Hacktoberfest 2026: los issues que los mantenedores marcaron para octubre, abiertos y aptos para principiantes. Explorar issues de Hacktoberfest

[Feature]: Low-rate, self-triggering TCs are reported Delayed/Timing-out by definition, even when data is complete

Abierto
  • ¿Algo no está bien?
#446 0 comentarios 0 reacciones 0 asignados Ver en GitHub

Nadie ha tomado este issue todavía.

Evaluación

Dificultad
3/5
Tiempo estimado
Medio día
Aptitud para principiantes
65/100
Tipo de issue
Nueva funcionalidad
Claridad
Bien especificado
Estado de actividad
Activo
Stack tecnológico
cpp
Área
backend

Línea de trabajo

Examine DefaultRequestHandlerModel::get_fragment_pieces() where the buffer timestamp comparison causes false Delayed/Timing-out classifications for self-triggering TCs. Override the completeness check for TC/TA objects to determine if the found fragments already cover the requested time window instead of requiring a newer buffer entry. The fix is complete when these TCs no longer show kIncomplete/kRequestWindowAfterBuffer status during data-taking runs.

Escrito por el modelo de indexación a partir del texto del issue.

Descripción

enhancement
Description

Some pictures to help with explanation:

Current state of trigger buffers for a common data-taking mode (using low rate random trigger):
Image

Unpacking the data:
Image

Description:
For a low-rate, self-triggering TC (e.g. Random, CTB), the dataflow request to read back its own TC-buffer entry is, by default, built from that same object's own time range. DefaultRequestHandlerModel::get_fragment_pieces() only reports kFound if the buffer's newest entry is timestamped strictly after the requested window's end. For an object reading back itself, both sides of that comparison come from the same object — so the comparison is unwinnable by construction. Every such request is classified Delayed, then Timing-out once retries exhaust (def-tc-handler-2), throughout the run.

Looking at the data, TC fragments and objects are actually present and complete — n_inputs==0 is expected for these TC types (no TPG->TAG chain) — despite being tagged kIncomplete/kRequestWindowAfterBuffer. This isn't specific to Random TCs: Hardware_Signal fragments show the identical pattern, for the same structural reason.

Potential impact radius

???

Reason for change

Dashboards/alerting built on these counters are currently unusable for these sources — they show permanent failure regardless of actual system health, so real problems in these sources can't be distinguished from this expected-by-construction behavior.

Suggested implementations
  • Override the request-handler's completeness check for TC(/TA) (the base classes are virtual and already overridden for TPs) to be object-aware: "does what we found already cover the requested window" instead of "is there something newer in the buffer." Fixes the single-source, no-merging case; doesn't generalize to multi-TC-source/merged-decision configs.
  • Per-source watermarking: each source publishes its own "processed up to T" marker independently. Avoids the single-point-of-failure/cross-source-delay problem that broke the earlier in-stream heartbeat/zipper attempt in trigger, since there's no shared ordering/merge point.
Image
  • Other options (using time sync, override the readout request 'to take all that is available without retries' for this case, ...)
Testing suggestions

No response

Anything else?

No response

Lenguaje dominante
C++
Estrellas
0
Forks
8
Merge medio
3 h 50 min
PR fusionados (30 d)
1

Preparar el entorno

  • Sin Dockerfile ni archivo de Docker Compose
  • Tiene una plantilla de pull request
  • Sin guía de contribución

Primeros pasos

  1. Lee el issue completo y luego la guía de contribución del proyecto.
  2. Comenta en el issue que vas a ocuparte — evita que dos personas hagan lo mismo.
  3. Haz un fork del repositorio y trabaja en una rama.
  4. Abre un pull request que haga referencia al número del issue.

Más de DUNE-DAQ/trigger

Todos los issues de DUNE-DAQ/trigger

Issues similares

Más issues de C++

Recibe los nuevos issues en tu correo

Un resumen breve de issues de GitHub para principiantes.