NodeInfo response should use a collection rather than fields (#54460)

This is a first cut at giving NodeInfo the ability to carry a flexible
list of heterogeneous info responses. The trick is to be able to
serialize and deserialize an arbitrary list of blocks of information. It
is convenient to be able to deserialize into usable Java objects so that
we can aggregate nodes stats for the cluster stats endpoint.

In order to provide a little bit of clarity about which objects can and
can't be used as info blocks, I've introduced a new interface called
"ReportingService."

I have removed the hard-coded getters (e.g., getOs()) in favor of a
flexible method that can return heterogeneous kinds of info blocks
(e.g., getInfo(OsInfo.class)). Taking a class as an argument removes the
need to cast in the client code.

Author: williamrandolph

modules/reindex/src/test/java/org/elasticsearch/index/reindex/ReindexFromRemoteWithAuthTests.java

@@ -42,6 +42,7 @@
 import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.NodeEnvironment;
+import org.elasticsearch.http.HttpInfo;
 import org.elasticsearch.plugins.ActionPlugin;
 import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.rest.RestHeaderDefinition;
@@ -99,7 +100,7 @@ public void setupSourceIndex() {
     @Before
     public void fetchTransportAddress() {
         NodeInfo nodeInfo = client().admin().cluster().prepareNodesInfo().get().getNodes().get(0);
-        address = nodeInfo.getHttp().getAddress().publishAddress();
+        address = nodeInfo.getInfo(HttpInfo.class).getAddress().publishAddress();
     }
 
     /**

modules/reindex/src/test/java/org/elasticsearch/index/reindex/RetryTests.java

@@ -31,6 +31,7 @@
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.transport.TransportAddress;
 import org.elasticsearch.common.util.concurrent.EsRejectedExecutionException;
+import org.elasticsearch.http.HttpInfo;
 import org.elasticsearch.index.query.QueryBuilders;
 import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.test.ESIntegTestCase;
@@ -116,7 +117,7 @@ public void testReindexFromRemote() throws Exception {
             }
             assertNotNull(masterNode);
 
-            TransportAddress address = masterNode.getHttp().getAddress().publishAddress();
+            TransportAddress address = masterNode.getInfo(HttpInfo.class).getAddress().publishAddress();
             RemoteInfo remote =
                 new RemoteInfo("http", address.getAddress(), address.getPort(), null,
                     new BytesArray("{\"match_all\":{}}"), null, null, emptyMap(),

modules/transport-netty4/src/test/java/org/elasticsearch/transport/netty4/Netty4TransportMultiPortIntegrationIT.java

@@ -28,6 +28,7 @@
 import org.elasticsearch.test.ESIntegTestCase.ClusterScope;
 import org.elasticsearch.test.ESIntegTestCase.Scope;
 import org.elasticsearch.test.junit.annotations.Network;
+import org.elasticsearch.transport.TransportInfo;
 
 import java.util.Locale;
 
@@ -65,9 +66,9 @@ protected Settings nodeSettings(int nodeOrdinal) {
     public void testThatInfosAreExposed() throws Exception {
         NodesInfoResponse response = client().admin().cluster().prepareNodesInfo().clear().setTransport(true).get();
         for (NodeInfo nodeInfo : response.getNodes()) {
-            assertThat(nodeInfo.getTransport().getProfileAddresses().keySet(), hasSize(1));
-            assertThat(nodeInfo.getTransport().getProfileAddresses(), hasKey("client1"));
-            BoundTransportAddress boundTransportAddress = nodeInfo.getTransport().getProfileAddresses().get("client1");
+            assertThat(nodeInfo.getInfo(TransportInfo.class).getProfileAddresses().keySet(), hasSize(1));
+            assertThat(nodeInfo.getInfo(TransportInfo.class).getProfileAddresses(), hasKey("client1"));
+            BoundTransportAddress boundTransportAddress = nodeInfo.getInfo(TransportInfo.class).getProfileAddresses().get("client1");
             for (TransportAddress transportAddress : boundTransportAddress.boundAddresses()) {
                 assertThat(transportAddress, instanceOf(TransportAddress.class));
             }

modules/transport-netty4/src/test/java/org/elasticsearch/transport/netty4/Netty4TransportPublishAddressIT.java

