Re-implement RotationsCache with more semantically correct names and structure

8 files changed, 270 insertions, 294 deletions

diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpoint.java b/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpoint.java
new file mode 100644
index 00000000000..fb1035b5a03
--- /dev/null
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpoint.java
@@ -0,0 +1,54 @@
+// Copyright 2019 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.config.server.tenant;
+
+import com.yahoo.vespa.applicationmodel.ClusterId;
+
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * ContainerEndpoint tracks the service names that a Container Cluster should be
+ * known as.  This is used during request routing both for regular requests and
+ * for health checks in traffic distribution.
+ *
+ * @author ogronnesby
+ */
+public class ContainerEndpoint {
+    private final ClusterId clusterId;
+    private final List<String> names;
+
+    ContainerEndpoint(ClusterId clusterId, List<String> names) {
+        this.clusterId = Objects.requireNonNull(clusterId);
+        this.names = List.copyOf(Objects.requireNonNull(names));
+    }
+
+    public ClusterId clusterId() {
+        return clusterId;
+    }
+
+    public List<String> names() {
+        return names;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        ContainerEndpoint that = (ContainerEndpoint) o;
+        return Objects.equals(clusterId, that.clusterId) &&
+                Objects.equals(names, that.names);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(clusterId, names);
+    }
+
+    @Override
+    public String toString() {
+        return "ContainerEndpoint{" +
+                "clusterId=" + clusterId +
+                ", names=" + names +
+                '}';
+    }
+}
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointSerializer.java b/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointSerializer.java
new file mode 100644
index 00000000000..83d65f5b38b
--- /dev/null
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointSerializer.java
@@ -0,0 +1,76 @@
+// Copyright 2019 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.config.server.tenant;
+
+import com.yahoo.slime.ArrayTraverser;
+import com.yahoo.slime.Cursor;
+import com.yahoo.slime.Inspector;
+import com.yahoo.slime.Slime;
+import com.yahoo.vespa.applicationmodel.ClusterId;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Contains all methods for de-/serializing ContainerEndpoints to/from JSON.
+ * Also supports de-/serializing lists of these values.
+ *
+ * @author ogronnesby
+ */
+public class ContainerEndpointSerializer {
+    private static final String clusterIdField = "clusterId";
+    private static final String namesField = "names";
+
+    public static ContainerEndpoint endpointFromSlime(Inspector inspector) {
+        final var clusterId = inspector.field(clusterIdField).asString();
+        final var namesInspector = inspector.field(namesField);
+
+        if (clusterId.isEmpty()) {
+            throw new IllegalStateException("'clusterId' missing on serialized ContainerEndpoint");
+        }
+
+        if (! namesInspector.valid()) {
+            throw new IllegalStateException("'names' missing on serialized ContainerEndpoint");
+        }
+
+        final var names = new ArrayList<String>();
+
+        namesInspector.traverse((ArrayTraverser) (idx, nameInspector) -> {
+            final var containerName = nameInspector.asString();
+            names.add(containerName);
+        });
+
+        return new ContainerEndpoint(new ClusterId(clusterId), names);
+    }
+
+    public static List<ContainerEndpoint> endpointListFromSlime(Slime slime) {
+        final var inspector = slime.get();
+        final var endpoints = new ArrayList<ContainerEndpoint>();
+
+        inspector.traverse((ArrayTraverser) (idx, endpointInspector) -> {
+            final var containerEndpoint = endpointFromSlime(endpointInspector);
+            endpoints.add(containerEndpoint);
+        });
+
+        return endpoints;
+    }
+
+
+    public static void endpointToSlime(Cursor cursor, ContainerEndpoint endpoint) {
+        cursor.setString(clusterIdField, endpoint.clusterId().toString());
+
+        final var namesInspector = cursor.setArray(namesField);
+        endpoint.names().forEach(namesInspector::addString);
+    }
+
+    public static Slime endpointListToSlime(List<ContainerEndpoint> endpoints) {
+        final var slime = new Slime();
+        final var cursor = slime.setArray();
+
+        endpoints.forEach(endpoint -> {
+            final var endpointCursor = cursor.addObject();
+            endpointToSlime(endpointCursor, endpoint);
+        });
+
+        return slime;
+    }
+}
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointsCache.java b/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointsCache.java
new file mode 100644
index 00000000000..eefbce697c6
--- /dev/null
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointsCache.java
@@ -0,0 +1,59 @@
+// Copyright 2019 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.config.server.tenant;
+
+import com.yahoo.config.provision.ApplicationId;
+import com.yahoo.path.Path;
+import com.yahoo.vespa.config.SlimeUtils;
+import com.yahoo.vespa.curator.Curator;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.util.List;
+
+
+/**
+ * Persists assignment of rotations to an application to ZooKeeper.
