telemetry_->start() ran at the end of ApplicationImp::start(), after
overlay_->start(). Spans are emitted well before that, during setup():
beginConsensus() runs the first consensus round there. SpanGuard drops a
span whenever the global Telemetry instance is not yet live, so that
round's spans were never recorded.
Move the start into setup(), behind a new startTelemetry() seam, right
after the node identity is known. getNodeIdentity() needs only the
cmdline, the config, or the wallet DB, and initRelationalDatabase()
has already created the latter -- the adjacent peerReservations_ load
proves it is usable -- so the identity block moves up with it.
The new position is bounded on both sides: after initRelationalDatabase()
because the identity needs the wallet DB and a DB failure aborts setup(),
and before beginConsensus() because that emits the first spans.
SpanGuard::span() and freshRoot() joined the prefix and suffix by hand with
reserve() + three append() calls. std::format expresses the same join in one
line; libstdc++ has shipped <format> since GCC 13 and the project floor is
GCC 15.2 (BUILD.md), so it is available on every supported compiler.
Both callers are noexcept and std::format can throw (std::bad_alloc, or
std::format_error on a malformed spec), so an escaping exception would
terminate the process. The call is wrapped in a joinSpanName() helper that
catches and returns std::nullopt; the caller then returns a null guard, which
is the same degrade-to-no-op path already taken when telemetry is disabled.
Telemetry must never bring the node down.
One helper rather than a try/catch at each site keeps both call sites a single
line and puts the exception-safety requirement in one documented place.
Addresses a review comment on PR #6437.
Conflict in OpenTelemetryPlan/03-implementation-strategy.md §3.9: both
branches independently fixed the same defect (stale hand-maintained line
counts) in different ways.
- 1b (0ff947454c) stripped the Lines Added / Lines Changed columns but kept
the §3.9.1 and §3.9.2 tables.
- 1a (3ad525a48a) removed both sections outright.
Resolved in favour of 1a's deletion. The tables were pre-implementation
estimates with no source of truth, so trimming the columns only defers the
next drift; the file/component lists duplicated §3.1's directory tree, which
1b already keeps current (DiscardFlag.h, FilteringSpanProcessor). Keeping the
upstream resolution also stops the same conflict recurring on 1c..10.
1b-specific content verified intact after the merge: §3.1 retains the
DiscardFlag.h entry, the FilteringSpanProcessor and discard() annotations,
and the TracingInstrumentation removal. No references to the deleted
sections remain in any plan doc.
The §3.9.1 "Files Modified Summary" and §3.9.2 "Detailed File Impact"
tables carried hand-maintained per-component line counts that had drifted
from the plan: the Lines Added column summed to 1,565 while the Total row
claimed ~1,670. Files (34) and Lines Changed (120) reconciled, so only the
Added total was stale — residue from expanding Core Telemetry 5 -> 11 files.
Rather than patch one cell, remove both tables. They were pre-implementation
estimates with no source of truth, so any figure in them drifts again on the
next phase. §3.1's directory tree remains the canonical list of the 11 new
telemetry files, and §3.9.3-3.9.7 (risk, architectural impact, backward
compatibility, rollback) carry the assessment without inventing line counts.
No references to the removed sections exist elsewhere in the plan docs.
