diff --git a/solr/CHANGES.txt b/solr/CHANGES.txt
index 93fc6ff64d0..2e54724220b 100644
--- a/solr/CHANGES.txt
+++ b/solr/CHANGES.txt
@@ -47,6 +47,19 @@ Jetty 9.4.14.v20181114
 Upgrade Notes
 ----------------------
 
+* Solr nodes can now listen and serve HTTP/2 requests. Most of internal requests (sent by UpdateShardHandler, HttpShardHandler)
+  Http2SolrClient is used. Since by default, internal requests are sent by using HTTP/2,
+  Solr 8.0 nodes can't talk to old nodes (7.x). However we can follow these steps to do rolling updates:
+  - Do rolling updates as normally, but the Solr 8.0 nodes must start with -Dsolr.http1=true as startup parameter.
+    By using this parameter internal requests are sent by using HTTP/1.1
+  - When all nodes are upgraded to 8.0, restart them, this time -Dsolr.http1 parameter should be removed.
+
+* ALPN is not supported in Java 8 or lower version therefore when a node started in Java 8 or a lower version with SSL enabled,
+  it will send and can only be able to handle HTTP/1.1 requests. In case of using SSL Java 9 or latter versions are recommended.
+
+* Custom AuthenticationPlugin must provide its own setup for Http2SolrClient through
+  implementing HttpClientBuilderPlugin.setup, if not internal requests can't be authenticated.    
+
 * LUCENE-7996: The 'func' query parser now returns scores that are equal to 0
   when a negative value is produced. This change is due to the fact that
   Lucene now requires scores to be positive. (Adrien Grand)
@@ -70,7 +83,18 @@ Upgrade Notes
 
 * SOLR-12593: The "extraction" contrib (Solr Cell) no longer does any date parsing, and thus no longer has the
   "date.formats" configuration.  To ensure date strings are properly parsed, use ParseDateFieldUpdateProcessorFactory
-  (an URP) commonly registered with the name "parse-date" in "schemaless mode".  (David Smiley, Bar Rotstein)
+  (an URP) commonly registered with the name "parse-date" in "schemaless mode".  (David Smiley, Bar Rotstein) 
+
+* SOLR-12643: Since Http2SolrClient does not support exposing connections related metrics. These metrics are no longer
+  available 'QUERY.httpShardHandler.{availableConnections, leasedConnections, maxConnections, pendingConnections}',
+  'UPDATE.updateShardHandler.{availableConnections, leasedConnections, maxConnections, pendingConnections}'
+
+* SOLR-12605: UpdateShardHandler's updateOnlyClient is now a Http2SolrClient (previous HttpSolrClient). This new
+  client does not support 'maxConnections','maxConnectionsPerHost' parameters.
+
+* SOLR-12640: HttpShardHandlerFactory's defaultClient is now a Http2SolrClient (previous HttpSolrClient). This new
+  client does not support 'maxConnections','maxConnectionsPerHost' parameters. LBHttpSolrClient.Req and LBHttpSolrClient.Rsp
+  are marked as deprecated, uses LBSolrClient.Req and LBSolrClient.Rsp instead.
 
 * SOLR-12754: The UnifiedHighlighter hl.weightMatches now defaults to true.  If there are unforseen highlight problems,
   this may be the culprit.
@@ -116,6 +140,8 @@ New Features
 
 * SOLR-12730: Implement staggered SPLITSHARD requests in IndexSizeTrigger. (ab)
 
+* SOLR-12639: Umbrella JIRA for adding support HTTP/2 (Cao Manh Dat)
+
 Bug Fixes
 ----------------------