Add empty-host-ttl to deployment spec

5 files changed, 310 insertions, 98 deletions

diff --git a/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentInstanceSpec.java b/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentInstanceSpec.java
index ac36e8e6c4d..fc170db5897 100644
--- a/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentInstanceSpec.java
+++ b/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentInstanceSpec.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.config.application.api;
 
+import ai.vespa.validation.Validation;
 import com.yahoo.config.provision.AthenzService;
 import com.yahoo.config.provision.CloudAccount;
 import com.yahoo.config.provision.ClusterSpec;
@@ -31,6 +32,7 @@ import static ai.vespa.validation.Validation.requireAtLeast;
 import static ai.vespa.validation.Validation.requireInRange;
 import static com.yahoo.config.application.api.DeploymentSpec.RevisionChange.whenClear;
 import static com.yahoo.config.application.api.DeploymentSpec.RevisionTarget.next;
+import static com.yahoo.config.application.api.DeploymentSpec.illegal;
 import static com.yahoo.config.provision.Environment.prod;
 
 /**
@@ -58,6 +60,7 @@ public class DeploymentInstanceSpec extends DeploymentSpec.Steps {
     private final Optional<String> globalServiceId;
     private final Optional<AthenzService> athenzService;
     private final Optional<CloudAccount> cloudAccount;
+    private final Optional<Duration> hostTTL;
     private final Notifications notifications;
     private final List<Endpoint> endpoints;
     private final Map<ClusterSpec.Id, Map<ZoneId, ZoneEndpoint>> zoneEndpoints;
@@ -75,6 +78,7 @@ public class DeploymentInstanceSpec extends DeploymentSpec.Steps {
                                   Optional<String> globalServiceId,
                                   Optional<AthenzService> athenzService,
                                   Optional<CloudAccount> cloudAccount,
+                                  Optional<Duration> hostTTL,
                                   Notifications notifications,
                                   List<Endpoint> endpoints,
                                   Map<ClusterSpec.Id, Map<ZoneId, ZoneEndpoint>> zoneEndpoints,
@@ -98,6 +102,7 @@ public class DeploymentInstanceSpec extends DeploymentSpec.Steps {
         this.globalServiceId = Objects.requireNonNull(globalServiceId);
         this.athenzService = Objects.requireNonNull(athenzService);
         this.cloudAccount = Objects.requireNonNull(cloudAccount);
+        this.hostTTL = Objects.requireNonNull(hostTTL);
         this.notifications = Objects.requireNonNull(notifications);
         this.endpoints = List.copyOf(Objects.requireNonNull(endpoints));
         Map<ClusterSpec.Id, Map<ZoneId, ZoneEndpoint>> zoneEndpointsCopy =  new HashMap<>();
@@ -108,6 +113,10 @@ public class DeploymentInstanceSpec extends DeploymentSpec.Steps {
         validateEndpoints(globalServiceId, this.endpoints);
         validateChangeBlockers(changeBlockers, now);
         validateBcp(bcp);
+        hostTTL.ifPresent(ttl -> {
+            if (cloudAccount.isEmpty()) illegal("Host TTL can only be specified with custom cloud accounts");
+            if (ttl.isNegative()) illegal("Host TTL cannot be negative");
+        });
     }
 
     public InstanceName name() { return name; }
@@ -269,6 +278,15 @@ public class DeploymentInstanceSpec extends DeploymentSpec.Steps {
                       .or(() -> cloudAccount);
     }
 
+    /** Returns the host TTL to use for given environment and region, if any */
+    public Optional<Duration> hostTTL(Environment environment, Optional<RegionName> region) {
+        return zones().stream()
+                      .filter(zone -> zone.concerns(environment, region))
+                      .findFirst()
+                      .flatMap(DeploymentSpec.DeclaredZone::hostTTL)
+                      .or(() -> hostTTL);
+    }
+
     /** Returns the notification configuration of these instances */
     public Notifications notifications() { return notifications; }
 
diff --git a/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentSpec.java b/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentSpec.java
index 1f44e599e11..43fdb32f3a2 100644
--- a/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentSpec.java
+++ b/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentSpec.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.config.application.api;
 
+import ai.vespa.validation.Validation;
 import com.yahoo.collections.Comparables;
 import com.yahoo.config.application.api.xml.DeploymentSpecXmlReader;
 import com.yahoo.config.provision.AthenzDomain;
@@ -45,6 +46,7 @@ public class DeploymentSpec {
                                                                   Optional.empty(),
                                                                   Optional.empty(),
                                                                   Optional.empty(),
+                                                                  Optional.empty(),
                                                                   List.of(),
                                                                   "<deployment version='1.0'/>",
                                                                   List.of());
@@ -56,6 +58,7 @@ public class DeploymentSpec {
     private final Optional<AthenzDomain> athenzDomain;
     private final Optional<AthenzService> athenzService;
     private final Optional<CloudAccount> cloudAccount;
+    private final Optional<Duration> hostTTL;
     private final List<Endpoint> endpoints;
     private final List<DeprecatedElement> deprecatedElements;
 
@@ -66,6 +69,7 @@ public class DeploymentSpec {
                           Optional<AthenzDomain> athenzDomain,
                           Optional<AthenzService> athenzService,
                           Optional<CloudAccount> cloudAccount,
+                          Optional<Duration> hostTTL,
                           List<Endpoint> endpoints,
                           String xmlForm,
                           List<DeprecatedElement> deprecatedElements) {
@@ -74,6 +78,7 @@ public class DeploymentSpec {
         this.athenzDomain = Objects.requireNonNull(athenzDomain);
         this.athenzService = Objects.requireNonNull(athenzService);
         this.cloudAccount = Objects.requireNonNull(cloudAccount);
+        this.hostTTL = Objects.requireNonNull(hostTTL);
         this.xmlForm = Objects.requireNonNull(xmlForm);
         this.endpoints = List.copyOf(Objects.requireNonNull(endpoints));
         this.deprecatedElements = List.copyOf(Objects.requireNonNull(deprecatedElements));
@@ -81,6 +86,10 @@ public class DeploymentSpec {
         validateUpgradePoliciesOfIncreasingConservativeness(steps);
         validateAthenz();
         validateApplicationEndpoints();
+        hostTTL.ifPresent(ttl -> {
+            if (cloudAccount.isEmpty()) illegal("Host TTL can only be specified with custom cloud accounts");
+            if (ttl.isNegative()) illegal("Host TTL cannot be negative");
+        });
     }
 
     public boolean isEmpty() { return this == empty; }
@@ -184,6 +193,14 @@ public class DeploymentSpec {
     public Optional<CloudAccount> cloudAccount() { return cloudAccount; }
 