+ * The entries are RotationAssignments, which keep track of the container
+ * cluster that is the target, the endpoint name, and the rotation used to
+ * give availability to that cluster.
+ *
+ * This is v2 of that storage in a new directory.  Previously we only stored
+ * the name of the rotation, since all the other information could be
+ * calculated runtime.
+ *
+ * @author ogronnesby
+ */
+public class ContainerEndpointsCache {
+    private final Path cachePath;
+    private final Curator curator;
+
+    ContainerEndpointsCache(Path tenantPath, Curator curator) {
+        this.cachePath = tenantPath.append("containerEndpointsCache/");
+        this.curator = curator;
+    }
+
+    public List<ContainerEndpoint> read(ApplicationId applicationId) {
+        final var optionalData = curator.getData(applicationPath(applicationId));
+        return optionalData
+                .map(SlimeUtils::jsonToSlime)
+                .map(ContainerEndpointSerializer::endpointListFromSlime)
+                .orElse(List.of());
+    }
+
+    public void write(ApplicationId applicationId, List<ContainerEndpoint> endpoints) {
+        if (endpoints.isEmpty()) return;
+
+        final var slime = ContainerEndpointSerializer.endpointListToSlime(endpoints);
+
+        try {
+            final var bytes = SlimeUtils.toJsonBytes(slime);
+            curator.set(applicationPath(applicationId), bytes);
+        } catch (IOException e) {
+            throw new UncheckedIOException("Error writing endpoints of: " + applicationId, e);
+        }
+    }
+
+    private Path applicationPath(ApplicationId applicationId) {
+        return cachePath.append(applicationId.serializedForm());
+    }
+}
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/RotationAssignment.java b/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/RotationAssignment.java
deleted file mode 100644
index 4c9e5b289b7..00000000000
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/RotationAssignment.java
+++ /dev/null
@@ -1,90 +0,0 @@
-// Copyright 2019 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.vespa.config.server.tenant;
-
-import com.yahoo.config.provision.Rotation;
-import com.yahoo.slime.Cursor;
-import com.yahoo.slime.Inspector;
-import com.yahoo.vespa.applicationmodel.ClusterId;
-
-import java.util.Objects;
-
-/**
- * RotationAssignment is an immutable dataclass that contains the
- * tuple for [endpoint, cluster, rotation].  This information is used
- * to keep track of
- *
- *  - Name of an endpoint used externally.
- *  - The container cluster that endpoint should point to.
- *  - The rotation used to give availability to that cluster endpoint.
