<Directory />

    Options FollowSymLinks

    AllowOverride All

    Order deny,allow

    Deny from all

</Directory>

Tomcat Connector關(guān)聯(lián)項(xiàng)增加

#加載mod_jk連接

LoadModule jk_module modules/mod_jk.so

### 配置 mod_jk

JkWorkersFile "conf\workers.properties" #加載集群中的workers

#此處是指定分配給tomcat的請求 例如*.do *.jsp

JkMount /*.jsp controller

JkLogFile logs/mod_jk.log #指定jk的日志輸出文件 

JkLogLevel warn #指定日志級別

    找到IfModule dir_module 修改默認(rèn)訪問地址，需要根據(jù)具體項(xiàng)目實(shí)際情況填寫，我這里使用的是index.jsp 修改如下：

<IfModule dir_module>

DirectoryIndex index.jsp

</IfModule>

    找到Virtual hosts 去掉虛擬主機(jī)注釋

# Virtual hosts

#Include conf/extra/httpd-vhosts.conf 將 “#”去掉

Include conf/extra/httpd-vhosts.conf

加載代理(暫時(shí)未去掉)

#LoadModule proxy_module modules/mod_proxy.so

#LoadModule proxy_ajp_module modules/mod_proxy_ajp.so

#LoadModule proxy_balancer_module modules/mod_proxy_balancer.so

#LoadModule proxy_connect_module modules/mod_proxy_connect.so

#LoadModule proxy_ftp_module modules/mod_proxy_ftp.so

#下面是分發(fā)控制器 注意不要放tomcat實(shí)例

worker.list=lbcontroller

 

#Tomcat1實(shí)例配置 這里要和Tomcat配置文件Service.xml的jvmRoute保持一致

worker.test1.host=localhost

worker.test1.port=8009

worker.test1.type=ajp13

#分發(fā)權(quán)重 值越大負(fù)載越大

worker.tomcat1.lbfactor=1

 

#Tomcat2實(shí)例配置

worker.test2.host=localhost

worker.test2.port=9009

worker.test2.type=ajp13

#分發(fā)權(quán)重 值越大負(fù)載越大

worker.tomcat2.lbfactor=1

 

#負(fù)載均衡分發(fā)控制器

worker.lbcontroller.type=lb

worker.lbcontroller.balance_workers=test1,test2

<!--jvmRoute在各個(gè)Tomcat配置中不能重復(fù)且要與worker.properties文件中的名稱一致-->

    <Engine name="Catalina" defaultHost="localhost" jvmRoute="test1">

 

<!--session復(fù)制內(nèi)容-->

       <Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"  

                 channelSendOptions="8">   

          <Manager className="org.apache.catalina.ha.session.DeltaManager"  

                   expireSessionsOnShutdown="false"  

                   notifyListenersOnReplication="true"/>   

  

<Channel className="org.apache.catalina.tribes.group.GroupChannel">   

<Membership className="org.apache.catalina.tribes.membership.McastService"  

                        address="228.0.0.4"  

                        port="45564"  

                        frequency="500"  

                        dropTime="3000"/>   

<Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"  

                      address="auto"  

                      port="4000"  

                      autoBind="100"  

                      selectorTimeout="5000"  

                      maxThreads="6"/>   

            <!-- timeout="60000"-->   

            <Sender className="org.apache.catalina.tribes.transport.ReplicationTransmitter">   

              <Transport className="org.apache.catalina.tribes.transport.nio.PooledParallelSender" />   

            </Sender>   

            <Interceptor className="org.apache.catalina.tribes.group.interceptors.TcpFailureDetector"/>   

            <Interceptor className="org.apache.catalina.tribes.group.interceptors.MessageDispatch15Interceptor"/>   

            <Interceptor className="org.apache.catalina.tribes.group.interceptors.ThroughputInterceptor"/>   

          </Channel>   

          <!--過濾的文件-->

          <Valve className="org.apache.catalina.ha.tcp.ReplicationValve"  filter=".*\.gif;.*\.js;.*\.jpg;.*\.png;.*\.htm;.*\.html;.*\.css;.*\.txt;"/>   

