{"record":{"id":"2c3c68041199fd35","repo":"redis/go-redis","slug":"redis-client-tracking-prefix-requires-bcast","errorCode":null,"errorMessage":"redis: CLIENT TRACKING PREFIX requires BCAST","messagePattern":"redis: CLIENT TRACKING PREFIX requires BCAST","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"error","filePath":"commands.go","lineNumber":634,"sourceCode":"}\n\n// ClientTrackingOff disables tracking on the serving connection. See\n// ClientTracking for the pooled-client and built-in-CSC caveats.\nfunc (c cmdable) ClientTrackingOff(ctx context.Context) *StatusCmd {\n\tcmd := NewStatusCmd(ctx, \"client\", \"tracking\", \"off\")\n\t_ = c(ctx, cmd)\n\treturn cmd\n}\n\nfunc validateClientTrackingOptions(opt *ClientTrackingOptions) error {\n\tif opt.OptIn && opt.OptOut {\n\t\treturn errors.New(\"redis: CLIENT TRACKING OPTIN and OPTOUT are mutually exclusive\")\n\t}\n\tif opt.Bcast && (opt.OptIn || opt.OptOut) {\n\t\treturn errors.New(\"redis: CLIENT TRACKING BCAST cannot be combined with OPTIN or OPTOUT\")\n\t}\n\tif len(opt.Prefixes) > 0 && !opt.Bcast {\n\t\treturn errors.New(\"redis: CLIENT TRACKING PREFIX requires BCAST\")\n\t}\n\treturn nil\n}\n\nfunc appendClientTrackingOptions(args []interface{}, opt *ClientTrackingOptions) []interface{} {\n\tif opt.Redirect != 0 {\n\t\targs = append(args, \"redirect\", opt.Redirect)\n\t}\n\tif opt.Bcast {\n\t\targs = append(args, \"bcast\")\n\t}\n\tfor _, p := range opt.Prefixes {\n\t\targs = append(args, \"prefix\", p)\n\t}\n\tif opt.OptIn {\n\t\targs = append(args, \"optin\")\n\t}\n\tif opt.OptOut {","sourceCodeStart":616,"sourceCodeEnd":652,"githubUrl":"https://github.com/redis/go-redis/blob/c5cad058c72f58370553b48566302303cf8a2e89/commands.go#L616-L652","documentation":"Error returned by validateClientTrackingOptions (commands.go:634) when ClientTrackingOptions specifies one or more Prefixes but Bcast is not enabled. Redis only supports key-prefix patterns with CLIENT TRACKING in BCAST mode, since prefixes define a broadcast invalidation scope rather than specific keys. Fix: set Bcast: true in ClientTrackingOptions when using Prefixes.","triggerScenarios":"Calling ClientTracking with ClientTrackingOptions{Prefixes: []string{\"user:\"}} and no Bcast: true.","commonSituations":"Trying targeted invalidation for key prefixes without realizing prefixes only work in broadcast mode; partially copying a BCAST example and omitting Bcast.","solutions":["Add Bcast: true to the options when specifying Prefixes.","Drop the Prefixes field if broadcast mode is not desired.","Validate options before the call."],"exampleFix":"// before\nrdb.ClientTracking(ctx, &redis.ClientTrackingOptions{Prefixes: []string{\"user:\"}})\n// after\nrdb.ClientTracking(ctx, &redis.ClientTrackingOptions{Bcast: true, Prefixes: []string{\"user:\"}})","handlingStrategy":"validation","validationCode":"func validTracking(o *redis.ClientTrackingOptions) bool {\n    return o != nil && (len(o.Prefixes) == 0 || o.Bcast)\n}","typeGuard":null,"tryCatchPattern":"if err := rdb.ClientTracking(ctx, opt).Err(); err != nil {\n    if strings.Contains(err.Error(), \"PREFIX requires BCAST\") {\n        // add Bcast: true and retry\n    }\n}","preventionTips":["Always pair Prefixes with Bcast: true.","Add a constructor that auto-sets Bcast when Prefixes are provided."],"tags":["client-tracking","validation","options"],"backgroundTag":"client-tracking-options-invalid","analyzedSha":"c5cad058c72f58370553b48566302303cf8a2e89","analyzedAt":"2026-09-01T06:50:53.388Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}