risingwave_frontend/handler/
alter_parallelism.rs

1// Copyright 2025 RisingWave Labs
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use pgwire::pg_response::StatementType;
16use risingwave_pb::meta::table_parallelism::{
17    AdaptiveParallelism, FixedParallelism, PbParallelism,
18};
19use risingwave_pb::meta::{PbTableParallelism, TableParallelism};
20use risingwave_sqlparser::ast::{ObjectName, SetVariableValue, SetVariableValueSingle, Value};
21use risingwave_sqlparser::keywords::Keyword;
22use thiserror_ext::AsReport;
23
24use super::alter_utils::resolve_streaming_job_id_for_alter;
25use super::{HandlerArgs, RwPgResponse};
26use crate::catalog::FragmentId;
27use crate::error::{ErrorCode, Result};
28use crate::handler::util::{LongRunningNotificationAction, execute_with_long_running_notification};
29
30pub async fn handle_alter_parallelism(
31    handler_args: HandlerArgs,
32    obj_name: ObjectName,
33    parallelism: SetVariableValue,
34    stmt_type: StatementType,
35    deferred: bool,
36) -> Result<RwPgResponse> {
37    let session = handler_args.session;
38
39    let job_id = resolve_streaming_job_id_for_alter(&session, obj_name, stmt_type, "parallelism")?;
40
41    let target_parallelism = extract_table_parallelism(parallelism)?;
42
43    let mut builder = RwPgResponse::builder(stmt_type);
44
45    let catalog_writer = session.catalog_writer()?;
46    execute_with_long_running_notification(
47        catalog_writer.alter_parallelism(job_id, target_parallelism, deferred),
48        &session,
49        "ALTER PARALLELISM",
50        LongRunningNotificationAction::SuggestRecover,
51    )
52    .await?;
53
54    if deferred {
55        builder = builder.notice("DEFERRED is used, please ensure that automatic parallelism control is enabled on the meta, otherwise, the alter will not take effect.".to_owned());
56    }
57
58    Ok(builder.into())
59}
60
61pub async fn handle_alter_fragment_parallelism(
62    handler_args: HandlerArgs,
63    fragment_ids: Vec<FragmentId>,
64    parallelism: SetVariableValue,
65) -> Result<RwPgResponse> {
66    let session = handler_args.session;
67    let target_parallelism = extract_fragment_parallelism(parallelism)?;
68
69    session
70        .env()
71        .meta_client()
72        .alter_fragment_parallelism(fragment_ids, target_parallelism)
73        .await?;
74
75    Ok(RwPgResponse::builder(StatementType::ALTER_FRAGMENT).into())
76}
77
78fn extract_table_parallelism(parallelism: SetVariableValue) -> Result<TableParallelism> {
79    let adaptive_parallelism = PbTableParallelism {
80        parallelism: Some(PbParallelism::Adaptive(AdaptiveParallelism {})),
81    };
82
83    // If the target parallelism is set to 0/auto/default, we would consider it as auto parallelism.
84    let target_parallelism = match parallelism {
85        SetVariableValue::Single(SetVariableValueSingle::Ident(ident))
86            if ident
87                .real_value()
88                .eq_ignore_ascii_case(&Keyword::ADAPTIVE.to_string()) =>
89        {
90            adaptive_parallelism
91        }
92
93        SetVariableValue::Default => adaptive_parallelism,
94        SetVariableValue::Single(SetVariableValueSingle::Literal(Value::Number(v))) => {
95            let fixed_parallelism = v.parse::<u32>().map_err(|e| {
96                ErrorCode::InvalidInputSyntax(format!(
97                    "target parallelism must be a valid number or adaptive: {}",
98                    e.as_report()
99                ))
100            })?;
101
102            if fixed_parallelism == 0 {
103                adaptive_parallelism
104            } else {
105                PbTableParallelism {
106                    parallelism: Some(PbParallelism::Fixed(FixedParallelism {
107                        parallelism: fixed_parallelism,
108                    })),
109                }
110            }
111        }
112
113        _ => {
114            return Err(ErrorCode::InvalidInputSyntax(
115                "target parallelism must be a valid number or adaptive".to_owned(),
116            )
117            .into());
118        }
119    };
120
121    Ok(target_parallelism)
122}
123
124fn extract_fragment_parallelism(parallelism: SetVariableValue) -> Result<Option<TableParallelism>> {
125    match parallelism {
126        SetVariableValue::Default => Ok(None),
127        other => extract_table_parallelism(other).map(Some),
128    }
129}
risingwave_frontend/handler/alter_parallelism.rs

risingwave_frontend/handler/
alter_parallelism.rs
