diff --git a/plugin/src/main/java/org/elasticsearch/xpack/ml/action/UpdateJobAction.java b/plugin/src/main/java/org/elasticsearch/xpack/ml/action/UpdateJobAction.java
index 252231f10b7..1f1cfd61f61 100644
--- a/plugin/src/main/java/org/elasticsearch/xpack/ml/action/UpdateJobAction.java
+++ b/plugin/src/main/java/org/elasticsearch/xpack/ml/action/UpdateJobAction.java
@@ -24,6 +24,7 @@ import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.util.concurrent.ConcurrentCollections;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -31,10 +32,15 @@ import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.transport.TransportService;
 import org.elasticsearch.xpack.ml.job.JobManager;
 import org.elasticsearch.xpack.ml.job.config.Job;
+import org.elasticsearch.xpack.ml.job.config.JobState;
 import org.elasticsearch.xpack.ml.job.config.JobUpdate;
+import org.elasticsearch.xpack.ml.job.metadata.MlMetadata;
+import org.elasticsearch.xpack.persistent.PersistentTasksInProgress;
 
 import java.io.IOException;
 import java.util.Objects;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.Semaphore;
 
 public class UpdateJobAction extends Action<UpdateJobAction.Request, PutJobAction.Response, UpdateJobAction.RequestBuilder> {
     public static final UpdateJobAction INSTANCE = new UpdateJobAction();
@@ -131,6 +137,7 @@ public class UpdateJobAction extends Action<UpdateJobAction.Request, PutJobActio
 
     public static class TransportAction extends TransportMasterNodeAction<UpdateJobAction.Request, PutJobAction.Response> {
 
+        private final ConcurrentMap<String, Semaphore> semaphoreByJob = ConcurrentCollections.newConcurrentMap();
         private final JobManager jobManager;
         private final Client client;
 
@@ -161,14 +168,33 @@ public class UpdateJobAction extends Action<UpdateJobAction.Request, PutJobActio
                 throw new IllegalArgumentException("Job Id " + Job.ALL + " cannot be for update");
             }
 
-            ActionListener<PutJobAction.Response> wrappedListener = listener;
-            if (request.getJobUpdate().isAutodetectProcessUpdate()) {
-                 wrappedListener = ActionListener.wrap(
+            PersistentTasksInProgress tasks = clusterService.state().custom(PersistentTasksInProgress.TYPE);
+            boolean jobIsOpen = MlMetadata.getJobState(request.getJobId(), tasks) == JobState.OPENED;
+
+            semaphoreByJob.computeIfAbsent(request.getJobId(), id -> new Semaphore(1)).acquire();
+
+            ActionListener<PutJobAction.Response> wrappedListener;
+            if (jobIsOpen && request.getJobUpdate().isAutodetectProcessUpdate()) {
+                wrappedListener = ActionListener.wrap(
                         response -> updateProcess(request, response, listener),
-                        listener::onFailure);
+                        e -> {
+                            releaseJobSemaphore(request.getJobId());
+                            listener.onFailure(e);
+                        });
+            }
+            else {
+                wrappedListener = ActionListener.wrap(
+                        response -> {
+                            releaseJobSemaphore(request.getJobId());
+                            listener.onResponse(response);
+                        },
+                        e -> {
+                            releaseJobSemaphore(request.getJobId());
+                            listener.onFailure(e);
+                        });
             }
 
-            jobManager.updateJob(request.getJobId(), request.getJobUpdate(), request, wrappedListener);
+            jobManager.updateJob(request.getJobId(), request.getJobUpdate(), request, client, wrappedListener);
         }
 
         private void updateProcess(Request request, PutJobAction.Response updateConfigResponse,
@@ -176,19 +202,26 @@ public class UpdateJobAction extends Action<UpdateJobAction.Request, PutJobActio
 
