From: Jim Jagielski Date: Tue, 13 Sep 2011 18:04:59 +0000 (+0000) Subject: List worker flags in a more useful manner and note Drain X-Git-Tag: 2.3.15~264 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ff9469c6a2bdc148c4228623f1a35e56242a38dc;p=apache List worker flags in a more useful manner and note Drain git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1170273 13f79535-47bb-0310-9956-ffa450edef68 --- diff --git a/docs/manual/mod/mod_proxy.xml b/docs/manual/mod/mod_proxy.xml index 39997277eb..0254f29561 100644 --- a/docs/manual/mod/mod_proxy.xml +++ b/docs/manual/mod/mod_proxy.xml @@ -53,7 +53,7 @@ capabilities
  • mod_proxy_balancer and one or more - balancer modules, if load balancing is required. (See + balancer modules, if load balancing is required. (See mod_proxy_balancer for more information.)
  • one or more proxy scheme, or protocol, modules: @@ -63,11 +63,11 @@ AJP13 (Apache JServe Protocol version 1.3)mod_proxy_ajp CONNECT (for - SSL)mod_proxy_connect + SSL)mod_proxy_connect FastCGImod_proxy_fcgi ftpmod_proxy_ftp HTTP/0.9, HTTP/1.0, and - HTTP/1.1mod_proxy_http + HTTP/1.1mod_proxy_http SCGImod_proxy_scgi
    • @@ -90,7 +90,7 @@ mod_proxy_balancer mod_ssl -
    Forward Proxies and Reverse + <section id="forwardreverse"><title>Forward Proxies and Reverse Proxies/Gateways

    Apache HTTP Server can be configured in both a forward and reverse proxy (also known as gateway) mode.

    @@ -389,7 +389,7 @@ chunked encoding.

    Under some circumstances, the server must spool request bodies - to disk to satisfy the requested handling of request bodies. For + to disk to satisfy the requested handling of request bodies. For example, this spooling will occur if the original body was sent with chunked encoding (and is large), but the administrator has asked for backend requests to be sent with Content-Length or as HTTP/1.0. @@ -414,7 +414,7 @@

    X-Forwarded-For
    The IP address of the client.
    X-Forwarded-Host
    -
    The original host requested by the client in the Host +
    The original host requested by the client in the Host HTTP request header.
    X-Forwarded-Server
    The hostname of the proxy server.
    @@ -489,7 +489,7 @@ response

    The ProxyBadHeader directive determines the behaviour of mod_proxy if it receives syntactically invalid - response header lines (i.e. containing no colon) from the origin + response header lines (i.e. containing no colon) from the origin server. The following arguments are possible:

    @@ -510,7 +510,7 @@ response ProxyMatch -Container for directives applied to regular-expression-matched +Container for directives applied to regular-expression-matched proxied resources <ProxyMatch regex> ...</ProxyMatch> server configvirtual host @@ -542,7 +542,7 @@ context in 2.3.3 and later. request to the proxied host, instead of the hostname specified in the ProxyPass line.

    -

    This option should normally be turned Off. It is mostly +

    This option should normally be turned Off. It is mostly useful in special configurations like proxied mass name-based virtual hosting, where the original Host header needs to be evaluated by the backend server.

    @@ -668,15 +668,15 @@ expressions     ProxyPass directives.

    One additional parameter is available only to BalancerMember directives: - loadfactor. This is the member load factor - a number between 1 - (default) and 100, which defines the weighted load to be applied to the + loadfactor. This is the member load factor - a number between 1 + (default) and 100, which defines the weighted load to be applied to the member in question.

    The balancerurl is only needed when not in <Proxy balancer://...> container directive. It corresponds to the url of a balancer defined in ProxyPass directive.

     - + ProxySet Set various Proxy balancer or member parameters @@ -775,7 +775,7 @@ expressions ProxyPass /mirror/foo/ http://backend.example.com/ - +

    If the first argument ends with a trailing /, the second argument should also end with a trailing / and vice @@ -845,7 +845,7 @@ expressions backend server's keep-alive timeout.

    The pool of connections is maintained per web server child - process, and max and other settings are not coordinated + process, and max and other settings are not coordinated among all child processes, except when only one child process is allowed by configuration or MPM design.

