1 files changed, 8 insertions, 0 deletions
diff --git a/vespa-hadoop/src/main/java/com/yahoo/vespa/hadoop/mapreduce/VespaRecordWriter.java b/vespa-hadoop/src/main/java/com/yahoo/vespa/hadoop/mapreduce/VespaRecordWriter.java
index c450d7cdeef..6d6c3789835 100644
--- a/vespa-hadoop/src/main/java/com/yahoo/vespa/hadoop/mapreduce/VespaRecordWriter.java
+++ b/vespa-hadoop/src/main/java/com/yahoo/vespa/hadoop/mapreduce/VespaRecordWriter.java
@@ -7,6 +7,7 @@ import ai.vespa.feed.client.JsonFeeder;
 import ai.vespa.feed.client.OperationParseException;
 import com.yahoo.vespa.hadoop.mapreduce.util.VespaConfiguration;
 import com.yahoo.vespa.hadoop.mapreduce.util.VespaCounters;
+import com.yahoo.vespa.http.client.config.FeedParams;
 import org.apache.hadoop.mapreduce.RecordWriter;
 import org.apache.hadoop.mapreduce.TaskAttemptContext;
 
@@ -84,11 +85,18 @@ public class VespaRecordWriter extends RecordWriter<Object, Object> {
 
     private void initializeOnFirstWrite() {
         if (initialized) return;
+        validateConfig();
         useRandomizedStartupDelayIfEnabled();
         feeder = createJsonStreamFeeder();
         initialized = true;
     }
 
+    private void validateConfig() {
+        if (config.dataFormat() != FeedParams.DataFormat.JSON_UTF8) {
+            throw new IllegalArgumentException("Only JSON is support by this feed client implementation");
+        }
+    }
+
     private void useRandomizedStartupDelayIfEnabled() {
         if (!config.dryrun() && config.randomStartupSleepMs() > 0) {
             int delay = ThreadLocalRandom.current().nextInt(config.randomStartupSleepMs());