- *
- * @author ogronnesby
- */
-public class RotationAssignment {
-    private final String endpointId;
-    private final Rotation rotation;
-    private final ClusterId containerId;
-
-    RotationAssignment(String endpointId, Rotation rotationName, ClusterId clusterId) {
-        this.endpointId = Objects.requireNonNull(endpointId);
-        this.rotation = Objects.requireNonNull(rotationName);
-        this.containerId = Objects.requireNonNull(clusterId);
-    }
-
-    public String getEndpointId() {
-        return endpointId;
-    }
-
-    public Rotation getRotation() {
-        return rotation;
-    }
-
-    public ClusterId getContainerId() {
-        return containerId;
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
-        RotationAssignment that = (RotationAssignment) o;
-        return Objects.equals(endpointId, that.endpointId) &&
-                Objects.equals(rotation, that.rotation) &&
-                Objects.equals(containerId, that.containerId);
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(endpointId, rotation, containerId);
-    }
-
-    static RotationAssignment fromSlime(Inspector inspector) {
-        final var endpointId = inspector.field("endpointId").asString();
-        final var rotationId = inspector.field("rotationId").asString();
-        final var containerId = inspector.field("containerId").asString();
-
-
-        if (endpointId.equals("")) {
-            throw new IllegalStateException("Missing 'endpointId' in RotationsCache");
-        }
-
-        if (rotationId.equals("")) {
-            throw new IllegalStateException("Missing 'rotationId' in RotationsCache");
-        }
-
-        if (containerId.equals("")) {
-            throw new IllegalStateException("Missing 'containerId' in RotationsCache");
-        }
-
-        return new RotationAssignment(
-                endpointId,
-                new Rotation(rotationId),
-                new ClusterId(containerId)
-        );
-    }
-
-    void toSlime(Cursor cursor) {
-        cursor.setString("endpointId", endpointId);
-        cursor.setString("rotationId", rotation.getId());
-        cursor.setString("containerId", containerId.toString());
-    }
-}
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/RotationsCache.java b/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/RotationsCache.java
deleted file mode 100644
index d24f6f3bfe1..00000000000
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/RotationsCache.java
+++ /dev/null
@@ -1,87 +0,0 @@
-// Copyright 2019 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.vespa.config.server.tenant;
-
-import com.yahoo.config.provision.ApplicationId;
-import com.yahoo.path.Path;
-import com.yahoo.slime.ObjectTraverser;
-import com.yahoo.slime.Slime;
-import com.yahoo.vespa.applicationmodel.ClusterId;
-import com.yahoo.vespa.config.SlimeUtils;
-import com.yahoo.vespa.curator.Curator;
-
-import java.io.IOException;
-import java.io.UncheckedIOException;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
-
-
-/**
- * Persists assignment of rotations to an application to ZooKeeper.
- * The entries are RotationAssignments, which keep track of the container
- * cluster that is the target, the endpoint name, and the rotation used to
- * give availability to that cluster.
- *
- * This is v2 of that storage in a new directory.  Previously we only stored
- * the name of the rotation, since all the other information could be
- * calculated runtime.
- *
- * @author ogronnesby
- */
-public class RotationsCache {
-    private final Path cachePath;
-    private final Curator curator;
-
-    public RotationsCache(Path tenantPath, Curator curator) {
-        this.cachePath = tenantPath.append("rotationsCache-v2/");
-        this.curator = curator;
-    }
-
-    public Map<ClusterId, RotationAssignment> read(ApplicationId applicationId) {
-        final var optionalData = curator.getData(applicationPath(applicationId));
-        return optionalData
-                .map(SlimeUtils::jsonToSlime)
-                .map(RotationsCache::entryFromSlime)
-                .orElse(Collections.emptyMap());
-    }
-
-    public void write(ApplicationId applicationId, Map<ClusterId, RotationAssignment> assignments) {
-        if (assignments.isEmpty()) return;
-        try {
-            curator.set(
-                    applicationPath(applicationId),
-                    SlimeUtils.toJsonBytes(entryToSlime(assignments))
-            );
-        } catch (IOException e) {
-            throw new UncheckedIOException("Error writing rotations of: " + applicationId, e);
