Engineering Logs for Troubleshooting & Debugging
Problem During the execution of integration tests on a Jenkins build agent, the CI job fails with a connection timeout when trying to reach the Haystack API server. In some runs the logs also show DNS resolution failures. The failure aborts the test suite and marks the build as unstable. [2026-10-13 02:14:37] INFO – Starting … Read more
Problem: Haystack pod rejected by admission controller after adding GPU request When deploying a Haystack inference service to a GPU‑enabled Kubernetes cluster (A100/H100 nodes), the pod creation fails with an admission controller error. The pod never reaches the Pending state; instead the API server returns a 400 Bad Request response indicating an invalid or missing … Read more
Problem After a bulk indexing run of several hundred thousand documents, the Haystack SearchQuerySet latency spikes dramatically. The 95th‑percentile response time, which normally sits around 0.8 s, climbs to 5 s–12 s for simple term queries. The issue appears only after the indexing job finishes; during indexing the query latency remains low. Typical symptoms observed in production: API … Read more
Problem In a multi‑region replication deployment of Haystack, queries that should be served from any replica start failing with a 400 Bad Request error. The failure appears only after a recent configuration change that introduced a new sampling parameter in the haystack.yaml file. The symptom is observed across all regions, but the primary region shows … Read more
Problem During peak traffic periods the API gateway that fronts a Haystack‑based search service starts returning 504 Gateway Timeout, 502 Bad Gateway and occasional 429 Too Many Requests errors. The downstream Haystack document store logs show repeated failures when trying to fetch source documents from the cloud storage provider (e.g., AWS S3, GCP Cloud Storage, … Read more
Problem – RuntimeError in Haystack RAG Query Decomposition Under High Concurrency When a Haystack Retrieval‑Augmented Generation (RAG) pipeline receives a complex multi‑sentence query, the DecomposeQuery node spawns several sub‑queries that are sent to the retriever. Under load on a mixed NVIDIA A100/H100 GPU Kubernetes cluster, the pipeline aborts with a RuntimeError similar to: Traceback (most … Read more
Problem – Inference Queue Backlog During CI/CD Pipeline Execution Symptoms and Impact During automated testing and deployment steps, Haystack inference calls start to time out. Typical log excerpts look like: 2024-08-24 12:03:45,212 [celery.worker] ERROR QueueFullError: Inference queue is full (maxsize=100) 2024-08-24 12:03:48,019 [haystack.client] ERROR TimeoutError: Inference request timed out after 30 seconds 2024-08-24 12:04:01,877 [celery.worker] … Read more
Problem Description The Haystack /document_ingestion endpoint returns a 504 Gateway Timeout when ingesting large batches of documents under load. The orchestrator logs show: Orchestrator log: Job 42 terminated due to timeout (504 Gateway Timeout) TaskTimeoutError: Task exceeded time limit of 300 seconds worker_1 | celery.exceptions.SoftTimeLimitExceeded ERROR haystack.pipeline.base: Execution exceeded max_execution_time Typical impact: Batch indexing jobs … Read more
Problem Description In a Haystack deployment that runs multi‑GPU training jobs, the scheduler pod remains Pending with events such as: 0/5 nodes are available: 5 Insufficient gpu or FailedScheduling: pod has unschedulable: no nodes match node selector These failures prevent the haystack-scheduler from launching training workers, effectively blocking any multi‑GPU training pipeline. Root Cause Analysis … Read more
Problem Description In a Kubernetes‑deployed Haystack microservice stack, the generate endpoint returns text that continues past the user‑specified stop sequence. The symptom is observable both in API responses and in logs such as: GenerationError: stop token not found in generated sequence – stop=’\nAnswer:’ Traceback (most recent call last): File “/app/pipelines/generation.py”, line 112, in _run_generation generated … Read more