diff --git a/cdap-app-fabric/src/main/java/io/cdap/cdap/gateway/handlers/AbstractAppLifecycleHttpHandler.java b/cdap-app-fabric/src/main/java/io/cdap/cdap/gateway/handlers/AbstractAppLifecycleHttpHandler.java
index ab3dd3476ef..14fbf55312e 100644
--- a/cdap-app-fabric/src/main/java/io/cdap/cdap/gateway/handlers/AbstractAppLifecycleHttpHandler.java
+++ b/cdap-app-fabric/src/main/java/io/cdap/cdap/gateway/handlers/AbstractAppLifecycleHttpHandler.java
@@ -183,6 +183,14 @@ protected void onFinish(HttpResponder responder, File uploadedFile) {
           AppRequest<?> appRequest = DECODE_GSON.fromJson(fileReader, AppRequest.class);
 
           try {
+            if (applicationLifecycleService.isAppAlreadyDeployed(appId, appRequest)) {
+              LOG.warn("Application {} is already deployed",appId );
+              io.cdap.cdap.proto.ApplicationDetail existingApp =
+                applicationLifecycleService.getLatestAppDetail(appId.getAppReference());
+              responder.sendJson(HttpResponseStatus.OK, GSON.toJson(new io.cdap.cdap.proto.ApplicationRecord(existingApp)));
+              return;
+            }
+
             ApplicationWithPrograms app = applicationLifecycleService.deployApp(appId, appRequest,
                 null, createProgramTerminator(), skipMarkingLatest);
             responder.sendJson(HttpResponseStatus.OK, GSON.toJson(getApplicationRecord(app)));
diff --git a/cdap-app-fabric/src/main/java/io/cdap/cdap/internal/app/services/ApplicationLifecycleService.java b/cdap-app-fabric/src/main/java/io/cdap/cdap/internal/app/services/ApplicationLifecycleService.java
index 22eef1f3280..4262a3ac645 100644
--- a/cdap-app-fabric/src/main/java/io/cdap/cdap/internal/app/services/ApplicationLifecycleService.java
+++ b/cdap-app-fabric/src/main/java/io/cdap/cdap/internal/app/services/ApplicationLifecycleService.java
@@ -741,6 +741,52 @@ private ApplicationId updateApplicationByArtifact(ApplicationId appId,
         allowedArtifactScopes, allowSnapshot, ownerAdmin.getOwner(appId), appSpec);
   }
 
+  /**
+   * Checks if the application already exists with the exact same artifact and
+   * configuration.
+   */
+  public boolean isAppAlreadyDeployed(ApplicationId appId, AppRequest<?> appRequest) throws Exception {
+    ApplicationMeta appMeta = store.getLatest(appId.getAppReference());
+    if (appMeta == null || appMeta.getSpec() == null) {
+      return false;
+    }
+
+    ArtifactSummary requestedArtifact = appRequest.getArtifact();
+    if (requestedArtifact == null) {
+      return false;
+    }
+
+    ArtifactId currentArtifactId = appMeta.getSpec().getArtifactId();
+    if (!currentArtifactId.getName().equals(requestedArtifact.getName()) ||
+      !currentArtifactId.getScope().equals(requestedArtifact.getScope())) {
+      return false;
+    }
+
+    try {
+      io.cdap.cdap.api.artifact.ArtifactVersionRange range = io.cdap.cdap.api.artifact.ArtifactVersionRange
+        .parse(requestedArtifact.getVersion());
+      if (!range.versionIsInRange(currentArtifactId.getVersion())) {
+        return false;
+      }
+    } catch (Exception e) {
+      return false;
+    }
+
+    Object config = appRequest.getConfig();
+    String requestedConfigStr = config == null ? null
+      : config instanceof String ? (String) config : GSON.toJson(config);
+    String currentConfigStr = appMeta.getSpec().getConfiguration();
+
+    String normRequestedConfig = requestedConfigStr == null ? "" : requestedConfigStr.trim();
+    String normCurrentConfig = currentConfigStr == null ? "" : currentConfigStr.trim();
+
+    if (!normRequestedConfig.equals(normCurrentConfig)) {
+      return false;
+    }
+
+    return true;
+  }
+
   /**
    * Updates an application config by applying given update actions. The app should know how to
    * apply these actions to its config.
diff --git a/cdap-storage-ext-spanner/src/main/java/io/cdap/cdap/storage/spanner/SpannerTransactionRunner.java b/cdap-storage-ext-spanner/src/main/java/io/cdap/cdap/storage/spanner/SpannerTransactionRunner.java
index fcd72a506c5..8aa033b4bd7 100644
--- a/cdap-storage-ext-spanner/src/main/java/io/cdap/cdap/storage/spanner/SpannerTransactionRunner.java
+++ b/cdap-storage-ext-spanner/src/main/java/io/cdap/cdap/storage/spanner/SpannerTransactionRunner.java
@@ -17,6 +17,7 @@
 package io.cdap.cdap.storage.spanner;
 
 import com.google.cloud.spanner.ErrorCode;
+import com.google.cloud.spanner.Options;
 import com.google.cloud.spanner.SpannerException;
 import io.cdap.cdap.spi.data.transaction.TransactionException;
 import io.cdap.cdap.spi.data.transaction.TransactionRunner;
@@ -36,7 +37,8 @@ public SpannerTransactionRunner(SpannerStructuredTableAdmin admin) {
   @Override
   public void run(TxRunnable runnable) throws TransactionException {
     try {
-      admin.getDatabaseClient().readWriteTransaction().allowNestedTransaction().run(context -> {
+      // enforce lock
+      admin.getDatabaseClient().readWriteTransaction(Options.optimisticLock()).allowNestedTransaction().run(context -> {
         runnable.run(new SpannerStructuredTableContext(context, admin));
         return null;
       });