Move curator-stuff from TenantApplications to ApplicationCuratorDatabase

3 files changed, 114 insertions, 47 deletions

diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/application/ApplicationCuratorDatabase.java b/configserver/src/main/java/com/yahoo/vespa/config/server/application/ApplicationCuratorDatabase.java
index 94eb6eeea57..4bc3066ee18 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/application/ApplicationCuratorDatabase.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/application/ApplicationCuratorDatabase.java
@@ -1,6 +1,7 @@
 // Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config.server.application;
 
+import com.yahoo.concurrent.StripedExecutor;
 import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.config.provision.TenantName;
 import com.yahoo.path.Path;
@@ -8,29 +9,113 @@ import com.yahoo.slime.Cursor;
 import com.yahoo.slime.Inspector;
 import com.yahoo.slime.Slime;
 import com.yahoo.slime.SlimeUtils;
+import com.yahoo.text.Utf8;
+import com.yahoo.transaction.Transaction;
 import com.yahoo.vespa.config.server.application.ApplicationReindexing.Cluster;
 import com.yahoo.vespa.config.server.application.ApplicationReindexing.Status;
 import com.yahoo.vespa.config.server.tenant.TenantRepository;
 import com.yahoo.vespa.curator.Curator;
+import com.yahoo.vespa.curator.Lock;
+import com.yahoo.vespa.curator.transaction.CuratorOperations;
+import com.yahoo.vespa.curator.transaction.CuratorTransaction;
 import com.yahoo.yolean.Exceptions;
+import org.apache.curator.framework.recipes.cache.PathChildrenCacheListener;
 
+import java.time.Duration;
 import java.time.Instant;
+import java.util.List;
+import java.util.Optional;
+import java.util.concurrent.ExecutorService;
+import java.util.stream.Collectors;
 
 import static java.util.stream.Collectors.toUnmodifiableMap;
 
 /**
- * Stores data and holds locks for application, backed by a {@link Curator}.
+ * Stores data and holds locks for the applications of a tenant, backed by a {@link Curator}.
+ *
+ * Each application is stored under /config/v2/tenants/<tenant>/applications/<application>,
+ * the root contains the currently active session, if any. Children of this node may hold more data.
+ * Locks for synchronising writes to these paths, and changes to the config of this application, are found
+ * under /config/v2/tenants/<tenant>/locks/<application>.
  *
  * @author jonmv
  */
 public class ApplicationCuratorDatabase {
 
+    final TenantName tenant;
+    final Path applicationsPath;
+    final Path locksPath;
+
     private final Curator curator;
 
-    public ApplicationCuratorDatabase(Curator curator) {
+    public ApplicationCuratorDatabase(TenantName tenant, Curator curator) {
+        this.tenant = tenant;
+        this.applicationsPath = TenantRepository.getApplicationsPath(tenant);
+        this.locksPath = TenantRepository.getLocksPath(tenant);
         this.curator = curator;
     }
 
+    /** Returns the lock for changing the session status of the given application. */
+    public Lock lock(ApplicationId id) {
+        return curator.lock(lockPath(id), Duration.ofMinutes(1)); // These locks shouldn't be held for very long.
+    }
+
+    public boolean exists(ApplicationId id) {
+        return curator.exists(applicationPath(id));
+    }
+
+    /**
+     * Creates a node for the given application, marking its existence.
+     */
+    public void createApplication(ApplicationId id) {
+        if ( ! id.tenant().equals(tenant))
+            throw new IllegalArgumentException("Cannot write application id '" + id + "' for tenant '" + tenant + "'");
+        try (Lock lock = lock(id)) {
+            curator.create(applicationPath(id));
+        }
+    }
+
+    /**
+     * Returns a transaction which writes the given session id as the currently active for the given application.
+     *
+     * @param applicationId An {@link ApplicationId} that represents an active application.
+     * @param sessionId Id of the session containing the application package for this id.
+     */
+    public Transaction createPutTransaction(ApplicationId applicationId, long sessionId) {
+        return new CuratorTransaction(curator).add(CuratorOperations.setData(applicationPath(applicationId).getAbsolute(), Utf8.toAsciiBytes(sessionId)));
+    }
+
+    /**
+     * Returns a transaction which deletes this application.
+     */
+    public CuratorTransaction createDeleteTransaction(ApplicationId applicationId) {
+        return CuratorTransaction.from(CuratorOperations.deleteAll(applicationPath(applicationId).getAbsolute(), curator), curator);
+    }
+
+    /**
+     * Returns the active session id for the given application.
+     * Returns Optional.empty if application not found or no active session exists.
+     */
+    public Optional<Long> activeSessionOf(ApplicationId id) {
+        Optional<byte[]> data = curator.getData(applicationPath(id));
+        return (data.isEmpty() || data.get().length == 0)
+               ? Optional.empty()
+               : data.map(bytes -> Long.parseLong(Utf8.toString(bytes)));
+    }
+
+    /**
+     * List the active applications of a tenant in this config server.
+     *
+     * @return a list of {@link ApplicationId}s that are active.
+     */
+    public List<ApplicationId> activeApplications() {
+        return curator.getChildren(applicationsPath).stream()
+                      .sorted()
+                      .map(ApplicationId::fromSerializedForm)
+                      .filter(id -> activeSessionOf(id).isPresent())
+                      .collect(Collectors.toUnmodifiableList());
+    }
+
     public ApplicationReindexing readReindexingStatus(ApplicationId id) {
         return curator.getData(reindexingDataPath(id))
                       .map(data -> ReindexingStatusSerializer.fromBytes(data))
@@ -41,15 +126,22 @@ public class ApplicationCuratorDatabase {
         curator.set(reindexingDataPath(id), ReindexingStatusSerializer.toBytes(status));
     }
 