     /**
+     * Additional host time-to-live for this application. Requires a custom cloud account to be set.
+     * This also applies only to zones with dynamic provisioning, and is then the time hosts are
+     * allowed remain empty, before being deprovisioned. This is useful for applications which frequently
+     * deploy to, e.g., test and staging zones, and want to avoid the delay of having to provision hosts.
+     */
+    public Optional<Duration> hostTTL() { return hostTTL; }
+
+    /**
      * Returns the most specific zone endpoint, where specificity is given, in decreasing order:
      * 1. The given instance has declared a zone endpoint for the cluster, for the given region.
      * 2. The given instance has declared a universal zone endpoint for the cluster.
@@ -262,7 +279,7 @@ public class DeploymentSpec {
     }
 
 
-    private static void illegal(String message) {
+    static void illegal(String message) {
         throw new IllegalArgumentException(message);
     }
 
@@ -403,14 +420,15 @@ public class DeploymentSpec {
         private final Optional<AthenzService> athenzService;
         private final Optional<String> testerFlavor;
         private final Optional<CloudAccount> cloudAccount;
+        private final Optional<Duration> hostTTL;
 
         public DeclaredZone(Environment environment) {
-            this(environment, Optional.empty(), false, Optional.empty(), Optional.empty(), Optional.empty());
+            this(environment, Optional.empty(), false, Optional.empty(), Optional.empty(), Optional.empty(), Optional.empty());
         }
 
         public DeclaredZone(Environment environment, Optional<RegionName> region, boolean active,
                             Optional<AthenzService> athenzService, Optional<String> testerFlavor,
-                            Optional<CloudAccount> cloudAccount) {
+                            Optional<CloudAccount> cloudAccount, Optional<Duration> hostTTL) {
             if (environment != Environment.prod && region.isPresent())
                 illegal("Non-prod environments cannot specify a region");
             if (environment == Environment.prod && region.isEmpty())
@@ -421,6 +439,11 @@ public class DeploymentSpec {
             this.athenzService = Objects.requireNonNull(athenzService);
             this.testerFlavor = Objects.requireNonNull(testerFlavor);
             this.cloudAccount = Objects.requireNonNull(cloudAccount);
+            this.hostTTL = Objects.requireNonNull(hostTTL);
+            hostTTL.ifPresent(ttl -> {
+                if (cloudAccount.isEmpty()) illegal("Host TTL can only be specified with custom cloud accounts");
+                if (ttl.isNegative()) illegal("Host TTL cannot be negative");
+            });
         }
 
         public Environment environment() { return environment; }
@@ -472,6 +495,10 @@ public class DeploymentSpec {
             return environment + (region.map(regionName -> "." + regionName).orElse(""));
         }
 
+        public Optional<Duration> hostTTL() {
+            return hostTTL;
+        }
+
     }
 
     /** A declared production test */
diff --git a/config-model-api/src/main/java/com/yahoo/config/application/api/xml/DeploymentSpecXmlReader.java b/config-model-api/src/main/java/com/yahoo/config/application/api/xml/DeploymentSpecXmlReader.java
index 89373d8bca0..db00ad4a421 100644
--- a/config-model-api/src/main/java/com/yahoo/config/application/api/xml/DeploymentSpecXmlReader.java
+++ b/config-model-api/src/main/java/com/yahoo/config/application/api/xml/DeploymentSpecXmlReader.java
@@ -94,6 +94,7 @@ public class DeploymentSpecXmlReader {
     private static final String majorVersionAttribute = "major-version";
     private static final String globalServiceIdAttribute = "global-service-id";
     private static final String cloudAccountAttribute = "cloud-account";
+    private static final String hostTTLAttribute = "empty-host-ttl";
 
     private final boolean validate;
     private final Clock clock;
@@ -165,6 +166,7 @@ public class DeploymentSpecXmlReader {
                                   stringAttribute(athenzDomainAttribute, root).map(AthenzDomain::from),
                                   stringAttribute(athenzServiceAttribute, root).map(AthenzService::from),
                                   stringAttribute(cloudAccountAttribute, root).map(CloudAccount::from),
+                                  stringAttribute(hostTTLAttribute, root).map(s -> toDuration(s, "empty host TTL")),
                                   applicationEndpoints,
                                   xmlForm,
                                   deprecatedElements);
@@ -204,6 +206,7 @@ public class DeploymentSpecXmlReader {
         List<DeploymentSpec.ChangeBlocker> changeBlockers = readChangeBlockers(instanceElement, parentTag);
         Optional<AthenzService> athenzService = mostSpecificAttribute(instanceElement, athenzServiceAttribute).map(AthenzService::from);
         Optional<CloudAccount> cloudAccount = mostSpecificAttribute(instanceElement, cloudAccountAttribute).map(CloudAccount::from);
+        Optional<Duration> hostTTL = mostSpecificAttribute(instanceElement, hostTTLAttribute).map(s -> toDuration(s, "empty host TTL"));
         Notifications notifications = readNotifications(instanceElement, parentTag);
 
         // Values where there is no default
@@ -233,6 +236,7 @@ public class DeploymentSpecXmlReader {
                                                              Optional.ofNullable(prodAttributes.get(globalServiceIdAttribute)),
                                                              athenzService,
                                                              cloudAccount,
+                                                             hostTTL,
                                                              notifications,
                                                              endpoints,
                                                              zoneEndpoints,
@@ -258,6 +262,7 @@ public class DeploymentSpecXmlReader {
     }
 
     // Consume the given tag as 0-N steps. 0 if it is not a step, >1 if it contains multiple nested steps that should be flattened
+    @SuppressWarnings("fallthrough")
     private List<Step> readNonInstanceSteps(Element stepTag, Map<String, String> prodAttributes, Element parentTag, Bcp defaultBcp) {
         Optional<AthenzService> athenzService = mostSpecificAttribute(stepTag, athenzServiceAttribute).map(AthenzService::from);
         Optional<String> testerFlavor = mostSpecificAttribute(stepTag, testerFlavorAttribute);
@@ -272,12 +277,10 @@ public class DeploymentSpecXmlReader {
             case testTag:
                 if (Stream.iterate(stepTag, Objects::nonNull, Node::getParentNode)
                           .anyMatch(node -> prodTag.equals(node.getNodeName()))) {
-                    // A production test
-                    return List.of(new DeclaredTest(RegionName.from(XML.getValue(stepTag).trim())));
+                    return List.of(new DeclaredTest(RegionName.from(XML.getValue(stepTag).trim()))); // A production test
                 }
-                return List.of(new DeclaredZone(Environment.from(stepTag.getTagName()), Optional.empty(), false, athenzService, testerFlavor, readCloudAccount(stepTag)));
-            case devTag, perfTag, stagingTag:
-                return List.of(new DeclaredZone(Environment.from(stepTag.getTagName()), Optional.empty(), false, athenzService, testerFlavor, readCloudAccount(stepTag)));
+            case devTag, perfTag, stagingTag: // Intentional fallthrough from test tag.
+                return List.of(new DeclaredZone(Environment.from(stepTag.getTagName()), Optional.empty(), false, athenzService, testerFlavor, readCloudAccount(stepTag), readHostTTL(stepTag)));
             case prodTag: // regions, delay and parallel may be nested within, but we can flatten them
                 return XML.getChildren(stepTag).stream()
                                                .flatMap(child -> readNonInstanceSteps(child, prodAttributes, stepTag, defaultBcp).stream())
@@ -682,13 +685,17 @@ public class DeploymentSpecXmlReader {
                                           Optional<String> testerFlavor, Element regionTag) {
         return new DeclaredZone(environment, Optional.of(RegionName.from(XML.getValue(regionTag).trim())),
                                 readActive(regionTag), athenzService, testerFlavor,
-                                readCloudAccount(regionTag));
+                                readCloudAccount(regionTag), readHostTTL(regionTag));
     }
 
     private Optional<CloudAccount> readCloudAccount(Element tag) {
         return mostSpecificAttribute(tag, cloudAccountAttribute).map(CloudAccount::from);
     }
 
