Update transport docs and settings for changes (#36913)

This is related to #36652. In 7.0 we plan to deprecate a number of
settings that make reference to the concept of a tcp transport. We
mostly just have a single transport type now (based on tcp). Settings
should only reference tcp if they are referring to socket options. This
commit updates the settings in the docs. Additionally it adds a missing
remote compress setting to the docs.

docs/reference/modules/discovery/zen.asciidoc

@@ -43,7 +43,7 @@ The list of hosts is set using the `discovery.zen.ping.unicast.hosts` static
 setting.  This is either an array of hosts or a comma-delimited string. Each
 value should be in the form of `host:port` or `host` (where `port` defaults to
 the setting `transport.profiles.default.port` falling back to
-`transport.tcp.port` if not set). Note that IPv6 hosts must be bracketed. The
+`transport.port` if not set). Note that IPv6 hosts must be bracketed. The
 default for this setting is `127.0.0.1, [::1]`
 
 Additionally, the `discovery.zen.ping.unicast.resolve_timeout` configures the

docs/reference/modules/network.asciidoc

@@ -50,7 +50,7 @@ range.
 +
 Defaults to `9200-9300`.
 
-`transport.tcp.port`::
+`transport.port`::
 
 Port to bind for communication between nodes. Accepts a single value or a
 range. If a range is specified, the node will bind to the first available port

docs/reference/modules/remote-clusters.asciidoc

@@ -161,6 +161,14 @@ PUT _cluster/settings
   are sent according to the global `transport.ping_schedule` setting, which
   defaults to ``-1` meaning that pings are not sent.
 
+`cluster.remote.${cluster_alias}.transport.compress`::
+
+  Per cluster boolean setting that enables you to configure compression for
+  requests to a specific remote cluster. This setting impacts only requests
+  sent to the remote cluster. If the inbound request is compressed,
+  Elasticsearch compresses the response. If unset, the global
+  `transport.compress` is used as the fallback setting.
+
 [float]
 [[retrieve-remote-clusters-info]]
 === Retrieving remote clusters info

docs/reference/modules/transport.asciidoc

@@ -15,21 +15,21 @@ being the ideal solution for scatter (broadcast) / gather operations such
 as search in Elasticsearch.
 
 [float]
-=== TCP Transport
+=== Transport Settings
 
-The TCP transport is an implementation of the transport module using
-TCP. It allows for the following settings:
+The internal transport communicates over TCP. You can configure it with the
+following settings:
 
 [cols="<,<",options="header",]
 |=======================================================================
 |Setting |Description
-|`transport.tcp.port` |A bind port range. Defaults to `9300-9400`.
+|`transport.port` |A bind port range. Defaults to `9300-9400`.
 
 |`transport.publish_port` |The port that other nodes in the cluster
 should use when communicating with this node. Useful when a cluster node
-is behind a proxy or firewall and the `transport.tcp.port` is not directly
+is behind a proxy or firewall and the `transport.port` is not directly
 addressable from the outside. Defaults to the actual port assigned via
-`transport.tcp.port`.
+`transport.port`.
 
 |`transport.bind_host` |The host address to bind the transport service to. Defaults to `transport.host` (if set) or `network.bind_host`.
 
@@ -38,11 +38,11 @@ addressable from the outside. Defaults to the actual port assigned via
 |`transport.host` |Used to set the `transport.bind_host` and the `transport.publish_host` Defaults to `transport.host` or `network.host`.
 
 
-|`transport.tcp.connect_timeout` |The socket connect timeout setting (in
+|`transport.connect_timeout` |The connect timeout for initiating a new connection (in
 time setting format). Defaults to `30s`.
 
-|`transport.tcp.compress` |Set to `true` to enable compression (`DEFLATE`)
-between all nodes. Defaults to `false`.
+|`transport.compress` |Set to `true` to enable compression (`DEFLATE`) between
+all nodes. Defaults to `false`.
 
 |`transport.ping_schedule` | Schedule a regular application-level ping message
 to ensure that transport connections between nodes are kept alive. Defaults to
@@ -57,7 +57,7 @@ It also uses the common
 <<modules-network,network settings>>.
 