-    private static Path applicationsRoot(TenantName tenant) {
-        return TenantRepository.getApplicationsPath(tenant);
+
+    /** Sets up a listenable cache with the given listener, over the applications path of this tenant. */
+    public Curator.DirectoryCache createApplicationsPathCache(ExecutorService zkCacheExecutor) {
+        return curator.createDirectoryCache(applicationsPath.getAbsolute(), false, false, zkCacheExecutor);
+    }
+
+
+    private Path lockPath(ApplicationId id) {
+        return locksPath.append(id.serializedForm());
     }
 
-    private static Path applicationPath(ApplicationId id) {
-        return applicationsRoot(id.tenant()).append(id.serializedForm());
+    private Path applicationPath(ApplicationId id) {
+        return applicationsPath.append(id.serializedForm());
     }
 
-    private static Path reindexingDataPath(ApplicationId id) {
+    private Path reindexingDataPath(ApplicationId id) {
         return applicationPath(id).append("reindexing");
     }
 
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/application/TenantApplications.java b/configserver/src/main/java/com/yahoo/vespa/config/server/application/TenantApplications.java
index a01ce2e2cc3..7c54fd39a74 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/application/TenantApplications.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/application/TenantApplications.java
@@ -49,11 +49,7 @@ import java.util.stream.Collectors;
 import static java.util.stream.Collectors.toSet;
 
 /**
- * The applications of a tenant, backed by ZooKeeper.
- *
- * Each application is stored under /config/v2/tenants/&lt;tenant&gt;/applications/&lt;application&gt;,
- * the root contains the currently active session, if any. Locks for synchronising writes to these paths, and changes
- * to the config of this application, are found under /config/v2/tenants/&lt;tenant&gt;/locks/&lt;application&gt;.
+ * The applications of a tenant.
  *
  * @author Ulf Lilleengen
  * @author jonmv
@@ -62,9 +58,7 @@ public class TenantApplications implements RequestHandler, HostValidator<Applica
 
     private static final Logger log = Logger.getLogger(TenantApplications.class.getName());
 
-    private final Curator curator;
-    private final Path applicationsPath;
-    private final Path locksPath;
+    private final ApplicationCuratorDatabase database;
     private final Curator.DirectoryCache directoryCache;
     private final Executor zkWatcherExecutor;
     private final Metrics metrics;
@@ -81,12 +75,10 @@ public class TenantApplications implements RequestHandler, HostValidator<Applica
                               ExecutorService zkCacheExecutor, Metrics metrics, ReloadListener reloadListener,
                               ConfigserverConfig configserverConfig, HostRegistry<ApplicationId> hostRegistry,
                               TenantFileSystemDirs tenantFileSystemDirs) {
-        this.curator = curator;
-        this.applicationsPath = TenantRepository.getApplicationsPath(tenant);
-        this.locksPath = TenantRepository.getLocksPath(tenant);
+        this.database = new ApplicationCuratorDatabase(tenant, curator);
         this.tenant = tenant;
         this.zkWatcherExecutor = command -> zkWatcherExecutor.execute(tenant, command);
-        this.directoryCache = curator.createDirectoryCache(applicationsPath.getAbsolute(), false, false, zkCacheExecutor);
+        this.directoryCache = database.createApplicationsPathCache(zkCacheExecutor);
         this.directoryCache.addListener(this::childEvent);
         this.directoryCache.start();
         this.metrics = metrics;
@@ -110,21 +102,20 @@ public class TenantApplications implements RequestHandler, HostValidator<Applica
                                       new TenantFileSystemDirs(componentRegistry.getConfigServerDB(), tenantName));
     }
 
