do not rewrite alter parallelism in frontend

Signed-off-by: Bugen Zhao <[email protected]>
risingwavelabs · Sep 17, 2024 · bf7205a · bf7205a
1 parent 3f10193
commit bf7205a
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Showing 2 changed files with 9 additions and 13 deletions.
diff --git a/src/frontend/src/handler/alter_parallelism.rs b/src/frontend/src/handler/alter_parallelism.rs
@@ -93,7 +93,7 @@ pub async fn handle_alter_parallelism(
         }
     };
 
-    let mut target_parallelism = extract_table_parallelism(parallelism)?;
+    let target_parallelism = extract_table_parallelism(parallelism)?;
 
     let available_parallelism = session
         .env()
@@ -103,26 +103,24 @@ pub async fn handle_alter_parallelism(
         .filter(|w| w.is_streaming_schedulable())
         .map(|w| w.parallelism)
         .sum::<u32>();
-    // TODO(var-vnode): get max parallelism from catalogs.
-    // Although the meta service will clamp the value for us, we should still check it here for better UI.
-    let max_parallelism = VirtualNode::COUNT_FOR_COMPAT;
 
     let mut builder = RwPgResponse::builder(stmt_type);
 
+    // TODO(var-vnode): get correct max parallelism from catalogs.
+    // Although the meta service will clamp the value for us and print warnings there,
+    // we may still check it here for better UI.
+    let max_parallelism = VirtualNode::COUNT_FOR_COMPAT;
+
     match &target_parallelism.parallelism {
         Some(Parallelism::Adaptive(_)) | Some(Parallelism::Auto(_)) => {
             if available_parallelism > max_parallelism as u32 {
-                builder = builder.notice(format!("Available parallelism exceeds the maximum parallelism limit, the actual parallelism will be limited to {max_parallelism}"));
+                builder = builder.notice("Available parallelism may exceed the maximum parallelism limit, the actual parallelism will be limited");
             }
         }
         Some(Parallelism::Fixed(FixedParallelism { parallelism })) => {
             if *parallelism > max_parallelism as u32 {
-                builder = builder.notice(format!("Provided parallelism exceeds the maximum parallelism limit, resetting to FIXED({max_parallelism})"));
-                target_parallelism = PbTableParallelism {
-                    parallelism: Some(PbParallelism::Fixed(FixedParallelism {
-                        parallelism: max_parallelism as u32,
-                    })),
-                };
+                builder = builder.notice("Provided parallelism may exceed the maximum parallelism limit, will be reset to FIXED(max_parallelism)");
+                // Rewriting will be done in meta service.
             }
         }
         _ => {}

diff --git a/src/meta/src/stream/scale.rs b/src/meta/src/stream/scale.rs
@@ -2226,8 +2226,6 @@ impl ScaleController {
                         }
                         TableParallelism::Fixed(mut n) => {
                             if n > max_parallelism {
-                                // This should be unreachable as it was already checked and rewritten in the frontend.
-                                // We still intercept it to prevent accidental modifications.
                                 tracing::warn!("specified parallelism {n} for table {table_id} is larger than max parallelism, force limit to {max_parallelism}");
                                 n = max_parallelism
                             }