Improve TEvVRange cost estimation, fix seek time calculation, KIKIMR-19499

Better TEvVRange cost estimation

2 files changed, 5 insertions, 5 deletions

diff --git a/ydb/core/blobstorage/vdisk/common/vdisk_costmodel.cpp b/ydb/core/blobstorage/vdisk/common/vdisk_costmodel.cpp
index 7592b2bdd34..6d6f86ef6a7 100644
--- a/ydb/core/blobstorage/vdisk/common/vdisk_costmodel.cpp
+++ b/ydb/core/blobstorage/vdisk/common/vdisk_costmodel.cpp
@@ -215,7 +215,7 @@ namespace NKikimr {
     }
 
     ui64 TCostModel::ReadCostBySize(ui64 size) const {
-        ui64 seekCost = (size / ReadBlockSize + 1) * SeekTimeUs;
+        ui64 seekCost = (size / ReadBlockSize + 1) * SeekTimeUs * 1000ull;
         ui64 readCost = size * ui64(1000000000) / ReadSpeedBps;
         return seekCost + readCost;
     }
@@ -231,7 +231,7 @@ namespace NKikimr {
                 cost += InMemReadCost();
             } else {
                 // we don't know cost of the query, it depends on number of elements and their size
-                cost += 10000000; // let's assume it's 10 ms
+                cost += 1000ull * SeekTimeUs + 2'000'000ull * 1'000'000'000 / ReadSpeedBps;
             }
         }
 
diff --git a/ydb/core/blobstorage/vdisk/common/vdisk_costmodel.h b/ydb/core/blobstorage/vdisk/common/vdisk_costmodel.h
index e10f519f60b..60da0557d0f 100644
--- a/ydb/core/blobstorage/vdisk/common/vdisk_costmodel.h
+++ b/ydb/core/blobstorage/vdisk/common/vdisk_costmodel.h
@@ -10,7 +10,7 @@ namespace NKikimr {
 
     ////////////////////////////////////////////////////////////////////////////
     // TCostModel -- estimate complexity of incoming request
-    // All estimations are performed in time (Us)
+    // All estimations are performed in time (ns)
     ////////////////////////////////////////////////////////////////////////////
     class TCostModel {
     public:
@@ -101,14 +101,14 @@ namespace NKikimr {
 
     protected:
         ui64 SmallWriteCost(ui64 size) const {
-            const ui64 seekCost = SeekTimeUs / 100u; // assume we do one seek per 100 log records
+            const ui64 seekCost = SeekTimeUs  * 1000ull / 100u; // assume we do one seek per 100 log records
             const ui64 writeCost = size * ui64(1000000000) / WriteSpeedBps;
             const ui64 cost = seekCost + writeCost;
             return cost ? cost : 1;
         }
 
         ui64 HugeWriteCost(ui64 size) const {
-            const ui64 seekCost = (size / WriteBlockSize + 1) * SeekTimeUs; // huge blocks may require several seeks
+            const ui64 seekCost = (size / WriteBlockSize + 1) * SeekTimeUs * 1000ull; // huge blocks may require several seeks
             const ui64 writeCost = size * ui64(1000000000) / WriteSpeedBps;
             const ui64 cost = seekCost + writeCost;
             Y_VERIFY_DEBUG(cost);