copy from xml/en/docs/stream/ngx_stream_upstream_module.xml
copy to xml/en/docs/stream/ngx_stream_upstream_hc_module.xml
--- a/xml/en/docs/stream/ngx_stream_upstream_module.xml
+++ b/xml/en/docs/stream/ngx_stream_upstream_hc_module.xml
@@ -6,18 +6,26 @@
 
 <!DOCTYPE module SYSTEM "../../../../dtd/module.dtd">
 
-<module name="Module ngx_stream_upstream_module"
-        link="/en/docs/stream/ngx_stream_upstream_module.html"
+<module name="Module ngx_stream_upstream_hc_module"
+        link="/en/docs/stream/ngx_stream_upstream_hc_module.html"
         lang="en"
-        rev="24">
+        rev="1">
 
 <section id="summary">
 
 <para>
-The <literal>ngx_stream_upstream_module</literal> module (1.9.0)
-is used to define groups of servers that can be referenced
-by the <link doc="ngx_stream_proxy_module.xml" id="proxy_pass"/>
-directive.
+The <literal>ngx_stream_upstream_hc_module</literal> module (1.9.0)
+allows enabling periodic health checks of the servers in a
+<link doc="ngx_stream_upstream_module.xml" id="upstream">group</link>.
+The server group must reside in the
+<link doc="ngx_stream_upstream_module.xml" id="zone">shared memory</link>.
+</para>
+
+<para>
+<note>
+This module is available as part of our
+<commercial_version>commercial subscription</commercial_version>.
+</note>
 </para>
 
 </section>
@@ -27,47 +35,20 @@ directive.
 
 <para>
 <example>
-upstream <emphasis>backend</emphasis> {
-    hash $remote_addr consistent;
-
-    server backend1.example.com:12345  weight=5;
-    server backend2.example.com:12345;
-    server unix:/tmp/backend3;
-
-    server backup1.example.com:12345   backup;
-    server backup2.example.com:12345   backup;
-}
-
-server {
-    listen 12346;
-    proxy_pass <emphasis>backend</emphasis>;
-}
-</example>
-</para>
-
-<para>
-Dynamically configurable group,
-available as part of our
-<commercial_version>commercial subscription</commercial_version>:
-<example>
-resolver 10.0.0.1;
-
-upstream <emphasis>dynamic</emphasis> {
-    zone upstream_dynamic 64k;
+upstream tcp {
+    zone upstream_tcp 64k;
 
     server backend1.example.com:12345 weight=5;
     server backend2.example.com:12345 fail_timeout=5s slow_start=30s;
     server 192.0.2.1:12345            max_fails=3;
-    server backend3.example.com:12345 resolve;
-    server backend4.example.com       service=http resolve;
 
     server backup1.example.com:12345  backup;
     server backup2.example.com:12345  backup;
 }
 
 server {
-    listen 12346;
-    proxy_pass <emphasis>dynamic</emphasis>;
+    listen     12346;
+    proxy_pass tcp;
     health_check;
 }
 </example>
@@ -78,420 +59,6 @@ server {
 