+    /** The curator backed ZK storage of this. */
+    public ApplicationCuratorDatabase database() { return database; }
+
     /**
      * List the active applications of a tenant in this config server.
      *
      * @return a list of {@link ApplicationId}s that are active.
      */
     public List<ApplicationId> activeApplications() {
-        return curator.getChildren(applicationsPath).stream()
-                      .sorted()
-                      .map(ApplicationId::fromSerializedForm)
-                      .filter(id -> activeSessionOf(id).isPresent())
-                      .collect(Collectors.toUnmodifiableList());
+        return database().activeApplications();
     }
 
     public boolean exists(ApplicationId id) {
-        return curator.exists(applicationPath(id));
+        return database().exists(id);
     }
 
     /**
@@ -132,10 +123,7 @@ public class TenantApplications implements RequestHandler, HostValidator<Applica
      * Returns Optional.empty if application not found or no active session exists.
      */
     public Optional<Long> activeSessionOf(ApplicationId id) {
-        Optional<byte[]> data = curator.getData(applicationPath(id));
-        return (data.isEmpty() || data.get().length == 0)
-                ? Optional.empty()
-                : data.map(bytes -> Long.parseLong(Utf8.toString(bytes)));
+        return database().activeSessionOf(id);
     }
 
     public boolean sessionExistsInFileSystem(long sessionId) {
@@ -149,18 +137,14 @@ public class TenantApplications implements RequestHandler, HostValidator<Applica
      * @param sessionId Id of the session containing the application package for this id.
      */
     public Transaction createPutTransaction(ApplicationId applicationId, long sessionId) {
-        return new CuratorTransaction(curator).add(CuratorOperations.setData(applicationPath(applicationId).getAbsolute(), Utf8.toAsciiBytes(sessionId)));
+        return database().createPutTransaction(applicationId, sessionId);
     }
 
     /**
      * Creates a node for the given application, marking its existence.
      */
     public void createApplication(ApplicationId id) {
-        if (! id.tenant().equals(tenant))
-            throw new IllegalArgumentException("Cannot write application id '" + id + "' for tenant '" + tenant + "'");
-        try (Lock lock = lock(id)) {
-            curator.create(applicationPath(id));
-        }
+        database().createApplication(id);
     }
 
     /**
@@ -179,7 +163,7 @@ public class TenantApplications implements RequestHandler, HostValidator<Applica
      * Returns a transaction which deletes this application.
      */
     public CuratorTransaction createDeleteTransaction(ApplicationId applicationId) {
-        return CuratorTransaction.from(CuratorOperations.deleteAll(applicationPath(applicationId).getAbsolute(), curator), curator);
+        return database().createDeleteTransaction(applicationId);
     }
 
     /**
@@ -198,7 +182,7 @@ public class TenantApplications implements RequestHandler, HostValidator<Applica
 
     /** Returns the lock for changing the session status of the given application. */
     public Lock lock(ApplicationId id) {
-        return curator.lock(lockPath(id), Duration.ofMinutes(1)); // These locks shouldn't be held for very long.
+        return database().lock(id);
     }
 
     private void childEvent(CuratorFramework ignored, PathChildrenCacheEvent event) {
@@ -232,15 +216,6 @@ public class TenantApplications implements RequestHandler, HostValidator<Applica
         log.log(Level.FINE, TenantRepository.logPre(applicationId) + "Application added: " + applicationId);
     }
 
-    // TODO jonmv: Move curator stuff to ApplicationCuratorDatabase
-    private Path applicationPath(ApplicationId id) {
-        return applicationsPath.append(id.serializedForm());
-    }
-
-    private Path lockPath(ApplicationId id) {
-        return locksPath.append(id.serializedForm());
-    }
-
     /**
      * Gets a config for the given app, or null if not found
      */
diff --git a/configserver/src/test/java/com/yahoo/vespa/config/server/application/ApplicationCuratorDatabaseTest.java b/configserver/src/test/java/com/yahoo/vespa/config/server/application/ApplicationCuratorDatabaseTest.java
index 96de2a8e4a4..89ee1dcccce 100644
--- a/configserver/src/test/java/com/yahoo/vespa/config/server/application/ApplicationCuratorDatabaseTest.java
+++ b/configserver/src/test/java/com/yahoo/vespa/config/server/application/ApplicationCuratorDatabaseTest.java
@@ -17,7 +17,7 @@ public class ApplicationCuratorDatabaseTest {
     @Test
     public void testReindexingStatusSerialization() {
         ApplicationId id = ApplicationId.defaultId();
-        ApplicationCuratorDatabase db = new ApplicationCuratorDatabase(new MockCurator());
+        ApplicationCuratorDatabase db = new ApplicationCuratorDatabase(id.tenant(), new MockCurator());
 
         assertEquals(ApplicationReindexing.empty(), db.readReindexingStatus(id));