The Data Collector

Introduce a new data-collector module which holds new Data Collector
functionality. There will eventually exist one Collector per database,
with the ability to collect various statistical operational data on the
database and it's usage pattern. Collection is controlled via procedures,
and a stub of the most fundamental procedure (retrieve) is included here.

community/common/src/main/java/org/neo4j/scheduler/Group.java

@@ -59,6 +59,9 @@ public enum Group
     /** Thread pool for parallel Cypher query execution. */
     CYPHER_WORKER( "CypherWorker", ExecutorServiceFactory.workStealing() ),
 
+    // DATA COLLECTOR
+    DATA_COLLECTOR( "DataCollector" ),
+
     // BOLT.
     /** Network IO threads for the Bolt protocol. */
     BOLT_NETWORK_IO( "BoltNetworkIO" ),

community/community-it/cypher-it/src/test/scala/org/neo4j/internal/collector/DataCollectorAcceptanceTest.scala

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2002-2018 "Neo4j,"
+ * Neo4j Sweden AB [http://neo4j.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.internal.collector
+
+import org.neo4j.cypher.ExecutionEngineFunSuite
+
+class DataCollectorAcceptanceTest extends ExecutionEngineFunSuite {
+
+  test("should retrieve correct section") {
+    val res = execute("CALL db.stats.retrieve('teddybear')")
+    res.toList should be(Seq(Map("section" -> "teddybear", "data" -> Map())))
+  }
+}

community/cypher/cypher/src/test/scala/org/neo4j/cypher/internal/RewindableExecutionResult.scala

@@ -43,6 +43,12 @@ trait RewindableExecutionResult {
   def size: Long = result.size
   def head(str: String): AnyRef = result.head(str)
 
+  def single: Map[String, AnyRef] =
+    if (result.size == 1)
+      result.head
+    else
+      throw new IllegalStateException(s"Result should have one row, but had ${result.size}")
+
   def executionPlanDescription(): InternalPlanDescription = planDescription
 
   def executionPlanString(): String = planDescription.toString

community/data-collector/NOTICE.txt

@@ -0,0 +1,62 @@
+Neo4j
+Copyright © 2002-2018 Neo4j Sweden AB (referred to in this notice as "Neo4j")
+[http://neo4j.com]
+
+This product includes software ("Software") developed by Neo4j.
+
+The copyright in the bundled Neo4j graph database (including the
+Software) is owned by Neo4j. The Software developed and owned
+by Neo4j is licensed under the GNU GENERAL PUBLIC LICENSE Version 3
+(http://www.fsf.org/licensing/licenses/gpl-3.0.html) ("GPL")
+to all third parties and that license, as required by the GPL, is
+included in the LICENSE.txt file.
+
+However, if you have executed an End User Software License and Services
+Agreement or an OEM Software License and Support Services Agreement, or
+another commercial license agreement with Neo4j or one of its
+affiliates (each, a "Commercial Agreement"), the terms of the license in
+such Commercial Agreement will supersede the GPL and you may use the
+software solely pursuant to the terms of the relevant Commercial
+Agreement.
+
+Full license texts are found in LICENSES.txt.
+
+
+Third-party licenses
+--------------------
+
+Apache Software License, Version 2.0
+  Apache Commons Lang
+  Lucene Core
+  Lucene Memory
+  Netty/All-in-One
+
+BSD - Scala License
+  Scala Library
+
+BSD License
+  Scala Compiler
+
+Bouncy Castle License
+  Bouncy Castle PKIX, CMS, EAC, TSP, PKCS, OCSP, CMP, and CRMF APIs
+  Bouncy Castle Provider
+
+Eclipse Distribution License - v 1.0
+  Eclipse Collections API
+  Eclipse Collections Main Library
+
+Eclipse Public License - v 1.0
+  Eclipse Collections API
+  Eclipse Collections Main Library
+
+Dependencies with multiple licenses
+-----------------------------------
+
+Eclipse Collections API
+  Eclipse Distribution License - v 1.0
+  Eclipse Public License - v 1.0
+
+Eclipse Collections Main Library
+  Eclipse Distribution License - v 1.0
+  Eclipse Public License - v 1.0
+