             UpdateProcessAction.Request updateProcessRequest = new UpdateProcessAction.Request(request.getJobId(),
                     request.getJobUpdate().getModelDebugConfig(), request.getJobUpdate().getDetectorUpdates());
+
             client.execute(UpdateProcessAction.INSTANCE, updateProcessRequest, new ActionListener<UpdateProcessAction.Response>() {
                 @Override
                 public void onResponse(UpdateProcessAction.Response response) {
+                    releaseJobSemaphore(request.getJobId());
                     listener.onResponse(updateConfigResponse);
                 }
 
                 @Override
                 public void onFailure(Exception e) {
+                    releaseJobSemaphore(request.getJobId());
                     listener.onFailure(e);
                 }
             });
         }
 
+        private void releaseJobSemaphore(String jobId) {
+            semaphoreByJob.remove(jobId).release();
+        }
+
         @Override
         protected ClusterBlockException checkBlock(UpdateJobAction.Request request, ClusterState state) {
             return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA_WRITE);
diff --git a/plugin/src/main/java/org/elasticsearch/xpack/ml/action/UpdateProcessAction.java b/plugin/src/main/java/org/elasticsearch/xpack/ml/action/UpdateProcessAction.java
index 192cdb49ad2..b036bcb5e6e 100644
--- a/plugin/src/main/java/org/elasticsearch/xpack/ml/action/UpdateProcessAction.java
+++ b/plugin/src/main/java/org/elasticsearch/xpack/ml/action/UpdateProcessAction.java
@@ -37,7 +37,6 @@ import java.util.Objects;
 public class UpdateProcessAction extends
         Action<UpdateProcessAction.Request, UpdateProcessAction.Response, UpdateProcessAction.RequestBuilder> {
 
-
     public static final UpdateProcessAction INSTANCE = new UpdateProcessAction();
     public static final String NAME = "cluster:admin/ml/job/update/process";
 
@@ -199,15 +198,8 @@ public class UpdateProcessAction extends
         protected void taskOperation(Request request, OpenJobAction.JobTask task, ActionListener<Response> listener) {
             threadPool.executor(MachineLearning.THREAD_POOL_NAME).execute(() -> {
                 try {
-                    if (request.getModelDebugConfig() != null) {
-                        processManager.writeUpdateModelDebugMessage(request.getJobId(), request.getModelDebugConfig());
-                    }
-                    if (request.getDetectorUpdates() != null) {
-                        for (JobUpdate.DetectorUpdate update : request.getDetectorUpdates()) {
-                            processManager.writeUpdateDetectorRulesMessage(request.getJobId(), update.getIndex(), update.getRules());
-                        }
-                    }
-
+                    processManager.writeUpdateProcessMessage(request.getJobId(), request.getDetectorUpdates(),
+                            request.getModelDebugConfig());
                     listener.onResponse(new Response());
                 } catch (Exception e) {
                     listener.onFailure(e);
diff --git a/plugin/src/main/java/org/elasticsearch/xpack/ml/job/JobManager.java b/plugin/src/main/java/org/elasticsearch/xpack/ml/job/JobManager.java
index 1d918d5f2f9..aa539c73f56 100644
--- a/plugin/src/main/java/org/elasticsearch/xpack/ml/job/JobManager.java
+++ b/plugin/src/main/java/org/elasticsearch/xpack/ml/job/JobManager.java
@@ -198,7 +198,9 @@ public class JobManager extends AbstractComponent {
                 });
     }
 
