssueId> deploymentIssueId, Optional<IssueId> ownershipIssueId, Optional<User> owner,
                               OptionalInt majorVersion, ApplicationMetrics metrics, Set<PublicKey> deployKeys,
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/LockedTenant.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/LockedTenant.java
index bcc3b9b54c7..7a0e60aacb4 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/LockedTenant.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/LockedTenant.java
@@ -6,6 +6,7 @@ import com.google.common.collect.HashBiMap;
 import com.google.common.collect.ImmutableBiMap;
 import com.yahoo.config.provision.TenantName;
 import com.yahoo.security.KeyUtils;
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.athenz.api.AthenzDomain;
 import com.yahoo.vespa.curator.Lock;
 import com.yahoo.vespa.hosted.controller.api.identifiers.Property;
@@ -46,7 +47,7 @@ public abstract class LockedTenant {
         this.lastLoginInfo = requireNonNull(lastLoginInfo);
     }
 
-    static LockedTenant of(Tenant tenant, Lock lock) {
+    static LockedTenant of(Tenant tenant, Mutex lock) {
         switch (tenant.type()) {
             case athenz:  return new Athenz((AthenzTenant) tenant);
             case cloud:   return new Cloud((CloudTenant) tenant);
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/TenantController.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/TenantController.java
index 138bf547655..beba1cdb358 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/TenantController.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/TenantController.java
@@ -3,6 +3,7 @@ package com.yahoo.vespa.hosted.controller;
 
 import com.yahoo.config.provision.TenantName;
 import com.yahoo.text.Text;
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.curator.Lock;
 import com.yahoo.vespa.hosted.controller.api.identifiers.TenantId;
 import com.yahoo.vespa.hosted.controller.application.SystemApplication;
@@ -74,7 +75,7 @@ public class TenantController {
 
     /** Locks a tenant for modification and applies the given action. */
     public <T extends LockedTenant> void lockIfPresent(TenantName name, Class<T> token, Consumer<T> action) {
-        try (Lock lock = lock(name)) {
+        try (Mutex lock = lock(name)) {
             get(name).map(tenant -> LockedTenant.of(tenant, lock))
                      .map(token::cast)
                      .ifPresent(action);
@@ -83,7 +84,7 @@ public class TenantController {
 
     /** Lock a tenant for modification and apply action. Throws if the tenant does not exist */
     public <T extends LockedTenant> void lockOrThrow(TenantName name, Class<T> token, Consumer<T> action) {
-        try (Lock lock = lock(name)) {
+        try (Mutex lock = lock(name)) {
             action.accept(token.cast(LockedTenant.of(require(name), lock)));
         }
     }
@@ -111,7 +112,7 @@ public class TenantController {
 
     /** Create a tenant, provided the given credentials are valid. */
     public void create(TenantSpec tenantSpec, Credentials credentials) {
-        try (Lock lock = lock(tenantSpec.tenant())) {
+        try (Mutex lock = lock(tenantSpec.tenant())) {
             TenantId.validate(tenantSpec.tenant().value());
             requireNonExistent(tenantSpec.tenant());
             curator.writeTenant(accessControl.createTenant(tenantSpec, controller.clock().instant(), credentials, asList()));
@@ -137,7 +138,7 @@ public class TenantController {
 
     /** Updates the tenant contained in the given tenant spec with new data. */
     public void update(TenantSpec tenantSpec, Credentials credentials) {
-        try (Lock lock = lock(tenantSpec.tenant())) {
+        try (Mutex lock = lock(tenantSpec.tenant())) {
             curator.writeTenant(accessControl.updateTenant(tenantSpec, credentials, asList(),
                                                            controller.applications().asList(tenantSpec.tenant())));
         }
@@ -148,7 +149,7 @@ public class TenantController {
      * new instant is later
      */
     public void updateLastLogin(TenantName tenantName, List<LastLoginInfo.UserLevel> userLevels, Instant loggedInAt) {
-        try (Lock lock = lock(tenantName)) {
+        try (Mutex lock = lock(tenantName)) {
             Tenant tenant = require(tenantName);
             LastLoginInfo loginInfo = tenant.lastLoginInfo();
             for (LastLoginInfo.UserLevel userLevel : userLevels)
@@ -161,7 +162,7 @@ public class TenantController {
 
     /** Deletes the given tenant. */
     public void delete(TenantName tenant, Optional<Credentials> credentials, boolean forget) {
-        try (Lock lock = lock(tenant)) {
+        try (Mutex lock = lock(tenant)) {
             Tenant oldTenant = get(tenant, true)
                     .orElseThrow(() -> new NotExistsException("Could not delete tenant '" + tenant + "': Tenant not found"));
 
