Foundation for new Monitor server and UI (apache#5012)

Created the initial foundation for a new Monitor implementation for
Accumulo 4.0. This change includes a new Thrift RPC endpoint in the
ServerProcess thrift service. The new endpoint returns a MetricResponse
object which contains information about the server and a set of
Micrometer Meters serialized as Google Flatbuffers. The new
Monitor implementation contains a class that periodically calls
this Thrift RPC method on all the server processes. The new
Monitor implementation makes this information, and other specific
information that it gathers available via a new JAX-RS API (see
the Endpoints class).



Co-authored-by: Dom G. <domgarguilo@apache.org>
Co-authored-by: Daniel Roberts ddanielr <ddanielr@gmail.com>
Co-authored-by: Keith Turner <kturner@apache.org>
Co-authored-by: Christopher Tubbs <ctubbsii@apache.org>

Author: 5 people

.gitattributes

@@ -18,3 +18,4 @@
 #
 
 core/src/main/thrift-gen-java/** linguist-generated=true
+core/src/main/flatbuffers-gen-java/** linguist-generated=true

assemble/pom.xml

@@ -56,6 +56,11 @@
       <artifactId>jackson-databind</artifactId>
       <optional>true</optional>
     </dependency>
+    <dependency>
+      <groupId>com.fasterxml.jackson.datatype</groupId>
+      <artifactId>jackson-datatype-jdk8</artifactId>
+      <optional>true</optional>
+    </dependency>
     <dependency>
       <groupId>com.fasterxml.jackson.jakarta.rs</groupId>
       <artifactId>jackson-jakarta-rs-base</artifactId>
@@ -81,6 +86,11 @@
       <artifactId>gson</artifactId>
       <optional>true</optional>
     </dependency>
+    <dependency>
+      <groupId>com.google.flatbuffers</groupId>
+      <artifactId>flatbuffers-java</artifactId>
+      <optional>true</optional>
+    </dependency>
     <dependency>
       <groupId>com.google.guava</groupId>
       <artifactId>failureaccess</artifactId>

core/pom.xml

@@ -51,6 +51,10 @@
       <groupId>com.google.code.gson</groupId>
       <artifactId>gson</artifactId>
     </dependency>
+    <dependency>
+      <groupId>com.google.flatbuffers</groupId>
+      <artifactId>flatbuffers-java</artifactId>
+    </dependency>
     <dependency>
       <groupId>com.google.guava</groupId>
       <artifactId>guava</artifactId>

core/src/main/flatbuffers-gen-java/org/apache/accumulo/core/metrics/flatbuffers/FMetric.java

@@ -0,0 +1,35 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+namespace org.apache.accumulo.core.metrics.flatbuffers;
+
+table FTag {
+  key:string;
+  value:string;
+}
+
+table FMetric {
+  name:string;
+  type:string;
+  tags:[FTag];
+  dvalue:double;
+  ivalue:int;
+  lvalue:long;
+}
+
+root_type FMetric;

core/src/main/flatbuffers-gen-java/org/apache/accumulo/core/metrics/flatbuffers/FTag.java

@@ -828,6 +828,12 @@ public enum Property {
           + " The resources that are used by default can be seen in"
           + " `accumulo/server/monitor/src/main/resources/templates/default.ftl`.",
       "2.0.0"),
+  MONITOR_FETCH_TIMEOUT("monitor.fetch.timeout", "5m", PropertyType.TIMEDURATION,
+      "The Monitor fetches information for display in a set of background threads. This property"
+          + " controls the amount of time that process should wait before cancelling any remaining"
+          + " tasks to fetch information. These background threads could end up waiting on servers"
+          + " to respond or for scans to complete.",
+      "4.0.0"),
   MONITOR_DEAD_LIST_RG_EXCLUSIONS("monitor.dead.server.rg.exclusions", "", PropertyType.STRING,
       "The Monitor displays information about servers that it believes have died recently."
           + " This property accepts a comma separated list of resource group names. If"

core/src/main/flatbuffers/metric.fbs

@@ -23,13 +23,23 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
+import java.util.Set;
 
 import com.google.common.net.HostAndPort;
 
 import io.micrometer.core.instrument.Tag;
 
 public interface MetricsInfo {
 
+  String INSTANCE_NAME_TAG_KEY = "instance.name";
+  String PROCESS_NAME_TAG_KEY = "process.name";
+  String RESOURCE_GROUP_TAG_KEY = "resource.group";
+  String HOST_TAG_KEY = "host";
+  String PORT_TAG_KEY = "port";
+
+  Set<String> allTags = Set.of(INSTANCE_NAME_TAG_KEY, PROCESS_NAME_TAG_KEY, RESOURCE_GROUP_TAG_KEY,
+      HOST_TAG_KEY, PORT_TAG_KEY);
+
   /**
    * Convenience method to create tag name / value pair for the instance name
    *
@@ -38,7 +48,7 @@ public interface MetricsInfo {
   static Tag instanceNameTag(final String instanceName) {
     Objects.requireNonNull(instanceName,
         "cannot create the tag without providing the instance name");
-    return Tag.of("instance.name", instanceName);
+    return Tag.of(INSTANCE_NAME_TAG_KEY, instanceName);
   }
 
   /**
@@ -48,7 +58,7 @@ static Tag instanceNameTag(final String instanceName) {
    */
   static Tag processTag(final String processName) {
     Objects.requireNonNull(processName, "cannot create the tag without providing the process name");
-    return Tag.of("process.name", processName);
+    return Tag.of(PROCESS_NAME_TAG_KEY, processName);
   }
 
   /**
@@ -58,9 +68,9 @@ static Tag processTag(final String processName) {
    */
   static Tag resourceGroupTag(final String resourceGroupName) {
     if (resourceGroupName == null || resourceGroupName.isEmpty()) {
-      return Tag.of("resource.group", "NOT_PROVIDED");
+      return Tag.of(RESOURCE_GROUP_TAG_KEY, "NOT_PROVIDED");
     }
-    return Tag.of("resource.group", resourceGroupName);
+    return Tag.of(RESOURCE_GROUP_TAG_KEY, resourceGroupName);
   }
 
   /**
@@ -72,10 +82,10 @@ static Tag resourceGroupTag(final String resourceGroupName) {
   static List<Tag> addressTags(final HostAndPort hostAndPort) {
     Objects.requireNonNull(hostAndPort, "cannot create the tag without providing the hostAndPort");
     List<Tag> tags = new ArrayList<>(2);
-    tags.add(Tag.of("host", hostAndPort.getHost()));
+    tags.add(Tag.of(HOST_TAG_KEY, hostAndPort.getHost()));
     int port = hostAndPort.getPort();
     if (port != 0) {
-      tags.add(Tag.of("port", Integer.toString(hostAndPort.getPort())));
+      tags.add(Tag.of(PORT_TAG_KEY, Integer.toString(hostAndPort.getPort())));
     }
     return Collections.unmodifiableList(tags);
   }