          <Valve className="org.apache.catalina.ha.session.JvmRouteBinderValve"/>   

  

          <Deployer className="org.apache.catalina.ha.deploy.FarmWarDeployer"  

                    tempDir="/tmp/war-temp/"  

                    deployDir="/tmp/war-deploy/"  

                    watchDir="/tmp/war-listen/"  

                    watchEnabled="false"/>   

          <ClusterListener className="org.apache.catalina.ha.session.JvmRouteSessionIDBinderListener"/>   

          <ClusterListener className="org.apache.catalina.ha.session.ClusterSessionListener"/>   

        </Cluster>

      <!--session復(fù)制內(nèi)容-->

*****************************************************************************

 如果需要實(shí)現(xiàn)session 復(fù)制 需要在Tomcat 下conf/web.xml 中加上<distributable/>

<?xml version="1.0" encoding="ISO-8859-1"?>

省略N多代碼。。。。。。

    <welcome-file-list>

        <welcome-file>index.html</welcome-file>

        <welcome-file>index.htm</welcome-file>

        <welcome-file>index.jsp</welcome-file>

    </welcome-file-list>

<distributable/>

</web-app>

*****************************************************************************

第二部分：httpd.conf文件

#
# This is the main Apache HTTP server configuration file.  It contains the
# configuration directives that give the server its instructions.
# See <URL:http://httpd.apache.org/docs/2.2> for detailed information.
# In particular, see 
# <URL:http://httpd.apache.org/docs/2.2/mod/directives.html>
# for a discussion of each configuration directive.
#
# Do NOT simply read the instructions in here without understanding
# what they do.  They're here only as hints or reminders.  If you are unsure
# consult the online docs. You have been warned.  
#
# Configuration and logfile names: If the filenames you specify for many
# of the server's control files begin with "/" (or "drive:/" for Win32), the
# server will use that explicit path.  If the filenames do *not* begin
# with "/", the value of ServerRoot is prepended -- so "logs/foo.log"
# with ServerRoot set to "D:/Program Files/Apache Software Foundation/Apache2.2" will be interpreted by the
# server as "D:/Program Files/Apache Software Foundation/Apache2.2/logs/foo.log".
#
# NOTE: Where filenames are specified, you must use forward slashes
# instead of backslashes (e.g., "c:/apache" instead of "c:\apache").
# If a drive letter is omitted, the drive on which httpd.exe is located
# will be used by default.  It is recommended that you always supply
# an explicit drive letter in absolute paths to avoid confusion.

#
# ServerRoot: The top of the directory tree under which the server's
# configuration, error, and log files are kept.
#
# Do not add a slash at the end of the directory path.  If you point
# ServerRoot at a non-local disk, be sure to point the LockFile directive
# at a local disk.  If you wish to share the same ServerRoot for multiple
# httpd daemons, you will need to change at least LockFile and PidFile.
#
ServerRoot "D:/Program Files/Apache Software Foundation/Apache2.2"

#
# Listen: Allows you to bind Apache to specific IP addresses and/or
# ports, instead of the default. See also the <VirtualHost>
# directive.
#
# Change this to Listen on specific IP addresses as shown below to 
# prevent Apache from glomming onto all bound IP addresses.
#
#Listen 12.34.56.78:80
Listen 8080