+    private Optional<Duration> readHostTTL(Element tag) {
+        return mostSpecificAttribute(tag, hostTTLAttribute).map(s -> toDuration(s, "empty host TTL"));
+    }
+
     private Optional<String> readGlobalServiceId(Element environmentTag) {
         String globalServiceId = environmentTag.getAttribute(globalServiceIdAttribute);
         if (globalServiceId.isEmpty()) return Optional.empty();
@@ -804,8 +811,8 @@ public class DeploymentSpecXmlReader {
     }
 
     /**
-     * Returns a string consisting of a number followed by "m" or "h" to a duration given in that unit,
-     * or zero duration if null of blank.
+     * Returns a string consisting of a number followed by "m", "h" or "d" to a duration given in that unit,
+     * or zero duration if null or blank.
      */
     private static Duration toDuration(String durationSpec, String sourceDescription) {
         try {
diff --git a/config-model-api/src/test/java/com/yahoo/config/application/api/DeploymentSpecTest.java b/config-model-api/src/test/java/com/yahoo/config/application/api/DeploymentSpecTest.java
index 89b7318739e..9cee6c57591 100644
--- a/config-model-api/src/test/java/com/yahoo/config/application/api/DeploymentSpecTest.java
+++ b/config-model-api/src/test/java/com/yahoo/config/application/api/DeploymentSpecTest.java
@@ -32,6 +32,11 @@ import java.util.stream.Collectors;
 import static com.yahoo.config.application.api.Notifications.Role.author;
 import static com.yahoo.config.application.api.Notifications.When.failing;
 import static com.yahoo.config.application.api.Notifications.When.failingCommit;
+import static com.yahoo.config.provision.Environment.dev;
+import static com.yahoo.config.provision.Environment.perf;
+import static com.yahoo.config.provision.Environment.prod;
+import static com.yahoo.config.provision.Environment.staging;
+import static com.yahoo.config.provision.Environment.test;
 import static com.yahoo.config.provision.zone.ZoneId.defaultId;
 import static com.yahoo.config.provision.zone.ZoneId.from;
 import static org.junit.Assert.assertEquals;
@@ -60,11 +65,11 @@ public class DeploymentSpecTest {
         assertEquals(specXml, spec.xmlForm());
         assertEquals(1, spec.requireInstance("default").steps().size());
         assertFalse(spec.majorVersion().isPresent());
-        assertTrue(spec.requireInstance("default").steps().get(0).concerns(Environment.test));
-        assertTrue(spec.requireInstance("default").concerns(Environment.test, Optional.empty()));
-        assertTrue(spec.requireInstance("default").concerns(Environment.test, Optional.of(RegionName.from("region1")))); // test steps specify no region
-        assertFalse(spec.requireInstance("default").concerns(Environment.staging, Optional.empty()));
-        assertFalse(spec.requireInstance("default").concerns(Environment.prod, Optional.empty()));
+        assertTrue(spec.requireInstance("default").steps().get(0).concerns(test));
+        assertTrue(spec.requireInstance("default").concerns(test, Optional.empty()));
+        assertTrue(spec.requireInstance("default").concerns(test, Optional.of(RegionName.from("region1")))); // test steps specify no region
+        assertFalse(spec.requireInstance("default").concerns(staging, Optional.empty()));
+        assertFalse(spec.requireInstance("default").concerns(prod, Optional.empty()));
         assertFalse(spec.requireInstance("default").globalServiceId().isPresent());
     }
 
@@ -97,10 +102,10 @@ public class DeploymentSpecTest {
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
         assertEquals(1, spec.steps().size());
         assertEquals(1, spec.requireInstance("default").steps().size());
-        assertTrue(spec.requireInstance("default").steps().get(0).concerns(Environment.staging));
-        assertFalse(spec.requireInstance("default").concerns(Environment.test, Optional.empty()));
-        assertTrue(spec.requireInstance("default").concerns(Environment.staging, Optional.empty()));
-        assertFalse(spec.requireInstance("default").concerns(Environment.prod, Optional.empty()));
+        assertTrue(spec.requireInstance("default").steps().get(0).concerns(staging));
+        assertFalse(spec.requireInstance("default").concerns(test, Optional.empty()));
+        assertTrue(spec.requireInstance("default").concerns(staging, Optional.empty()));
+        assertFalse(spec.requireInstance("default").concerns(prod, Optional.empty()));
         assertFalse(spec.requireInstance("default").globalServiceId().isPresent());
     }
 
@@ -121,17 +126,17 @@ public class DeploymentSpecTest {
         assertEquals(1, spec.steps().size());
         assertEquals(2, spec.requireInstance("default").steps().size());
 
-        assertTrue(spec.requireInstance("default").steps().get(0).concerns(Environment.prod, Optional.of(RegionName.from("us-east1"))));
+        assertTrue(spec.requireInstance("default").steps().get(0).concerns(prod, Optional.of(RegionName.from("us-east1"))));
         assertFalse(((DeploymentSpec.DeclaredZone)spec.requireInstance("default").steps().get(0)).active());
 
-        assertTrue(spec.requireInstance("default").steps().get(1).concerns(Environment.prod, Optional.of(RegionName.from("us-west1"))));
+        assertTrue(spec.requireInstance("default").steps().get(1).concerns(prod, Optional.of(RegionName.from("us-west1"))));
         assertTrue(((DeploymentSpec.DeclaredZone)spec.requireInstance("default").steps().get(1)).active());
 