 <section id="directives" name="Directives">
 
-<directive name="upstream">
-<syntax block="yes"><value>name</value></syntax>
-<default/>
-<context>stream</context>
-
-<para>
-Defines a group of servers.
-Servers can listen on different ports.
-In addition, servers listening on TCP and UNIX-domain sockets
-can be mixed.
-</para>
-
-<para>
-Example:
-<example>
-upstream backend {
-    server backend1.example.com:12345 weight=5;
-    server 127.0.0.1:12345            max_fails=3 fail_timeout=30s;
-    server unix:/tmp/backend2;
-    server backend3.example.com:12345 resolve;
-
-    server backup1.example.com:12345  backup;
-}
-</example>
-</para>
-
-<para>
-By default, connections are distributed between the servers using a
-weighted round-robin balancing method.
-In the above example, each 7 connections will be distributed as follows:
-5 connections go to <literal>backend1.example.com:12345</literal>
-and one connection to each of the second and third servers.
-If an error occurs during communication with a server, the connection will
-be passed to the next server, and so on until all of the functioning
-servers will be tried.
-If communication with all servers fails, the connection will be closed.
-</para>
-
-</directive>
-
-
-<directive name="server">
-<syntax><value>address</value> [<value>parameters</value>]</syntax>
-<default/>
-<context>upstream</context>
-
-<para>
-Defines the <value>address</value> and other <value>parameters</value>
-of a server.
-The address can be specified as a domain name or IP address
-with an obligatory port, or as a UNIX-domain socket path
-specified after the “<literal>unix:</literal>” prefix.
-A domain name that resolves to several IP addresses defines
-multiple servers at once.
-</para>
-
-<para>
-The following parameters can be defined:
-<list type="tag">
-
-<tag-name id="weight">
-<literal>weight</literal>=<value>number</value>
-</tag-name>
-<tag-desc>
-sets the weight of the server, by default, 1.
-</tag-desc>
-
-<tag-name id="max_conns">
-<literal>max_conns</literal>=<value>number</value>
-</tag-name>
-<tag-desc>
-limits the maximum <value>number</value> of simultaneous
-connections to the proxied server (1.11.5).
-Default value is zero, meaning there is no limit.
-If the server group does not reside in the <link id="zone">shared memory</link>,
-the limitation works per each worker process.
-<note>
-Prior to version 1.11.5, this parameter was available as part of our
-<commercial_version>commercial subscription</commercial_version>.
-</note>
-</tag-desc>
-
-<tag-name id="max_fails">
-<literal>max_fails</literal>=<value>number</value>
-</tag-name>
-<tag-desc>
-sets the number of unsuccessful attempts to communicate with the server
-that should happen in the duration set by the <literal>fail_timeout</literal>
-parameter to consider the server unavailable for a duration also set by the
-<literal>fail_timeout</literal> parameter.
-By default, the number of unsuccessful attempts is set to 1.
-The zero value disables the accounting of attempts.
-Here, an unsuccessful attempt is an error or timeout
-while establishing a connection with the server.
-</tag-desc>
-
-<tag-name id="fail_timeout">
-<literal>fail_timeout</literal>=<value>time</value>
-</tag-name>
-<tag-desc>
-sets
-<list type="bullet">
-
-<listitem>
-the time during which the specified number of unsuccessful attempts to
-communicate with the server should happen to consider the server unavailable;
-</listitem>
-
-<listitem>
-and the period of time the server will be considered unavailable.
-</listitem>
-
-</list>
-By default, the parameter is set to 10 seconds.
-</tag-desc>
-
-<tag-name id="backup">
-<literal>backup</literal>
-</tag-name>
-<tag-desc>
-marks the server as a backup server.
-Connections to the backup server will be passed
-when the primary servers are unavailable.
-</tag-desc>
-
-<tag-name id="down">
-<literal>down</literal>
-</tag-name>
-<tag-desc>
-marks the server as permanently unavailable.
-</tag-desc>
-
-</list>
-</para>
-
-<para>
-Additionally,
-the following parameters are available as part of our
-<commercial_version>commercial subscription</commercial_version>:
-<list type="tag">
-
-<tag-name id="resolve">
-<literal>resolve</literal>
-</tag-name>
-<tag-desc>
