Remove dependency on whenAllComplete method which is not supported in…

… the maximum allowed version of Guava in 2.1. Also, cease attempting to upload empty files. To adhere to our original logic, they should be deleted before we reach that point. (#987)

priam/src/main/java/com/netflix/priam/aws/S3FileSystem.java

@@ -176,11 +176,8 @@ protected long uploadFileImpl(AbstractBackupPath path, Instant target)
         File localFile = Paths.get(path.getBackupFile().getAbsolutePath()).toFile();
         if (localFile.length() >= config.getBackupChunkSize()) return uploadMultipart(path, target);
         byte[] chunk = getFileContents(path);
-        // C* snapshots may have empty files. That is probably unintentional.
-        if (chunk.length > 0) {
-            rateLimiter.acquire(chunk.length);
-            dynamicRateLimiter.acquire(path, target, chunk.length);
-        }
+        rateLimiter.acquire(chunk.length);
+        dynamicRateLimiter.acquire(path, target, chunk.length);
         try {
             new BoundedExponentialRetryCallable<PutObjectResult>(1000, 10000, 5) {
                 @Override

priam/src/main/java/com/netflix/priam/backup/IncrementalBackup.java

@@ -17,9 +17,7 @@
 package com.netflix.priam.backup;
 
 import com.google.common.collect.ImmutableList;
-import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
-import com.google.common.util.concurrent.MoreExecutors;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
@@ -127,6 +125,8 @@ protected void processColumnFamily(File backupDir) throws Exception {
         // upload SSTables and components
         ImmutableList<ListenableFuture<AbstractBackupPath>> futures =
                 uploadAndDeleteAllFiles(backupDir, fileType, config.enableAsyncIncremental());
-        Futures.whenAllComplete(futures).call(() -> null, MoreExecutors.directExecutor());
+        for (ListenableFuture<AbstractBackupPath> future : futures) {
+            future.get();
+        }
     }
 }