First make sure you are familiar with the design of gold by reading the architectural overview doc.
The following dashboard is for the skia-public instances: https://grafana2.skia.org/d/m8kl1amWk/gold-panel-public.
The following dashboard is for the skia-corp instances: https://skia-mon.corp.goog/d/m8kl1amWk/gold-panel-corp
Some things to look for:
To determine load of various services, we can use the fact that there are defer metrics2.FuncTimer().Stop() all around the code base to get a rough idea of QPS/load.
On https://prom2.skia.org or https://skia-prom.corp.goog, try doing the search:
rate(timer_func_timer_ns_count{appgroup=~"gold.+"}[1m])
You can even search by package, e.g. all Firestore related functions:
rate(timer_func_timer_ns_count{package=~".+fs_.+"}[1m])
If you find something problematic, then timer_func_timer_ns{appgroup=~"gold.+"}/1000000000 is how to see how many milliseconds a given timer actually took.
Logs for Gold instances in skia-public/skia-corp are in the usual GKE container grouping, for example: https://console.cloud.google.com/logs/viewer?project=skia-public&resource=container&logName=projects%2Fskia-public%2Flogs%2Fgold-flutter-skiacorrectness
Items below here should include target links from alerts.
Gold has a pubsub subscription for events created in its bucket. This alert means we haven‘t successfully ingested a file in over 24 hours. This could mean that ingestion is throwing errors on every file or the repo isn’t very busy.
This has happened before because gitsync stopped, so check that out too.
Key metrics: liveness_gold_bt_s{metric=“last-successful-process”}, liveness_last_successful_git_sync_s
Gold regularly polls its GCS buckets for any files that were not successfully ingested via PubSub event when the file was created (aka “streaming”). This alert means it has been at least 10 minutes since this happened; this should happen every 5 minutes or so, even in not-busy repos.
This has happened before because gitsync stopped, so check that out too.
Key metrics: liveness_gold_bt_s{metric=“since-last-run”}, liveness_last_successful_git_sync_s
This alert means gold was unable to calculate which ignore rules were expired. Search the logs for “ignorestore.go” to get a hint as to why.
This has happened before because of manually-edited (and incorrect) Datastore data so maybe check out the raw data https://console.cloud.google.com/datastore/entities;kind=IgnoreRule;ns=gold-flutter/query/kind?project=skia-public and https://console.cloud.google.com/datastore/entities;kind=HelperRecentKeys;ns=gold-flutter/query/kind?project=skia-public
Key metrics: gold_expired_ignore_rules_monitoring
Too much time has elapsed since Gold noticed a commit. This occasionally is a false positive if a commit simply hasn't landed in the repo we are tracking.
In the past, this has indicated git-sync might have had problems, so check out the logs of the relevant git-sync instance.
Key metrics: gold_last_commit_age_s
Gold has noticed there is a newer commit available for processing, but hasn't succeeded on moving forward.
This would usually indicate an issue with Gold itself, so check the logs of the Gold instance.
Key metrics: gold_last_commit_age_s
Gold has been unable to re-process some of the data used to keep the frontend up to date.
This hasn't happened yet, but likely would indicate a problem with something in golden/go/status.go
Key metrics: liveness_gold_status_monitoring_s
The recent rate of errors for ingestion is high, it is typically well below 0.1. See the error logs for the given instance for more.
The recent rate of errors for the diff server is high, it is typically well below 0.1. See the error logs for the given instance for more.
The recent rate of errors for the main gold instance is high, it is typically well below 0.1. See the error logs for the given instance for more.
Currently, our baseline servers use QuerySnapshotIterators when fetching expectations out of Firestore. Those run on goroutines. This alert will be active if any of those sharded iterators are down, thus yielding stale results.
To fix, delete one baseliner pod of the affected instance at a time until all of them have restarted and are healthy.
If this alert fires, it probably means the related logic in fs_expstore needs to be rethought.
This section covers both GoldCorruptTryJobParamMaps and GoldTryJobResultsIncompleteData which are probably both active or both inactive. TryJobResults are stored in firestore in a separate document from the Param maps that store the keys so as to lower request data. However, if somehow data was only partially uploaded or corrupted, there might be TryJobResults that reference Params that don't exist.
If this happens, we might need to re-ingest the TryJob data to re-construct the missing data.