reifydb-profiler 0.8.1

Always-on database profiler primitives: tracing layer, per-scope capture, dimension interning
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
// SPDX-License-Identifier: Apache-2.0
// Copyright (c) 2026 ReifyDB

use std::sync::Arc;

use reifydb_runtime::context::clock::{Clock, Instant};
use reifydb_value::reifydb_assertions;
use tracing::{
	Metadata, Subscriber,
	span::{Attributes, Id, Record},
	subscriber::Interest,
};
use tracing_subscriber::{Layer, layer::Context, registry::LookupSpan};

use crate::{
	callsite,
	category::{CategorySet, ProfilerCategory},
	intern::DimInterner,
	record::{DimIdx, MAX_EXTRAS, MinimalSpanRecord},
	scope::{ProfilerScope, REGISTRY, ScopeState, active_scope},
	sink::ProfilerSink,
	visit::FlowApplyFields,
};

pub struct ProfilerLayer {
	sink: Arc<dyn ProfilerSink>,
	categories: CategorySet,
	interner: Arc<DimInterner>,
	ambient_scope: Arc<ScopeState>,
	clock: Clock,
}

impl ProfilerLayer {
	pub fn new(
		sink: Arc<dyn ProfilerSink>,
		categories: CategorySet,
		interner: Arc<DimInterner>,
		clock: Clock,
	) -> Self {
		let ambient_scope = ProfilerScope::ambient("profiler.global", Arc::clone(&sink), &clock);
		Self {
			sink,
			categories,
			interner,
			ambient_scope,
			clock,
		}
	}
}

#[derive(Clone)]
struct SpanExt {
	category: ProfilerCategory,
	scope: Arc<ScopeState>,
	callsite_id: u64,
	started_at: Instant,
	flow_fields: Option<FlowApplyFields>,
}

fn metadata_callsite_id(metadata: &'static Metadata<'static>) -> u64 {
	let ptr: *const Metadata<'static> = metadata;
	ptr as usize as u64
}

fn discover_scope<S>(ctx: &Context<'_, S>, span_id: &Id) -> Option<Arc<ScopeState>>
where
	S: Subscriber + for<'a> LookupSpan<'a>,
{
	if let Some(span) = ctx.span(span_id) {
		for ancestor in span.scope() {
			let ext = ancestor.extensions();
			if let Some(ent) = ext.get::<SpanExt>() {
				return Some(Arc::clone(&ent.scope));
			}
		}
	}
	let id = active_scope()?;
	REGISTRY.get(id)
}

impl<S> Layer<S> for ProfilerLayer
where
	S: Subscriber + for<'a> LookupSpan<'a>,
{
	fn register_callsite(&self, metadata: &'static Metadata<'static>) -> Interest {
		if !metadata.is_span() {
			return Interest::never();
		}
		let Some(c) = ProfilerCategory::from_span_name(metadata.name()) else {
			return Interest::never();
		};
		let Some(max) = self.categories.level_for(c) else {
			return Interest::never();
		};
		if max.admits(metadata.level()) {
			Interest::always()
		} else {
			Interest::never()
		}
	}

	fn enabled(&self, metadata: &Metadata<'_>, _ctx: Context<'_, S>) -> bool {
		if !metadata.is_span() {
			return false;
		}
		let Some(c) = ProfilerCategory::from_span_name(metadata.name()) else {
			return false;
		};
		self.categories.level_for(c).map(|max| max.admits(metadata.level())).unwrap_or(false)
	}

	fn on_new_span(&self, attrs: &Attributes<'_>, id: &Id, ctx: Context<'_, S>) {
		let metadata = attrs.metadata();
		let Some(category) = self.resolve_admitted_category(metadata) else {
			return;
		};
		let scope = self.discover_span_scope(&ctx, id);
		let callsite_id = self.register_span_callsite(metadata);
		let flow_fields = self.extract_flow_fields(category, attrs, metadata);
		self.insert_span_ext(&ctx, id, category, scope, callsite_id, flow_fields);
	}

	fn on_record(&self, id: &Id, values: &Record<'_>, ctx: Context<'_, S>) {
		let Some(span) = ctx.span(id) else {
			return;
		};
		let mut ext = span.extensions_mut();
		if let Some(entry) = ext.get_mut::<SpanExt>()
			&& let Some(fields) = entry.flow_fields.as_mut()
		{
			values.record(fields);
		}
	}

	fn on_close(&self, id: Id, ctx: Context<'_, S>) {
		let Some(entry) = self.take_span_ext(&ctx, &id) else {
			return;
		};
		let record = self.build_record(&entry);
		self.emit_record(&entry.scope, record);
	}
}

impl ProfilerLayer {
	#[inline]
	fn resolve_admitted_category(&self, metadata: &'static Metadata<'static>) -> Option<ProfilerCategory> {
		let category = ProfilerCategory::from_span_name(metadata.name())?;
		let max = self.categories.level_for(category)?;
		if max.admits(metadata.level()) {
			Some(category)
		} else {
			None
		}
	}