-        assertFalse(spec.requireInstance("default").concerns(Environment.test, Optional.empty()));
-        assertFalse(spec.requireInstance("default").concerns(Environment.staging, Optional.empty()));
-        assertTrue(spec.requireInstance("default").concerns(Environment.prod, Optional.of(RegionName.from("us-east1"))));
-        assertTrue(spec.requireInstance("default").concerns(Environment.prod, Optional.of(RegionName.from("us-west1"))));
-        assertFalse(spec.requireInstance("default").concerns(Environment.prod, Optional.of(RegionName.from("no-such-region"))));
+        assertFalse(spec.requireInstance("default").concerns(test, Optional.empty()));
+        assertFalse(spec.requireInstance("default").concerns(staging, Optional.empty()));
+        assertTrue(spec.requireInstance("default").concerns(prod, Optional.of(RegionName.from("us-east1"))));
+        assertTrue(spec.requireInstance("default").concerns(prod, Optional.of(RegionName.from("us-west1"))));
+        assertFalse(spec.requireInstance("default").concerns(prod, Optional.of(RegionName.from("no-such-region"))));
         assertFalse(spec.requireInstance("default").globalServiceId().isPresent());
 
         assertEquals(DeploymentSpec.UpgradePolicy.defaultPolicy, spec.requireInstance("default").upgradePolicy());
@@ -293,7 +298,7 @@ public class DeploymentSpecTest {
         assertEquals(1, instance2.steps().size());
         assertEquals(1, instance2.zones().size());
 
-        assertTrue(instance2.steps().get(0).concerns(Environment.prod, Optional.of(RegionName.from("us-central1"))));
+        assertTrue(instance2.steps().get(0).concerns(prod, Optional.of(RegionName.from("us-central1"))));
     }
 
     @Test
@@ -322,25 +327,25 @@ public class DeploymentSpecTest {
         assertEquals(5, instance.steps().size());
         assertEquals(4, instance.zones().size());
 
-        assertTrue(instance.steps().get(0).concerns(Environment.test));
+        assertTrue(instance.steps().get(0).concerns(test));
 
-        assertTrue(instance.steps().get(1).concerns(Environment.staging));
+        assertTrue(instance.steps().get(1).concerns(staging));
 
-        assertTrue(instance.steps().get(2).concerns(Environment.prod, Optional.of(RegionName.from("us-east1"))));
+        assertTrue(instance.steps().get(2).concerns(prod, Optional.of(RegionName.from("us-east1"))));
         assertFalse(((DeploymentSpec.DeclaredZone)instance.steps().get(2)).active());
 
         assertTrue(instance.steps().get(3) instanceof DeploymentSpec.Delay);
         assertEquals(3 * 60 * 60 + 30 * 60, instance.steps().get(3).delay().getSeconds());
 
-        assertTrue(instance.steps().get(4).concerns(Environment.prod, Optional.of(RegionName.from("us-west1"))));
+        assertTrue(instance.steps().get(4).concerns(prod, Optional.of(RegionName.from("us-west1"))));
         assertTrue(((DeploymentSpec.DeclaredZone)instance.steps().get(4)).active());
 
-        assertTrue(instance.concerns(Environment.test, Optional.empty()));
-        assertTrue(instance.concerns(Environment.test, Optional.of(RegionName.from("region1")))); // test steps specify no region
-        assertTrue(instance.concerns(Environment.staging, Optional.empty()));
-        assertTrue(instance.concerns(Environment.prod, Optional.of(RegionName.from("us-east1"))));
-        assertTrue(instance.concerns(Environment.prod, Optional.of(RegionName.from("us-west1"))));
-        assertFalse(instance.concerns(Environment.prod, Optional.of(RegionName.from("no-such-region"))));
+        assertTrue(instance.concerns(test, Optional.empty()));
+        assertTrue(instance.concerns(test, Optional.of(RegionName.from("region1")))); // test steps specify no region
+        assertTrue(instance.concerns(staging, Optional.empty()));
+        assertTrue(instance.concerns(prod, Optional.of(RegionName.from("us-east1"))));
+        assertTrue(instance.concerns(prod, Optional.of(RegionName.from("us-west1"))));
+        assertFalse(instance.concerns(prod, Optional.of(RegionName.from("no-such-region"))));
         assertFalse(instance.globalServiceId().isPresent());
     }
 
@@ -563,7 +568,7 @@ public class DeploymentSpecTest {
 
         DeploymentInstanceSpec instance = spec.instances().get(0);
         assertEquals("default", instance.name().value());
-        assertEquals("service", instance.athenzService(Environment.prod, RegionName.defaultName()).get().value());
+        assertEquals("service", instance.athenzService(prod, RegionName.defaultName()).get().value());
     }
 
     @Test
@@ -695,9 +700,9 @@ public class DeploymentSpecTest {
         List<DeploymentSpec.Step> innerParallelSteps = secondSerialSteps.get(2).steps();
         assertEquals(3, innerParallelSteps.size());
         assertEquals("prod.ap-northeast-1", innerParallelSteps.get(0).toString());
-        assertEquals("no-service", spec.requireInstance("instance").athenzService(Environment.prod, RegionName.from("ap-northeast-1")).get().value());
+        assertEquals("no-service", spec.requireInstance("instance").athenzService(prod, RegionName.from("ap-northeast-1")).get().value());
         assertEquals("prod.ap-southeast-2", innerParallelSteps.get(1).toString());
-        assertEquals("in-service", spec.requireInstance("instance").athenzService(Environment.prod, RegionName.from("ap-southeast-2")).get().value());
+        assertEquals("in-service", spec.requireInstance("instance").athenzService(prod, RegionName.from("ap-southeast-2")).get().value());
         assertEquals("tests for prod.aws-us-east-1a", innerParallelSteps.get(2).toString());
     }
 
@@ -956,7 +961,7 @@ public class DeploymentSpecTest {
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
         assertEquals("domain", spec.athenzDomain().get().value());
         assertEquals("service", spec.athenzService().get().value());
-        assertEquals("service", spec.requireInstance("instance1").athenzService(Environment.prod,
+        assertEquals("service", spec.requireInstance("instance1").athenzService(prod,
                                                                                 RegionName.from("us-west-1")).get().value());
     }
 
@@ -979,11 +984,11 @@ public class DeploymentSpecTest {
         assertEquals("domain", spec.athenzDomain().get().value());
         assertEquals("service", spec.athenzService().get().value());
 
-        assertEquals("prod-service", spec.requireInstance("instance1").athenzService(Environment.prod,
+        assertEquals("prod-service", spec.requireInstance("instance1").athenzService(prod,
                                                                                      RegionName.from("us-central-1")).get().value());
-        assertEquals("prod-service", spec.requireInstance("instance1").athenzService(Environment.prod,
+        assertEquals("prod-service", spec.requireInstance("instance1").athenzService(prod,
                                                                                      RegionName.from("us-west-1")).get().value());
-        assertEquals("prod-service", spec.requireInstance("instance1").athenzService(Environment.prod,
+        assertEquals("prod-service", spec.requireInstance("instance1").athenzService(prod,
                                                                                      RegionName.from("us-east-3")).get().value());
     }
 
