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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520
// Copyright (C) Parity Technologies (UK) Ltd.
// This file is part of Polkadot.
// Polkadot is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// Polkadot is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Polkadot. If not, see <http://www.gnu.org/licenses/>.
//! Polkadot Jaeger span definitions.
//!
//! ```rust
//! # use polkadot_primitives::{CandidateHash, Hash};
//! # fn main() {
//! use polkadot_node_jaeger as jaeger;
//!
//! let relay_parent = Hash::default();
//! let candidate = CandidateHash::default();
//!
//! #[derive(Debug, Default)]
//! struct Foo {
//! a: u8,
//! b: u16,
//! c: u32,
//! };
//!
//! let foo = Foo::default();
//!
//! let span =
//! jaeger::Span::new(relay_parent, "root_of_aaall_spans")
//! // explicit well defined items
//! .with_candidate(candidate)
//! // anything that implements `trait std::fmt::Debug`
//! .with_string_fmt_debug_tag("foo", foo)
//! // anything that implements `trait std::str::ToString`
//! .with_string_tag("again", 1337_u32)
//! // add a `Stage` for [`dot-jaeger`](https://github.com/paritytech/dot-jaeger)
//! .with_stage(jaeger::Stage::CandidateBacking);
//! // complete by design, no completion required
//! # }
//! ```
//!
//! In a few cases additional annotations might want to be added
//! over the course of a function, for this purpose use the non-consuming
//! `fn` variants, i.e.
//! ```rust
//! # use polkadot_primitives::{CandidateHash, Hash};
//! # fn main() {
//! # use polkadot_node_jaeger as jaeger;
//!
//! # let relay_parent = Hash::default();
//! # let candidate = CandidateHash::default();
//!
//! # #[derive(Debug, Default)]
//! # struct Foo {
//! # a: u8,
//! # b: u16,
//! # c: u32,
//! # };
//! #
//! # let foo = Foo::default();
//!
//! let root_span =
//! jaeger::Span::new(relay_parent, "root_of_aaall_spans");
//!
//! // the preferred way of adding additional delayed information:
//! let span = root_span.child("inner");
//!
//! // ... more operations ...
//!
//! // but this is also possible:
//!
//! let mut root_span = root_span;
//! root_span.add_string_fmt_debug_tag("foo_constructed", &foo);
//! root_span.add_string_tag("bar", true);
//! # }
//! ```
use codec::Encode;
use polkadot_node_primitives::PoV;
use polkadot_primitives::{
BlakeTwo256, CandidateHash, ChunkIndex, Hash, HashT, Id as ParaId, ValidatorIndex,
};
use sc_network_types::PeerId;
use std::{fmt, sync::Arc};
use super::INSTANCE;
/// A special "per leaf span".
///
/// Essentially this span wraps two spans:
///
/// 1. The span that is created per leaf in the overseer.
/// 2. Some child span of the per-leaf span.
///
/// This just works as auxiliary structure to easily store both.
#[derive(Debug)]
pub struct PerLeafSpan {
leaf_span: Arc<Span>,
span: Span,
}
impl PerLeafSpan {
/// Creates a new instance.
///
/// Takes the `leaf_span` that is created by the overseer per leaf and a name for a child span.
/// Both will be stored in this object, while the child span is implicitly accessible by using
/// the [`Deref`](std::ops::Deref) implementation.
pub fn new(leaf_span: Arc<Span>, name: &'static str) -> Self {
let span = leaf_span.child(name);
Self { span, leaf_span }
}
/// Returns the leaf span.
pub fn leaf_span(&self) -> &Arc<Span> {
&self.leaf_span
}
}
/// Returns a reference to the child span.