@@ -202,7 +203,7 @@ public class TenantController {
      * Any operation which stores a tenant need to first acquire this lock, then read, modify
      * and store the tenant, and finally release (close) the lock.
      */
-    private Lock lock(TenantName tenant) {
+    private Mutex lock(TenantName tenant) {
         return curator.lock(tenant);
     }
 
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/auditlog/AuditLogger.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/auditlog/AuditLogger.java
index 78d65766075..34e7955e02a 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/auditlog/AuditLogger.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/auditlog/AuditLogger.java
@@ -2,6 +2,7 @@
 package com.yahoo.vespa.hosted.controller.auditlog;
 
 import com.yahoo.container.jdisc.HttpRequest;
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.curator.Lock;
 import com.yahoo.vespa.hosted.controller.persistence.CuratorDb;
 
@@ -70,7 +71,7 @@ public class AuditLogger {
         Instant now = clock.instant();
         AuditLog.Entry entry = new AuditLog.Entry(now, principal.getName(), method.get(), pathAndQueryOf(request.getUri()),
                                                   Optional.of(new String(data, StandardCharsets.UTF_8)));
-        try (Lock lock = db.lockAuditLog()) {
+        try (Mutex lock = db.lockAuditLog()) {
             AuditLog auditLog = db.readAuditLog()
                                   .pruneBefore(now.minus(entryTtl))
                                   .with(entry)
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTrigger.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTrigger.java
index 54703308102..c98b3b76292 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTrigger.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTrigger.java
@@ -8,6 +8,7 @@ import com.yahoo.config.application.api.DeploymentSpec;
 import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.config.provision.InstanceName;
 import com.yahoo.text.Text;
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.curator.Lock;
 import com.yahoo.vespa.hosted.controller.Application;
 import com.yahoo.vespa.hosted.controller.ApplicationController;
@@ -275,7 +276,7 @@ public class DeploymentTrigger {
 
         if (existingRun.isPresent()) {
             Run run = existingRun.get();
-            try (Lock lock = controller.curator().lockDeploymentRetriggerQueue()) {
+            try (Mutex lock = controller.curator().lockDeploymentRetriggerQueue()) {
                 List<RetriggerEntry> retriggerEntries = controller.curator().readRetriggerEntries();
                 List<RetriggerEntry> newList = new ArrayList<>(retriggerEntries);
                 RetriggerEntry requiredEntry = new RetriggerEntry(new JobId(deployment.applicationId(), jobType), run.id().number() + 1);
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/JobController.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/JobController.java
index d1c19476929..4b8339cccb1 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/JobController.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/JobController.java
@@ -6,6 +6,7 @@ import com.yahoo.component.Version;
 import com.yahoo.component.VersionCompatibility;
 import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.config.provision.zone.ZoneId;
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.curator.Lock;
 import com.yahoo.vespa.hosted.controller.Application;
 import com.yahoo.vespa.hosted.controller.ApplicationController;
@@ -132,7 +133,7 @@ public class JobController {
 
     /** Returns the logged entries for the given run, which are after the given id threshold. */
     public Optional<RunLog> details(RunId id, long after) {
-        try (Lock __ = curator.lock(id.application(), id.type())) {
+        try (Mutex __ = curator.lock(id.application(), id.type())) {
             Run run = runs(id.application(), id.type()).get(id);
             if (run == null)
                 return Optional.empty();
@@ -378,7 +379,7 @@ public class JobController {
      * Throws TimeoutException if some step in this job is still being run.
      */
     public void finish(RunId id) throws TimeoutException {
-        List<Lock> locks = new ArrayList<>();
+        List<Mutex> locks = new ArrayList<>();
         try {
             // Ensure no step is still running before we finish the run — report depends transitively on all the other steps.
             Run unlockedRun = run(id).get();
@@ -426,7 +427,7 @@ public class JobController {
             });
         }
         finally {
-            for (Lock lock : locks)
+            for (Mutex lock : locks)
                 lock.close();
         }
     }
@@ -658,7 +659,7 @@ public class JobController {
                        TesterId tester = TesterId.of(id);
                        for (JobType type : jobs(id))
                            locked(id, type, deactivateTester, __ -> {
-                               try (Lock ___ = curator.lock(id, type)) {
+                               try (Mutex ___ = curator.lock(id, type)) {
                                    try {
                                        deactivateTester(tester, type);
                                    }
@@ -684,7 +685,7 @@ public class JobController {
     /** Locks all runs and modifies the list of historic runs for the given application and job type. */
     private void locked(ApplicationId id, JobType type, Consumer<SortedMap<RunId, Run>> modifications) {
         Application application = controller.applications().requireApplication(TenantAndApplicationId.from(id));
-        try (Lock __ = curator.lock(id, type)) {
+        try (Mutex __ = curator.lock(id, type)) {
             SortedMap<RunId, Run> runs = new TreeMap<>(curator.readHistoricRuns(id, type));
             modifications.accept(runs);
             curator.writeHistoricRuns(id, type, runs.values(), application);
@@ -694,7 +695,7 @@ public class JobController {
     /** Locks and modifies the run with the given id, provided it is still active. */
     public void locked(RunId id, UnaryOperator<Run> modifications) {
         Application application = controller.applications().requireApplication(TenantAndApplicationId.from(id.application()));
-        try (Lock __ = curator.lock(id.application(), id.type())) {
+        try (Mutex __ = curator.lock(id.application(), id.type())) {
             active(id).ifPresent(run -> {
                 run = modifications.apply(run);
                 curator.writeLastRun(run, application);
@@ -704,9 +705,9 @@ public class JobController {
 
