Add 2-step verification for POST requests.

config/cruisecontrol.properties

@@ -287,3 +287,15 @@ webserver.accesslog.path=access.log
 
 # HTTP Request Log retention days
 webserver.accesslog.retention.days=14
+
+# Configurations for servlet
+# ==========================
+
+# Enable two-step verification for processing POST requests.
+two.step.verification.enabled=false
+
+# The maximum time in milliseconds to retain the requests in two-step (verification) purgatory.
+two.step.purgatory.retention.time.ms=1209600000
+
+# The maximum number of requests in two-step (verification) purgatory.
+two.step.purgatory.max.requests=25

cruise-control/src/main/java/com/linkedin/kafka/cruisecontrol/KafkaCruiseControl.java

@@ -32,15 +32,17 @@
 import com.linkedin.kafka.cruisecontrol.monitor.metricdefinition.KafkaMetricDef;
 import com.linkedin.kafka.cruisecontrol.servlet.parameters.AdminParameters;
 import com.linkedin.kafka.cruisecontrol.servlet.parameters.BootstrapParameters;
+import com.linkedin.kafka.cruisecontrol.servlet.parameters.KafkaClusterStateParameters;
 import com.linkedin.kafka.cruisecontrol.servlet.parameters.PauseResumeParameters;
+import com.linkedin.kafka.cruisecontrol.servlet.parameters.StopProposalParameters;
 import com.linkedin.kafka.cruisecontrol.servlet.parameters.TrainParameters;
 import com.linkedin.kafka.cruisecontrol.servlet.response.AdminResult;
 import com.linkedin.kafka.cruisecontrol.servlet.response.BootstrapResult;
 import com.linkedin.kafka.cruisecontrol.servlet.response.KafkaClusterState;
 import com.linkedin.kafka.cruisecontrol.servlet.response.CruiseControlState;
 import com.linkedin.kafka.cruisecontrol.servlet.response.PauseSamplingResult;
 import com.linkedin.kafka.cruisecontrol.servlet.response.ResumeSamplingResult;
-import com.linkedin.kafka.cruisecontrol.servlet.response.StopProposalExecutionResult;
+import com.linkedin.kafka.cruisecontrol.servlet.response.StopProposalResult;
 import com.linkedin.kafka.cruisecontrol.servlet.response.TrainResult;
 import com.linkedin.kafka.cruisecontrol.servlet.response.stats.BrokerStats;
 import java.io.InputStream;
@@ -843,11 +845,12 @@ private void executeDemotion(Collection<ExecutionProposal> proposals,
   /**
    * Stop the executor if it is executing the proposals.
    *
+   * @param parameters Stop proposal parameters (not used -- added for standardization and for extensibility).
    * @return Stop proposal execution result.
    */
-  public StopProposalExecutionResult stopProposalExecution() {
+  public StopProposalResult stopProposalExecution(StopProposalParameters parameters) {
     _executor.userTriggeredStopExecution();
-    return new StopProposalExecutionResult();
+    return new StopProposalResult();
   }
 
   /**
@@ -872,8 +875,11 @@ public CruiseControlState state(OperationProgress operationProgress,
 
   /**
    * Get the cluster state for Kafka.
+   *
+   * @param parameters Kafka cluster state parameters (not used -- added for standardization and for extensibility).
+   * @return Kafka cluster state.
    */
-  public KafkaClusterState kafkaClusterState() {
+  public KafkaClusterState kafkaClusterState(KafkaClusterStateParameters parameters) {
     return new KafkaClusterState(_loadMonitor.kafkaCluster());
   }
 

cruise-control/src/main/java/com/linkedin/kafka/cruisecontrol/KafkaCruiseControlMain.java

@@ -104,11 +104,9 @@ public static void main(String[] args) throws Exception {
     context.addServlet(holderWebapp, webuiPathPrefix);
 
     // Kafka Cruise Control servlet data
-    long maxBlockMs = config.getLong(KafkaCruiseControlConfig.WEBSERVER_REQUEST_MAX_BLOCK_TIME_MS);
-    long sessionExpiryMs = config.getLong(KafkaCruiseControlConfig.WEBSERVER_SESSION_EXPIRY_MS);
     String apiUrlPrefix = config.getString(KafkaCruiseControlConfig.WEBSERVER_API_URLPREFIX);
-    KafkaCruiseControlServlet kafkaCruiseControlServlet =
-        new KafkaCruiseControlServlet(kafkaCruiseControl, maxBlockMs, sessionExpiryMs, dropwizardMetricsRegistry, config);
+    KafkaCruiseControlServlet kafkaCruiseControlServlet = new KafkaCruiseControlServlet(kafkaCruiseControl,
+                                                                                        dropwizardMetricsRegistry);
     ServletHolder servletHolder = new ServletHolder(kafkaCruiseControlServlet);
     context.addServlet(servletHolder, apiUrlPrefix);
 

cruise-control/src/main/java/com/linkedin/kafka/cruisecontrol/config/KafkaCruiseControlConfig.java