impl std::ops::Deref for PerLeafSpan {
type Target = Span;
fn deref(&self) -> &Span {
&self.span
}
}
/// A helper to annotate the stage with a numerical value
/// to ease the life of the tooling team creating viable
/// statistical metrics for which stage of the inclusion
/// pipeline drops a significant amount of candidates,
/// statistically speaking.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[repr(u8)]
#[non_exhaustive]
pub enum Stage {
CandidateBacking = 2,
StatementDistribution = 3,
PoVDistribution = 4,
AvailabilityDistribution = 5,
AvailabilityRecovery = 6,
BitfieldDistribution = 7,
ApprovalChecking = 8,
ApprovalDistribution = 9,
// Expand as needed, numbers should be ascending according to the stage
// through the inclusion pipeline, or according to the descriptions
// in [the path of a para chain block]
// (https://polkadot.network/the-path-of-a-parachain-block/)
// see [issue](https://github.com/paritytech/polkadot/issues/2389)
}
/// A wrapper type for a span.
///
/// Handles running with and without jaeger.
pub enum Span {
/// Running with jaeger being enabled.
Enabled(mick_jaeger::Span),
/// Running with jaeger disabled.
Disabled,
}
/// Alias for the 16 byte unique identifier used with jaeger.
pub(crate) type TraceIdentifier = u128;
/// A helper to convert the hash to the fixed size representation
/// needed for jaeger.
#[inline]
pub fn hash_to_trace_identifier(hash: Hash) -> TraceIdentifier {
let mut buf = [0u8; 16];
buf.copy_from_slice(&hash.as_ref()[0..16]);
// The slice bytes are copied in reading order, so if interpreted
// in string form by a human, that means lower indices have higher
// values and hence corresponds to BIG endian ordering of the individual
// bytes.
u128::from_be_bytes(buf) as TraceIdentifier
}
/// Helper to unify lazy proxy evaluation.
pub trait LazyIdent {
/// Evaluate the type to a unique trace identifier.
/// Called lazily on demand.
fn eval(&self) -> TraceIdentifier;
/// Annotate a new root item with these additional spans
/// at construction.
fn extra_tags(&self, _span: &mut Span) {}
}
impl<'a> LazyIdent for &'a [u8] {
fn eval(&self) -> TraceIdentifier {
hash_to_trace_identifier(BlakeTwo256::hash_of(self))
}
}
impl LazyIdent for &PoV {
fn eval(&self) -> TraceIdentifier {
hash_to_trace_identifier(self.hash())
}
fn extra_tags(&self, span: &mut Span) {
span.add_pov(self)
}
}
impl LazyIdent for Hash {
fn eval(&self) -> TraceIdentifier {
hash_to_trace_identifier(*self)
}
fn extra_tags(&self, span: &mut Span) {
span.add_string_fmt_debug_tag("relay-parent", self);
}
}
impl LazyIdent for &Hash {
fn eval(&self) -> TraceIdentifier {
hash_to_trace_identifier(**self)
}
fn extra_tags(&self, span: &mut Span) {
span.add_string_fmt_debug_tag("relay-parent", self);
}
}
impl LazyIdent for CandidateHash {
fn eval(&self) -> TraceIdentifier {
hash_to_trace_identifier(self.0)
}
fn extra_tags(&self, span: &mut Span) {
span.add_string_fmt_debug_tag("candidate-hash", &self.0);
// A convenience for usage with the grafana tempo UI,
// not a technical requirement. It merely provides an easy anchor
// where the true trace identifier of the span is not based on
// a candidate hash (which it should be!), but is required to
// continue investigating.
span.add_string_tag("traceID", self.eval().to_string());
}
}
impl Span {
/// Creates a new span builder based on anything that can be lazily evaluated
/// to and identifier.
///
/// Attention: The primary identifier will be used for identification
/// and as such should be
pub fn new<I: LazyIdent>(identifier: I, span_name: &'static str) -> Span {
let mut span = INSTANCE
.read_recursive()
.span(|| <I as LazyIdent>::eval(&identifier), span_name)
.into();
<I as LazyIdent>::extra_tags(&identifier, &mut span);
span
}
/// Creates a new span builder based on an encodable type.