     /** Locks the given step and checks none of its prerequisites are running, then performs the given actions. */
     public void locked(ApplicationId id, JobType type, Step step, Consumer<LockedStep> action) throws TimeoutException {
-        try (Lock lock = curator.lock(id, type, step)) {
+        try (Mutex lock = curator.lock(id, type, step)) {
             for (Step prerequisite : step.allPrerequisites(last(id, type).get().steps().keySet())) // Check that no prerequisite is still running.
-                try (Lock __ = curator.lock(id, type, prerequisite)) { ; }
+                try (Mutex __ = curator.lock(id, type, prerequisite)) { ; }
 
             action.accept(new LockedStep(lock, step));
         }
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/LockedStep.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/LockedStep.java
index d46516582be..8147ccb3180 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/LockedStep.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/LockedStep.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.controller.deployment;
 
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.curator.Lock;
 
 /**
@@ -9,7 +10,7 @@ import com.yahoo.vespa.curator.Lock;
 public class LockedStep {
 
     private final Step step;
-    LockedStep(Lock lock, Step step) { this.step = step; }
+    LockedStep(Mutex lock, Step step) { this.step = step; }
     public Step get() { return step; }
 
 }
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/dns/NameServiceForwarder.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/dns/NameServiceForwarder.java
index aecb1e7a2c1..540e8489e6d 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/dns/NameServiceForwarder.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/dns/NameServiceForwarder.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.controller.dns;
 
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.curator.Lock;
 import com.yahoo.vespa.hosted.controller.api.integration.dns.AliasTarget;
 import com.yahoo.vespa.hosted.controller.api.integration.dns.NameService;
@@ -79,7 +80,7 @@ public class NameServiceForwarder {
     }
 
     protected void forward(NameServiceRequest request, NameServiceQueue.Priority priority) {
-        try (Lock lock = db.lockNameServiceQueue()) {
+        try (Mutex lock = db.lockNameServiceQueue()) {
             NameServiceQueue queue = db.readNameServiceQueue();
             var queued = queue.requests().size();
             if (queued >= QUEUE_CAPACITY) {
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/EndpointCertificateMaintainer.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/EndpointCertificateMaintainer.java
index 15f8d6380c0..faa42e5caef 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/EndpointCertificateMaintainer.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/EndpointCertificateMaintainer.java
@@ -6,6 +6,7 @@ import com.google.inject.Inject;
 import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.container.jdisc.secretstore.SecretNotFoundException;
 import com.yahoo.container.jdisc.secretstore.SecretStore;
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.curator.Lock;
 import com.yahoo.vespa.hosted.controller.Controller;
 import com.yahoo.vespa.hosted.controller.Instance;
@@ -82,7 +83,7 @@ public class EndpointCertificateMaintainer extends ControllerMaintainer {
                 var refreshedCertificateMetadata = endpointCertificateMetadata
                         .withVersion(latestAvailableVersion.getAsInt())
                         .withLastRefreshed(clock.instant().getEpochSecond());
-                try (Lock lock = lock(applicationId)) {
+                try (Mutex lock = lock(applicationId)) {
                     if (Optional.of(endpointCertificateMetadata).equals(curator.readEndpointCertificateMetadata(applicationId))) {
                         curator.writeEndpointCertificateMetadata(applicationId, refreshedCertificateMetadata); // Certificate not validated here, but on deploy.
                     }
@@ -128,7 +129,7 @@ public class EndpointCertificateMaintainer extends ControllerMaintainer {
         curator.readAllEndpointCertificateMetadata().forEach((applicationId, storedMetaData) -> {
             var lastRequested = Instant.ofEpochSecond(storedMetaData.lastRequested());
             if (lastRequested.isBefore(oneMonthAgo) && hasNoDeployments(applicationId)) {
-                try (Lock lock = lock(applicationId)) {
+                try (Mutex lock = lock(applicationId)) {
                     if (Optional.of(storedMetaData).equals(curator.readEndpointCertificateMetadata(applicationId))) {
                         log.log(Level.INFO, "Cert for app " + applicationId.serializedForm()
                                 + " has not been requested in a month and app has no deployments, deleting from provider and ZK");
@@ -140,7 +141,7 @@ public class EndpointCertificateMaintainer extends ControllerMaintainer {
         });
     }
 