-    public void updateJob(String jobId, JobUpdate jobUpdate, AckedRequest request, ActionListener<PutJobAction.Response> actionListener) {
+    public void updateJob(String jobId, JobUpdate jobUpdate, AckedRequest request, Client client,
+                          ActionListener<PutJobAction.Response> actionListener) {
+
         clusterService.submitStateUpdateTask("update-job-" + jobId,
                 new AckedClusterStateUpdateTask<PutJobAction.Response>(request, actionListener) {
                     private Job updatedJob;
diff --git a/plugin/src/main/java/org/elasticsearch/xpack/ml/job/process/autodetect/AutodetectProcessManager.java b/plugin/src/main/java/org/elasticsearch/xpack/ml/job/process/autodetect/AutodetectProcessManager.java
index 467433a9585..d2825ba5fed 100644
--- a/plugin/src/main/java/org/elasticsearch/xpack/ml/job/process/autodetect/AutodetectProcessManager.java
+++ b/plugin/src/main/java/org/elasticsearch/xpack/ml/job/process/autodetect/AutodetectProcessManager.java
@@ -19,9 +19,9 @@ import org.elasticsearch.rest.RestStatus;
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.xpack.ml.MachineLearning;
 import org.elasticsearch.xpack.ml.job.JobManager;
-import org.elasticsearch.xpack.ml.job.config.DetectionRule;
 import org.elasticsearch.xpack.ml.job.config.Job;
 import org.elasticsearch.xpack.ml.job.config.JobState;
+import org.elasticsearch.xpack.ml.job.config.JobUpdate;
 import org.elasticsearch.xpack.ml.job.config.MlFilter;
 import org.elasticsearch.xpack.ml.job.config.ModelDebugConfig;
 import org.elasticsearch.xpack.ml.job.persistence.JobDataCountsPersister;
@@ -168,23 +168,25 @@ public class AutodetectProcessManager extends AbstractComponent {
         }
     }
 
-    public void writeUpdateModelDebugMessage(String jobId, ModelDebugConfig config) throws IOException {
+    public void writeUpdateProcessMessage(String jobId, List<JobUpdate.DetectorUpdate> updates, ModelDebugConfig config)
+            throws IOException {
         AutodetectCommunicator communicator = autoDetectCommunicatorByJob.get(jobId);
         if (communicator == null) {
             logger.debug("Cannot update model debug config: no active autodetect process for job {}", jobId);
             return;
         }
-        communicator.writeUpdateModelDebugMessage(config);
-        // TODO check for errors from autodetects
-    }
 
-    public void writeUpdateDetectorRulesMessage(String jobId, int detectorIndex, List<DetectionRule> rules) throws IOException {
-        AutodetectCommunicator communicator = autoDetectCommunicatorByJob.get(jobId);
-        if (communicator == null) {
-            logger.debug("Cannot update model debug config: no active autodetect process for job {}", jobId);
-            return;
+        if (config != null) {
+            communicator.writeUpdateModelDebugMessage(config);
+        }
+
+        if (updates != null) {
+            for (JobUpdate.DetectorUpdate update : updates) {
+                if (update.getRules() != null) {
+                    communicator.writeUpdateDetectorRulesMessage(update.getIndex(), update.getRules());
+                }
+            }
         }
-        communicator.writeUpdateDetectorRulesMessage(detectorIndex, rules);
         // TODO check for errors from autodetects
     }
 
diff --git a/plugin/src/test/java/org/elasticsearch/xpack/ml/job/config/JobTests.java b/plugin/src/test/java/org/elasticsearch/xpack/ml/job/config/JobTests.java
index b3d46ef5be6..e8165f3b8d5 100644
--- a/plugin/src/test/java/org/elasticsearch/xpack/ml/job/config/JobTests.java
+++ b/plugin/src/test/java/org/elasticsearch/xpack/ml/job/config/JobTests.java
@@ -12,7 +12,6 @@ import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.xpack.ml.job.messages.Messages;
 import org.elasticsearch.xpack.ml.support.AbstractSerializingTestCase;
 