/// The encoded bytes are then used to derive the true trace identifier.
pub fn from_encodable<I: Encode>(identifier: I, span_name: &'static str) -> Span {
INSTANCE
.read_recursive()
.span(
move || {
let bytes = identifier.encode();
LazyIdent::eval(&bytes.as_slice())
},
span_name,
)
.into()
}
/// Derive a child span from `self`.
pub fn child(&self, name: &str) -> Self {
match self {
Self::Enabled(inner) => Self::Enabled(inner.child(name)),
Self::Disabled => Self::Disabled,
}
}
/// Attach a 'traceID' tag set to the decimal representation of the candidate hash.
#[inline(always)]
pub fn with_trace_id(mut self, candidate_hash: CandidateHash) -> Self {
self.add_string_tag("traceID", hash_to_trace_identifier(candidate_hash.0));
self
}
#[inline(always)]
pub fn with_string_tag<V: ToString>(mut self, tag: &'static str, val: V) -> Self {
self.add_string_tag::<V>(tag, val);
self
}
/// Attach a peer-id tag to the span.
#[inline(always)]
pub fn with_peer_id(self, peer: &PeerId) -> Self {
self.with_string_tag("peer-id", &peer.to_base58())
}
/// Attach a `peer-id` tag to the span when peer is present.
#[inline(always)]
pub fn with_optional_peer_id(self, peer: Option<&PeerId>) -> Self {
if let Some(peer) = peer {
self.with_peer_id(peer)
} else {
self
}
}
/// Attach a candidate hash to the span.
#[inline(always)]
pub fn with_candidate(self, candidate_hash: CandidateHash) -> Self {
self.with_string_fmt_debug_tag("candidate-hash", &candidate_hash.0)
}
/// Attach a para-id to the span.
#[inline(always)]
pub fn with_para_id(self, para_id: ParaId) -> Self {
self.with_int_tag("para-id", u32::from(para_id) as i64)
}
/// Attach a candidate stage.
/// Should always come with a `CandidateHash`.
#[inline(always)]
pub fn with_stage(self, stage: Stage) -> Self {
self.with_string_tag("candidate-stage", stage as u8)
}
#[inline(always)]
pub fn with_validator_index(self, validator: ValidatorIndex) -> Self {
self.with_string_tag("validator-index", &validator.0)
}
#[inline(always)]
pub fn with_chunk_index(self, chunk_index: ChunkIndex) -> Self {
self.with_string_tag("chunk-index", &chunk_index.0)
}
#[inline(always)]
pub fn with_relay_parent(self, relay_parent: Hash) -> Self {
self.with_string_fmt_debug_tag("relay-parent", relay_parent)
}
#[inline(always)]
pub fn with_claimed_validator_index(self, claimed_validator_index: ValidatorIndex) -> Self {
self.with_string_tag("claimed-validator", &claimed_validator_index.0)
}
#[inline(always)]
pub fn with_pov(mut self, pov: &PoV) -> Self {
self.add_pov(pov);
self
}
/// Add an additional int tag to the span without consuming.
///
/// Should be used sparingly, introduction of new types is preferred.
#[inline(always)]
pub fn with_int_tag(mut self, tag: &'static str, i: i64) -> Self {
self.add_int_tag(tag, i);
self
}
#[inline(always)]
pub fn with_uint_tag(mut self, tag: &'static str, u: u64) -> Self {
self.add_uint_tag(tag, u);
self
}
#[inline(always)]
pub fn with_string_fmt_debug_tag<V: fmt::Debug>(mut self, tag: &'static str, val: V) -> Self {
self.add_string_tag(tag, format!("{:?}", val));
self
}
/// Adds the `FollowsFrom` relationship to this span with respect to the given one.