-    private Lock lock(ApplicationId applicationId) {
+    private Mutex lock(ApplicationId applicationId) {
         return curator.lock(TenantAndApplicationId.from(applicationId));
     }
 
@@ -169,7 +170,7 @@ public class EndpointCertificateMaintainer extends ControllerMaintainer {
                     EndpointCertificateMetadata storedAppMetadata = storedAppEntry.getValue();
                     if (storedAppMetadata.certName().equals(unknownCertDetails.cert_key_keyname())) {
                         matchFound = true;
-                        try (Lock lock = lock(storedApp)) {
+                        try (Mutex lock = lock(storedApp)) {
                             if (Optional.of(storedAppMetadata).equals(curator.readEndpointCertificateMetadata(storedApp))) {
                                 log.log(Level.INFO, "Cert for app " + storedApp.serializedForm()
                                         + " has a new leafRequestId " + unknownCertDetails.request_id() + ", updating in ZK");
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/Upgrader.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/Upgrader.java
index fa5afa3a216..4ed34a91029 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/Upgrader.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/Upgrader.java
@@ -4,6 +4,7 @@ package com.yahoo.vespa.hosted.controller.maintenance;
 import com.yahoo.component.Version;
 import com.yahoo.config.application.api.DeploymentSpec.UpgradePolicy;
 import com.yahoo.config.provision.ApplicationId;
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.curator.Lock;
 import com.yahoo.vespa.hosted.controller.Controller;
 import com.yahoo.vespa.hosted.controller.application.ApplicationList;
@@ -176,7 +177,7 @@ public class Upgrader extends ControllerMaintainer {
                                                " for version " + version.toFullString() +
                                                ": Version may be in use by applications");
         }
-        try (Lock lock = curator.lockConfidenceOverrides()) {
+        try (Mutex lock = curator.lockConfidenceOverrides()) {
             Map<Version, Confidence> overrides = new LinkedHashMap<>(curator.readConfidenceOverrides());
             overrides.put(version, confidence);
             curator.writeConfidenceOverrides(overrides);
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/notification/NotificationsDb.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/notification/NotificationsDb.java
index aa62028749b..7876099cb21 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/notification/NotificationsDb.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/notification/NotificationsDb.java
@@ -5,6 +5,7 @@ import com.yahoo.collections.Pair;
 import com.yahoo.config.provision.ClusterSpec;
 import com.yahoo.config.provision.TenantName;
 import com.yahoo.text.Text;
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.curator.Lock;
 import com.yahoo.vespa.hosted.controller.Controller;
 import com.yahoo.vespa.hosted.controller.api.application.v4.model.ClusterMetrics;
@@ -65,7 +66,7 @@ public class NotificationsDb {
      */
     public void setNotification(NotificationSource source, Type type, Level level, List<String> messages) {
         Optional<Notification> changed = Optional.empty();
-        try (Lock lock = curatorDb.lockNotifications(source.tenant())) {
+        try (Mutex lock = curatorDb.lockNotifications(source.tenant())) {
             var existingNotifications = curatorDb.readNotifications(source.tenant());
             List<Notification> notifications = existingNotifications.stream()
                     .filter(notification -> !source.equals(notification.source()) || type != notification.type())
@@ -82,7 +83,7 @@ public class NotificationsDb {
 
     /** Remove the notification with the given source and type */
     public void removeNotification(NotificationSource source, Type type) {
-        try (Lock lock = curatorDb.lockNotifications(source.tenant())) {
+        try (Mutex lock = curatorDb.lockNotifications(source.tenant())) {
             List<Notification> initial = curatorDb.readNotifications(source.tenant());
             List<Notification> filtered = initial.stream()
                     .filter(notification -> !source.equals(notification.source()) || type != notification.type())
@@ -94,7 +95,7 @@ public class NotificationsDb {
 
     /** Remove all notifications for this source or sources contained by this source */
     public void removeNotifications(NotificationSource source) {
-        try (Lock lock = curatorDb.lockNotifications(source.tenant())) {
+        try (Mutex lock = curatorDb.lockNotifications(source.tenant())) {
             if (source.application().isEmpty()) { // Source is tenant
                 curatorDb.deleteNotifications(source.tenant());
                 return;
@@ -130,7 +131,7 @@ public class NotificationsDb {
                 .collect(Collectors.toUnmodifiableList());
 