@@ -1014,11 +1019,11 @@ public class DeploymentSpecTest {
                 """;
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
         assertEquals("domain", spec.athenzDomain().get().value());
-        assertEquals("service", spec.requireInstance("instance1").athenzService(Environment.prod,
+        assertEquals("service", spec.requireInstance("instance1").athenzService(prod,
                                                                                 RegionName.from("us-west-1")).get().value());
-        assertEquals("service", spec.requireInstance("instance1").athenzService(Environment.prod,
+        assertEquals("service", spec.requireInstance("instance1").athenzService(prod,
                                                                                 RegionName.from("us-east-3")).get().value());
-        assertEquals("service", spec.requireInstance("instance2").athenzService(Environment.prod,
+        assertEquals("service", spec.requireInstance("instance2").athenzService(prod,
                                                                                 RegionName.from("us-east-3")).get().value());
     }
 
@@ -1036,7 +1041,7 @@ public class DeploymentSpecTest {
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
         assertEquals("domain", spec.athenzDomain().get().value());
         assertEquals(Optional.empty(), spec.athenzService());
-        assertEquals("service", spec.requireInstance("default").athenzService(Environment.prod, RegionName.from("us-west-1")).get().value());
+        assertEquals("service", spec.requireInstance("default").athenzService(prod, RegionName.from("us-west-1")).get().value());
     }
 
     @Test
@@ -1054,13 +1059,13 @@ public class DeploymentSpecTest {
         );
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
         assertEquals("service",
-                     spec.requireInstance("default").athenzService(Environment.test,
+                     spec.requireInstance("default").athenzService(test,
                                                                    RegionName.from("us-east-1")).get().value());
         assertEquals("staging-service",
-                     spec.requireInstance("default").athenzService(Environment.staging,
+                     spec.requireInstance("default").athenzService(staging,
                                                                    RegionName.from("us-north-1")).get().value());
         assertEquals("prod-service",
-                     spec.requireInstance("default").athenzService(Environment.prod,
+                     spec.requireInstance("default").athenzService(prod,
                                                                    RegionName.from("us-west-1")).get().value());
     }
 
@@ -1273,8 +1278,8 @@ public class DeploymentSpecTest {
 
         assertEquals(List.of(RegionName.from("us-east")), spec.requireInstance("default").endpoints().get(0).regions());
 
-        var zone = from(Environment.prod, RegionName.from("us-east"));
-        var testZone = from(Environment.test, RegionName.from("us-east"));
+        var zone = from(prod, RegionName.from("us-east"));
+        var testZone = from(test, RegionName.from("us-east"));
         assertEquals(ZoneEndpoint.defaultEndpoint,
                      spec.zoneEndpoint(InstanceName.from("custom"), zone, ClusterSpec.Id.from("bax")));
         assertEquals(ZoneEndpoint.defaultEndpoint,
@@ -1778,23 +1783,142 @@ public class DeploymentSpecTest {
                 """;
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
         assertEquals(Optional.of(CloudAccount.from("100000000000")), spec.cloudAccount());
-        assertCloudAccount("800000000000", spec.requireInstance("alpha"), Environment.prod, "us-east-1");
-        assertCloudAccount("200000000000", spec.requireInstance("beta"), Environment.prod, "us-west-1");
-        assertCloudAccount("600000000000", spec.requireInstance("beta"), Environment.staging, "");
-        assertCloudAccount("700000000000", spec.requireInstance("beta"), Environment.perf, "");
-        assertCloudAccount("200000000000", spec.requireInstance("beta"), Environment.dev, "");
-        assertCloudAccount("300000000000", spec.requireInstance("main"), Environment.prod, "us-east-1");
-        assertCloudAccount("100000000000", spec.requireInstance("main"), Environment.prod, "eu-west-1");
-        assertCloudAccount("400000000000", spec.requireInstance("main"), Environment.dev, "");
-        assertCloudAccount("500000000000", spec.requireInstance("main"), Environment.test, "");
-        assertCloudAccount("100000000000", spec.requireInstance("main"), Environment.staging, "");
-        assertCloudAccount("default", spec.requireInstance("beta"), Environment.prod, "us-west-2");
+        assertCloudAccount("800000000000", spec.requireInstance("alpha"), prod, "us-east-1");
+        assertCloudAccount("200000000000", spec.requireInstance("beta"), prod, "us-west-1");
+        assertCloudAccount("600000000000", spec.requireInstance("beta"), staging, "");
+        assertCloudAccount("700000000000", spec.requireInstance("beta"), perf, "");
+        assertCloudAccount("200000000000", spec.requireInstance("beta"), dev, "");
+        assertCloudAccount("300000000000", spec.requireInstance("main"), prod, "us-east-1");
+        assertCloudAccount("100000000000", spec.requireInstance("main"), prod, "eu-west-1");
+        assertCloudAccount("400000000000", spec.requireInstance("main"), dev, "");
+        assertCloudAccount("500000000000", spec.requireInstance("main"), test, "");
+        assertCloudAccount("100000000000", spec.requireInstance("main"), staging, "");
+        assertCloudAccount("default", spec.requireInstance("beta"), prod, "us-west-2");
+    }
+
+    @Test
+    public void hostTTL() {
+        String r =
+                """
+                <deployment version='1.0' cloud-account='100000000000' empty-host-ttl='1h'>
+                  <instance id='alpha'>
+                    <staging />
+                    <prod empty-host-ttl='1m'>
+                        <region>us-east</region>
+                        <region empty-host-ttl='2m'>us-west</region>
+                    </prod>
+                  </instance>
+                  <instance id='beta'>
+                    <staging empty-host-ttl='3d'/>
+                    <perf empty-host-ttl='4h'/>
+                    <prod>
+                        <region>us-east</region>
+                        <region empty-host-ttl='0d'>us-west</region>
+                    </prod>
+                  </instance>
+                  <instance id='gamma' empty-host-ttl='6h'>
+                    <dev empty-host-ttl='7d'/>
+                    <prod>
+                        <region>us-east</region>
+                    </prod>
+                  </instance>
+                </deployment>
+                """;
+        DeploymentSpec spec = DeploymentSpec.fromXml(r);
+        assertEquals(Optional.of(CloudAccount.from("100000000000")), spec.cloudAccount());
+
+        assertHostTTL(Duration.ofHours(1), spec, "alpha", test, null);
+        assertHostTTL(Duration.ofHours(1), spec, "alpha", staging, null);
+        assertHostTTL(Duration.ofHours(1), spec, "alpha", dev, null);
+        assertHostTTL(Duration.ofHours(1), spec, "alpha", perf, null);
+        assertHostTTL(Duration.ofMinutes(1), spec, "alpha", prod, "us-east");
+        assertHostTTL(Duration.ofMinutes(2), spec, "alpha", prod, "us-west");
+
+        assertHostTTL(Duration.ofHours(1), spec, "beta", test, null);
+        assertHostTTL(Duration.ofDays(3), spec, "beta", staging, null);
+        assertHostTTL(Duration.ofHours(1), spec, "beta", dev, null);
+        assertHostTTL(Duration.ofHours(4), spec, "beta", perf, null);
+        assertHostTTL(Duration.ofHours(1), spec, "beta", prod, "us-east");
+        assertHostTTL(Duration.ZERO, spec, "beta", prod, "us-west");
+
+        assertHostTTL(Duration.ofHours(6), spec, "gamma", test, null);
+        assertHostTTL(Duration.ofHours(6), spec, "gamma", staging, null);
+        assertHostTTL(Duration.ofDays(7), spec, "gamma", dev, null);
+        assertHostTTL(Duration.ofHours(6), spec, "gamma", perf, null);
+        assertHostTTL(Duration.ofHours(6), spec, "gamma", prod, "us-east");
+        assertHostTTL(Duration.ofHours(6), spec, "gamma", prod, "us-west");
+
+        assertHostTTL(Duration.ofHours(1), spec, "nope", test, null);
+        assertHostTTL(Duration.ofHours(1), spec, "nope", staging, null);
+        assertHostTTL(Duration.ofHours(1), spec, "nope", dev, null);
+        assertHostTTL(Duration.ofHours(1), spec, "nope", perf, null);
+        assertHostTTL(Duration.ofHours(1), spec, "nope", prod, "us-east");
+        assertHostTTL(Duration.ofHours(1), spec, "nope", prod, "us-west");
+
+        assertEquals("Host TTL can only be specified with custom cloud accounts",
+                     assertThrows(IllegalArgumentException.class,
+                                  () -> DeploymentSpec.fromXml("""
+                                                  <deployment version='1.0' empty-host-ttl='0m'>
+                                                    <instance id='main'>
+                                                      <prod>
+                                                        <region>us-east-1</region>
+                                                      </prod>
+                                                    </instance>
+                                                  </deployment>
+                                                  """))
+                             .getMessage());
+
+        assertEquals("Host TTL can only be specified with custom cloud accounts",
+                     assertThrows(IllegalArgumentException.class,
+                                  () -> DeploymentSpec.fromXml("""
+                                                  <deployment version='1.0'>
+                                                    <instance id='main' empty-host-ttl='0m'>
+                                                      <prod>
+                                                        <region>us-east-1</region>
+                                                      </prod>
+                                                    </instance>
+                                                  </deployment>
+                                                  """))
+                             .getMessage());
+
+        assertEquals("Host TTL can only be specified with custom cloud accounts",
+                     assertThrows(IllegalArgumentException.class,
+                                  () -> DeploymentSpec.fromXml("""
+                                                  <deployment version='1.0'>
+                                                    <instance id='main'>
+                                                      <prod empty-host-ttl='0m'>
+                                                        <region>us-east-1</region>
+                                                      </prod>
+                                                    </instance>
+                                                  </deployment>
+                                                  """))
+                             .getMessage());
+
+        assertEquals("Host TTL can only be specified with custom cloud accounts",
+        assertThrows(IllegalArgumentException.class,
+                     () -> DeploymentSpec.fromXml("""
+                                                  <deployment version='1.0'>
+                                                    <instance id='main'>
+                                                      <prod>
+                                                        <region empty-host-ttl='0m'>us-east-1</region>
+                                                      </prod>
+                                                    </instance>
+                                                  </deployment>
+                                                  """))
+                .getMessage());
+
     }
 
