From 16dfdd17c7db49a20df1246b478c47c423a41ba6 Mon Sep 17 00:00:00 2001
From: Serkant Karaca <serkantkaraca@users.noreply.github.com>
Date: Fri, 18 Sep 2020 07:37:04 -0700
Subject: [PATCH] Increase diagnostics-id overhead in EventDataBatch (#15193)

---
 .../Microsoft.Azure.EventHubs/src/EventDataBatch.cs         | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sdk/eventhub/Microsoft.Azure.EventHubs/src/EventDataBatch.cs b/sdk/eventhub/Microsoft.Azure.EventHubs/src/EventDataBatch.cs
index ce4ccc8fd593..850529850880 100644
--- a/sdk/eventhub/Microsoft.Azure.EventHubs/src/EventDataBatch.cs
+++ b/sdk/eventhub/Microsoft.Azure.EventHubs/src/EventDataBatch.cs
@@ -14,7 +14,11 @@ namespace Microsoft.Azure.EventHubs
     public class EventDataBatch : IDisposable
     {
         const int MaxSizeLimit = 4 * 1024 * 1024;
-        const int DiagnosticsIdOverhead = 64;
+
+        // System.Diagnostics.Activity.Id is 1024 bytes or shorter.
+        // However we will keep overhead at 128 bytes which should be enough for most scenarios.
+        // Any client in need of longer Ids should create batch with an appropriate mac-batch-size.
+        const int DiagnosticsIdOverhead = 128;
 
         readonly List<EventData> eventDataList;
         readonly long maxSize;