-import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Date;
diff --git a/plugin/src/test/java/org/elasticsearch/xpack/ml/job/process/autodetect/AutodetectProcessManagerTests.java b/plugin/src/test/java/org/elasticsearch/xpack/ml/job/process/autodetect/AutodetectProcessManagerTests.java
index a15334aefb1..7bd909275bf 100644
--- a/plugin/src/test/java/org/elasticsearch/xpack/ml/job/process/autodetect/AutodetectProcessManagerTests.java
+++ b/plugin/src/test/java/org/elasticsearch/xpack/ml/job/process/autodetect/AutodetectProcessManagerTests.java
@@ -22,6 +22,7 @@ import org.elasticsearch.xpack.ml.job.config.DetectionRule;
 import org.elasticsearch.xpack.ml.job.config.Detector;
 import org.elasticsearch.xpack.ml.job.config.Job;
 import org.elasticsearch.xpack.ml.job.config.JobState;
+import org.elasticsearch.xpack.ml.job.config.JobUpdate;
 import org.elasticsearch.xpack.ml.job.config.MlFilter;
 import org.elasticsearch.xpack.ml.job.config.ModelDebugConfig;
 import org.elasticsearch.xpack.ml.job.persistence.JobDataCountsPersister;
@@ -270,19 +271,14 @@ public class AutodetectProcessManagerTests extends ESTestCase {
         assertEquals("[foo] exception while flushing job", e.getMessage());
     }
 
-    public void testWriteUpdateModelDebugMessage() throws IOException {
+    public void testwriteUpdateProcessMessage() throws IOException {
         AutodetectCommunicator communicator = mock(AutodetectCommunicator.class);
         AutodetectProcessManager manager = createManagerAndCallProcessData(communicator, "foo");
         ModelDebugConfig debugConfig = mock(ModelDebugConfig.class);
-        manager.writeUpdateModelDebugMessage("foo", debugConfig);
-        verify(communicator).writeUpdateModelDebugMessage(debugConfig);
-    }
-
-    public void testWriteUpdateDetectorRulesMessage() throws IOException {
-        AutodetectCommunicator communicator = mock(AutodetectCommunicator.class);
-        AutodetectProcessManager manager = createManagerAndCallProcessData(communicator, "foo");
         List<DetectionRule> rules = Collections.singletonList(mock(DetectionRule.class));
-        manager.writeUpdateDetectorRulesMessage("foo", 2, rules);
+        List<JobUpdate.DetectorUpdate> detectorUpdates = Collections.singletonList(new JobUpdate.DetectorUpdate(2, null, rules));
+        manager.writeUpdateProcessMessage("foo", detectorUpdates, debugConfig);
+        verify(communicator).writeUpdateModelDebugMessage(debugConfig);
         verify(communicator).writeUpdateDetectorRulesMessage(2, rules);
     }
 
diff --git a/plugin/src/test/resources/rest-api-spec/test/ml/jobs_crud.yaml b/plugin/src/test/resources/rest-api-spec/test/ml/jobs_crud.yaml
index 82f39605214..4de016d6054 100644
--- a/plugin/src/test/resources/rest-api-spec/test/ml/jobs_crud.yaml
+++ b/plugin/src/test/resources/rest-api-spec/test/ml/jobs_crud.yaml
@@ -214,12 +214,23 @@
           }
   - match: { job_id: "to-update" }
 
+  - do:
+      xpack.ml.open_job:
+        job_id: to-update
+
   - do:
       xpack.ml.update_job:
         job_id: to-update
         body:  >
           {
             "description":"Post update description",
+            "detectors": [{"index": 0, "rules": {"target_field_name": "airline",
+                                      "rule_conditions": [ { "condition_type": "numerical_actual",
+                                                             "condition": {"operator": "gt", "value": "10" } } ] } },
+                          {"index": 1, "description": "updated description"}],
+            "model_debug_config": {
+              "bounds_percentile": 99.0
+            },
             "analysis_limits": {
               "model_memory_limit": 20
             },
@@ -234,8 +245,11 @@
           }
   - match: { job_id: "to-update" }
   - match: { description: "Post update description" }
+  - match: { model_debug_config.bounds_percentile: 99.0 }
   - match: { analysis_limits.model_memory_limit: 20 }
   - match: { analysis_config.categorization_filters: ["cat3.*"] }
+  - match: { analysis_config.detectors.0.detector_rules.0.target_field_name: "airline" }
+  - match: { analysis_config.detectors.1.detector_description: "updated description" }
   - match: { renormalization_window_days: 10 }
   - match: { background_persist_interval: 10800 }
   - match: { model_snapshot_retention_days: 30 }