From 742bed5153f05e816eaac3f7931523e8cc73f8aa Mon Sep 17 00:00:00 2001
From: Harald Musum <musum@yahooinc.com>
Date: Sun, 12 Dec 2021 15:26:32 +0100
Subject: Add exponential backoff if starting download fails

---
 .../vespa/filedistribution/FileReferenceDownloader.java    | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/filedistribution/src/main/java/com/yahoo/vespa/filedistribution/FileReferenceDownloader.java b/filedistribution/src/main/java/com/yahoo/vespa/filedistribution/FileReferenceDownloader.java
index e3edee2956f..1f7649b4dbc 100644
--- a/filedistribution/src/main/java/com/yahoo/vespa/filedistribution/FileReferenceDownloader.java
+++ b/filedistribution/src/main/java/com/yahoo/vespa/filedistribution/FileReferenceDownloader.java
@@ -57,14 +57,14 @@ public class FileReferenceDownloader {
         int retryCount = 0;
         Connection connection = connectionPool.getCurrent();
         do {
+            backoff(retryCount);
+
             if (FileDownloader.fileReferenceExists(fileReference, downloadDirectory))
                 return;
             if (startDownloadRpc(fileReferenceDownload, retryCount, connection))
                 return;
 
-            try { Thread.sleep(sleepBetweenRetries.toMillis()); } catch (InterruptedException e) { /* ignored */}
             retryCount++;
-
             // There is no one connection that will always work for each file reference (each file reference might
             // exist on just one config server, and which one could be different for each file reference), so we
             // should get a new connection for every retry
@@ -75,6 +75,16 @@ public class FileReferenceDownloader {
         downloads.remove(fileReference);
     }
 
+    private void backoff(int retryCount) {
+        if (retryCount > 0) {
+            try {
+                Thread.sleep((long) (Math.pow(2, retryCount)) * sleepBetweenRetries.toMillis());
+            } catch (InterruptedException e) {
+                /* ignored */
+            }
+        }
+    }
+
     Future<Optional<File>> startDownload(FileReferenceDownload fileReferenceDownload) {
         FileReference fileReference = fileReferenceDownload.fileReference();
         Optional<FileReferenceDownload> inProgress = downloads.get(fileReference);
-- 
cgit v1.2.3


From f30c2b36d91658b27d9cdae672aaab17cb4759fb Mon Sep 17 00:00:00 2001
From: Harald Musum <musum@yahooinc.com>
Date: Sun, 12 Dec 2021 16:41:25 +0100
Subject: Make sure sleep time never exceeds 120 seconds

---
 .../java/com/yahoo/vespa/filedistribution/FileReferenceDownloader.java | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/filedistribution/src/main/java/com/yahoo/vespa/filedistribution/FileReferenceDownloader.java b/filedistribution/src/main/java/com/yahoo/vespa/filedistribution/FileReferenceDownloader.java
index 1f7649b4dbc..73d40a40e6f 100644
--- a/filedistribution/src/main/java/com/yahoo/vespa/filedistribution/FileReferenceDownloader.java
+++ b/filedistribution/src/main/java/com/yahoo/vespa/filedistribution/FileReferenceDownloader.java
@@ -78,7 +78,8 @@ public class FileReferenceDownloader {
     private void backoff(int retryCount) {
         if (retryCount > 0) {
             try {
-                Thread.sleep((long) (Math.pow(2, retryCount)) * sleepBetweenRetries.toMillis());
+                long sleepTime = Math.min(120_000, (long) (Math.pow(2, retryCount)) * sleepBetweenRetries.toMillis());
+                Thread.sleep(sleepTime);
             } catch (InterruptedException e) {
                 /* ignored */
             }
-- 
cgit v1.2.3