#
# Dynamic Shared Object (DSO) Support
#
# To be able to use the functionality of a module which was built as a DSO you
# have to place corresponding `LoadModule' lines at this location so the
# directives contained in it are actually available _before_ they are used.
# Statically compiled modules (those listed by `httpd -l') do not need
# to be loaded here.
#
# Example:
# LoadModule foo_module modules/mod_foo.so
#
LoadModule actions_module modules/mod_actions.so
LoadModule alias_module modules/mod_alias.so
LoadModule asis_module modules/mod_asis.so
LoadModule auth_basic_module modules/mod_auth_basic.so
#LoadModule auth_digest_module modules/mod_auth_digest.so
#LoadModule authn_alias_module modules/mod_authn_alias.so
#LoadModule authn_anon_module modules/mod_authn_anon.so
#LoadModule authn_dbd_module modules/mod_authn_dbd.so
#LoadModule authn_dbm_module modules/mod_authn_dbm.so
LoadModule authn_default_module modules/mod_authn_default.so
LoadModule authn_file_module modules/mod_authn_file.so
#LoadModule authnz_ldap_module modules/mod_authnz_ldap.so
#LoadModule authz_dbm_module modules/mod_authz_dbm.so
LoadModule authz_default_module modules/mod_authz_default.so
LoadModule authz_groupfile_module modules/mod_authz_groupfile.so
LoadModule authz_host_module modules/mod_authz_host.so
#LoadModule authz_owner_module modules/mod_authz_owner.so
LoadModule authz_user_module modules/mod_authz_user.so
LoadModule autoindex_module modules/mod_autoindex.so
#LoadModule cache_module modules/mod_cache.so
#LoadModule cern_meta_module modules/mod_cern_meta.so
LoadModule cgi_module modules/mod_cgi.so
#LoadModule charset_lite_module modules/mod_charset_lite.so
#LoadModule dav_module modules/mod_dav.so
#LoadModule dav_fs_module modules/mod_dav_fs.so
#LoadModule dav_lock_module modules/mod_dav_lock.so
#LoadModule dbd_module modules/mod_dbd.so
#LoadModule deflate_module modules/mod_deflate.so
LoadModule dir_module modules/mod_dir.so
#LoadModule disk_cache_module modules/mod_disk_cache.so
#LoadModule dumpio_module modules/mod_dumpio.so
LoadModule env_module modules/mod_env.so
#LoadModule expires_module modules/mod_expires.so
#LoadModule ext_filter_module modules/mod_ext_filter.so
#LoadModule file_cache_module modules/mod_file_cache.so
#LoadModule filter_module modules/mod_filter.so
#LoadModule headers_module modules/mod_headers.so
#LoadModule ident_module modules/mod_ident.so
#LoadModule imagemap_module modules/mod_imagemap.so
LoadModule include_module modules/mod_include.so
#LoadModule info_module modules/mod_info.so
LoadModule isapi_module modules/mod_isapi.so
#LoadModule ldap_module modules/mod_ldap.so
#LoadModule logio_module modules/mod_logio.so
LoadModule log_config_module modules/mod_log_config.so
#LoadModule log_forensic_module modules/mod_log_forensic.so
#LoadModule mem_cache_module modules/mod_mem_cache.so
LoadModule mime_module modules/mod_mime.so
#LoadModule mime_magic_module modules/mod_mime_magic.so
LoadModule negotiation_module modules/mod_negotiation.so
#LoadModule proxy_module modules/mod_proxy.so
#LoadModule proxy_ajp_module modules/mod_proxy_ajp.so
#LoadModule proxy_balancer_module modules/mod_proxy_balancer.so
#LoadModule proxy_connect_module modules/mod_proxy_connect.so
#LoadModule proxy_ftp_module modules/mod_proxy_ftp.so
#LoadModule proxy_http_module modules/mod_proxy_http.so
#LoadModule proxy_scgi_module modules/mod_proxy_scgi.so
#LoadModule reqtimeout_module modules/mod_reqtimeout.so
#url偽靜態(tài)
LoadModule rewrite_module modules/mod_rewrite.so
LoadModule setenvif_module modules/mod_setenvif.so
#LoadModule speling_module modules/mod_speling.so
#LoadModule ssl_module modules/mod_ssl.so
#LoadModule status_module modules/mod_status.so
#LoadModule substitute_module modules/mod_substitute.so
#LoadModule unique_id_module modules/mod_unique_id.so
#LoadModule userdir_module modules/mod_userdir.so
#LoadModule usertrack_module modules/mod_usertrack.so
#LoadModule version_module modules/mod_version.so
#LoadModule vhost_alias_module modules/mod_vhost_alias.so