     private void assertCloudAccount(String expected, DeploymentInstanceSpec instance, Environment environment, String region) {
         assertEquals(Optional.of(expected).map(CloudAccount::from), instance.cloudAccount(environment, Optional.of(region).filter(s -> !s.isEmpty()).map(RegionName::from)));
     }
 
+    private void assertHostTTL(Duration expected, DeploymentSpec spec, String instance, Environment environment, String region) {
+        assertEquals(Optional.of(expected), spec.instance(InstanceName.from(instance))
+                                                .flatMap(iSpec -> iSpec.hostTTL(environment, Optional.ofNullable(region).map(RegionName::from)))
+                                                .or(spec::hostTTL));
+    }
+
     private static void assertInvalid(String deploymentSpec, String errorMessagePart) {
         assertInvalid(deploymentSpec, errorMessagePart, new ManualClock());
     }
diff --git a/config-model-api/src/test/java/com/yahoo/config/application/api/DeploymentSpecWithoutInstanceTest.java b/config-model-api/src/test/java/com/yahoo/config/application/api/DeploymentSpecWithoutInstanceTest.java
index 38410cc5b37..ed8074ddc61 100644
--- a/config-model-api/src/test/java/com/yahoo/config/application/api/DeploymentSpecWithoutInstanceTest.java
+++ b/config-model-api/src/test/java/com/yahoo/config/application/api/DeploymentSpecWithoutInstanceTest.java
@@ -25,6 +25,9 @@ import java.util.stream.Collectors;
 import static com.yahoo.config.application.api.Notifications.Role.author;
 import static com.yahoo.config.application.api.Notifications.When.failing;
 import static com.yahoo.config.application.api.Notifications.When.failingCommit;
+import static com.yahoo.config.provision.Environment.dev;
+import static com.yahoo.config.provision.Environment.prod;
+import static com.yahoo.config.provision.Environment.test;
 import static com.yahoo.config.provision.zone.ZoneId.defaultId;
 import static com.yahoo.config.provision.zone.ZoneId.from;
 import static org.junit.Assert.assertEquals;
@@ -49,11 +52,11 @@ public class DeploymentSpecWithoutInstanceTest {
         assertEquals(specXml, spec.xmlForm());
         assertEquals(1, spec.steps().size());
         assertFalse(spec.majorVersion().isPresent());
-        assertTrue(spec.steps().get(0).concerns(Environment.test));
-        assertTrue(spec.requireInstance("default").concerns(Environment.test, Optional.empty()));
-        assertTrue(spec.requireInstance("default").concerns(Environment.test, Optional.of(RegionName.from("region1")))); // test steps specify no region
+        assertTrue(spec.steps().get(0).concerns(test));
+        assertTrue(spec.requireInstance("default").concerns(test, Optional.empty()));
+        assertTrue(spec.requireInstance("default").concerns(test, Optional.of(RegionName.from("region1")))); // test steps specify no region
         assertFalse(spec.requireInstance("default").concerns(Environment.staging, Optional.empty()));
-        assertFalse(spec.requireInstance("default").concerns(Environment.prod, Optional.empty()));
+        assertFalse(spec.requireInstance("default").concerns(prod, Optional.empty()));
         assertFalse(spec.requireInstance("default").globalServiceId().isPresent());
     }
 