	#[inline]
	fn register_span_callsite(&self, metadata: &'static Metadata<'static>) -> u64 {
		let callsite_id = metadata_callsite_id(metadata);
		callsite::register(callsite_id, metadata.name());
		callsite_id
	}

	#[inline]
	fn extract_flow_fields(
		&self,
		category: ProfilerCategory,
		attrs: &Attributes<'_>,
		metadata: &'static Metadata<'static>,
	) -> Option<FlowApplyFields> {
		if category == ProfilerCategory::Flow && metadata.name() == "flow::engine::apply" {
			let mut fields = FlowApplyFields::default();
			attrs.record(&mut fields);
			Some(fields)
		} else {
			None
		}
	}

	#[inline]
	fn build_record(&self, entry: &SpanExt) -> MinimalSpanRecord {
		let mut record = MinimalSpanRecord::new(entry.category, entry.callsite_id, 0);
		match (entry.category, &entry.flow_fields) {
			(ProfilerCategory::Flow, Some(f)) => {
				record.duration_us = u32::try_from(f.apply_time_us).unwrap_or(u32::MAX);
				let mut dims: [DimIdx; 2] = [0, 0];
				if !f.node_type.is_empty() {
					dims[0] = self.interner.intern(&f.node_type);
				}
				if !f.node_id.is_empty() {
					dims[1] = self.interner.intern(&f.node_id);
				}
				record.dim_indices = dims;
				let mut extras = [0u64; MAX_EXTRAS];
				extras[0] = f.input_rows;
				extras[1] = f.output_rows;
				extras[2] = f.lock_wait_us;
				record.extras = extras;
			}
			_ => {
				reifydb_assertions! {
					let now = self.clock.instant();
					assert!(
						now >= entry.started_at,
						"span close observed a clock instant before its start, so elapsed() would saturate \
						 to zero and silently report a missing duration for an untracked-flow span; the \
						 profiler relies on a monotonic clock for span timing (now_us={}, started_us={})",
						now.elapsed().as_micros(),
						entry.started_at.elapsed().as_micros()
					);
				}
				let elapsed = entry.started_at.elapsed().as_micros();
				record.duration_us = u32::try_from(elapsed).unwrap_or(u32::MAX);
			}
		}
		record
	}

	#[inline]
	fn emit_record(&self, scope: &ScopeState, record: MinimalSpanRecord) {
		self.sink.on_span_record(&record);
		scope.attach_interner(Arc::clone(&self.interner));
		scope.push(record);
	}
}

impl ProfilerLayer {
	#[inline]
	fn discover_span_scope<S>(&self, ctx: &Context<'_, S>, id: &Id) -> Arc<ScopeState>
	where
		S: Subscriber + for<'a> LookupSpan<'a>,
	{
		discover_scope(ctx, id).unwrap_or_else(|| Arc::clone(&self.ambient_scope))
	}

	#[inline]
	fn insert_span_ext<S>(
		&self,
		ctx: &Context<'_, S>,
		id: &Id,
		category: ProfilerCategory,
		scope: Arc<ScopeState>,
		callsite_id: u64,
		flow_fields: Option<FlowApplyFields>,
	) where
		S: Subscriber + for<'a> LookupSpan<'a>,
	{
		let ext = SpanExt {
			category,
			scope,
			callsite_id,
			started_at: self.clock.instant(),
			flow_fields,
		};
		if let Some(span) = ctx.span(id) {
			span.extensions_mut().insert(ext);
		}
	}

	#[inline]
	fn take_span_ext<S>(&self, ctx: &Context<'_, S>, id: &Id) -> Option<SpanExt>
	where
		S: Subscriber + for<'a> LookupSpan<'a>,
	{
		let span = ctx.span(id)?;
		span.extensions_mut().remove::<SpanExt>()
	}
}

#[cfg(test)]
mod tests {
	use std::sync::Arc;

	use reifydb_runtime::{context::clock::Clock, sync::mutex::Mutex as StdMutex};
	use tracing::{debug_span, subscriber::with_default, trace_span};
	use tracing_subscriber::{Registry, layer::SubscriberExt};

	use super::*;
	use crate::{category::ProfilerLevel, scope::ProfilerScope, sink::ProfilerSink, summary::ProfilerSummary};