@@ -29,6 +29,7 @@
 import org.elasticsearch.common.transport.TransportAddress;
 import org.elasticsearch.test.ESIntegTestCase;
 import org.elasticsearch.transport.Netty4Plugin;
+import org.elasticsearch.transport.TransportInfo;
 
 import java.net.Inet4Address;
 
@@ -68,7 +69,7 @@ public void testDifferentPorts() throws Exception {
         logger.info("--> checking if boundAddress matching publishAddress has same port");
         NodesInfoResponse nodesInfoResponse = client().admin().cluster().prepareNodesInfo().get();
         for (NodeInfo nodeInfo : nodesInfoResponse.getNodes()) {
-            BoundTransportAddress boundTransportAddress = nodeInfo.getTransport().getAddress();
+            BoundTransportAddress boundTransportAddress = nodeInfo.getInfo(TransportInfo.class).getAddress();
             if (nodeInfo.getNode().getName().equals(ipv4OnlyNode)) {
                 assertThat(boundTransportAddress.boundAddresses().length, equalTo(1));
                 assertThat(boundTransportAddress.boundAddresses()[0].getPort(), equalTo(boundTransportAddress.publishAddress().getPort()));

server/src/main/java/org/elasticsearch/action/admin/cluster/node/info/NodeInfo.java

@@ -33,10 +33,13 @@
 import org.elasticsearch.monitor.jvm.JvmInfo;
 import org.elasticsearch.monitor.os.OsInfo;
 import org.elasticsearch.monitor.process.ProcessInfo;
+import org.elasticsearch.node.ReportingService;
 import org.elasticsearch.threadpool.ThreadPoolInfo;
 import org.elasticsearch.transport.TransportInfo;
 
 import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
 
 /**
  * Node information (static, does not change over time).
@@ -49,29 +52,12 @@ public class NodeInfo extends BaseNodeResponse {
     @Nullable
     private Settings settings;
 
-    @Nullable
-    private OsInfo os;
-
-    @Nullable
-    private ProcessInfo process;
-
-    @Nullable
-    private JvmInfo jvm;
-
-    @Nullable
-    private ThreadPoolInfo threadPool;
-
-    @Nullable
-    private TransportInfo transport;
-
-    @Nullable
-    private HttpInfo http;
-
-    @Nullable
-    private PluginsAndModules plugins;
-
-    @Nullable
-    private IngestInfo ingest;
+    /**
+     * Do not expose this map to other classes. For type safety, use {@link #getInfo(Class)}
+     * to retrieve items from this map and {@link #addInfoIfNonNull(Class, ReportingService.Info)}
+     * to retrieve items from it.
+     */
+    private Map<Class<? extends ReportingService.Info>, ReportingService.Info> infoMap = new HashMap<>();
 
     @Nullable
     private ByteSizeValue totalIndexingBuffer;
@@ -88,14 +74,14 @@ public NodeInfo(StreamInput in) throws IOException {
         if (in.readBoolean()) {
             settings = Settings.readSettingsFromStream(in);
         }
-        os = in.readOptionalWriteable(OsInfo::new);
-        process = in.readOptionalWriteable(ProcessInfo::new);
-        jvm = in.readOptionalWriteable(JvmInfo::new);
-        threadPool = in.readOptionalWriteable(ThreadPoolInfo::new);
-        transport = in.readOptionalWriteable(TransportInfo::new);
-        http = in.readOptionalWriteable(HttpInfo::new);
-        plugins = in.readOptionalWriteable(PluginsAndModules::new);
-        ingest = in.readOptionalWriteable(IngestInfo::new);
+        addInfoIfNonNull(OsInfo.class, in.readOptionalWriteable(OsInfo::new));
+        addInfoIfNonNull(ProcessInfo.class, in.readOptionalWriteable(ProcessInfo::new));
+        addInfoIfNonNull(JvmInfo.class, in.readOptionalWriteable(JvmInfo::new));
+        addInfoIfNonNull(ThreadPoolInfo.class, in.readOptionalWriteable(ThreadPoolInfo::new));
+        addInfoIfNonNull(TransportInfo.class, in.readOptionalWriteable(TransportInfo::new));
+        addInfoIfNonNull(HttpInfo.class, in.readOptionalWriteable(HttpInfo::new));
+        addInfoIfNonNull(PluginsAndModules.class, in.readOptionalWriteable(PluginsAndModules::new));
+        addInfoIfNonNull(IngestInfo.class, in.readOptionalWriteable(IngestInfo::new));
     }
 
