LiteSpeed Web Server Users' Manual - Load Balancer Context
Description: LiteSpeed Web Server Users' Manual - Load Balancer Context.

## LiteSpeed Web Server
Users' Manual

### Version 6.3 — Rev. 4

- License Enterprise
- Introduction
- Installation
- Administration
- Security
- Configuration
  - Server General
  - Server Log
  - Server Tuning
  - Server Security
  - Page Cache
  - PageSpeed Config
  - External Apps
  - Fast CGI App
  - Fast CGI Authorizer
  - LSAPI App
  - Servlet Engine
  - Web Server
  - Piped logger
  - Load Balancer
  - Script Handler
  - PHP
  - App Server Settings
  - Listener General
  - Listener SSL
  - Virtual Host Templates
  - Virtual Host Basic
  - Virtual Host General
  - Virtual Host Security
  - Virtual Host SSL
  - Virtual Host PageSpeed Config
  - Rewrite
  - Context
  - Static Context
  - Java Web App Context
  - Servlet Context
  - Fast CGI Context
  - LSAPI Context
  - Proxy Context
  - CGI Context
  - Load Balancer Context
  - Redirect Context
  - App Server Context
  - Rack/Rails Context
  - Add-ons
- Web Console
  - Admin Console General
  - Admin Console Security
  - Admin Listener General
  - Admin Listener SSL

# Load Balancer Context

## Table of Contents

### Load Balancer Context⇑

#### Description

Like other external applications, load balancer worker applications cannot be used directly. They must be mapped to a URL through a context. A Load Balancer Context will associate a URI to be load balanced by the load balancer workers.

### URI⇑

#### Description

Specifies the URI for this context.

#### Syntax

The URI can be a plain URI (starting with "/") or a Perl compatible regular expression URI (starting with "exp:"). If a plain URI ends with a "/", then this context will include all sub-URIs under this URI. If the context maps to a directory on the file system, a trailing "/" must be added.

#### See Also

Location

### Load Balancer⇑

#### Description

Specifies the name of the load balancer to be associated to this context. This load balancer is a virtual application, and must be defined in the External Apps section at the server or virtual host level.

#### Syntax

Select from drop down list

### Header Operations⇑

#### Description

Specifies additional response/request headers to be added. Multiple header directives can be added with one directive per line. "NONE" can be used to disable parent header inheritance. If no directive is provided 'Header' is assumed.

#### Syntax

[Header]|RequestHeader [condition] set|append|merge|add|unset header [value] [early|env=[!]variable]

#### Example

set Cache-control no-cache
append Cache-control no-store
Header set My-header cust_header_val
RequestHeader set My-req-header cust_req_header_val

#### Tips

Syntax and usage are similar to Apache's mod_headers directives for supported operations.
The 'Header' directive is is optional and can be excluded or left in when copying rules from elsewhere without issue.

### Allow Override⇑

#### Description

Specifies what directives in an access control file are allowed. An access control file can be placed in a directory to control the accessibility of files under that directory.

- When nothing is checked, inherited default settings will be used.
- When None is checked, access control files will be ignored.
- When Limit is checked, directives "Allow", "Deny", and "Order" are allowed. <Limit> and <LimitExcept> directives are also allowed with limited support for GET, HEAD, and POST requests.
- When Auth is checked, directives "AuthGroupFile", "AuthName", "AuthType", "AuthUserFile", "Require", and "Satisfy" are allowed. <Limit> and <LimitExcept> directives are also allowed with limited support for GET, HEAD, and POST requests.
- When FileInfo is checked, directives "AddDefaultCharset", "AddType", "DefaultType", "ForceType", "Redirect", "RedirectPermanent", "RedirectTemp", "RewriteBase", "RewriteCond", "RewriteEngine", "RewriteOptions", and "RewriteRule" are allowed.
- When Indexes is checked, directives "DirectoryIndex", "ExpiresActive", "ExpiresByType", and "ExpiresDefault" are allowed.
- When Options is checked, directive "Options" is allowed.

Allow Override configuration is available at the Server, Virtual Host, and Context levels. If a configuration is unchecked at the Server level, those controlled directives will be disabled for the entire server regardless of settings at lower levels. Lower levels can disable a setting that is enabled at a higher level, but cannot enable a setting that is disabled at an upper level.
Default values:
Server level: "None" (ignore access control file)
VH level: Inherit Server level setting
Context level Inherit VH level setting

#### Syntax

Select from checkbox

#### Tips

If there is no need for directory level configuration customization, check None.

### Realm⇑

#### Description

Specifies the authorization realm for this context. When specified, a valid username and password must be provided in order to access this context. Authorization Realms are set up in the Virtual Host Security section. This setting uses each realm's Realm Name.

#### Syntax

Select from drop down list

### Authentication Name⇑

#### Description

Specifies an alternative name for the authorization realm for the current context. If not specified, the original realm name will be used. The authentication name is displayed on the browser's login pop-up.

### Require (Authorized Users/Groups)⇑

#### Description

Specifies which user/group can access this context. This allows you to use one user/group database (specified in Realm) across a number of contexts, but only allow certain users/groups from that database to access this context.

