{"record":{"id":"096957cfdcaea627","repo":"vxcontrol/pentagi","slug":"failed-to-delete-assistant-d-w","errorCode":null,"errorMessage":"failed to delete assistant %d: %w","messagePattern":"failed to delete assistant (.+?): %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"backend/pkg/controller/flow.go","lineNumber":615,"sourceCode":"\n\treturn nil, fmt.Errorf(\"assistant %d not found\", assistantID)\n}\n\nfunc (fw *flowWorker) DeleteAssistant(ctx context.Context, assistantID int64) error {\n\tfw.awsMX.Lock()\n\tdefer fw.awsMX.Unlock()\n\n\taw, ok := fw.aws[assistantID]\n\tif ok {\n\t\tif err := aw.Finish(ctx); err != nil {\n\t\t\treturn fmt.Errorf(\"failed to finish assistant %d: %w\", assistantID, err)\n\t\t}\n\n\t\tdelete(fw.aws, assistantID)\n\t}\n\n\tif assistant, err := fw.flowCtx.DB.DeleteAssistant(ctx, assistantID); err != nil {\n\t\treturn fmt.Errorf(\"failed to delete assistant %d: %w\", assistantID, err)\n\t} else {\n\t\tfw.flowCtx.Publisher.AssistantDeleted(ctx, assistant)\n\t}\n\n\treturn nil\n}\n\nfunc (fw *flowWorker) ListAssistants(ctx context.Context) []AssistantWorker {\n\tfw.awsMX.Lock()\n\tdefer fw.awsMX.Unlock()\n\n\tassistants := make([]AssistantWorker, 0, len(fw.aws))\n\tfor _, aw := range fw.aws {\n\t\tassistants = append(assistants, aw)\n\t}\n\n\tslices.SortFunc(assistants, func(a, b AssistantWorker) int {\n\t\treturn int(a.GetAssistantID() - b.GetAssistantID())","sourceCodeStart":597,"sourceCodeEnd":633,"githubUrl":"https://github.com/vxcontrol/pentagi/blob/ea665308baaff015b226f308438a68d929d0f29b/backend/pkg/controller/flow.go#L597-L633","documentation":"DeleteAssistant wraps the error from fw.flowCtx.DB.DeleteAssistant(ctx, assistantID) — the database delete of the assistant row. The in-memory worker was already finished and removed; only the persistence layer failed, so the AssistantDeleted event is not published and the assistant record remains in the database.","triggerScenarios":"Calling DeleteAssistant when the SQLC/database DeleteAssistant query fails: DB connection dropped, row already deleted (constraint or NoRows behavior), transaction deadlock, or context cancelled during the query.","commonSituations":"PostgreSQL restarted or connection pool exhausted under load; two concurrent DeleteAssistant calls racing on the same assistantID; migration drift leaving the assistants table in an unexpected state; long-running request whose ctx times out mid-query.","solutions":["Inspect the wrapped DB error: if it's a connection/pool issue, verify PostgreSQL is reachable and pool settings are adequate.","Handle the already-deleted race: check for sql.ErrNoRows / duplicate-key semantics and treat idempotent deletes as success.","Retry the delete with a fresh context after the DB recovers; the assistant is already gone from memory.","Ensure the DB migrations are current (goose) so the assistants table schema matches the queries."],"exampleFix":"// before\nctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond)\ndefer cancel()\nerr := fw.DeleteAssistant(ctx, id) // ctx expires mid-DELETE\n// after\nctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)\ndefer cancel()\nerr := fw.DeleteAssistant(ctx, id)","handlingStrategy":"retry","validationCode":"if err := db.PingContext(ctx); err != nil {\n    return fmt.Errorf(\"database unreachable before delete: %w\", err)\n}","typeGuard":"func isNoRows(err error) bool {\n    return errors.Is(err, sql.ErrNoRows)\n}","tryCatchPattern":"if err := fw.DeleteAssistant(ctx, id); err != nil {\n    if errors.Is(err, sql.ErrNoRows) {\n        return nil // already deleted; idempotent success\n    }\n    if isTransientDBErr(err) {\n        return retryWithBackoff(3, func() error { return fw.DeleteAssistant(ctx, id) })\n    }\n    return err\n}","preventionTips":["Treat delete as idempotent: handle already-deleted rows as success.","Use contexts with adequate deadlines for DB operations.","Monitor PostgreSQL pool saturation before bulk assistant operations.","Avoid concurrent DeleteAssistant calls for the same ID."],"tags":["go","database","postgres","delete"],"backgroundTag":"database-delete-failed","analyzedSha":"ea665308baaff015b226f308438a68d929d0f29b","analyzedAt":"2026-09-01T14:16:31.421Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}