Improve data distribution: solve LP task on failure domains instead of individual OSDs

This greatly speeds up PG placement and makes it more uniform both because the LP task becomes simpler and because the distribution of individual OSDs is optimised manually
2025-04-27 01:44:46 +03:00
parent 1393a2671c
commit a2278be84d
6 changed files with 364 additions and 14 deletions
@@ -0,0 +1,96 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.1 (see README.md for details)
+
+const assert = require('assert');
+const { fold_failure_domains, unfold_failure_domains, adjust_distribution } = require('./fold.js');
+const DSL = require('./dsl_pgs.js');
+const LPOptimizer = require('./lp_optimizer.js');
+const stableStringify = require('../stable-stringify.js');
+
+async function run()
+{
+    // Test run adjust_distribution
+    console.log('adjust_distribution');
+    const rand = [];
+    for (let i = 0; i < 100; i++)
+    {
+        rand.push(1 + Math.floor(10*Math.random()));
+        // or rand.push(0);
+    }
+    const adj = adjust_distribution({ 1: 1, 2: 1, 3: 1, 4: 1, 5: 1, 6: 1, 7: 1, 8: 1, 9: 1, 10: 1 }, rand);
+    //console.log(rand.join(' '));
+    console.log(rand.reduce((a, c) => { a[c] = (a[c]||0)+1; return a; }, {}));
+    //console.log(adj.join(' '));
+    console.log(adj.reduce((a, c) => { a[c] = (a[c]||0)+1; return a; }, {}));
+    console.log('Movement: '+rand.reduce((a, c, i) => a+(rand[i] != adj[i] ? 1 : 0), 0)+'/'+rand.length);
+
+    console.log('\nfold_failure_domains');
+    console.log(JSON.stringify(fold_failure_domains(
+        [
+            { id: 1,       level: 'osd',  size: 1, parent: 'disk1' },
+            { id: 2,       level: 'osd',  size: 2, parent: 'disk1' },
+            { id: 'disk1', level: 'disk', parent: 'host1' },
+            { id: 'host1', level: 'host', parent: 'dc1' },
+            { id: 'dc1',   level: 'dc' },
+        ],
+        [ [ [ 'dc' ], [ 'host' ] ] ]
+    ), 0, 2));
+
+    console.log('\noptimize_folded');
+    // 5 DCs, 2 hosts per DC, 10 OSD per host
+    const nodes = [];
+    for (let i = 1; i <= 100; i++)
+    {
+        nodes.push({ id: i, level: 'osd', size: 1, parent: 'host'+(1+(0|((i-1)/10))) });
+    }
+    for (let i = 1; i <= 10; i++)
+    {
+        nodes.push({ id: 'host'+i, level: 'host', parent: 'dc'+(1+(0|((i-1)/2))) });
+    }
+    for (let i = 1; i <= 5; i++)
+    {
+        nodes.push({ id: 'dc'+i, level: 'dc' });
+    }
+
+    // Check rules
+    const rules = DSL.parse_level_indexes({ dc: '112233', host: '123456' }, [ 'dc', 'host', 'osd' ]);
+    assert.deepEqual(rules, [[],[["dc","=",1],["host","!=",[1]]],[["dc","!=",[1]]],[["dc","=",3],["host","!=",[3]]],[["dc","!=",[1,3]]],[["dc","=",5],["host","!=",[5]]]]);
+
+    // Check tree folding
+    const { nodes: folded_nodes, leaves: folded_leaves } = fold_failure_domains(nodes, rules);
+    const expected_folded = [];
+    const expected_leaves = {};
+    for (let i = 1; i <= 10; i++)
+    {
+        expected_folded.push({ id: 100+i, name: 'host'+i, level: 'host', size: 10, parent: 'dc'+(1+(0|((i-1)/2))) });
+        expected_leaves[100+i] = [ ...new Array(10).keys() ].map(k => ({ id: 10*(i-1)+k+1, level: 'osd', size: 1, parent: 'host'+i }));
+    }
+    for (let i = 1; i <= 5; i++)
+    {
+        expected_folded.push({ id: 'dc'+i, level: 'dc' });
+    }
+    assert.equal(stableStringify(folded_nodes), stableStringify(expected_folded));
+    assert.equal(stableStringify(folded_leaves), stableStringify(expected_leaves));
+
+    // Now optimise it
+    console.log('1000 PGs, EC 112233');
+    const leaf_weights = folded_nodes.reduce((a, c) => { if (Number(c.id)) { a[c.id] = c.size; } return a; }, {});
+    let res = await LPOptimizer.optimize_initial({
+        osd_weights: leaf_weights,
+        combinator: new DSL.RuleCombinator(folded_nodes, rules, 10000, false),
+        pg_size: 6,
+        pg_count: 1000,
+        ordered: false,
+    });
+    LPOptimizer.print_change_stats(res, false);
+    assert.equal(res.space, 100, 'Initial distribution');
+
+    const unfolded_res = { ...res };
+    unfolded_res.int_pgs = unfold_failure_domains(res.int_pgs, null, folded_leaves);
+    const osd_weights = nodes.reduce((a, c) => { if (Number(c.id)) { a[c.id] = c.size; } return a; }, {});
+    unfolded_res.space = unfolded_res.pg_effsize * LPOptimizer.pg_list_space_efficiency(unfolded_res.int_pgs, osd_weights, 0, 1);
+    LPOptimizer.print_change_stats(unfolded_res, false);
+    assert.equal(res.space, 100, 'Initial distribution');
+}
+
+run().catch(console.error);