         NotificationSource deploymentSource = NotificationSource.from(deploymentId);
-        try (Lock lock = curatorDb.lockNotifications(deploymentSource.tenant())) {
+        try (Mutex lock = curatorDb.lockNotifications(deploymentSource.tenant())) {
             List<Notification> initial = curatorDb.readNotifications(deploymentSource.tenant());
             List<Notification> updated = Stream.concat(
                     initial.stream()
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/persistence/CuratorDb.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/persistence/CuratorDb.java
index 0bfdd53eeab..5e6cfa8b43f 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/persistence/CuratorDb.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/persistence/CuratorDb.java
@@ -13,6 +13,7 @@ import com.yahoo.config.provision.zone.ZoneId;
 import com.yahoo.path.Path;
 import com.yahoo.slime.Slime;
 import com.yahoo.slime.SlimeUtils;
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.curator.Curator;
 import com.yahoo.vespa.curator.Lock;
 import com.yahoo.vespa.curator.MultiplePathsLock;
@@ -149,14 +150,15 @@ public class CuratorDb {
 
     // -------------- Locks ---------------------------------------------------
 
-    public Lock lock(TenantName name) {
+    public Mutex lock(TenantName name) {
         return curator.lock(lockPath(name), defaultLockTimeout.multipliedBy(2));
     }
 
-    public Lock lock(TenantAndApplicationId id) {
+    public Mutex lock(TenantAndApplicationId id) {
         switch (lockScheme.value()) {
             case "BOTH":
-                return new MultiplePathsLock(lockPath(id), legacyLockPath(id), defaultLockTimeout.multipliedBy(2), curator);
+                return new MultiplePathsLock(curator.lock(legacyLockPath(id), defaultLockTimeout.multipliedBy(2)),
+                                             curator.lock(lockPath(id), defaultLockTimeout.multipliedBy(2)));
             case "OLD":
                 return curator.lock(legacyLockPath(id), defaultLockTimeout.multipliedBy(2));
             case "NEW":
@@ -166,10 +168,11 @@ public class CuratorDb {
         }
     }
 
-    public Lock lockForDeployment(ApplicationId id, ZoneId zone) {
+    public Mutex lockForDeployment(ApplicationId id, ZoneId zone) {
         switch (lockScheme.value()) {
             case "BOTH":
-                return new MultiplePathsLock(lockPath(id, zone), legacyLockPath(id, zone), deployLockTimeout, curator);
+                return new MultiplePathsLock(curator.lock(legacyLockPath(id, zone), defaultLockTimeout),
+                                             curator.lock(lockPath(id, zone), defaultLockTimeout));
             case "OLD":
                 return curator.lock(legacyLockPath(id, zone), deployLockTimeout);
             case "NEW":
@@ -179,10 +182,11 @@ public class CuratorDb {
         }
     }
 
-    public Lock lock(ApplicationId id, JobType type) {
+    public Mutex lock(ApplicationId id, JobType type) {
         switch (lockScheme.value()) {
             case "BOTH":
-                return new MultiplePathsLock(lockPath(id, type), legacyLockPath(id, type), defaultLockTimeout, curator);
+                return new MultiplePathsLock(curator.lock(legacyLockPath(id, type), defaultLockTimeout),
+                                             curator.lock(lockPath(id, type), defaultLockTimeout));
             case "OLD":
                 return curator.lock(legacyLockPath(id, type), defaultLockTimeout);
             case "NEW":
@@ -192,10 +196,10 @@ public class CuratorDb {
         }
     }
 
-    public Lock lock(ApplicationId id, JobType type, Step step) throws TimeoutException {
+    public Mutex lock(ApplicationId id, JobType type, Step step) throws TimeoutException {
         switch (lockScheme.value()) {
             case "BOTH":
-                return tryLock(lockPath(id, type, step), legacyLockPath(id, type, step));
+                return tryLock(legacyLockPath(id, type, step), lockPath(id, type, step));
             case "OLD":
                 return tryLock(legacyLockPath(id, type, step));
             case "NEW":
@@ -205,15 +209,15 @@ public class CuratorDb {
         }
     }
 
-    public Lock lockRotations() {
+    public Mutex lockRotations() {
         return curator.lock(lockRoot.append("rotations"), defaultLockTimeout);
     }
 
-    public Lock lockConfidenceOverrides() {
+    public Mutex lockConfidenceOverrides() {
         return curator.lock(lockRoot.append("confidenceOverrides"), defaultLockTimeout);
     }
 