 [float]
-==== TCP Transport Profiles
+==== Transport Profiles
 
 Elasticsearch allows you to bind to multiple ports on different interfaces by
 the use of transport profiles. See this example configuration
@@ -82,11 +82,11 @@ example above:
 * `port`: The port to bind to
 * `bind_host`: The host to bind
 * `publish_host`: The host which is published in informational APIs
-* `tcp_no_delay`: Configures the `TCP_NO_DELAY` option for this socket
-* `tcp_keep_alive`: Configures the `SO_KEEPALIVE` option for this socket
-* `reuse_address`: Configures the `SO_REUSEADDR` option for this socket
-* `tcp_send_buffer_size`: Configures the send buffer size of the socket
-* `tcp_receive_buffer_size`: Configures the receive buffer size of the socket
+* `tcp.no_delay`: Configures the `TCP_NO_DELAY` option for this socket
+* `tcp.keep_alive`: Configures the `SO_KEEPALIVE` option for this socket
+* `tcp.reuse_address`: Configures the `SO_REUSEADDR` option for this socket
+* `tcp.send_buffer_size`: Configures the send buffer size of the socket
+* `tcp.receive_buffer_size`: Configures the receive buffer size of the socket
 
 [float]
 ==== Long-lived idle connections
@@ -97,7 +97,7 @@ period of time. Nonetheless, Elasticsearch requires these connections to remain
 open, and it can disrupt the operation of the cluster if any inter-node
 connections are closed by an external influence such as a firewall. It is
 important to configure your network to preserve long-lived idle connections
-between Elasticsearch nodes, for instance by leaving `tcp_keep_alive` enabled
+between Elasticsearch nodes, for instance by leaving `tcp.keep_alive` enabled
 and ensuring that the keepalive interval is shorter than any timeout that might
 cause idle connections to be closed, or by setting `transport.ping_schedule` if
 keepalives cannot be configured.

docs/reference/settings/audit-settings.asciidoc

@@ -176,8 +176,8 @@ To index audit events to a remote {es} cluster, you configure the following
 `xpack.security.audit.index.client.hosts`::
 Specifies a comma-separated list of `host:port` pairs. These hosts should be
 nodes in the remote cluster. If you are using default values for the 
-<<common-network-settings,`transport.tcp.port`>> setting, you can omit the 
-`port` value. Otherwise, it must match the `transport.tcp.port` setting. 
+<<common-network-settings,`transport.port`>> setting, you can omit the
+`port` value. Otherwise, it must match the `transport.port` setting.
 
 `xpack.security.audit.index.client.cluster.name`::
 Specifies the name of the remote cluster.

docs/reference/setup/important-settings/discovery-settings.asciidoc

@@ -26,7 +26,7 @@ discovery.zen.ping.unicast.hosts:
    - seeds.mydomain.com <2>
 --------------------------------------------------
 <1> The port will default to `transport.profiles.default.port` and fallback to
-    `transport.tcp.port` if not specified.
+    `transport.port` if not specified.
 <2> A hostname that resolves to multiple IP addresses will try all resolved
     addresses.
 

server/src/test/java/org/elasticsearch/discovery/single/SingleNodeDiscoveryIT.java

@@ -129,7 +129,7 @@ public Settings nodeSettings(int nodeOrdinal) {
                          * We align the port ranges of the two as then with zen discovery these two
                          * nodes would find each other.
                          */
-                        .put("transport.tcp.port", port + "-" + (port + 5 - 1))
+                        .put("transport.port", port + "-" + (port + 5 - 1))
                         .build();
             }
 

test/framework/src/main/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java

@@ -2602,34 +2602,34 @@ public void testProfileSettings() {
             .build();
 
