Tag: Observability

Loki ingester encounters "object too large for cache" errors when attempting to store log entries exceeding memcache's configured size limit (typically 1MB). Large log lines remain in the ingester buffer causing continuous failed ingest attempts, pod health degradation, and eventual recycling.The accumulation of oversized entries can lead to buffer exhaustion and ingester instability.

Loki compactor encounters schema configuration mismatches when it finds index tables in object storagethat don't correspond to any configured schema period in the Loki configuration. This causes the compactorto skip compaction for those tables, leading to storage inefficiency and potential query performance degradation.The issue typically occurs after schema migrations, configuration changes, or when legacy data exists withdifferent table naming conventions.

Loki distributor encounters "empty ring" errors when attempting to send streams to pattern ingesters.This occurs when pattern ingestion is enabled in the configuration but no pattern-ingester pods are running or properly registered in the ring. The distributor's pattern-tee component cannot find anyavailable pattern ingesters to process pattern extraction, leading to high error spam in logs whilenormal log ingestion continues to function.

DataDog Agent encounters "empty targets meta in director local store" errors when attempting toretrieve remote configuration. This issue affects APM (Application Performance Monitoring) remoteconfiguration functionality in DataDog Agent versions between 7.61.0 and 7.68.0. The error preventsproper retrieval and parsing of remote configuration from DataDog's backend, causing APM tracerlibraries to fail when attempting to fetch dynamic configuration updates.

Grafana Mimir's distributor rejects incoming Prometheus series when the number of labelnames on a single series exceeds the configured per-tenant limit. When this occurs, logscontain the message "received a series whose number of labels exceeds the limit" and theaffected samples are dropped. This typically arises from excessive or dynamic labeling inscrape targets or relabeling rules that generate many unique label names per series.To adjust the per-tenant limit, configure the distributor with`-validation.max-label-names-per-series`. When deploying via the `mimir-distributed` Helmchart, set `mimir.structuredConfig.limits.max_label_names_per_series` to a higher value(default is 30). Increase limits cautiously to avoid cardinality explosions and memorypressure. Prefer reducing label names at the source where possible.

Loki ingester reports memcached errors indicating out-of-memory conditions while cachingobjects, logging messages such as "SERVER_ERROR out of memory storing object". When thisoccurs, cache writes fail and can lead to degraded ingestion performance, retries, andincreased memory pressure on the ingester.