-monitors changes of the IP addresses
-that correspond to a domain name of the server,
-and automatically modifies the upstream configuration
-without the need of restarting nginx.
-The server group must reside in the <link id="zone">shared memory</link>.
-<para>
-In order for this parameter to work,
-the <link doc="ngx_stream_core_module.xml" id="resolver"/> directive
-must be specified in the
-<link doc="ngx_stream_core_module.xml" id="stream"/> block.
-Example:
-<example>
-stream {
-    resolver 10.0.0.1;
-
-    upstream u {
-        zone ...;
-        ...
-        server example.com:12345 resolve;
-    }
-}
-</example>
-</para>
-</tag-desc>
-
-<tag-name id="service">
-<literal>service</literal>=<value>name</value>
-</tag-name>
-<tag-desc>
-enables resolving of DNS
-<link url="https://tools.ietf.org/html/rfc2782">SRV</link>
-records and sets the service <value>name</value> (1.9.13).
-In order for this parameter to work, it is necessary to specify
-the <link id="resolve"/> parameter for the server
-and specify a hostname without a port number.
-<para>
-If the service name does not contain a dot (“<literal>.</literal>”), then
-the <link url="https://tools.ietf.org/html/rfc2782">RFC</link>-compliant name
-is constructed
-and the TCP protocol is added to the service prefix.
-For example, to look up the
-<literal>_http._tcp.backend.example.com</literal> SRV record,
-it is necessary to specify the directive:
-<example>
-server backend.example.com service=http resolve;
-</example>
-If the service name contains one or more dots, then the name is constructed
-by joining the service prefix and the server name.
-For example, to look up the <literal>_http._tcp.backend.example.com</literal>
-and <literal>server1.backend.example.com</literal> SRV records,
-it is necessary to specify the directives:
-<example>
-server backend.example.com service=_http._tcp resolve;
-server example.com service=server1.backend resolve;
-</example>
-</para>
-
-<para>
-Highest-priority SRV records
-(records with the same lowest-number priority value)
-are resolved as primary servers,
-the rest of SRV records are resolved as backup servers.
-If the <link id="backup"/> parameter is specified for the server,
-high-priority SRV records are resolved as backup servers,
-the rest of SRV records are ignored.
-</para>
-</tag-desc>
-
-<tag-name id="slow_start">
-<literal>slow_start</literal>=<value>time</value>
-</tag-name>
-<tag-desc>
-sets the <value>time</value> during which the server will recover its weight
-from zero to a nominal value, when unhealthy server becomes
-<link id="health_check">healthy</link>,
-or when the server becomes available after a period of time
-it was considered <link id="fail_timeout">unavailable</link>.
-Default value is zero, i.e. slow start is disabled.
-<note>
-The parameter cannot be used along with the
-<link id="hash"/> load balancing method.
-</note>
-</tag-desc>
-
-</list>
-</para>
-
-<para>
-<note>
-If there is only a single server in a group, <literal>max_fails</literal>,
-<literal>fail_timeout</literal> and <literal>slow_start</literal> parameters
-are ignored, and such a server will never be considered unavailable.
-</note>
-</para>
-
-</directive>
-
-
-<directive name="zone">
-<syntax><value>name</value> [<value>size</value>]</syntax>
-<default/>
-<context>upstream</context>
-
-<para>
-Defines the <value>name</value> and <value>size</value> of the shared
-memory zone that keeps the group’s configuration and run-time state that are
-shared between worker processes.
-Several groups may share the same zone.
-In this case, it is enough to specify the zone size only once.
-</para>
-
-<para>
-Additionally,
-as part of our <commercial_version>commercial subscription</commercial_version>,
-such groups allow changing the group membership
-or modifying the settings of a particular server
-without the need of restarting nginx.
-The configuration is accessible via a special location
-handled by
-<link doc="../http/ngx_http_upstream_conf_module.xml" id="upstream_conf"/>.
-</para>
-
-</directive>
-
-
-<directive name="state">
-<syntax><value>file</value></syntax>
-<default/>
-<context>upstream</context>
-<appeared-in>1.9.7</appeared-in>
-
-<para>
-Specifies a <value>file</value> that keeps the state