     public NodeInfo(Version version, Build build, DiscoveryNode node, @Nullable Settings settings,
@@ -106,14 +92,14 @@ public NodeInfo(Version version, Build build, DiscoveryNode node, @Nullable Sett
         this.version = version;
         this.build = build;
         this.settings = settings;
-        this.os = os;
-        this.process = process;
-        this.jvm = jvm;
-        this.threadPool = threadPool;
-        this.transport = transport;
-        this.http = http;
-        this.plugins = plugins;
-        this.ingest = ingest;
+        addInfoIfNonNull(OsInfo.class, os);
+        addInfoIfNonNull(ProcessInfo.class, process);
+        addInfoIfNonNull(JvmInfo.class, jvm);
+        addInfoIfNonNull(ThreadPoolInfo.class, threadPool);
+        addInfoIfNonNull(TransportInfo.class, transport);
+        addInfoIfNonNull(HttpInfo.class, http);
+        addInfoIfNonNull(PluginsAndModules.class, plugins);
+        addInfoIfNonNull(IngestInfo.class, ingest);
         this.totalIndexingBuffer = totalIndexingBuffer;
     }
 
@@ -148,57 +134,32 @@ public Settings getSettings() {
     }
 
     /**
-     * Operating System level information.
+     * Get a particular info object, e.g. {@link JvmInfo} or {@link OsInfo}. This
+     * generic method handles all casting in order to spare client classes the
+     * work of explicit casts. This {@link NodeInfo} class guarantees type
+     * safety for these stored info blocks.
+     *
+     * @param clazz Class for retrieval.
+     * @param <T>   Specific subtype of ReportingService.Info to retrieve.
+     * @return      An object of type T.
      */
-    @Nullable
-    public OsInfo getOs() {
-        return this.os;
+    public <T extends ReportingService.Info> T getInfo(Class<T> clazz) {
+        return clazz.cast(infoMap.get(clazz));
     }
 
-    /**
-     * Process level information.
-     */
     @Nullable
-    public ProcessInfo getProcess() {
-        return process;
+    public ByteSizeValue getTotalIndexingBuffer() {
+        return totalIndexingBuffer;
     }
 
     /**
-     * JVM level information.
+     * Add a value to the map of information blocks. This method guarantees the
+     * type safety of the storage of heterogeneous types of reporting service information.
      */
-    @Nullable
-    public JvmInfo getJvm() {
-        return jvm;
-    }
-
-    @Nullable
-    public ThreadPoolInfo getThreadPool() {
-        return this.threadPool;
-    }
-
-    @Nullable
-    public TransportInfo getTransport() {
-        return transport;
-    }
-
-    @Nullable
-    public HttpInfo getHttp() {
-        return http;
-    }
-
-    @Nullable
-    public PluginsAndModules getPlugins() {
-        return this.plugins;
-    }
-
-    @Nullable
-    public IngestInfo getIngest() {
-        return ingest;
-    }
-
-    @Nullable
-    public ByteSizeValue getTotalIndexingBuffer() {
-        return totalIndexingBuffer;
+    private <T extends ReportingService.Info> void addInfoIfNonNull(Class<T> clazz, T info) {
+        if (info != null) {
+            infoMap.put(clazz, info);
+        }
     }
 
     @Override
@@ -218,13 +179,13 @@ public void writeTo(StreamOutput out) throws IOException {
             out.writeBoolean(true);
             Settings.writeSettingsToStream(settings, out);
         }
-        out.writeOptionalWriteable(os);
-        out.writeOptionalWriteable(process);
-        out.writeOptionalWriteable(jvm);
-        out.writeOptionalWriteable(threadPool);
-        out.writeOptionalWriteable(transport);
-        out.writeOptionalWriteable(http);
-        out.writeOptionalWriteable(plugins);
-        out.writeOptionalWriteable(ingest);
+        out.writeOptionalWriteable(getInfo(OsInfo.class));
+        out.writeOptionalWriteable(getInfo(ProcessInfo.class));
+        out.writeOptionalWriteable(getInfo(JvmInfo.class));
+        out.writeOptionalWriteable(getInfo(ThreadPoolInfo.class));
+        out.writeOptionalWriteable(getInfo(TransportInfo.class));
+        out.writeOptionalWriteable(getInfo(HttpInfo.class));
+        out.writeOptionalWriteable(getInfo(PluginsAndModules.class));
+        out.writeOptionalWriteable(getInfo(IngestInfo.class));
     }
 }

server/src/main/java/org/elasticsearch/action/admin/cluster/node/info/NodesInfoResponse.java

