diff --git a/swh/dataset/cli.py b/swh/dataset/cli.py
--- a/swh/dataset/cli.py
+++ b/swh/dataset/cli.py
@@ -51,7 +51,15 @@
 
 @graph.command("export")
 @click.argument("export-path", type=click.Path())
-@click.option("--export-id", "-e", help="Unique ID of the export run.")
+@click.option(
+    "--export-id",
+    "-e",
+    help=(
+        "Unique ID of the export run. This is appended to the kafka "
+        "group_id config file option. If group_id is not set in the "
+        "'journal' section of the config file, defaults to 'swh-dataset-export-'."
+    ),
+)
 @click.option(
     "--formats",
     "-f",
diff --git a/swh/dataset/journalprocessor.py b/swh/dataset/journalprocessor.py
--- a/swh/dataset/journalprocessor.py
+++ b/swh/dataset/journalprocessor.py
@@ -164,7 +164,8 @@
         """
         self.config = config
         self.exporters = exporters
-        self.group_id = "swh-dataset-export-{}".format(export_id)
+        prefix = self.config["journal"].get("group_id", "swh-dataset-export-")
+        self.group_id = f"{prefix}{export_id}"
         self.obj_type = obj_type
         self.processes = processes
         self.node_sets_path = node_sets_path
@@ -180,11 +181,10 @@
         If available, use committed offsets as lo offset boundaries.
         """
         if self.offsets is None:
-            client = JournalClient(
-                **self.config["journal"],
-                object_types=[self.obj_type],
-                group_id=self.group_id,
-            )
+            cfg = self.config["journal"].copy()
+            cfg["object_types"] = [self.obj_type]
+            cfg["group_id"] = self.group_id
+            client = JournalClient(**cfg)
             topic_name = client.subscription[0]
             topics = client.consumer.list_topics(topic_name).topics
             partitions = topics[topic_name].partitions
@@ -379,8 +379,9 @@
         Start a Journal client on the given assignment and process all the
         incoming messages.
         """
-        client = JournalClientOffsetRanges(
-            **self.config["journal"],
+        logger.debug("Start the JournalProcessorWorker")
+        cfg = self.config["journal"].copy()
+        cfg.update(
             object_types=[self.obj_type],
             group_id=self.group_id,
             debug="cgrp,broker",
@@ -389,6 +390,7 @@
             progress_queue=self.progress_queue,
             **{"message.max.bytes": str(500 * 1024 * 1024)},
         )
+        client = JournalClientOffsetRanges(**cfg)
         client.process(self.process_messages)
 
     def process_messages(self, messages):