change docs https to xrefs

Author: aimurphy

docs/modules/ROOT/pages/backfill-cli.adoc

@@ -64,7 +64,7 @@ The Pulsar-admin extension is packaged with the IBM Elite Support for Apache Pul
 
 . Move the generated NAR archive to the /cliextensions folder of your Pulsar installation (e.g. /pulsar/cliextensions).
 . Modify the client.conf file of your Pulsar installation to include: `customCommandFactories=cassandra-cdc`.
-. Run the following command (this assumes the https://docs.datastax.com/en/dse/6.8/installing/tarball-dse.html[default tarball installation of DSE]):
+. Run the following command (this assumes the xref:6.9@dse:installing:tarball-dse.adoc[default tarball installation of DSE]):
 +
 [source,shell]
 ----

docs/modules/ROOT/pages/monitor.adoc

@@ -146,7 +146,7 @@ pulsar_source_user_metric__sum{tenant="public",namespace="public/default",name="
 
 == Monitoring and Alerting resources
 
-* The change agent exposes metrics with https://docs.datastax.com/en/planning/dse/metrics-alerts.html[JMX], a technology within Java that provides tools for managing and monitoring applications.
-* https://docs.datastax.com/en/opscenter/6.8/overview/opscenter-about.html[DSE Ops Center] can collect these exposed metrics for visualization and alerts, and pass them on to https://docs.datastax.com/en/monitoring/ops-use-metrics-collector.html[DSE Metrics Collector] for additional integration with Prometheus and Grafana.
+* The change agent exposes metrics with xref:planning:ROOT:metrics-alerts.adoc[JMX], a technology within Java that provides tools for managing and monitoring applications.
+* xref:opscenter:overview:opscenter-about.adoc[DSE Ops Center] can collect these exposed metrics for visualization and alerts, and pass them on to xref:monitoring:ROOT:ops-use-metrics-collector.adoc[DSE Metrics Collector] for additional integration with Prometheus and Grafana.
 * The https://github.com/datastax/metric-collector-for-apache-cassandra[Metrics Collector for Apache Cassandra] with Prometheus and Grafana dashboards provides the same functionality as DSE Metrics Collector, built on the well-supported collectd agent.
 * Other monitoring tools like https://github.com/prometheus/jmx_exporter[JMX Exporter] by Prometheus are available, but may require additional tuning.