[yt/cpp/mapreduce] YT-20588: Add more logs for readers and fix client_reader retries

1 files changed, 6 insertions, 2 deletions

diff --git a/yt/cpp/mapreduce/client/client_reader.cpp b/yt/cpp/mapreduce/client/client_reader.cpp
index 606ac1c2974..b080da26048 100644
--- a/yt/cpp/mapreduce/client/client_reader.cpp
+++ b/yt/cpp/mapreduce/client/client_reader.cpp
@@ -145,6 +145,9 @@ void TClientReader::CreateRequest(const TMaybe<ui32>& rangeIndex, const TMaybe<u
     if (!CurrentRequestRetryPolicy_) {
         CurrentRequestRetryPolicy_ = ClientRetryPolicy_->CreatePolicyForGenericRequest();
     }
+
+    bool areRangesUpdated = false;
+
     while (true) {
         CurrentRequestRetryPolicy_->NotifyNewAttempt();
 
@@ -170,7 +173,7 @@ void TClientReader::CreateRequest(const TMaybe<ui32>& rangeIndex, const TMaybe<u
 
         header.SetResponseCompression(ToString(Context_.Config->AcceptEncoding));
 
-        if (rowIndex.Defined()) {
+        if (rowIndex.Defined() && !areRangesUpdated) {
             auto& ranges = Path_.MutableRanges();
             if (ranges.Empty()) {
                 ranges.ConstructInPlace(TVector{TReadRange()});
@@ -183,6 +186,7 @@ void TClientReader::CreateRequest(const TMaybe<ui32>& rangeIndex, const TMaybe<u
                 ranges->erase(ranges->begin(), ranges->begin() + rangeIndex.GetOrElse(0));
             }
             ranges->begin()->LowerLimit(TReadLimit().RowIndex(*rowIndex));
+            areRangesUpdated = true;
         }
 
         header.MergeParameters(FormIORequestParameters(Path_, Options_));
@@ -196,7 +200,7 @@ void TClientReader::CreateRequest(const TMaybe<ui32>& rangeIndex, const TMaybe<u
 
             Input_ = Response_->GetResponseStream();
 
-            YT_LOG_DEBUG("RSP %v - table stream", requestId);
+            YT_LOG_DEBUG("RSP %v - table stream (RequestId: %v, RangeIndex: %v, RowIndex: %v)", requestId, rangeIndex, rowIndex);
 
             return;
         } catch (const TErrorResponse& e) {