-    public Lock lockMaintenanceJob(String jobName) {
+    public Mutex lockMaintenanceJob(String jobName) {
         try {
             return tryLock(lockRoot.append("maintenanceJobLocks").append(jobName));
         } catch (TimeoutException e) {
@@ -221,52 +225,51 @@ public class CuratorDb {
         }
     }
 
-    @SuppressWarnings("unused") // Called by internal code
-    public Lock lockProvisionState(String provisionStateId) {
+    public Mutex lockProvisionState(String provisionStateId) {
         return curator.lock(lockPath(provisionStateId), Duration.ofSeconds(1));
     }
 
-    public Lock lockOsVersions() {
+    public Mutex lockOsVersions() {
         return curator.lock(lockRoot.append("osTargetVersion"), defaultLockTimeout);
     }
 
-    public Lock lockOsVersionStatus() {
+    public Mutex lockOsVersionStatus() {
         return curator.lock(lockRoot.append("osVersionStatus"), defaultLockTimeout);
     }
 
-    public Lock lockRoutingPolicies() {
+    public Mutex lockRoutingPolicies() {
         return curator.lock(lockRoot.append("routingPolicies"), defaultLockTimeout);
     }
 
-    public Lock lockAuditLog() {
+    public Mutex lockAuditLog() {
         return curator.lock(lockRoot.append("auditLog"), defaultLockTimeout);
     }
 
-    public Lock lockNameServiceQueue() {
+    public Mutex lockNameServiceQueue() {
         return curator.lock(lockRoot.append("nameServiceQueue"), defaultLockTimeout);
     }
 
-    public Lock lockMeteringRefreshTime() throws TimeoutException {
+    public Mutex lockMeteringRefreshTime() throws TimeoutException {
         return tryLock(lockRoot.append("meteringRefreshTime"));
     }
 
-    public Lock lockArchiveBuckets(ZoneId zoneId) {
+    public Mutex lockArchiveBuckets(ZoneId zoneId) {
         return curator.lock(lockRoot.append("archiveBuckets").append(zoneId.value()), defaultLockTimeout);
     }
 
-    public Lock lockChangeRequests() {
+    public Mutex lockChangeRequests() {
         return curator.lock(lockRoot.append("changeRequests"), defaultLockTimeout);
     }
 
-    public Lock lockNotifications(TenantName tenantName) {
+    public Mutex lockNotifications(TenantName tenantName) {
         return curator.lock(lockRoot.append("notifications").append(tenantName.value()), defaultLockTimeout);
     }
 
-    public Lock lockSupportAccess(DeploymentId deploymentId) {
+    public Mutex lockSupportAccess(DeploymentId deploymentId) {
         return curator.lock(lockRoot.append("supportAccess").append(deploymentId.dottedString()), defaultLockTimeout);
     }
 
-    public Lock lockDeploymentRetriggerQueue() {
+    public Mutex lockDeploymentRetriggerQueue() {
         return curator.lock(lockRoot.append("deploymentRetriggerQueue"), defaultLockTimeout);
     }
 
@@ -276,7 +279,7 @@ public class CuratorDb {
      *
      * Useful for maintenance jobs, where there is no point in running the jobs back to back.
      */
-    private Lock tryLock(Path path) throws TimeoutException {
+    private Mutex tryLock(Path path) throws TimeoutException {
         try {
             return curator.lock(path, tryLockTimeout);
         }
@@ -289,9 +292,9 @@ public class CuratorDb {
      *
      * Useful for maintenance jobs, where there is no point in running the jobs back to back.
      */
-    private Lock tryLock(Path path, Path path2) throws TimeoutException {
+    private Mutex tryLock(Path path, Path path2) throws TimeoutException {
         try {
-            return new MultiplePathsLock(path, path2, tryLockTimeout, curator);
+            return new MultiplePathsLock(curator.lock(path, tryLockTimeout), curator.lock(path2, tryLockTimeout));
         }
         catch (UncheckedTimeoutException e) {
             throw new TimeoutException(e.getMessage());
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/routing/RoutingPolicies.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/routing/RoutingPolicies.java
index 850a8cab123..a5a09ab6551 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/routing/RoutingPolicies.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/routing/RoutingPolicies.java
@@ -6,6 +6,7 @@ import com.yahoo.config.application.api.DeploymentSpec;
 import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.config.provision.zone.RoutingMethod;
 import com.yahoo.config.provision.zone.ZoneId;
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.curator.Lock;
 import com.yahoo.vespa.hosted.controller.Application;
 import com.yahoo.vespa.hosted.controller.Controller;
@@ -152,7 +153,7 @@ public class RoutingPolicies {
     }
 