-        }
-    }
-
-    static Map<ClusterId, RotationAssignment> entryFromSlime(Slime slime) {
-        final var assignmentMap = new HashMap<ClusterId, RotationAssignment>();
-
-        slime.get().traverse((ObjectTraverser) (name, inspector) -> {
-            final var containerId = new ClusterId(name);
-            final var assignment = RotationAssignment.fromSlime(inspector);
-            assignmentMap.put(containerId, assignment);
-        });
-
-        return Map.copyOf(assignmentMap);
-    }
-
-    static Slime entryToSlime(Map<ClusterId, RotationAssignment> assignments) {
-        final var slime = new Slime();
-        final var cursor = slime.setObject();
-
-        assignments.forEach((clusterId, assignment) -> {
-            final var assignmentCursor = cursor.setObject(clusterId.toString());
-            assignment.toSlime(assignmentCursor);
-        });
-
-        return slime;
-    }
-
-    private Path applicationPath(ApplicationId applicationId) {
-        return cachePath.append(applicationId.serializedForm());
-    }
-}
diff --git a/configserver/src/test/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointSerializerTest.java b/configserver/src/test/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointSerializerTest.java
new file mode 100644
index 00000000000..b4d52e6d37c
--- /dev/null
+++ b/configserver/src/test/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointSerializerTest.java
@@ -0,0 +1,45 @@
+package com.yahoo.vespa.config.server.tenant;
+
+import com.yahoo.slime.Slime;
+import com.yahoo.vespa.applicationmodel.ClusterId;
+import org.junit.Test;
+
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+
+public class ContainerEndpointSerializerTest {
+    @Test
+    public void readSingleEndpoint() {
+        final var slime = new Slime();
+        final var entry = slime.setObject();
+
+        entry.setString("clusterId", "foobar");
+        final var entryNames = entry.setArray("names");
+        entryNames.addString("a");
+        entryNames.addString("b");
+
+        final var endpoint = ContainerEndpointSerializer.endpointFromSlime(slime.get());
+        assertEquals("foobar", endpoint.clusterId().toString());
+        assertEquals(List.of("a", "b"), endpoint.names());
+    }
+
+    @Test
+    public void writeReadSingleEndpoint() {
+        final var endpoint = new ContainerEndpoint(new ClusterId("foo"), List.of("a", "b"));
+        final var serialized = new Slime();
+        ContainerEndpointSerializer.endpointToSlime(serialized.setObject(), endpoint);
+        final var deserialized = ContainerEndpointSerializer.endpointFromSlime(serialized.get());
+
+        assertEquals(endpoint, deserialized);
+    }
+
+    @Test
+    public void writeReadEndpoints() {
+        final var endpoints = List.of(new ContainerEndpoint(new ClusterId("foo"), List.of("a", "b")));
+        final var serialized = ContainerEndpointSerializer.endpointListToSlime(endpoints);
+        final var deserialized = ContainerEndpointSerializer.endpointListFromSlime(serialized);
+
+        assertEquals(endpoints, deserialized);
+    }
+}
diff --git a/configserver/src/test/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointsCacheTest.java b/configserver/src/test/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointsCacheTest.java
new file mode 100644
index 00000000000..3598b6e63c3
--- /dev/null
+++ b/configserver/src/test/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointsCacheTest.java
@@ -0,0 +1,36 @@
+// Copyright 2019 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.config.server.tenant;
+
+import com.yahoo.config.provision.ApplicationId;
+import com.yahoo.path.Path;
+import com.yahoo.vespa.applicationmodel.ClusterId;
+import com.yahoo.vespa.curator.mock.MockCurator;
+import org.junit.Test;
+
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+public class ContainerEndpointsCacheTest {
+    @Test
+    public void readWriteFromCache() {
+        final var cache = new ContainerEndpointsCache(Path.createRoot(), new MockCurator());
+        final var endpoints = List.of(
+                new ContainerEndpoint(new ClusterId("the-cluster-1"), List.of("a", "b", "c"))
+        );
+
+        cache.write(ApplicationId.defaultId(), endpoints);
+
+        final var deserialized = cache.read(ApplicationId.defaultId());
+
+        assertEquals(endpoints, deserialized);
+    }
+
+    @Test
+    public void readingNonExistingEntry() {
+        final var cache = new ContainerEndpointsCache(Path.createRoot(), new MockCurator());
+        final var endpoints = cache.read(ApplicationId.defaultId());
