meta_srv/selector/
lease_based.rs

1// Copyright 2023 Greptime Team
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 std::collections::HashSet;
16use std::sync::Arc;
17
18use common_meta::peer::Peer;
19
20use crate::error::Result;
21use crate::lease;
22use crate::metasrv::SelectorContext;
23use crate::node_excluder::NodeExcluderRef;
24use crate::selector::common::{choose_items, filter_out_excluded_peers};
25use crate::selector::weighted_choose::{RandomWeightedChoose, WeightedItem};
26use crate::selector::{Selector, SelectorOptions};
27
28/// Select all alive datanodes based using a random weighted choose.
29pub struct LeaseBasedSelector {
30    node_excluder: NodeExcluderRef,
31}
32
33impl LeaseBasedSelector {
34    pub fn new(node_excluder: NodeExcluderRef) -> Self {
35        Self { node_excluder }
36    }
37}
38
39impl Default for LeaseBasedSelector {
40    fn default() -> Self {
41        Self {
42            node_excluder: Arc::new(Vec::new()),
43        }
44    }
45}
46
47#[async_trait::async_trait]
48impl Selector for LeaseBasedSelector {
49    type Context = SelectorContext;
50    type Output = Vec<Peer>;
51
52    async fn select(&self, ctx: &Self::Context, opts: SelectorOptions) -> Result<Self::Output> {
53        // 1. get alive datanodes.
54        let lease_kvs = lease::alive_datanodes(&ctx.meta_peer_client, ctx.datanode_lease_secs)
55            .with_condition(lease::is_datanode_accept_ingest_workload)
56            .await?;
57
58        // 2. compute weight array, but the weight of each item is the same.
59        let mut weight_array = lease_kvs
60            .into_iter()
61            .map(|(k, v)| WeightedItem {
62                item: Peer {
63                    id: k.node_id,
64                    addr: v.node_addr.clone(),
65                },
66                weight: 1.0,
67            })
68            .collect();
69
70        // 3. choose peers by weight_array.
71        let mut exclude_peer_ids = self
72            .node_excluder
73            .excluded_datanode_ids()
74            .iter()
75            .cloned()
76            .collect::<HashSet<_>>();
77        exclude_peer_ids.extend(opts.exclude_peer_ids.iter());
78        filter_out_excluded_peers(&mut weight_array, &exclude_peer_ids);
79        let mut weighted_choose = RandomWeightedChoose::new(weight_array);
80        let selected = choose_items(&opts, &mut weighted_choose)?;
81
82        Ok(selected)
83    }
84}
meta_srv/selector/lease_based.rs

meta_srv/selector/
lease_based.rs