#[inline(always)]
pub fn add_follows_from(&mut self, other: &Self) {
match (self, other) {
(Self::Enabled(ref mut inner), Self::Enabled(ref other_inner)) =>
inner.add_follows_from(&other_inner),
_ => {},
}
}
/// Add a PoV hash meta tag with lazy hash evaluation, without consuming the span.
#[inline(always)]
pub fn add_pov(&mut self, pov: &PoV) {
if self.is_enabled() {
// avoid computing the PoV hash if jaeger is not enabled
self.add_string_fmt_debug_tag("pov", pov.hash());
}
}
#[inline(always)]
pub fn add_para_id(&mut self, para_id: ParaId) {
self.add_int_tag("para-id", u32::from(para_id) as i64);
}
/// Add a string tag, without consuming the span.
pub fn add_string_tag<V: ToString>(&mut self, tag: &'static str, val: V) {
match self {
Self::Enabled(ref mut inner) => inner.add_string_tag(tag, val.to_string().as_str()),
Self::Disabled => {},
}
}
/// Add a string tag, without consuming the span.
pub fn add_string_fmt_debug_tag<V: fmt::Debug>(&mut self, tag: &'static str, val: V) {
match self {
Self::Enabled(ref mut inner) =>
inner.add_string_tag(tag, format!("{:?}", val).as_str()),
Self::Disabled => {},
}
}
pub fn add_int_tag(&mut self, tag: &'static str, value: i64) {
match self {
Self::Enabled(ref mut inner) => inner.add_int_tag(tag, value),
Self::Disabled => {},
}
}
pub fn add_uint_tag(&mut self, tag: &'static str, value: u64) {
match self {
Self::Enabled(ref mut inner) => inner.add_int_tag(tag, value as i64),
Self::Disabled => {},
}
}
/// Check whether jaeger is enabled
/// in order to avoid computational overhead.
pub const fn is_enabled(&self) -> bool {
match self {
Span::Enabled(_) => true,
_ => false,
}
}
/// Obtain the trace identifier for this set of spans.
pub fn trace_id(&self) -> Option<TraceIdentifier> {
match self {
Span::Enabled(inner) => Some(inner.trace_id().get()),
_ => None,
}
}
}
impl std::fmt::Debug for Span {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
write!(f, "<jaeger span>")
}
}
impl From<Option<mick_jaeger::Span>> for Span {
fn from(src: Option<mick_jaeger::Span>) -> Self {
if let Some(span) = src {
Self::Enabled(span)
} else {
Self::Disabled
}
}
}
impl From<mick_jaeger::Span> for Span {
fn from(src: mick_jaeger::Span) -> Self {
Self::Enabled(src)
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::Jaeger;
// make sure to not use `::repeat_*()` based samples, since this does not verify endianness
const RAW: [u8; 32] = [
0xFF, 0xAA, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x78, 0x89, 0x9A, 0xAB, 0xBC, 0xCD, 0xDE,
0xEF, 0x00, 0x01, 0x02, 0x03, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C,
0x0E, 0x0F,
];
#[test]
fn hash_derived_identifier_is_leading_16bytes() {
let candidate_hash = dbg!(Hash::from(&RAW));
let trace_id = dbg!(hash_to_trace_identifier(candidate_hash));
for (idx, (a, b)) in candidate_hash
.as_bytes()
.iter()
.take(16)
.zip(trace_id.to_be_bytes().iter())
.enumerate()
{
assert_eq!(*a, *b, "Index [{}] does not match: {} != {}", idx, a, b);
}
}
#[test]
fn extra_tags_do_not_change_trace_id() {
Jaeger::test_setup();
let candidate_hash = dbg!(Hash::from(&RAW));
let trace_id = hash_to_trace_identifier(candidate_hash);
let span = Span::new(candidate_hash, "foo");
assert_eq!(span.trace_id(), Some(trace_id));
let span = span.with_int_tag("tag", 7i64);
assert_eq!(span.trace_id(), Some(trace_id));
}
}