Update monitor-health.adoc (#872)

modules/manage/partials/monitor-health.adoc

@@ -137,11 +137,12 @@ rate(redpanda_kafka_request_latency_seconds_count{redpanda_request="produce"}[5m
 
 ==== Internal RPC latency
 
-To monitor Redpanda internal RPC latency, use the xref:reference:public-metrics-reference.adoc#redpanda_rpc_request_latency_seconds[`redpanda_rpc_request_latency_seconds`] histogram. For example, create a query for the 99th percentile latency:
+To monitor Redpanda internal RPC latency, use the  xref:reference:public-metrics-reference.adoc#redpanda_rpc_request_latency_seconds[`redpanda_rpc_request_latency_seconds`] histogram with 
+the `redpanda_server="internal"` label. For example, create a query for the 99th percentile latency:
 
 [,promql]
 ----
-histogram_quantile(0.99, (sum(rate(redpanda_rpc_request_latency_seconds_bucket[5m])) by (le, provider, region, instance, namespace, pod, redpanda_server)))
+histogram_quantile(0.99, (sum(rate(redpanda_rpc_request_latency_seconds_bucket{redpanda_server="internal"}[5m])) by (le, provider, region, instance, namespace, pod)))
 ----
 
 You can monitor the rate of internal RPC requests with xref:reference:public-metrics-reference.adoc#redpanda_rpc_request_latency_seconds[`redpanda_rpc_request_latency_seconds`] histogram's count:
@@ -263,4 +264,4 @@ rate(redpanda_rest_proxy_request_errors_total[5m])
 
 === Data transforms
 
-See xref:develop:data-transforms/monitor.adoc[].
+See xref:develop:data-transforms/monitor.adoc[].