-of the dynamically configurable group.
-</para>
-
-<para>
-Examples:
-<example>
-state /var/lib/nginx/state/servers.conf; # path for Linux
-state /var/db/nginx/state/servers.conf;  # path for FreeBSD
-</example>
-</para>
-
-<para>
-The state is currently limited to the list of servers with their parameters.
-The file is read when parsing the configuration and is updated each time
-the upstream configuration is
-<link doc="ngx_http_upstream_conf_module.xml" id="upstream_conf">changed</link>.
-Changing the file content directly should be avoided.
-The directive cannot be used
-along with the <link id="server"/> directive.
-</para>
-
-<para>
-<note>
-Changes made during
-<link doc="../control.xml" id="reconfiguration">configuration reload</link>
-or <link doc="../control.xml" id="upgrade">binary upgrade</link>
-can be lost.
-</note>
-</para>
-
-<para>
-<note>
-This directive is available as part of our
-<commercial_version>commercial subscription</commercial_version>.
-</note>
-</para>
-
-</directive>
-
-
-<directive name="hash">
-<syntax><value>key</value> [<literal>consistent</literal>]</syntax>
-<default/>
-<context>upstream</context>
-
-<para>
-Specifies a load balancing method for a server group
-where client-server mapping is based on the hashed <value>key</value> value.
-The <value>key</value> can contain text, variables,
-and their combinations (1.11.2).
-Usage example:
-<example>
-hash $remote_addr;
-</example>
-Note that adding or removing a server from the group
-may result in remapping most of the keys to different servers.
-The method is compatible with the
-<link url="http://search.cpan.org/perldoc?Cache%3A%3AMemcached">Cache::Memcached</link>
-Perl library.
-</para>
-
-<para>
-If the <literal>consistent</literal> parameter is specified,
-the <link url="http://www.last.fm/user/RJ/journal/2007/04/10/392555/">ketama</link>
-consistent hashing method will be used instead.
-The method ensures that only a few keys
-will be remapped to different servers
-when a server is added to or removed from the group.
-This helps to achieve a higher cache hit ratio for caching servers.
-The method is compatible with the
-<link url="http://search.cpan.org/perldoc?Cache%3A%3AMemcached%3A%3AFast">Cache::Memcached::Fast</link>
-Perl library with the <value>ketama_points</value> parameter set to 160.
-</para>
-
-</directive>
-
-
-<directive name="least_conn">
-<syntax/>
-<default/>
-<context>upstream</context>
-
-<para>
-Specifies that a server group should use a load balancing method
-where a connection
-is passed to the server with the least number of active connections,
-taking into account weights of servers.
-If there are several such servers, they are tried in turn using a
-weighted round-robin balancing method.
-</para>
-
-</directive>
-
-
-<directive name="least_time">
-<syntax>
-    <literal>connect</literal> |
-    <literal>first_byte</literal> |
-    <literal>last_byte</literal>
-    [<literal>inflight</literal>]</syntax>
-<default/>
-<context>upstream</context>
-
-<para>
-Specifies that a group should use a load balancing method where a connection
-is passed to the server with the least average time and
-least number of active connections, taking into account weights of servers.
-If there are several such servers, they are tried in turn using a
-weighted round-robin balancing method.
-</para>
-
-<para>
-If the <literal>connect</literal> parameter is specified,
-time to connect to the upstream server is used.
-If the <literal>first_byte</literal> parameter is specified,
-time to receive the first byte of data is used.
-If the <literal>last_byte</literal> is specified,
-time to receive the last byte of data is used.
-If the <literal>inflight</literal> parameter is specified (1.11.6),
-incomplete connections are also taken into account.
-<note>
-Prior to version 1.11.6,
-incomplete connections were taken into account by default.
-</note>
-</para>
-
-<para>
-<note>
-This directive is available as part of our
-<commercial_version>commercial subscription</commercial_version>.
-</note>
-</para>
-
-</directive>
-
-
 <directive name="health_check">
 <syntax>[<value>parameters</value>]</syntax>
 <default/>
@@ -499,7 +66,7 @@ This directive is available as part of o
 
