split size

Signed-off-by: bufferflies <[email protected]>

proto/raft_cmdpb.proto

@@ -146,8 +146,10 @@ message SplitRequest {
     // left region use new_region_id.
     // Will be ignored in batch split, use `BatchSplitRequest::right_derive` instead.
     bool right_derive = 4 [deprecated=true];
-    // It should be false iff the region split by user key such as split table or create partion table etc, and new region's size should be zero. 
-    // It should be true iff the region's load reach the threshold such as size、keys、load check etc, and new region's size will amortize the origin region.
+    // It should be false iff the region split by user key such as split table or create partion table etc, 
+    // the new region's will not amortize the source region size, so it's region size is zero.
+    // It should be true iff the region's load reach the threshold such as size、keys、load check etc,
+    // the new region's size will amortize the origin region, so it's region size is half of the source region.
     bool amortize_source_region_size = 5;
 }
 
@@ -161,8 +163,10 @@ message BatchSplitRequest {
     // If true, the last region derive the origin region_id, 
     // other regions use new ids.
     bool right_derive = 2;
-    // It should be false iff the region split by user key such as split table or create partion table etc, and new region's size should be zero. 
-    // It should be true iff the region's load reach the threshold such as size、keys、load check etc, and new region's size will amortize the origin region.
+    // It should be false iff the region split by user key such as split table or create partion table etc, 
+    // the new region's will not amortize the source region size, so it's region size is zero.
+    // It should be true iff the region's load reach the threshold such as size、keys、load check etc,
+    // the new region's size will amortize the origin region, so it's region size is half of the source region.
     bool amortize_source_region_size = 3;
 }