@@ -698,6 +698,25 @@ public class KafkaCruiseControlConfig extends AbstractConfig {
   public static final String WEBSERVER_ACCESSLOG_RETENTION_DAYS = "webserver.accesslog.retention.days";
   private static final String WEBSERVER_ACCESSLOG_RETENTION_DAYS_DOC = "HTTP Request log retention days";
 
+  /**
+   * <code>two.step.verification.enabled</code>
+   */
+  public static final String TWO_STEP_VERIFICATION_ENABLED_CONFIG = "two.step.verification.enabled";
+  private static final String TWO_STEP_VERIFICATION_ENABLED_DOC = "Enable two-step verification for processing POST requests.";
+
+  /**
+   * <code>two.step.purgatory.retention.time.ms</code>
+   */
+  public static final String TWO_STEP_PURGATORY_RETENTION_TIME_MS_CONFIG = "two.step.purgatory.retention.time.ms";
+  private static final String TWO_STEP_PURGATORY_RETENTION_TIME_MS_DOC = "The maximum time in milliseconds to "
+      + "retain the requests in two-step (verification) purgatory.";
+
+  /**
+   * <code>two.step.purgatory.max.requests</code>
+   */
+  public static final String TWO_STEP_PURGATORY_MAX_REQUESTS_CONFIG = "two.step.purgatory.max.requests";
+  private static final String TWO_STEP_PURGATORY_MAX_REQUESTS_DOC = "The maximum number of requests in two-step "
+      + "(verification) purgatory.";
 
   static {
     CONFIG = new ConfigDef()
@@ -707,6 +726,8 @@ public class KafkaCruiseControlConfig extends AbstractConfig {
                 WEBSERVER_HTTP_ADDRESS_DOC)
         .define(WEBSERVER_HTTP_CORS_ENABLED_CONFIG, ConfigDef.Type.BOOLEAN, false, ConfigDef.Importance.LOW,
                 WEBSERVER_HTTP_CORS_ENABLED_DOC)
+        .define(TWO_STEP_VERIFICATION_ENABLED_CONFIG, ConfigDef.Type.BOOLEAN, false, ConfigDef.Importance.MEDIUM,
+                TWO_STEP_VERIFICATION_ENABLED_DOC)
         .define(WEBSERVER_HTTP_CORS_ORIGIN_CONFIG, ConfigDef.Type.STRING, "*", ConfigDef.Importance.LOW,
                 WEBSERVER_HTTP_CORS_ORIGIN_DOC)
         .define(WEBSERVER_HTTP_CORS_ALLOWMETHODS_CONFIG, ConfigDef.Type.STRING, "OPTIONS, GET, POST", ConfigDef.Importance.HIGH,
@@ -808,6 +829,16 @@ public class KafkaCruiseControlConfig extends AbstractConfig {
                 atLeast(0),
                 ConfigDef.Importance.MEDIUM,
                 REMOVAL_HISTORY_RETENTION_TIME_MS_DOC)
+        .define(TWO_STEP_PURGATORY_RETENTION_TIME_MS_CONFIG,
+                ConfigDef.Type.LONG,
+                TimeUnit.HOURS.toMillis(336),
+                atLeast(TimeUnit.HOURS.toMillis(1)),
+                ConfigDef.Importance.MEDIUM, TWO_STEP_PURGATORY_RETENTION_TIME_MS_DOC)
+        .define(TWO_STEP_PURGATORY_MAX_REQUESTS_CONFIG,
+                ConfigDef.Type.INT,
+                25,
+                atLeast(1),
+                ConfigDef.Importance.MEDIUM, TWO_STEP_PURGATORY_MAX_REQUESTS_DOC)
         .define(MAX_CACHED_COMPLETED_USER_TASKS_CONFIG,
                 ConfigDef.Type.INT,
                 100,

cruise-control/src/main/java/com/linkedin/kafka/cruisecontrol/servlet/EndPoint.java

@@ -28,7 +28,8 @@ public enum EndPoint {
   KAFKA_CLUSTER_STATE,
   DEMOTE_BROKER,
   USER_TASKS,
-  ADMIN;
+  ADMIN,
+  REVIEW;
 
   private static final List<EndPoint> GET_ENDPOINT = Arrays.asList(BOOTSTRAP,
                                                                    TRAIN,
@@ -45,7 +46,8 @@ public enum EndPoint {
                                                                     PAUSE_SAMPLING,
                                                                     RESUME_SAMPLING,
                                                                     DEMOTE_BROKER,
-                                                                    ADMIN);
+                                                                    ADMIN,
+                                                                    REVIEW);
   private static final List<EndPoint> CACHED_VALUES = Collections.unmodifiableList(Arrays.asList(values()));
 
   public static List<EndPoint> getEndpoint() {