         Settings transportSettings = Settings.builder()
-            .put("transport.tcp_no_delay", enable)
+            .put("transport.tcp.no_delay", enable)
             .put("transport.tcp.keep_alive", enable)
             .put("transport.tcp.reuse_address", enable)
             .put("transport.tcp.send_buffer_size", "43000b")
             .put("transport.tcp.receive_buffer_size", "42000b")
             .put("transport.publish_host", "the_publish_host")
-            .put("transport.tcp.port", "9700-9800")
+            .put("transport.port", "9700-9800")
             .put("transport.bind_host", "the_bind_host")
             .put(globalSettings2)
             .build();
 
         Settings transportSettings2 = Settings.builder()
-            .put("transport.tcp_no_delay", !enable)
+            .put("transport.tcp.no_delay", !enable)
             .put("transport.tcp.keep_alive", !enable)
             .put("transport.tcp.reuse_address", !enable)
             .put("transport.tcp.send_buffer_size", "5b")
             .put("transport.tcp.receive_buffer_size", "6b")
             .put("transport.publish_host", "another_publish_host")
-            .put("transport.tcp.port", "9702-9802")
+            .put("transport.port", "9702-9802")
             .put("transport.bind_host", "another_bind_host")
             .put(globalSettings2)
             .build();
         Settings defaultProfileSettings = Settings.builder()
-            .put("transport.profiles.default.tcp_no_delay", enable)
-            .put("transport.profiles.default.tcp_keep_alive", enable)
+            .put("transport.profiles.default.tcp.no_delay", enable)
+            .put("transport.profiles.default.tcp.keep_alive", enable)
             .put("transport.profiles.default.reuse_address", enable)
-            .put("transport.profiles.default.send_buffer_size", "43000b")
-            .put("transport.profiles.default.receive_buffer_size", "42000b")
+            .put("transport.profiles.default.tcp.send_buffer_size", "43000b")
+            .put("transport.profiles.default.tcp.receive_buffer_size", "42000b")
             .put("transport.profiles.default.port", "9700-9800")
             .put("transport.profiles.default.publish_host", "the_publish_host")
             .put("transport.profiles.default.bind_host", "the_bind_host")
@@ -2638,11 +2638,11 @@ public void testProfileSettings() {
             .build();
 
         Settings profileSettings = Settings.builder()
-            .put("transport.profiles.some_profile.tcp_no_delay", enable)
-            .put("transport.profiles.some_profile.tcp_keep_alive", enable)
+            .put("transport.profiles.some_profile.tcp.no_delay", enable)
+            .put("transport.profiles.some_profile.tcp.keep_alive", enable)
             .put("transport.profiles.some_profile.reuse_address", enable)
-            .put("transport.profiles.some_profile.send_buffer_size", "43000b")
-            .put("transport.profiles.some_profile.receive_buffer_size", "42000b")
+            .put("transport.profiles.some_profile.tcp.send_buffer_size", "43000b")
+            .put("transport.profiles.some_profile.tcp.receive_buffer_size", "42000b")
             .put("transport.profiles.some_profile.port", "9700-9800")
             .put("transport.profiles.some_profile.publish_host", "the_publish_host")
             .put("transport.profiles.some_profile.bind_host", "the_bind_host")

x-pack/docs/en/security/auditing/forwarding-logs.asciidoc

@@ -20,7 +20,7 @@ xpack.security.audit.index.client.cluster.name: logging-prod <2>
 xpack.security.audit.index.client.xpack.security.user: myuser:mypassword <3>
 --------------------------------------------------
 <1> A list of hosts in the remote cluster. If you are not using the default 
-value for the `transport.tcp.port` setting on the remote cluster, you must 
+value for the `transport.port` setting on the remote cluster, you must
 specify the appropriate port number (prefixed by a colon) after each host. 
 <2> The remote cluster name.
 <3> A valid user and password, which must have authority to create the