diff --git a/RFS/src/main/java/com/rfs/common/OpenSearchClient.java b/RFS/src/main/java/com/rfs/common/OpenSearchClient.java
index cc8e5b5af..0d79a4c24 100644
--- a/RFS/src/main/java/com/rfs/common/OpenSearchClient.java
+++ b/RFS/src/main/java/com/rfs/common/OpenSearchClient.java
@@ -30,11 +30,15 @@ public class OpenSearchClient {
     private final RestClient client;
 
     public OpenSearchClient(ConnectionContext connectionContext) {
-        this.client = new RestClient(connectionContext);
+        this(new RestClient(connectionContext));
     }
 
     public OpenSearchClient(ConnectionContext connectionContext, int maxConnections) {
-        this.client = new RestClient(connectionContext, maxConnections);
+        this(new RestClient(connectionContext, maxConnections));
+    }
+
+    OpenSearchClient(RestClient client) {
+        this.client = client;
     }
 
     /*
diff --git a/RFS/src/test/java/com/rfs/common/OpenSearchClientTest.java b/RFS/src/test/java/com/rfs/common/OpenSearchClientTest.java
new file mode 100644
index 000000000..5b2a81bc8
--- /dev/null
+++ b/RFS/src/test/java/com/rfs/common/OpenSearchClientTest.java
@@ -0,0 +1,113 @@
+package com.rfs.common;
+
+import java.util.Optional;
+
+import com.fasterxml.jackson.core.StreamReadFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.json.JsonMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.junit.jupiter.api.Test;
+
+import com.rfs.common.http.HttpResponse;
+import com.rfs.tracing.IRfsContexts.ICheckedIdempotentPutRequestContext;
+import lombok.SneakyThrows;
+import reactor.core.publisher.Mono;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+class OpenSearchClientTest {
+    private static final ObjectMapper OBJECT_MAPPER = JsonMapper.builder()
+        .enable(StreamReadFeature.INCLUDE_SOURCE_IN_LOCATION)
+        .build();
+
+    @Test
+    void testCreateIndex() {
+        // Setup
+        var checkIfExistsResponse = new HttpResponse(404, "", null, "does not exist");
+        var createdItemRawJson = "{\"created\":\"yup!\"}";
+        var createItemResponse = new HttpResponse(200, "", null, createdItemRawJson);
+
+        var restClient = mock(RestClient.class);
+        when(restClient.getAsync(any(), any())).thenReturn(Mono.just(checkIfExistsResponse));
+        when(restClient.putAsync(any(), any(), any())).thenReturn(Mono.just(createItemResponse));
+
+        // Action
+        var rawJson = "{ }";
+        var result = createIndex(restClient, rawJson);
+
+        // Assertions
+        assertThat(result.get().toPrettyString(), containsString(rawJson));
+        // The interface is to send back the passed json if on success
+        assertThat(result.get().toPrettyString(), not(containsString(createdItemRawJson)));
+    }
+
+    @Test
+    void testCreateIndex_alreadyExists() {
+        var checkIfExistsResponse = new HttpResponse(200, "", null, "I exist!");
+
+        var restClient = mock(RestClient.class);
+        when(restClient.getAsync(any(), any())).thenReturn(Mono.just(checkIfExistsResponse));
+
+        var rawJson = "{ }";
+        var result = createIndex(restClient, rawJson);
+
+        assertThat(result, equalTo(Optional.empty()));
+    }
+
+    @Test
+    void testCreateIndex_errorOnCreation_retried() {
+        // Setup
+        var checkIfExistsResponse = new HttpResponse(404, "", null, "does not exist");
+        var createdItemRawJson = "{\"error\":\"unauthorized\"}";
+        var createItemResponse = new HttpResponse(403, "", null, createdItemRawJson);
+
+        var restClient = mock(RestClient.class);
+        when(restClient.getAsync(any(), any())).thenReturn(Mono.just(checkIfExistsResponse));
+        when(restClient.putAsync(any(), any(), any())).thenReturn(Mono.just(createItemResponse));
+
+        // Action
+        var rawJson = "{ }";
+        var exception = assertThrows(IllegalStateException.class, () -> createIndex(restClient, rawJson));
+
+        // Assertions
+        assertThat(exception.getClass().getName(), containsString("RetryExhaustedException"));
+        assertThat(exception.getMessage(), containsString("Retries exhausted"));
+        assertThat(exception.getCause().getMessage(), containsString("403"));
+        assertThat(exception.getCause().getMessage(), containsString("unauthorized"));
+        // The interface is to send back the passed json if on success
+    }
+
+    @Test
+    void testCreateIndex_errorOnCreation_notRetriedOnBadRequest() {
+        // Setup
+        var checkIfExistsResponse = new HttpResponse(404, "", null, "does not exist");
+        var createdItemRawJson = "{\"error\":\"illegal_argument_exception\"}";
+        var createItemResponse = new HttpResponse(400, "", null, createdItemRawJson);
+
+        var restClient = mock(RestClient.class);
+        when(restClient.getAsync(any(), any())).thenReturn(Mono.just(checkIfExistsResponse));
+        when(restClient.putAsync(any(), any(), any())).thenReturn(Mono.just(createItemResponse));
+
+        // Action
+        var rawJson = "{ }";
+        var exception = assertThrows(InvalidResponse.class, () -> createIndex(restClient, rawJson));
+
+        // Assertions
+        assertThat(exception.getMessage(), containsString("illegal_argument_exception"));
+    }
+
+    @SneakyThrows
+    private Optional<ObjectNode> createIndex(RestClient restClient, String rawJson) {
+        var openSearchClient = new OpenSearchClient(restClient);
+
+        var body = (ObjectNode) OBJECT_MAPPER.readTree(rawJson);
+        return openSearchClient.createIndex("indexName", body, mock(ICheckedIdempotentPutRequestContext.class));
+    }
+}