@@ -83,9 +86,9 @@ public class DeploymentSpecWithoutInstanceTest {
         assertEquals(1, spec.steps().size());
         assertEquals(1, spec.requireInstance("default").steps().size());
         assertTrue(spec.requireInstance("default").steps().get(0).concerns(Environment.staging));
-        assertFalse(spec.requireInstance("default").concerns(Environment.test, Optional.empty()));
+        assertFalse(spec.requireInstance("default").concerns(test, Optional.empty()));
         assertTrue(spec.requireInstance("default").concerns(Environment.staging, Optional.empty()));
-        assertFalse(spec.requireInstance("default").concerns(Environment.prod, Optional.empty()));
+        assertFalse(spec.requireInstance("default").concerns(prod, Optional.empty()));
         assertFalse(spec.requireInstance("default").globalServiceId().isPresent());
     }
 
@@ -104,17 +107,17 @@ public class DeploymentSpecWithoutInstanceTest {
         assertEquals(1, spec.steps().size());
         assertEquals(2, spec.requireInstance("default").steps().size());
 
-        assertTrue(spec.requireInstance("default").steps().get(0).concerns(Environment.prod, Optional.of(RegionName.from("us-east1"))));
+        assertTrue(spec.requireInstance("default").steps().get(0).concerns(prod, Optional.of(RegionName.from("us-east1"))));
         assertFalse(((DeploymentSpec.DeclaredZone)spec.requireInstance("default").steps().get(0)).active());
 
-        assertTrue(spec.requireInstance("default").steps().get(1).concerns(Environment.prod, Optional.of(RegionName.from("us-west1"))));
+        assertTrue(spec.requireInstance("default").steps().get(1).concerns(prod, Optional.of(RegionName.from("us-west1"))));
         assertTrue(((DeploymentSpec.DeclaredZone)spec.requireInstance("default").steps().get(1)).active());
 
-        assertFalse(spec.requireInstance("default").concerns(Environment.test, Optional.empty()));
+        assertFalse(spec.requireInstance("default").concerns(test, Optional.empty()));
         assertFalse(spec.requireInstance("default").concerns(Environment.staging, Optional.empty()));
-        assertTrue(spec.requireInstance("default").concerns(Environment.prod, Optional.of(RegionName.from("us-east1"))));
-        assertTrue(spec.requireInstance("default").concerns(Environment.prod, Optional.of(RegionName.from("us-west1"))));
-        assertFalse(spec.requireInstance("default").concerns(Environment.prod, Optional.of(RegionName.from("no-such-region"))));
+        assertTrue(spec.requireInstance("default").concerns(prod, Optional.of(RegionName.from("us-east1"))));
+        assertTrue(spec.requireInstance("default").concerns(prod, Optional.of(RegionName.from("us-west1"))));
+        assertFalse(spec.requireInstance("default").concerns(prod, Optional.of(RegionName.from("no-such-region"))));
         assertFalse(spec.requireInstance("default").globalServiceId().isPresent());
         
         assertEquals(DeploymentSpec.UpgradePolicy.defaultPolicy, spec.requireInstance("default").upgradePolicy());
@@ -139,25 +142,25 @@ public class DeploymentSpecWithoutInstanceTest {
         assertEquals(5, spec.requireInstance("default").steps().size());
         assertEquals(4, spec.requireInstance("default").zones().size());
 
-        assertTrue(spec.requireInstance("default").steps().get(0).concerns(Environment.test));
+        assertTrue(spec.requireInstance("default").steps().get(0).concerns(test));
 
         assertTrue(spec.requireInstance("default").steps().get(1).concerns(Environment.staging));
 
-        assertTrue(spec.requireInstance("default").steps().get(2).concerns(Environment.prod, Optional.of(RegionName.from("us-east1"))));
+        assertTrue(spec.requireInstance("default").steps().get(2).concerns(prod, Optional.of(RegionName.from("us-east1"))));
         assertFalse(((DeploymentSpec.DeclaredZone)spec.requireInstance("default").steps().get(2)).active());
 
         assertTrue(spec.requireInstance("default").steps().get(3) instanceof DeploymentSpec.Delay);
         assertEquals(3 * 60 * 60 + 30 * 60, spec.requireInstance("default").steps().get(3).delay().getSeconds());
 
-        assertTrue(spec.requireInstance("default").steps().get(4).concerns(Environment.prod, Optional.of(RegionName.from("us-west1"))));
+        assertTrue(spec.requireInstance("default").steps().get(4).concerns(prod, Optional.of(RegionName.from("us-west1"))));
         assertTrue(((DeploymentSpec.DeclaredZone)spec.requireInstance("default").steps().get(4)).active());
 
-        assertTrue(spec.requireInstance("default").concerns(Environment.test, Optional.empty()));
-        assertTrue(spec.requireInstance("default").concerns(Environment.test, Optional.of(RegionName.from("region1")))); // test steps specify no region
+        assertTrue(spec.requireInstance("default").concerns(test, Optional.empty()));
+        assertTrue(spec.requireInstance("default").concerns(test, Optional.of(RegionName.from("region1")))); // test steps specify no region
         assertTrue(spec.requireInstance("default").concerns(Environment.staging, Optional.empty()));
-        assertTrue(spec.requireInstance("default").concerns(Environment.prod, Optional.of(RegionName.from("us-east1"))));
-        assertTrue(spec.requireInstance("default").concerns(Environment.prod, Optional.of(RegionName.from("us-west1"))));
-        assertFalse(spec.requireInstance("default").concerns(Environment.prod, Optional.of(RegionName.from("no-such-region"))));
+        assertTrue(spec.requireInstance("default").concerns(prod, Optional.of(RegionName.from("us-east1"))));
+        assertTrue(spec.requireInstance("default").concerns(prod, Optional.of(RegionName.from("us-west1"))));
+        assertFalse(spec.requireInstance("default").concerns(prod, Optional.of(RegionName.from("no-such-region"))));
         assertFalse(spec.requireInstance("default").globalServiceId().isPresent());
     }
 
@@ -436,9 +439,9 @@ public class DeploymentSpecWithoutInstanceTest {
         List<DeploymentSpec.Step> innerParallelSteps = secondSerialSteps.get(2).steps();
         assertEquals(3, innerParallelSteps.size());
         assertEquals("prod.ap-northeast-1", innerParallelSteps.get(0).toString());
-        assertEquals("no-service", spec.requireInstance("default").athenzService(Environment.prod, RegionName.from("ap-northeast-1")).get().value());
+        assertEquals("no-service", spec.requireInstance("default").athenzService(prod, RegionName.from("ap-northeast-1")).get().value());
         assertEquals("prod.ap-southeast-2", innerParallelSteps.get(1).toString());
-        assertEquals("service", spec.requireInstance("default").athenzService(Environment.prod, RegionName.from("ap-southeast-2")).get().value());
+        assertEquals("service", spec.requireInstance("default").athenzService(prod, RegionName.from("ap-southeast-2")).get().value());
         assertEquals("tests for prod.aws-us-east-1a", innerParallelSteps.get(2).toString());
     }
 