+        assertTrue(endpoints.isEmpty());
+    }
+}
\ No newline at end of file
diff --git a/configserver/src/test/java/com/yahoo/vespa/config/server/tenant/RotationsCacheTest.java b/configserver/src/test/java/com/yahoo/vespa/config/server/tenant/RotationsCacheTest.java
deleted file mode 100644
index e5d361feb9d..00000000000
--- a/configserver/src/test/java/com/yahoo/vespa/config/server/tenant/RotationsCacheTest.java
+++ /dev/null
@@ -1,117 +0,0 @@
-// Copyright 2019 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.vespa.config.server.tenant;
-
-import com.yahoo.config.provision.ApplicationId;
-import com.yahoo.config.provision.Rotation;
-import com.yahoo.path.Path;
-import com.yahoo.slime.Slime;
-import com.yahoo.vespa.applicationmodel.ClusterId;
-import com.yahoo.vespa.curator.mock.MockCurator;
-import org.junit.Test;
-
-import java.util.HashMap;
-import java.util.Set;
-
-import static org.junit.Assert.assertEquals;
-
-public class RotationsCacheTest {
-    @Test
-    public void assignmentDeserialization() {
-        final var slime = new Slime();
-        final var cursor = slime.setObject();
-
-        cursor.setString("endpointId", "nallefisk");
-        cursor.setString("containerId", "froskelosk");
-        cursor.setString("rotationId", "rotterott");
-
-        final var assignment = RotationAssignment.fromSlime(cursor);
-        assertEquals("nallefisk", assignment.getEndpointId());
-        assertEquals("froskelosk", assignment.getContainerId().toString());
-        assertEquals("rotterott", assignment.getRotation().getId());
-    }
-
-    @Test
-    public void assignmentSerialization() {
-        final var assignment = new RotationAssignment(
-                "sluttpeker",
-                new Rotation("rotasjon"),
-                new ClusterId("klynge")
-        );
-
-        final var serialized = new Slime();
-        assignment.toSlime(serialized.setObject());
-
-        assertEquals(assignment, RotationAssignment.fromSlime(serialized.get()));
-    }
-
-    @Test
-    public void mapDeserialization() {
-        final var slime = new Slime();
-        final var cursor = slime.setObject();
-
-        final var clusterId = new ClusterId("nalle");
-
-        final var entry = cursor.setObject("nalle");
-        entry.setString("endpointId", "nallefisk");
-        entry.setString("containerId", clusterId.toString());
-        entry.setString("rotationId", "rotterott");
-
-        final var assignments = RotationsCache.entryFromSlime(slime);
-        assertEquals(Set.of(clusterId), assignments.keySet());
-
-        // check the entry
-        final var assignment = assignments.get(clusterId);
-        assertEquals(clusterId, assignment.getContainerId());
-        assertEquals("nallefisk", assignment.getEndpointId());
-        assertEquals(new Rotation("rotterott"), assignment.getRotation());
-    }
-
-    @Test
-    public void mapSerialization() {
-        final var assignments = new HashMap<ClusterId, RotationAssignment>();
-
-        assignments.put(
-                new ClusterId("the-nallefisk-1"),
-                new RotationAssignment(
-                        "the-endpoint-1",
-                        new Rotation("the-rotation-1"),
-                        new ClusterId("the-cluster-1")
-                )
-        );
-
-        assignments.put(
-                new ClusterId("the-nallefisk-2"),
-                new RotationAssignment(
-                        "the-endpoint-2",
-                        new Rotation("the-rotation-2"),
-                        new ClusterId("the-cluster-2")
-                )
-        );
-
-        final var serialized = RotationsCache.entryToSlime(assignments);
-        final var deserialized = RotationsCache.entryFromSlime(serialized);
-
-        assertEquals(assignments, deserialized);
-    }
-
-    @Test
-    public void cacheStoreAndLoad() {
-        final var rotations = new RotationsCache(Path.createRoot().append("foo"), new MockCurator());
-        final var assignments = new HashMap<ClusterId, RotationAssignment>();
-
-        assignments.put(
-                new ClusterId("the-nallefisk-1"),
-                new RotationAssignment(
-                        "the-endpoint-1",
-                        new Rotation("the-rotation-1"),
-                        new ClusterId("the-cluster-1")
-                )
-        );
-
-        rotations.write(ApplicationId.defaultId(), assignments);
-        final var fetched = rotations.read(ApplicationId.defaultId());
-
-        assertEquals(assignments, fetched);
-    }
-
-}