Files
hermes-agent/agent/context_compressor_telemetry.py
Teknium c2383a6806 feat(compression): one prepared summary per compaction, newer messages join the tail
Maintainer ruling on the prepared-compaction design, plus the review findings
(ours and Greptile's) on #144684:

- One pass per compaction. The extension passes (a new summary call every ~8k
  tokens of growth) and the "stale after one tail budget" check are gone: the
  summary splices at its own boundary and every message after it, however
  many, stays verbatim in the tail. No second summary is ever paid for.
- The splice check compares message structure, not text: role, tool call
  ids/names, tool result ids, plus the durable message_uid where both sides
  carry one. Plugins that rewrite text in place (redaction, pre-compaction
  notes) no longer throw the summary away; a dropped/inserted message or a
  rewind into the window (new message_uids) still misses. This also settles
  the fingerprint gap on input_text/output_text parts: text is not compared.
- A pass that recovered on the main model after the summary model failed now
  hands that over on a splice, as an inline call would: summary_model goes
  sticky to the main model, and the "configured compression model failed"
  warning reaches the user. The attempt telemetry carries the pass's aux call
  (model, tokens, duration, fallback) and a new prepared_summary flag.
- The first compaction that needs memory-provider context stops further
  passes for the agent; each would have been discarded and paid twice.
- Turn-end passes are skipped for cron runs and delegated children, whose
  sessions end with the turn.
2026-10-25 22:55:11 -07:00