     /** Update global DNS records for given policies */
-    private void updateGlobalDnsOf(RoutingPolicyList instancePolicies, Set<ZoneId> inactiveZones, @SuppressWarnings("unused") Lock lock) {
+    private void updateGlobalDnsOf(RoutingPolicyList instancePolicies, Set<ZoneId> inactiveZones, @SuppressWarnings("unused") Mutex lock) {
         Map<RoutingId, List<RoutingPolicy>> routingTable = instancePolicies.asInstanceRoutingTable();
         for (Map.Entry<RoutingId, List<RoutingPolicy>> routeEntry : routingTable.entrySet()) {
             RoutingId routingId = routeEntry.getKey();
@@ -225,7 +226,7 @@ public class RoutingPolicies {
     }
 
 
-    private void updateApplicationDnsOf(RoutingPolicyList routingPolicies, Set<ZoneId> inactiveZones, @SuppressWarnings("unused") Lock lock) {
+    private void updateApplicationDnsOf(RoutingPolicyList routingPolicies, Set<ZoneId> inactiveZones, @SuppressWarnings("unused") Mutex lock) {
         // In the context of single deployment (which this is) there is only one routing policy per routing ID. I.e.
         // there is no scenario where more than one deployment within an instance can be a member the same
         // application-level endpoint. However, to allow this in the future the routing table remains
@@ -307,7 +308,7 @@ public class RoutingPolicies {
      *
      * @return the updated policies
      */
-    private RoutingPolicyList storePoliciesOf(LoadBalancerAllocation allocation, RoutingPolicyList instancePolicies, @SuppressWarnings("unused") Lock lock) {
+    private RoutingPolicyList storePoliciesOf(LoadBalancerAllocation allocation, RoutingPolicyList instancePolicies, @SuppressWarnings("unused") Mutex lock) {
         Map<RoutingPolicyId, RoutingPolicy> policies = new LinkedHashMap<>(instancePolicies.asMap());
         for (LoadBalancer loadBalancer : allocation.loadBalancers) {
             if (loadBalancer.hostname().isEmpty()) continue;
@@ -343,7 +344,7 @@ public class RoutingPolicies {
      *
      * @return the updated policies
      */
-    private RoutingPolicyList removePoliciesUnreferencedBy(LoadBalancerAllocation allocation, RoutingPolicyList instancePolicies, @SuppressWarnings("unused") Lock lock) {
+    private RoutingPolicyList removePoliciesUnreferencedBy(LoadBalancerAllocation allocation, RoutingPolicyList instancePolicies, @SuppressWarnings("unused") Mutex lock) {
         Map<RoutingPolicyId, RoutingPolicy> newPolicies = new LinkedHashMap<>(instancePolicies.asMap());
         Set<RoutingPolicyId> activeIds = allocation.asPolicyIds();
         RoutingPolicyList removable = instancePolicies.deployment(allocation.deployment)
@@ -363,7 +364,7 @@ public class RoutingPolicies {
     }
 
     /** Remove unreferenced instance endpoints from DNS */
-    private void removeGlobalDnsUnreferencedBy(LoadBalancerAllocation allocation, RoutingPolicyList deploymentPolicies, @SuppressWarnings("unused") Lock lock) {
+    private void removeGlobalDnsUnreferencedBy(LoadBalancerAllocation allocation, RoutingPolicyList deploymentPolicies, @SuppressWarnings("unused") Mutex lock) {
         Set<RoutingId> removalCandidates = new HashSet<>(deploymentPolicies.asInstanceRoutingTable().keySet());
         Set<RoutingId> activeRoutingIds = instanceRoutingIds(allocation);
         removalCandidates.removeAll(activeRoutingIds);
@@ -380,7 +381,7 @@ public class RoutingPolicies {
     }
 
     /** Remove unreferenced application endpoints in given allocation from DNS */
-    private void removeApplicationDnsUnreferencedBy(LoadBalancerAllocation allocation, RoutingPolicyList deploymentPolicies, @SuppressWarnings("unused") Lock lock) {
+    private void removeApplicationDnsUnreferencedBy(LoadBalancerAllocation allocation, RoutingPolicyList deploymentPolicies, @SuppressWarnings("unused") Mutex lock) {
         Map<RoutingId, List<RoutingPolicy>> routingTable = deploymentPolicies.asApplicationRoutingTable();
         Set<RoutingId> removalCandidates = new HashSet<>(routingTable.keySet());
         Set<RoutingId> activeRoutingIds = applicationRoutingIds(allocation);
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/routing/rotation/RotationLock.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/routing/rotation/RotationLock.java
index 36a43f80e9a..39fc70aac64 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/routing/rotation/RotationLock.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/routing/rotation/RotationLock.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.controller.routing.rotation;
 
