Remove redundant metrics which were deprecated in 0.27.0.

1 files changed, 11 insertions, 0 deletions

diff --git a/docs/metrics-howto.rst b/docs/metrics-howto.rst

index 8acc479bc3..5e2d7c52ec 100644
--- a/docs/metrics-howto.rst
+++ b/docs/metrics-howto.rst
@@ -34,6 +34,17 @@ How to monitor Synapse metrics using Prometheus
    Restart prometheus.
 
 
+Deprecated metrics removed in 0.28.0
+------------------------------------
+
+Synapse 0.28.0 removes all of the metrics deprecated by 0.27.0, which are those
+listed under "Old name" below. This has been done to reduce the bandwidth used
+by gathering metrics and the storage requirements for the Prometheus server, as
+well as reducing CPU overhead for both Synapse and Prometheus.
+
+Administrators should update any alerts or monitoring dashboards to use the
+"New name" listed below.
+
 Block and response metrics renamed for 0.27.0
 ---------------------------------------------