163 lines
9.6 KiB
Python

"""Content-free per-attempt compression telemetry for ContextCompressor.
Split from ``agent/context_compressor.py`` (file size cap), which imports it at module level; this module
must never import that module at module level (import cycle).
"""
from __future__ import annotations
import uuid
from typing import Any
from agent.model_metadata import estimate_messages_tokens_rough
from agent.model_metadata_token_memo import forget_message_token_memo
def _safe_int(value: Any) -> int | None:
"""Best-effort integer coercion for telemetry fields."""
try:
return int(value)
except (TypeError, ValueError):
return None
class CompressionTelemetryMixin:
"""Per-attempt telemetry dict: seeded at attempt start, filled by each compression phase."""
def _begin_compression_telemetry(
self, *, current_tokens: int | None, attempt_id: str | None = None, session_id: str | None = None,
trigger_source: str | None = None,
) -> dict[str, Any]:
"""Initialize content-free per-attempt compression telemetry."""
seed = getattr(self, "_compression_telemetry_seed", None)
seed = seed if isinstance(seed, dict) else {}
attempt_id = attempt_id or seed.get("attempt_id")
session_id = session_id or seed.get("session_id")
trigger_source = trigger_source or seed.get("trigger_source")
telemetry: dict[str, Any] = {
"event": "compression_attempt", "attempt_id": attempt_id or uuid.uuid4().hex,
"session_id": session_id or "", "trigger_source": trigger_source or "unknown",
"overflow_reason": seed.get("overflow_reason"),
"main_provider": self.provider or "", "main_model": self.model or "",
"main_context_limit": _safe_int(self.context_length),
"current_estimated_tokens": _safe_int(current_tokens),
"effective_threshold": _safe_int(self.threshold_tokens), "protected_head_tokens": None,
"protected_tail_tokens": None, "middle_window_tokens": None, "prellm_skip_count": 0,
"aux_prompt_tokens": None, "aux_output_reservation": None, "aux_provider": "", "aux_model": "",
"effective_aux_context": None, "fit_margin": None, "chunking": False, "chunk_count": 0,
"total_duration_ms": None, "aux_call_duration_ms": None, "queue_wait_ms": None, "prompt_build_ms": None,
"time_to_first_progress_ms": None, "summary_generation_ms": None, "commit_ms": None,
"fallback_used": False, "commit_status": "unknown", "split_status": "unknown", "failure_class": None,
# Lean-sampling coverage (filled by _record_summary_input_coverage; None on the legacy path).
"summary_input_chars": None, "summary_input_sampled_chars": None, "summary_input_omitted_chars": None,
"summary_input_record_count": None, "summary_input_sampled_record_count": None,
"summary_input_elided_record_count": None,
# Candidate effect is captured by the compressor, then replaced with the exact committed shape.
"method": "none", "items_dropped": 0, "messages_before": None, "messages_after": None,
"tokens_before": None, "tokens_after": None, "tokens_reclaimed": None, "token_count_method": None,
"tool_results_pruned": None, "reasoning_items_pruned": None, "has_focus_topic": False,
# True when the summary came from an opt-in prepared (background) pass (compression.prepare_ahead).
"prepared_summary": False,
}
self._active_compression_telemetry = self._last_compression_telemetry = telemetry
return telemetry
def _record_compression_regions(
self, *, head_messages: list[dict[str, Any]], middle_messages: list[dict[str, Any]],
tail_messages: list[dict[str, Any]],
) -> None:
telemetry = getattr(self, "_active_compression_telemetry", None)
if isinstance(telemetry, dict):
telemetry["protected_head_tokens"] = estimate_messages_tokens_rough(head_messages)
telemetry["middle_window_tokens"] = estimate_messages_tokens_rough(middle_messages)
telemetry["protected_tail_tokens"] = estimate_messages_tokens_rough(tail_messages)
def _record_aux_compression_call(
self, *, prompt_messages: list[dict[str, Any]], max_tokens: int | None, duration_ms: int,
aux_provider: str | None = None, aux_model: str | None = None,
effective_aux_context: int | None = None, phase_timings: dict[str, Any] | None = None,
) -> None:
telemetry = getattr(self, "_active_compression_telemetry", None)
if not isinstance(telemetry, dict):
return
telemetry["aux_prompt_tokens"] = estimate_messages_tokens_rough(prompt_messages)
# The summary prompt is built fresh per attempt and never estimated again; don't let the memo pin it.
forget_message_token_memo(prompt_messages)
telemetry["aux_output_reservation"] = _safe_int(max_tokens)
if aux_provider:
telemetry["aux_provider"] = aux_provider
if aux_model:
telemetry["aux_model"] = aux_model
if effective_aux_context is not None:
telemetry["effective_aux_context"] = _safe_int(effective_aux_context)
if telemetry["effective_aux_context"] is not None and telemetry["aux_prompt_tokens"] is not None:
telemetry["fit_margin"] = (telemetry["effective_aux_context"] - telemetry["aux_prompt_tokens"]
- (telemetry["aux_output_reservation"] or 0))
telemetry["aux_call_duration_ms"] = (telemetry.get("aux_call_duration_ms") or 0) + max(0, int(duration_ms))
for key in ("queue_wait_ms", "prompt_build_ms", "time_to_first_progress_ms", "summary_generation_ms", "commit_ms"):
if not isinstance(phase_timings, dict) or key not in phase_timings:
continue
value = _safe_int(phase_timings[key])
# Wait and generation phases accumulate across retries; the rest are point readings.
accumulate = key in {"queue_wait_ms", "summary_generation_ms"} and value is not None
telemetry[key] = (telemetry.get(key) or 0) + value if accumulate else value
def _note_aux_route_fallback(self, route: dict[str, str]) -> None:
"""``call_llm`` answered the summary from a fallback route after the configured one failed (dead
endpoint, quota): record it like the compressor's own main-model fallback, so telemetry says
``fallback_used`` and, when the main model answered, the user is told their compression model is broken."""
failed_model = route.get("failed_model")
if not failed_model:
return
telemetry = getattr(self, "_active_compression_telemetry", None)
if isinstance(telemetry, dict):
telemetry["fallback_used"] = True
telemetry["failure_class"] = telemetry.get("failure_class") or "aux_model_fallback"
# The user warning says "summarised with your main model": only the main-agent route earns it, never a
# fallback_chain entry that happens to share the model name on another provider.
if str(route.get("fallback_label") or "").startswith("main-agent("):
self._last_aux_model_failure_model = failed_model
failure = route.get("failure") or "unknown error"
self._last_aux_model_failure_error = failure if len(failure) <= 220 else failure[:217].rstrip() + "..."
def _compression_method(self) -> str:
"""How the summary that replaced the middle window was produced."""
if getattr(self, "_last_summary_fallback_used", False):
return "deterministic_fallback"
if getattr(self, "_last_aux_model_failure_error", None):
return "aux_fallback_main"
return "llm_summary"
def _record_compression_effect(
self, messages_before: int, compressed: list[dict[str, Any]], tokens_before: int, tool_results_pruned: int,
reasoning_items_pruned: int,
) -> None:
"""Record what a finished rewrite did. ``tokens_before`` and the after count are rough message-only
estimates (system prompt and tool schemas excluded), so they compare like for like."""
telemetry = getattr(self, "_active_compression_telemetry", None)
if not isinstance(telemetry, dict):
return
tokens_after = estimate_messages_tokens_rough(compressed)
telemetry.update(
method=self._compression_method(), items_dropped=getattr(self, "_last_summary_dropped_count", 0) or 0,
messages_before=messages_before, messages_after=len(compressed), tokens_before=tokens_before,
tokens_after=tokens_after, tokens_reclaimed=tokens_before - tokens_after,
token_count_method="estimate_rough", tool_results_pruned=tool_results_pruned,
reasoning_items_pruned=reasoning_items_pruned,
)
def _record_committed_compression_effect(
self, messages_before: list[dict[str, Any]], messages_after: list[dict[str, Any]],
) -> None:
"""Replace candidate counts with the exact transcript shape that crossed the commit boundary."""
telemetry = getattr(self, "_active_compression_telemetry", None)
if not isinstance(telemetry, dict):
return
tokens_before = estimate_messages_tokens_rough(messages_before)
tokens_after = estimate_messages_tokens_rough(messages_after)
telemetry.update(
messages_before=len(messages_before), messages_after=len(messages_after),
tokens_before=tokens_before, tokens_after=tokens_after,
tokens_reclaimed=tokens_before - tokens_after, token_count_method="estimate_rough",
)