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.curator.Lock;
 
 import java.util.Objects;
@@ -12,9 +13,9 @@ import java.util.Objects;
  */
 public class RotationLock implements AutoCloseable {
 
-    private final Lock lock;
+    private final Mutex lock;
 
-    RotationLock(Lock lock) {
+    RotationLock(Mutex lock) {
         this.lock = Objects.requireNonNull(lock, "lock cannot be null");
     }
 
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/support/access/SupportAccessControl.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/support/access/SupportAccessControl.java
index cd6e3a49c46..27b61a4fd17 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/support/access/SupportAccessControl.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/support/access/SupportAccessControl.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.controller.support.access;
 
+import com.yahoo.transaction.Mutex;
 import com.yahoo.vespa.athenz.api.AthenzUser;
 import com.yahoo.vespa.curator.Lock;
 import com.yahoo.vespa.hosted.controller.Controller;
@@ -35,7 +36,7 @@ public class SupportAccessControl {
     }
 
     public SupportAccess disallow(DeploymentId deployment, String by) {
-        try (Lock lock = controller.curator().lockSupportAccess(deployment)) {
+        try (Mutex lock = controller.curator().lockSupportAccess(deployment)) {
             var now = controller.clock().instant();
             SupportAccess supportAccess = forDeployment(deployment);
             if (supportAccess.currentStatus(now).state() == NOT_ALLOWED) {
@@ -49,7 +50,7 @@ public class SupportAccessControl {
     }
 
     public SupportAccess allow(DeploymentId deployment, Instant until, String by) {
-        try (Lock lock = controller.curator().lockSupportAccess(deployment)) {
+        try (Mutex lock = controller.curator().lockSupportAccess(deployment)) {
             var now = controller.clock().instant();
             if (until.isAfter(now.plus(MAX_SUPPORT_ACCESS_TIME))) {
                 throw new IllegalArgumentException("Support access cannot be allowed for more than 10 days");
@@ -61,7 +62,7 @@ public class SupportAccessControl {
     }
 
     public SupportAccess registerGrant(DeploymentId deployment, String by, X509Certificate certificate) {
-        try (Lock lock = controller.curator().lockSupportAccess(deployment)) {
+        try (Mutex lock = controller.curator().lockSupportAccess(deployment)) {
             var now = controller.clock().instant();
             SupportAccess supportAccess = forDeployment(deployment);
             if (certificate.getNotAfter().toInstant().isBefore(now)) {
diff --git a/zkfacade/src/main/java/com/yahoo/vespa/curator/MultiplePathsLock.java b/zkfacade/src/main/java/com/yahoo/vespa/curator/MultiplePathsLock.java
index 2520a0682ed..f71f9c6149e 100644
--- a/zkfacade/src/main/java/com/yahoo/vespa/curator/MultiplePathsLock.java
+++ b/zkfacade/src/main/java/com/yahoo/vespa/curator/MultiplePathsLock.java
@@ -2,8 +2,10 @@
 package com.yahoo.vespa.curator;
 
 import com.yahoo.path.Path;
+import com.yahoo.transaction.Mutex;
 
 import java.time.Duration;
+import java.util.List;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -14,26 +16,28 @@ import java.util.logging.Logger;
  *
  * @author hmusum
  */
-public class MultiplePathsLock extends Lock {
+public class MultiplePathsLock implements Mutex {
 
     private static final Logger log = Logger.getLogger(MultiplePathsLock.class.getName());
 
-    private final Lock oldLock;
+    private final List<Lock> locks;
 
-    public MultiplePathsLock(Path newLockPath, Path oldLockPath, Duration timeout, Curator curator) {
-        super(newLockPath.getAbsolute(), curator);
-        log.log(Level.INFO, "Acquiring lock " + oldLockPath);
-        this.oldLock = curator.lock(oldLockPath, timeout);;
-        log.log(Level.INFO, "Acquiring lock " + lockPath());
-        super.acquire(timeout);
+    /** Wrapped locks, in acquisition order. */
+    public MultiplePathsLock(Lock... locks) {
+        this.locks = List.of(locks);
     }
 
     @Override
     public void close() {
-        log.log(Level.INFO, "Closing lock " + lockPath());
-        super.close();
-        log.log(Level.INFO, "Closing lock " + oldLock.lockPath());
-        oldLock.close();
+        close(0);
+    }
+
+    private void close(int i) {
+        if (i < locks.size())
+            try (Lock lock = locks.get(i)) {
+                close(i + 1);
+                log.log(Level.INFO, "Closing lock " + lock.lockPath());
+            }
     }
 
 }