	#[derive(Default)]
	struct RecordingSink {
		records: StdMutex<Vec<MinimalSpanRecord>>,
		summaries: StdMutex<Vec<ProfilerSummary>>,
	}

	impl ProfilerSink for RecordingSink {
		fn on_span_record(&self, record: &MinimalSpanRecord) {
			self.records.lock().push(*record);
		}
		fn on_scope_closed(&self, summary: &ProfilerSummary) {
			self.summaries.lock().push(summary.clone());
		}
		fn on_scope_batch(&self, summary: &ProfilerSummary) {
			self.summaries.lock().push(summary.clone());
		}
	}

	fn build_layer(sink: Arc<dyn ProfilerSink>, categories: CategorySet) -> (ProfilerLayer, Arc<DimInterner>) {
		let interner = Arc::new(DimInterner::new());
		(ProfilerLayer::new(sink, categories, interner.clone(), Clock::Real), interner)
	}

	#[test]
	fn out_of_scope_span_captured_via_ambient_scope() {
		let sink: Arc<RecordingSink> = Arc::new(RecordingSink::default());
		let (layer, _interner) = build_layer(sink.clone(), CategorySet::all());
		let subscriber = Registry::default().with(layer);
		with_default(subscriber, || {
			let span = debug_span!("flow::engine::apply", node_id = "n1", node_type = "map");
			let _g = span.enter();
		});
		let recs = sink.records.lock();
		assert_eq!(recs.len(), 1, "ambient scope must capture unscoped tracked spans for always-on profiling");
	}

	#[test]
	fn admits_at_or_below_category_level() {
		let sink: Arc<RecordingSink> = Arc::new(RecordingSink::default());
		let categories = CategorySet::empty().with_level(ProfilerCategory::Flow, ProfilerLevel::Debug);
		let (layer, _interner) = build_layer(sink.clone(), categories);
		let subscriber = Registry::default().with(layer);

		with_default(subscriber, || {
			let handle = ProfilerScope::start_with_sink("scope", sink.clone(), Clock::Real);
			handle.run_sync(|| {
				let trace_span =
					trace_span!("flow::engine::apply", node_id = "n", node_type = "trace_op");
				let _g1 = trace_span.enter();
				let debug_span = debug_span!("flow::engine::process_batch", batch_size = 1u64);
				let _g2 = debug_span.enter();
			});
			let _ = handle.finish();
		});

		let recs = sink.records.lock();
		assert_eq!(
			recs.len(),
			1,
			"DEBUG-level filter must admit process_batch (debug) but reject apply (trace), got: {:?}",
			recs
		);
	}

	#[test]
	fn disabled_category_short_circuits() {
		let sink: Arc<RecordingSink> = Arc::new(RecordingSink::default());
		let (layer, _interner) = build_layer(sink.clone(), CategorySet::empty().with(ProfilerCategory::Query));
		let subscriber = Registry::default().with(layer);
		with_default(subscriber, || {
			let handle = ProfilerScope::start_with_sink("scope", sink.clone(), Clock::Real);
			handle.run_sync(|| {
				let _ = trace_span!("flow::engine::apply", node_id = "n", node_type = "m");
			});
			let _ = handle.finish();
		});
		assert!(sink.records.lock().is_empty());
	}

	#[test]
	fn flow_apply_captures_fields_and_interns_dims() {
		let sink: Arc<RecordingSink> = Arc::new(RecordingSink::default());
		let (layer, _interner) = build_layer(sink.clone(), CategorySet::all());
		let subscriber = Registry::default().with(layer);
		with_default(subscriber, || {
			let handle = ProfilerScope::start_with_sink("scope", sink.clone(), Clock::Real);
			handle.run_sync(|| {
				let span = trace_span!(
					"flow::engine::apply",
					node_id = "n1",
					node_type = "map",
					input_rows = 10u64,
					output_rows = 5u64,
					apply_time_us = 200u64,
					lock_wait_us = 3u64,
				);
				let _g = span.enter();
			});
			let _summary = handle.finish();
		});
		let recs = sink.records.lock();
		assert_eq!(recs.len(), 1);
		let rec = recs[0];
		assert_eq!(rec.category(), ProfilerCategory::Flow);
		assert_eq!(rec.duration_us, 200);
		assert_eq!(rec.extras[0], 10);
		assert_eq!(rec.extras[1], 5);
		assert_eq!(rec.extras[2], 3);
	}

	#[test]
	fn ancestor_walk_inherits_scope_across_spans() {
		let sink: Arc<RecordingSink> = Arc::new(RecordingSink::default());
		let (layer, _interner) = build_layer(sink.clone(), CategorySet::all());
		let subscriber = Registry::default().with(layer);
		with_default(subscriber, || {
			let handle = ProfilerScope::start_with_sink("scope", sink.clone(), Clock::Real);
			handle.run_sync(|| {
				let outer = debug_span!("flow::engine::process_batch", batch_size = 3u64);
				let _g = outer.enter();
				let inner = trace_span!("flow::engine::apply", node_id = "n", node_type = "filter");
				let _g2 = inner.enter();
			});
			let _ = handle.finish();
		});
		let recs = sink.records.lock();
		assert_eq!(recs.len(), 2);
	}
}