EnvKafkaVersion       = "MINIO_AUDIT_KAFKA_VERSION"
	EnvKafkaQueueDir      = "MINIO_AUDIT_KAFKA_QUEUE_DIR"
	EnvKafkaQueueSize     = "MINIO_AUDIT_KAFKA_QUEUE_SIZE"

	loggerTargetNamePrefix = "logger-"
	auditTargetNamePrefix  = "audit-"
)

var (
	errInvalidQueueSize = errors.New("invalid queue_size value")
	errInvalidBatchSize = errors.New("invalid batch_size value")
)

	WebhookAuthToken  = "auth_token"
	WebhookQueueDir   = "queue_dir"
	WebhookQueueLimit = "queue_limit"
	WebhookClientCert = "client_cert"
	WebhookClientKey  = "client_key"

	EnvWebhookEnable     = "MINIO_NOTIFY_WEBHOOK_ENABLE"
	EnvWebhookEndpoint   = "MINIO_NOTIFY_WEBHOOK_ENDPOINT"
	EnvWebhookAuthToken  = "MINIO_NOTIFY_WEBHOOK_AUTH_TOKEN"
	EnvWebhookQueueDir   = "MINIO_NOTIFY_WEBHOOK_QUEUE_DIR"

	saramatls "github.com/IBM/sarama/tools/tls"
)

// Kafka input constants
const (
	KafkaBrokers          = "brokers"
	KafkaTopic            = "topic"
	KafkaQueueDir         = "queue_dir"
	KafkaQueueLimit       = "queue_limit"
	KafkaTLS              = "tls"
	KafkaTLSSkipVerify    = "tls_skip_verify"
	KafkaTLSClientAuth    = "tls_client_auth"
	KafkaSASL             = "sasl"
	KafkaSASLUsername     = "sasl_username"

	NATSPassword      = "password"
	NATSToken         = "token"
	NATSTLS           = "tls"
	NATSTLSSkipVerify = "tls_skip_verify"
	NATSPingInterval  = "ping_interval"
	NATSQueueDir      = "queue_dir"
	NATSQueueLimit    = "queue_limit"
	NATSCertAuthority = "cert_authority"
	NATSClientCert    = "client_cert"
	NATSClientKey     = "client_key"

	// Streaming constants - deprecated
	NATSStreaming                   = "streaming"

	notificationEventsSkippedTotalMD    = NewCounterMD(notificationEventsSkippedTotal, "Events that were skipped to be sent to the targets due to the in-memory queue being full")
)

// loadClusterNotificationMetrics - `MetricsLoaderFn` for cluster notification metrics.
func loadClusterNotificationMetrics(_ context.Context, m MetricValues, _ *metricsCache) error {

	Events []Name `xml:"Event" json:"Event"`
}

// Queue - represents elements inside <QueueConfiguration>
type Queue struct {
	common
	ARN ARN `xml:"Queue"`
}

// UnmarshalXML - decodes XML data.
func (q *Queue) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
	// Make subtype to avoid recursive UnmarshalXML().
	type queue Queue
	parsedQueue := queue{}

MinIO server allows to throttle incoming requests:

- limit the number of active requests allowed across the cluster
- limit the wait duration for each request in the queue

These values are enabled using server's configuration or environment variables.

## Examples

### Configuring connection limit

"},{"key":"connection_string","value":""},{"key":"table","value":""},{"key":"queue_dir","value":""},{"key":"queue_limit","value":"0"},{"key":"max_open_connections","value":"2"}]},"notify_redis":{"_":[{"key":"enable","value":"off"},{"key":"format","value":"namespace"},{"key":"address","value":""},{"key":"key","value":""},{"key":"password","value":""},{"key":"user","value":""},{"key":"queue_dir","value":""},{"key":"queue_limit","value":"0"}]},"notify_webhook":{"_":[{"key":"enable","value":"off"},{...

	getProgressFunc := s3Select.getProgress
	if !s3Select.Progress.Enabled {
		getProgressFunc = nil
	}
	writer := newMessageWriter(w, getProgressFunc)

	var outputQueue []sql.Record

	// Create queue based on the type.
	if s3Select.statement.IsAggregated() {
		outputQueue = make([]sql.Record, 0, 1)
	} else {
		outputQueue = make([]sql.Record, 0, 100)
	}
	var err error
	sendRecord := func() bool {

				})
				metrics = append(metrics, MetricV2{
					Description: MetricDescription{
						Namespace: minioNamespace,
						Subsystem: notifySubsystem,
						Name:      "target_queue_length",
						Help:      "Number of events currently staged in the queue_dir configured for the target",
						Type:      gaugeMetric,
					},
					VariableLabels: map[string]string{"target_id": id.ID, "target_name": id.Name},