@@ -534,7 +537,7 @@ public class DeploymentSpecWithoutInstanceTest {
         );
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
         assertEquals(spec.athenzDomain().get().value(), "domain");
-        assertEquals(spec.requireInstance("default").athenzService(Environment.prod, RegionName.from("us-west-1")).get().value(), "service");
+        assertEquals(spec.requireInstance("default").athenzService(prod, RegionName.from("us-west-1")).get().value(), "service");
     }
 
     @Test
@@ -553,11 +556,11 @@ public class DeploymentSpecWithoutInstanceTest {
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
         assertEquals("domain", spec.athenzDomain().get().value());
         assertEquals("service", spec.athenzService().get().value());
-        assertEquals("prod-service", spec.requireInstance("default").athenzService(Environment.prod, RegionName.from("us-central-1"))
+        assertEquals("prod-service", spec.requireInstance("default").athenzService(prod, RegionName.from("us-central-1"))
                                          .get().value());
-        assertEquals("prod-service", spec.requireInstance("default").athenzService(Environment.prod, RegionName.from("us-west-1"))
+        assertEquals("prod-service", spec.requireInstance("default").athenzService(prod, RegionName.from("us-west-1"))
                                          .get().value());
-        assertEquals("prod-service", spec.requireInstance("default").athenzService(Environment.prod, RegionName.from("us-east-3"))
+        assertEquals("prod-service", spec.requireInstance("default").athenzService(prod, RegionName.from("us-east-3"))
                                          .get().value());
     }
 
@@ -575,9 +578,9 @@ public class DeploymentSpecWithoutInstanceTest {
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
         assertEquals("service", spec.athenzService().get().value());
         assertEquals(spec.athenzDomain().get().value(), "domain");
-        assertEquals(spec.requireInstance("default").athenzService(Environment.test, RegionName.from("us-east-1")).get().value(), "service");
+        assertEquals(spec.requireInstance("default").athenzService(test, RegionName.from("us-east-1")).get().value(), "service");
         assertEquals(spec.requireInstance("default").athenzService(Environment.staging, RegionName.from("us-north-1")).get().value(), "staging-service");
-        assertEquals(spec.requireInstance("default").athenzService(Environment.prod, RegionName.from("us-west-1")).get().value(), "prod-service");
+        assertEquals(spec.requireInstance("default").athenzService(prod, RegionName.from("us-west-1")).get().value(), "prod-service");
     }
 
     @Test(expected = IllegalArgumentException.class)
@@ -694,7 +697,7 @@ public class DeploymentSpecWithoutInstanceTest {
 
         assertEquals(List.of(RegionName.from("us-east")), spec.requireInstance("default").endpoints().get(0).regions());
 
-        var zone = from(Environment.prod, RegionName.from("us-east"));
+        var zone = from(prod, RegionName.from("us-east"));
         assertEquals(ZoneEndpoint.defaultEndpoint,
                      spec.zoneEndpoint(InstanceName.from("custom"), zone, ClusterSpec.Id.from("bax")));
         assertEquals(ZoneEndpoint.defaultEndpoint,
@@ -742,8 +745,8 @@ public class DeploymentSpecWithoutInstanceTest {
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
         DeploymentInstanceSpec instance = spec.requireInstance("default");
         assertEquals(Optional.of(CloudAccount.from("012345678912")), spec.cloudAccount());
-        assertEquals(Optional.of(CloudAccount.from("219876543210")), instance.cloudAccount(Environment.prod, Optional.of(RegionName.from("us-east-1"))));
-        assertEquals(Optional.of(CloudAccount.from("012345678912")), instance.cloudAccount(Environment.prod, Optional.of(RegionName.from("us-west-1"))));
+        assertEquals(Optional.of(CloudAccount.from("219876543210")), instance.cloudAccount(prod, Optional.of(RegionName.from("us-east-1"))));
+        assertEquals(Optional.of(CloudAccount.from("012345678912")), instance.cloudAccount(prod, Optional.of(RegionName.from("us-west-1"))));
         assertEquals(Optional.of(CloudAccount.from("012345678912")), instance.cloudAccount(Environment.staging, Optional.empty()));
 
         r = new StringReader(
@@ -756,8 +759,41 @@ public class DeploymentSpecWithoutInstanceTest {
         );
         spec = DeploymentSpec.fromXml(r);
         assertEquals(Optional.empty(), spec.cloudAccount());
-        assertEquals(Optional.of(CloudAccount.from("219876543210")), spec.requireInstance("default").cloudAccount(Environment.prod, Optional.of(RegionName.from("us-east-1"))));
-        assertEquals(Optional.empty(), spec.requireInstance("default").cloudAccount(Environment.prod, Optional.of(RegionName.from("us-west-1"))));
+        assertEquals(Optional.of(CloudAccount.from("219876543210")), spec.requireInstance("default").cloudAccount(prod, Optional.of(RegionName.from("us-east-1"))));
+        assertEquals(Optional.empty(), spec.requireInstance("default").cloudAccount(prod, Optional.of(RegionName.from("us-west-1"))));
+    }
+
+    @Test
+    public void productionSpecWithHostTTL() {
+        String r = """
+                   <deployment version='1.0' cloud-account='012345678912' empty-host-ttl='1d'>
+                       <prod>
+                           <region empty-host-ttl='1m'>us-east-1</region>
+                           <region>us-west-1</region>
+                       </prod>
+                   </deployment>
+                   """;
+        DeploymentSpec spec = DeploymentSpec.fromXml(r);
+        assertEquals(Optional.of(Duration.ofDays(1)), spec.hostTTL());
+        DeploymentInstanceSpec instance = spec.requireInstance("default");
+        assertEquals(Optional.of(Duration.ofMinutes(1)), instance.hostTTL(prod, Optional.of(RegionName.from("us-east-1"))));
+        assertEquals(Optional.of(Duration.ofDays(1)), instance.hostTTL(prod, Optional.of(RegionName.from("us-west-1"))));
+        assertEquals(Optional.of(Duration.ofDays(1)), instance.hostTTL(test, Optional.empty()));
+
+        r = """
+                   <deployment version='1.0' cloud-account='012345678912'>
+                       <prod empty-host-ttl='1d'>
+                           <region empty-host-ttl='1m'>us-east-1</region>
+                           <region>us-west-1</region>
+                       </prod>
+                   </deployment>
+                   """;
+        spec = DeploymentSpec.fromXml(r);
+        assertEquals(Optional.empty(), spec.hostTTL());
+        instance = spec.requireInstance("default");
+        assertEquals(Optional.of(Duration.ofMinutes(1)), instance.hostTTL(prod, Optional.of(RegionName.from("us-east-1"))));
+        assertEquals(Optional.of(Duration.ofDays(1)), instance.hostTTL(prod, Optional.of(RegionName.from("us-west-1"))));
+        assertEquals(Optional.empty(), instance.hostTTL(test, Optional.empty()));
     }
 
     private static Set<String> endpointRegions(String endpointId, DeploymentSpec spec) {