community/data-collector/pom.xml

@@ -0,0 +1,145 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <parent>
+    <groupId>org.neo4j</groupId>
+    <artifactId>parent</artifactId>
+    <version>3.5.0-SNAPSHOT</version>
+    <relativePath>../..</relativePath>
+  </parent>
+
+  <properties>
+    <license-text.header>headers/GPL-3-header.txt</license-text.header>
+    <licensing.prepend.text>licensing/notice-gpl-prefix.txt</licensing.prepend.text>
+    <moduleName>org.neo4j.common</moduleName>
+  </properties>
+
+  <modelVersion>4.0.0</modelVersion>
+  <artifactId>neo4j-data-collector</artifactId>
+  <version>3.5.0-SNAPSHOT</version>
+
+  <packaging>jar</packaging>
+  <name>Neo4j - Data Collector</name>
+  <description>The Neo4j data collector deamon.</description>
+  <url>http://components.neo4j.org/${project.artifactId}/${project.version}</url>
+
+  <scm>
+    <connection>scm:git:git://github.com/neo4j/neo4j.git</connection>
+    <developerConnection>scm:git:git@github.com:neo4j/neo4j.git</developerConnection>
+    <url>https://github.com/neo4j/neo4j</url>
+  </scm>
+
+  <licenses>
+    <license>
+      <name>GNU General Public License, Version 3</name>
+      <url>http://www.gnu.org/licenses/gpl-3.0-standalone.html</url>
+      <comments>The software ("Software") developed and owned by Neo4j Sweden AB (referred to in this notice as "Neo4j") is
+licensed under the GNU GENERAL PUBLIC LICENSE Version 3 to all third
+parties and that license is included below.
+
+However, if you have executed an End User Software License and Services
+Agreement or an OEM Software License and Support Services Agreement, or
+another commercial license agreement with Neo4j or one of its
+affiliates (each, a "Commercial Agreement"), the terms of the license in
+such Commercial Agreement will supersede the GNU GENERAL PUBLIC LICENSE
+Version 3 and you may use the Software solely pursuant to the terms of
+the relevant Commercial Agreement.
+      </comments>
+    </license>
+  </licenses>
+
+  <build>
+    <plugins>
+          <plugin>
+              <groupId>net.alchim31.maven</groupId>
+              <artifactId>scala-maven-plugin</artifactId>
+          </plugin>
+      </plugins>
+
+      <pluginManagement>
+          <plugins>
+              <plugin>
+                  <groupId>org.scalastyle</groupId>
+                  <artifactId>scalastyle-maven-plugin</artifactId>
+                  <version>1.0.0</version>
+                  <configuration>
+                      <verbose>false</verbose>
+                      <failOnViolation>true</failOnViolation>
+                      <includeTestSourceDirectory>true</includeTestSourceDirectory>
+                      <failOnWarning>false</failOnWarning>
+                      <inputEncoding>UTF-8</inputEncoding>
+                      <sourceDirectory>${basedir}/src/main/scala</sourceDirectory>
+                      <testSourceDirectory>${basedir}/src/test/scala</testSourceDirectory>
+                      <configLocation>${project.basedir}/../scalastyle_config.xml</configLocation>
+                      <outputFile>${basedir}/target/scalastyle-output.xml</outputFile>
+                      <outputEncoding>UTF-8</outputEncoding>
+                  </configuration>
+                  <executions>
+                      <execution>
+                          <goals>
+                              <goal>check</goal>
+                          </goals>
+                      </execution>
+                  </executions>
+              </plugin>
+          </plugins>
+      </pluginManagement>
+  </build>
+
+    <dependencies>
+
+        <!-- scala -->
+
+        <dependency>
+            <groupId>org.scala-lang</groupId>
+            <artifactId>scala-library</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.scala-lang</groupId>
+            <artifactId>scala-reflect</artifactId>
+        </dependency>
+
+        <!-- neo4j -->
+
+        <dependency>
+            <groupId>org.neo4j</groupId>
+            <artifactId>neo4j-procedure-api</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.neo4j</groupId>
+            <artifactId>neo4j-kernel</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+
+        <!-- neo4j testing -->
+
+        <!-- Test are located with other IT tests to solve problems with depending of TestGraphDatabaseFactory et.c. -->
+
+        <!-- tests -->
+
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-migrationsupport</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.vintage</groupId>
+            <artifactId>junit-vintage-engine</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest-core</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest-library</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+        </dependency>
+    </dependencies>
+</project>

community/data-collector/src/main/java/org/neo4j/internal/collector/CollectorProcedures.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2002-2018 "Neo4j,"
+ * Neo4j Sweden AB [http://neo4j.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.internal.collector;
+
+import java.util.Collections;
+import java.util.stream.Stream;
+
+import org.neo4j.procedure.Description;
+import org.neo4j.procedure.Mode;
+import org.neo4j.procedure.Name;
+import org.neo4j.procedure.Procedure;
+
+@SuppressWarnings( "WeakerAccess" )
+public class CollectorProcedures
+{
+    @Description( "Retrieve statistical data about the current database." )
+    @Procedure( name = "db.stats.retrieve", mode = Mode.READ )
+    public Stream<RetrieveResult> retrieve( @Name( value = "section", defaultValue = "all" ) String section )
+    {
+        return Stream.of( new RetrieveResult( section, Collections.emptyMap() ) );
+    }
+}

community/data-collector/src/main/java/org/neo4j/internal/collector/DataCollectorModule.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2002-2018 "Neo4j,"
+ * Neo4j Sweden AB [http://neo4j.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.internal.collector;
+
+import org.neo4j.internal.kernel.api.Kernel;
+import org.neo4j.internal.kernel.api.exceptions.KernelException;
+import org.neo4j.kernel.impl.proc.Procedures;
+import org.neo4j.scheduler.JobScheduler;
+import org.neo4j.util.Preconditions;
+
+public class DataCollectorModule
+{
+    private DataCollectorModule()
+    {
+    }
+
+    public static void setupDataCollector( Procedures procedures,
+                                           JobScheduler jobScheduler,
+                                           Kernel kernel ) throws KernelException
+    {
+        Preconditions.checkState( kernel != null, "Kernel was null" );
+        procedures.registerProcedure( CollectorProcedures.class );
+    }
+}

community/data-collector/src/main/java/org/neo4j/internal/collector/RetrieveResult.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2002-2018 "Neo4j,"
+ * Neo4j Sweden AB [http://neo4j.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.internal.collector;
+import java.util.Map;
+
+@SuppressWarnings( "WeakerAccess" )
+public class RetrieveResult
+{
+    public final String section;
+    public final Map<String, Object> data;
+    public RetrieveResult( String section, Map<String,Object> data )
+    {
+        this.section = section;
+        this.data = data;
+    }
+}

community/neo4j/pom.xml

@@ -73,6 +73,11 @@ the relevant Commercial Agreement.
             <artifactId>neo4j-udc</artifactId>
             <version>${project.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.neo4j</groupId>
+            <artifactId>neo4j-data-collector</artifactId>
+            <version>${project.version}</version>
+        </dependency>
         <dependency>
             <groupId>org.neo4j</groupId>
             <artifactId>neo4j-cypher</artifactId>