 <para>
 Enables periodic health checks of the servers in a
-<link id="upstream">group</link>.
+<link doc="ngx_stream_upstream_module.xml" id="upstream">group</link>.
 </para>
 
 <para>
@@ -576,7 +143,8 @@ parameters.
 <tag-desc>
 defines the port used when connecting to a server
 to perform a health check (1.9.7).
-By default, equals the <link id="server"/> port.
+By default, equals the
+<link doc="ngx_stream_upstream_module.xml" id="server"/> port.
 </tag-desc>
 
 <tag-name id="health_check_udp">
@@ -614,7 +182,8 @@ and referenced in the <literal>match</li
 </para>
 
 <para>
-The server group must reside in the <link id="zone">shared memory</link>.
+The server group must reside in the
+<link doc="ngx_stream_upstream_module.xml" id="zone">shared memory</link>.
 </para>
 
 <para>
@@ -623,13 +192,6 @@ a single failure of any check will make 
 considered unhealthy.
 </para>
 
-<para>
-<note>
-This directive is available as part of our
-<commercial_version>commercial subscription</commercial_version>.
-</note>
-</para>
-
 </directive>
 
 
@@ -645,13 +207,6 @@ Overrides the
 value for health checks.
 </para>
 
-<para>
-<note>
-This directive is available as part of our
-<commercial_version>commercial subscription</commercial_version>.
-</note>
-</para>
-
 </directive>
 
 
@@ -747,79 +302,8 @@ bytes of data obtained from the server a
 </note>
 </para>
 
-<para>
-<note>
-This directive is available as part of our
-<commercial_version>commercial subscription</commercial_version>.
-</note>
-</para>
-
 </directive>
 
 </section>
 
-
-<section id="variables" name="Embedded Variables">
-
-<para>
-The <literal>ngx_stream_upstream_module</literal> module
-supports the following embedded variables:
-<list type="tag">
-
-<tag-name id="var_upstream_addr"><var>$upstream_addr</var></tag-name>
-<tag-desc>
-keeps the IP address and port,
-or the path to the UNIX-domain socket of the upstream server (1.11.4).
-If several servers were contacted during proxying,
-their addresses are separated by commas, e.g.
-“<literal>192.168.1.1:12345, 192.168.1.2:12345, unix:/tmp/sock</literal>”.
-</tag-desc>
-
-<tag-name id="var_upstream_bytes_sent"><var>$upstream_bytes_sent</var></tag-name>
-<tag-desc>
-number of bytes sent to an upstream server (1.11.4).
-Values from several connections
-are separated by commas like addresses in the
-<link id="var_upstream_addr">$upstream_addr</link> variable.
-</tag-desc>
-
-<tag-name id="var_upstream_bytes_received"><var>$upstream_bytes_received</var></tag-name>
-<tag-desc>
-number of bytes received from an upstream server (1.11.4).
-Values from several connections
-are separated by commas like addresses in the
-<link id="var_upstream_addr">$upstream_addr</link> variable.
-</tag-desc>
-
-<tag-name id="var_upstream_connect_time"><var>$upstream_connect_time</var></tag-name>
-<tag-desc>
-time to connect to the upstream server (1.11.4);
-the time is kept in seconds with millisecond resolution.
-Times of several connections
-are separated by commas like addresses in the
-<link id="var_upstream_addr">$upstream_addr</link> variable.
-</tag-desc>
-
-<tag-name id="var_upstream_first_byte_time"><var>$upstream_first_byte_time</var></tag-name>
-<tag-desc>
-time to receive the first byte of data (1.11.4);
-the time is kept in seconds with millisecond resolution.
-Times of several connections
-are separated by commas like addresses in the
-<link id="var_upstream_addr">$upstream_addr</link> variable.
-</tag-desc>
-
-<tag-name id="var_upstream_session_time"><var>$upstream_session_time</var></tag-name>
-<tag-desc>
-session duration in seconds with millisecond resolution (1.11.4).
-Times of several connections
-are separated by commas like addresses in the
-<link id="var_upstream_addr">$upstream_addr</link> variable.
-</tag-desc>
-
-</list>
-</para>
-
-</section>
-
 </module>