@@ -30,6 +30,13 @@
 import org.elasticsearch.common.xcontent.ToXContentFragment;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
+import org.elasticsearch.http.HttpInfo;
+import org.elasticsearch.ingest.IngestInfo;
+import org.elasticsearch.monitor.jvm.JvmInfo;
+import org.elasticsearch.monitor.os.OsInfo;
+import org.elasticsearch.monitor.process.ProcessInfo;
+import org.elasticsearch.threadpool.ThreadPoolInfo;
+import org.elasticsearch.transport.TransportInfo;
 
 import java.io.IOException;
 import java.util.List;
@@ -95,29 +102,29 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
                 builder.endObject();
             }
 
-            if (nodeInfo.getOs() != null) {
-                nodeInfo.getOs().toXContent(builder, params);
+            if (nodeInfo.getInfo(OsInfo.class) != null) {
+                nodeInfo.getInfo(OsInfo.class).toXContent(builder, params);
             }
-            if (nodeInfo.getProcess() != null) {
-                nodeInfo.getProcess().toXContent(builder, params);
+            if (nodeInfo.getInfo(ProcessInfo.class) != null) {
+                nodeInfo.getInfo(ProcessInfo.class).toXContent(builder, params);
             }
-            if (nodeInfo.getJvm() != null) {
-                nodeInfo.getJvm().toXContent(builder, params);
+            if (nodeInfo.getInfo(JvmInfo.class) != null) {
+                nodeInfo.getInfo(JvmInfo.class).toXContent(builder, params);
             }
-            if (nodeInfo.getThreadPool() != null) {
-                nodeInfo.getThreadPool().toXContent(builder, params);
+            if (nodeInfo.getInfo(ThreadPoolInfo.class) != null) {
+                nodeInfo.getInfo(ThreadPoolInfo.class).toXContent(builder, params);
             }
-            if (nodeInfo.getTransport() != null) {
-                nodeInfo.getTransport().toXContent(builder, params);
+            if (nodeInfo.getInfo(TransportInfo.class) != null) {
+                nodeInfo.getInfo(TransportInfo.class).toXContent(builder, params);
             }
-            if (nodeInfo.getHttp() != null) {
-                nodeInfo.getHttp().toXContent(builder, params);
+            if (nodeInfo.getInfo(HttpInfo.class) != null) {
+                nodeInfo.getInfo(HttpInfo.class).toXContent(builder, params);
             }
-            if (nodeInfo.getPlugins() != null) {
-                nodeInfo.getPlugins().toXContent(builder, params);
+            if (nodeInfo.getInfo(PluginsAndModules.class) != null) {
+                nodeInfo.getInfo(PluginsAndModules.class).toXContent(builder, params);
             }
-            if (nodeInfo.getIngest() != null) {
-                nodeInfo.getIngest().toXContent(builder, params);
+            if (nodeInfo.getInfo(IngestInfo.class) != null) {
+                nodeInfo.getInfo(IngestInfo.class).toXContent(builder, params);
             }
 
             builder.endObject();

server/src/main/java/org/elasticsearch/action/admin/cluster/node/info/PluginsAndModules.java

@@ -21,10 +21,8 @@
 
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
-import org.elasticsearch.common.io.stream.Writeable;
-import org.elasticsearch.common.xcontent.ToXContent.Params;
-import org.elasticsearch.common.xcontent.ToXContentFragment;
 import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.node.ReportingService;
 import org.elasticsearch.plugins.PluginInfo;
 
 import java.io.IOException;
@@ -36,7 +34,7 @@
 /**
  * Information about plugins and modules
  */
-public class PluginsAndModules implements Writeable, ToXContentFragment {
+public class PluginsAndModules implements ReportingService.Info {
     private final List<PluginInfo> plugins;
     private final List<PluginInfo> modules;