    @@ -905,7 +905,7 @@ expressions the backend server (regardless of protocol) tends to silently drop connections or when backends themselves may be under round- robin DNS. To disable connection pooling reuse, - set this property value to On. + set this property value to On. flushpackets off @@ -934,9 +934,9 @@ expressions This flag will tell the Operating System to send KEEP_ALIVE messages on inactive connections and thus prevent the firewall to drop the connection. To enable keepalive set this property value to On.

    -

    The frequency of initial and subsequent TCP keepalive probes +

    The frequency of initial and subsequent TCP keepalive probes depends on global OS settings, and may be as high as 2 hours. To be useful, - the frequency configured in the OS must be smaller than the threshold used + the frequency configured in the OS must be smaller than the threshold used by the firewall.

    lbset @@ -996,9 +996,18 @@ expressions status - Single letter value defining the initial status of - this worker: 'D' is disabled, 'S' is stopped, 'I' is ignore-errors, - 'H' is hot-standby and 'E' is in an error state. Status - can be set (which is the default) by prepending with '+' or + this worker. + + + + + + + +
    D: Worker is disabled and will not accept any requests.
    S: Worker is administratively stopped.
    I: Worker is in ignore-errors mode, and will always be considered available.
    H: Worker is in hot-standby mode and will only be used if no other + viable workers are available.
    E: Worker is in an error state.
    N: Worker is in drain mode, and will only accept existing sticky sessions + destined for itself and ignore all other requests.
    Status + can be set (which is the default) by prepending with '+' or cleared by prepending with '-'. Thus, a setting of 'S-E' sets this worker to Stopped and clears the in-error flag. @@ -1019,7 +1028,7 @@ expressions

    If the Proxy directive scheme starts with the - balancer:// (eg: balancer://cluster/, + balancer:// (eg: balancer://cluster/, any path information is ignored) then a virtual worker that does not really communicate with the backend server will be created. Instead it is responsible for the management of several "real" workers. In that case the special set of @@ -1036,12 +1045,12 @@ expressions Balancer load-balance method. Select the load-balancing scheduler method to use. Either byrequests, to perform weighted request counting, bytraffic, to perform weighted - traffic byte count balancing, or bybusyness, to perform + traffic byte count balancing, or bybusyness, to perform pending request balancing. Default is byrequests. maxattempts One less than the number of workers, or 1 with a single worker. - Maximum number of failover attempts before giving up. + Maximum number of failover attempts before giving up. nofailover Off @@ -1068,7 +1077,7 @@ expressions timeout 0 Balancer timeout in seconds. If set this will be the maximum time - to wait for a free worker. Default is not to wait. + to wait for a free worker. Default is not to wait. failonstatus - @@ -1091,9 +1100,9 @@ expressions growth 0 Number of additional BalancerMembers to allow to be added - to this balancer in addition to those defined at configuration. + to this balancer in addition to those defined at configuration. - +

    A sample balancer setup

    @@ -1148,7 +1157,7 @@ expressions LocationMatch section, however ProxyPass does not interpret the regexp as such, so it is necessary to use ProxyPassMatch in this situation instead.

    - +

    This directive is not supported in Directory or Files sections.

    @@ -1402,14 +1411,14 @@ connections

    In almost every case there's no reason to change that value.

    If used with AJP this directive sets the maximum AJP packet size in - bytes. If you change it from the default, you must also change the + bytes. If you change it from the default, you must also change the packetSize attribute of your AJP connector on the Tomcat side! The attribute packetSize is only available in Tomcat 5.5.20+ and 6.0.2+

    Normally it is not necessary to change the maximum packet size. Problems with the default value have been reported when sending certificates or certificate chains.

    - +     @@ -1485,7 +1494,7 @@ directly >Hostnames (both syntactically and semantically; a DNS domain can have a DNS A record, too!), Domains are always written with a leading period.

    - + Note

    Domain name comparisons are done without regard to the case, and Domains are always assumed to be anchored in the root of the @@ -1530,7 +1539,7 @@ directly Example 192.168.123.7 - + Note

    An IPAddr does not need to be resolved by the DNS system, so it can result in more effective apache performance.

    @@ -1654,8 +1663,8 @@ header for proxied requests Available in version 2.0 and later -

    This directive is useful for reverse-proxy setups, where you want to - have a common look and feel on the error pages seen by the end user. +

    This directive is useful for reverse-proxy setups, where you want to + have a common look and feel on the error pages seen by the end user. This also allows for included files (via mod_include's SSI) to get the error code and act accordingly (default behavior would display