Try using a JobDTO which doesn't have an enum to avoid serialisation …

…issues in RPC framework.

management-api-agent-common/src/main/java/com/datastax/mgmtapi/NodeOpsProvider.java

@@ -9,6 +9,7 @@
 import com.datastax.mgmtapi.rpc.RpcParam;
 import com.datastax.mgmtapi.rpc.RpcRegistry;
 import com.datastax.mgmtapi.util.Job;
+import com.datastax.mgmtapi.util.JobDto;
 import com.datastax.mgmtapi.util.JobExecutor;
 import com.datastax.oss.driver.api.core.CqlIdentifier;
 import com.datastax.oss.driver.api.core.metadata.schema.ClusteringOrder;
@@ -79,22 +80,29 @@ public synchronized void unregister() {
   }
 
   @Rpc(name = "jobStatus")
-  public Map<String, String> getJobStatus(@RpcParam(name = "job_id") String jobId) {
-    Map<String, String> resultMap = new HashMap<>();
+  public JobDto getJobStatus(@RpcParam(name = "job_id") String jobId) {
     Job jobWithId = service.getJobWithId(jobId);
     if (jobWithId == null) {
-      return resultMap;
-    }
-    resultMap.put("id", jobWithId.getJobId());
-    resultMap.put("type", jobWithId.getJobType());
-    resultMap.put("status", jobWithId.getStatus().name());
-    resultMap.put("submit_time", String.valueOf(jobWithId.getSubmitTime()));
-    resultMap.put("end_time", String.valueOf(jobWithId.getFinishedTime()));
+      return new JobDto(null, null);
+    }
+    JobDto jobStatus = new JobDto(jobWithId.getJobType(), jobWithId.getJobId());
+    jobStatus.setStatus(jobWithId.getStatus().name());
+    jobWithId.statusChanges.stream()
+        .forEach(
+            statusChange -> {
+              JobDto.StatusChange changeToAdd =
+                  jobStatus.new StatusChange(statusChange.getStatus(), statusChange.message);
+              changeToAdd.changeTime = statusChange.getChangeTime();
+              jobStatus.statusChanges.add(changeToAdd);
+            });
+    jobStatus.submitTime = jobWithId.getSubmitTime();
+    jobStatus.finishedTime = jobWithId.getFinishedTime();
+    jobStatus.startTime = jobWithId.startTime;
     if (jobWithId.getStatus() == Job.JobStatus.ERROR) {
-      resultMap.put("error", jobWithId.getError().getLocalizedMessage());
+      jobStatus.setError(jobWithId.getError());
     }
 
-    return resultMap;
+    return jobStatus;
   }
 
   @Rpc(name = "setFullQuerylog")

management-api-agent-common/src/main/java/com/datastax/mgmtapi/util/Job.java

@@ -17,19 +17,19 @@ public enum JobStatus {
     WAITING;
   }
 
-  private String jobId;
-  private String jobType;
-  private JobStatus status;
-  private long submitTime;
-  private long startTime;
-  private long finishedTime;
-  private Throwable error;
+  public String jobId;
+  public String jobType;
+  public JobStatus status;
+  public long submitTime;
+  public long startTime;
+  public long finishedTime;
+  public Throwable error;
 
   public class StatusChange {
-    ProgressEventType status;
-    long changeTime;
+    public ProgressEventType status;
+    public long changeTime;
 
-    String message;
+    public String message;
 
     public StatusChange(ProgressEventType type, String message) {
       changeTime = System.currentTimeMillis();
@@ -50,7 +50,7 @@ public String getMessage() {
     }
   }
 
-  private List<StatusChange> statusChanges;
+  public List<StatusChange> statusChanges;
 
   public Job(String jobType, String jobId) {
     this.jobType = jobType;

management-api-agent-common/src/main/java/com/datastax/mgmtapi/util/JobDto.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright DataStax, Inc.
+ *
+ * Please see the included license file for details.
+ */
+package com.datastax.mgmtapi.util;
+
+import com.google.common.annotations.VisibleForTesting;
+import java.util.ArrayList;
+import java.util.List;
+import org.apache.cassandra.utils.progress.ProgressEventType;
+
+public class JobDto {
+
+  public String jobId;
+  public String jobType;
+  public String status;
+  public long submitTime;
+  public long startTime;
+  public long finishedTime;
+  public Throwable error;
+
+  public class StatusChange {
+    public ProgressEventType status;
+    public long changeTime;
+
+    public String message;
+
+    public StatusChange(ProgressEventType type, String message) {
+      changeTime = System.currentTimeMillis();
+      status = type;
+      this.message = message;
+    }
+
+    public ProgressEventType getStatus() {
+      return status;
+    }
+
+    public long getChangeTime() {
+      return changeTime;
+    }
+
+    public String getMessage() {
+      return message;
+    }
+  }
+
+  public List<StatusChange> statusChanges;
+
+  public JobDto(String jobType, String jobId) {
+    this.jobType = jobType;
+    this.jobId = jobId;
+    submitTime = System.currentTimeMillis();
+    status = "WAITING";
+    statusChanges = new ArrayList<>();
+  }
+
+  @VisibleForTesting
+  // This method is only for testing purposes
+  public void setJobId(String jobId) {
+    this.jobId = jobId;
+  }
+
+  public String getJobId() {
+    return jobId;
+  }
+
+  public String getJobType() {
+    return jobType;
+  }
+
+  public String getStatus() {
+    return status;
+  }
+
+  public void setStatus(String status) {
+    this.status = status;
+  }
+
+  public void setStatusChange(ProgressEventType type, String message) {
+    statusChanges.add(new StatusChange(type, message));
+  }
+
+  public List<StatusChange> getStatusChanges() {
+    return statusChanges;
+  }
+
+  public long getSubmitTime() {
+    return submitTime;
+  }
+
+  public long getFinishedTime() {
+    return finishedTime;
+  }
+
+  public void setFinishedTime(long finishedTime) {
+    this.finishedTime = finishedTime;
+  }
+
+  public Throwable getError() {
+    return error;
+  }
+
+  public void setError(Throwable error) {
+    this.error = error;
+  }
+
+  public void setStartTime(long startTime) {
+    this.startTime = startTime;
+  }
+}