#### Syntax

Syntax is compatible with Apache's Require directive. For example:

- user username [username ...]
  Only listed users can access this context.
- group groupid [groupid ...]
  Only users belonging to the listed groups can access this context.

If this setting is not specified, all valid users will be allowed to access this resource.

### Access Allowed⇑

#### Description

Specifies which IPs or sub-networks are allowed to access resources under this context. Together with Access Denied and server/virtual host level access control, accessibility is determined by the smallest scope that a client's IP address falls into.

#### Syntax

Comma-delimited list of IPs/sub-networks.

#### Example

Sub-networks can be written as 192.168.1.0/255.255.255.0, 192.168.1, or 192.168.1.*.

### Access Denied⇑

#### Description

Specifies which IPs or sub-networks are NOT allowed to access resources under this context. Together with Access Allowed and server/virtual host-level access control, accessibility is determined by the smallest scope that a client's IP address falls into.

#### Syntax

Comma-delimited list of IPs/sub-networks.

#### Example

Sub-networks can be written as 192.168.1.0/255.255.255.0, 192.168.1, or 192.168.1.*.

### Authorizer⇑

#### Description

Specifies an external application that can be used to generate authorized/unauthorized decisions. Currently, only the FastCGI Authorizer is available. For more details about the FastCGI Authorizer role, please visit https://fastcgi-archives.github.io/ .

#### Syntax

Select from drop down list

### Add Default Charset⇑

#### Description

Specifies whether to add a character set tag to the "Content-Type" response header, when content type is either "text/html" or "text/plain" without any parameters. When set to Off, this function is disabled. When set to On, either the character set specified by Customized Default Charset or the default "iso-8859-1" will be added.

#### Syntax

Select from radio box

### Customized Default Charset⇑

#### Description

Specifies a character set to be used when Add Default Charset is On. This is optional. The default value is iso-8859-1. This entry has no effect when Add Default Charset is Off.

#### Syntax

Name of a character set.

#### Example

utf-8

### Cache Stale Age (seconds)⇑

#### Description

Specifies how long an object will continue to be served from cache after it has expired but before a new cached copy is available. The default is "10" seconds.

#### Syntax

Integer number

### Publicly Cache All⇑

#### Description

Publicly cache all URLs served under the current context (virtual host, or context level).
Virtual hosts configured through Apache's httpd.conf can use the "CacheEnable" and "CacheDisable" directives at the server, virtual host, context, file, and location level or in .htaccess. "CacheEnable" and "CacheDisable" directives are compatible with Apache mod_cache directives. However, when used at the context, file, or location level, or in .htaccess, "CacheEnable" and "CacheDisable" will only be applied to directories below the current level. URL parameters will be ignored.

#### Syntax

Select from radio box

#### Tips

Disabled by default. Do not enabled this setting if you are using any LSCache plugins.

### Cache Expire Time (seconds)⇑

#### Description

Specifies how long an object will be cached. The default is "86400" seconds (one day).

#### Syntax

Integer number

### Privately Cache All⇑

#### Description

Privately cache all URLs served under the current context (virtual host, or context level).
A separate cached copy will be made per user based on their IP and set cookies.
Virtual hosts configured through Apache's httpd.conf can use the "CacheEnable private /url" and "CacheDisable private /url" directives at server, virtual host, directory, file, and location levels or in a .htaccess file. "CacheEnable private" and "CacheDisable private" are compatible with Apache's mod_cache directives and will be applied to all directories below the current level. However, when used at the directory, file, or location level, or in a .htaccess file, "CacheEnable private" and "CacheDisable private" will only be applied to directories below the current level. URL parameters will be ignored.

#### Syntax

Select from radio box

#### Tips

Disabled by default. Do not enabled this setting if you are using any LSCache plugins.

### Private Cache Expire Time (seconds)⇑

#### Description

Specifies how long an object will be cached in private cache. The default is "60" seconds.

#### Syntax

Integer number

### Micro Cache 5XX Response⇑

#### Description

Cache pages responding with HTTP status code 5xx (500, 503, etc) for 10 seconds when the cache response header indicates that the page is cacheable.
Default values:
Server level: Yes
VH level: Inherit Server level setting
Context-level Inherit VH level setting

#### Syntax

Select from radio box

#### Tips

Enabling this setting is useful for avoiding bad requests but can also act as some added DDoS protection.

### Enable POST cache⇑

#### Description

Specifies if POST requests can be cached using the "x-litespeed-cache-control" header.
Default value: No

#### Syntax

Select from radio box

### Enable GeoLocation Lookup⇑

#### Description

Enterprise Edition Only Specifies whether to enable/disable IP Geolocation lookup. Can be set at server, virtual host, or context level. IP Geolocation is disabled by default when using value "Not Set".

#### Syntax

Select from radio box

#### See Also

Use Client IP in Header, DB File Path,

### Enable PageSpeed Optimization⇑

#### Description

Choose whether or not to enable PageSpeed optimization.

#### Syntax

Select from radio box

#### Tips

This can be set at the Server Level and overridden at the Virtual Host and Context Levels. Context Level settings will override Virtual Host Level settings.

### PageSpeed Settings⇑

#### Description

Set parameters using Google default filter sets.

#### Example

pagespeed FileCachePath /tmp/lshttpd/pagespeed;
pagespeed RewriteLevel CoreFilters;