Always load earlier major versions

Since we have extended the semantics of major-version to also mean
"upgrade this application also if you generally don't upgrade",
we need to make sure specifying this doesn't cause config models
on *earlier* versions to not load.

2 files changed, 39 insertions, 9 deletions

diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/modelfactory/ModelsBuilder.java b/configserver/src/main/java/com/yahoo/vespa/config/server/modelfactory/ModelsBuilder.java
index 24309569c9d..92d4471c41c 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/modelfactory/ModelsBuilder.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/modelfactory/ModelsBuilder.java
@@ -78,10 +78,14 @@ public abstract class ModelsBuilder<MODELRESULT extends ModelResult> {
                                          Instant now) {
         Set<Version> versions = modelFactoryRegistry.allVersions();
 
-        // If the application specifies a major, load models only for that
+        // If the application specifies a major, skip models on a newer major
         Optional<Integer> requestedMajorVersion = applicationPackage.getMajorVersion();
-        if (requestedMajorVersion.isPresent())
-            versions = filterByMajorVersion(requestedMajorVersion.get(), versions);
+        if (requestedMajorVersion.isPresent()) {
+            versions = keepUpToMajorVersion(requestedMajorVersion.get(), versions);
+            if (versions.isEmpty())
+                throw new UnknownVespaVersionException("No Vespa versions on or before major version " +
+                                                       requestedMajorVersion.get() + " are present");
+        }
 
         // Load models by one major version at the time as new major versions are allowed to be non-loadable
         // in the case where an existing application is incompatible with a new major version
@@ -95,7 +99,7 @@ public abstract class ModelsBuilder<MODELRESULT extends ModelResult> {
         List<MODELRESULT> allApplicationModels = new ArrayList<>();
         for (int i = 0; i < majorVersions.size(); i++) {
             try {
-                allApplicationModels.addAll(buildModelVersions(filterByMajorVersion(majorVersions.get(i), versions),
+                allApplicationModels.addAll(buildModelVersions(keepMajorVersion(majorVersions.get(i), versions),
                                                                applicationId, wantedNodeVespaVersion, applicationPackage,
                                                                allocatedHosts, now));
 
@@ -181,11 +185,12 @@ public abstract class ModelsBuilder<MODELRESULT extends ModelResult> {
         return versions;
     }
 
-    private Set<Version> filterByMajorVersion(int majorVersion, Set<Version> versions) {
-        Set<Version> filteredVersions = versions.stream().filter(v -> v.getMajor() == majorVersion).collect(Collectors.toSet());
-        if (filteredVersions.isEmpty())
-            throw new UnknownVespaVersionException("No Vespa versions matching major version " + majorVersion + " are present");
-        return filteredVersions;
+    private Set<Version> keepMajorVersion(int majorVersion, Set<Version> versions) {
+        return versions.stream().filter(v -> v.getMajor() == majorVersion).collect(Collectors.toSet());
+    }
+
+    private Set<Version> keepUpToMajorVersion(int majorVersion, Set<Version> versions) {
+        return versions.stream().filter(v -> v.getMajor() <= majorVersion).collect(Collectors.toSet());
     }
 
     private Version findLatest(Set<Version> versionSet) {
diff --git a/configserver/src/test/java/com/yahoo/vespa/config/server/session/RemoteSessionTest.java b/configserver/src/test/java/com/yahoo/vespa/config/server/session/RemoteSessionTest.java
index ea0b187dee2..7a70e7958f8 100644
--- a/configserver/src/test/java/com/yahoo/vespa/config/server/session/RemoteSessionTest.java
+++ b/configserver/src/test/java/com/yahoo/vespa/config/server/session/RemoteSessionTest.java
@@ -42,6 +42,7 @@ import static org.junit.Assert.assertTrue;
 
 /**
  * @author Ulf Lilleengen
+ * @author bratseth
  */
 public class RemoteSessionTest {
 
@@ -188,6 +189,30 @@ public class RemoteSessionTest {
     }
 
     @Test
+    public void require_that_an_application_package_can_limit_to_one_higher_major_version() {
+        ApplicationPackage application =
+                new MockApplicationPackage.Builder().withServices("<services version='1.0'/>")
+                                                    .withDeploymentSpec("<deployment version='1.0' major-version='3'/>")
+                                                    .build();
+        assertTrue(application.getMajorVersion().isPresent());
+        assertEquals(3, (int)application.getMajorVersion().get());
+
+        MockModelFactory failingFactory = new MockModelFactory();
+        failingFactory.vespaVersion = Version.fromIntValues(4, 0, 0);
+        failingFactory.throwErrorOnLoad = true;
+
+        MockModelFactory okFactory = new MockModelFactory();
+        okFactory.vespaVersion = Version.fromIntValues(2, 0, 0);
+        okFactory.throwErrorOnLoad = false;
+
+        SessionZooKeeperClient zkc = new MockSessionZKClient(curator, tenantName, 3, application);
+        RemoteSession session = createSession(4, zkc, Arrays.asList(okFactory, failingFactory), failingFactory.clock());
+        session.loadPrepared();
+
+        // Does not cause an error because model version 4 is skipped
+    }
+
+    @Test
     public void require_that_session_status_is_updated() {
         SessionZooKeeperClient zkc = new MockSessionZKClient(curator, tenantName, 3);
         RemoteSession session = createSession(3, zkc, Clock.systemUTC());