#加載mod_jk連接
LoadModule jk_module modules/mod_jk.so
#加載集群中的workers
JkWorkersFile "conf/workers.properties" 
#此處是指定分配給tomcat的請求 例如*.do *.jsp
JkMount /*.jsp lbcontroller
#指定jk的日志輸出文件
JkLogFile "logs/mod_jk.log"
#指定日志級別
JkLogLevel warn 




<IfModule !mpm_netware_module>
<IfModule !mpm_winnt_module>
#
# If you wish httpd to run as a different user or group, you must run
# httpd as root initially and it will switch.  
#
# User/Group: The name (or #number) of the user/group to run httpd as.
# It is usually good practice to create a dedicated user and group for
# running httpd, as with most system services.
#
User daemon
Group daemon

</IfModule>
</IfModule>

# 'Main' server configuration
#
# The directives in this section set up the values used by the 'main'
# server, which responds to any requests that aren't handled by a
# <VirtualHost> definition.  These values also provide defaults for
# any <VirtualHost> containers you may define later in the file.
#
# All of these directives may appear inside <VirtualHost> containers,
# in which case these default settings will be overridden for the
# virtual host being defined.
#

#
# ServerAdmin: Your address, where problems with the server should be
# e-mailed.  This address appears on some server-generated pages, such
# as error documents.  e.g. admin@your-domain.com
#
ServerAdmin localhost

#
# ServerName gives the name and port that the server uses to identify itself.
# This can often be determined automatically, but we recommend you specify
# it explicitly to prevent problems during startup.
#
# If your host doesn't have a registered DNS name, enter its IP address here.
#
ServerName localhost:8080
#
# DocumentRoot: The directory out of which you will serve your
# documents. By default, all requests are taken from this directory, but
# symbolic links and aliases may be used to point to other locations.
#
DocumentRoot "D:/work/work_bz/test/WebRoot"
#
# Each directory to which Apache has access can be configured with respect
# to which services and features are allowed and/or disabled in that
# directory (and its subdirectories). 
#
# First, we configure the "default" to be a very restrictive set of 
# features.  
#    默認(rèn)為 AllowOverride None
<Directory />
    Options FollowSymLinks
    AllowOverride All
    #Order deny,allow
      #Deny from all
       Order allow,deny
    Allow from all
    Satisfy all
</Directory>

#首次訪問頁面
<IfModule dir_module>
    DirectoryIndex index.jsp
</IfModule>

#
# The following lines prevent .htaccess and .htpasswd files from being 
# viewed by Web clients. 
#
<FilesMatch "^\.ht">
    Order allow,deny
    Deny from all
    Satisfy All
</FilesMatch>

#
# ErrorLog: The location of the error log file.
# If you do not specify an ErrorLog directive within a <VirtualHost>
# container, error messages relating to that virtual host will be
# logged here.  If you *do* define an error logfile for a <VirtualHost>
# container, that host's errors will be logged there and not here.
#
ErrorLog "logs/error.log"

#
# LogLevel: Control the number of messages logged to the error_log.
# Possible values include: debug, info, notice, warn, error, crit,
# alert, emerg.
#
LogLevel warn

<IfModule log_config_module>
    #
    # The following directives define some format nicknames for use with
    # a CustomLog directive (see below).
    #
    LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
    LogFormat "%h %l %u %t \"%r\" %>s %b" common

    <IfModule logio_module>
      # You need to enable mod_logio.c to use %I and %O
      LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" %I %O" combinedio
    </IfModule>

    #
    # The location and format of the access logfile (Common Logfile Format).
    # If you do not define any access logfiles within a <VirtualHost>
    # container, they will be logged here.  Contrariwise, if you *do*
    # define per-<VirtualHost> access logfiles, transactions will be
    # logged therein and *not* in this file.
    #
    CustomLog "logs/access.log" common

    #
    # If you prefer a logfile with access, agent, and referer information
    # (Combined Logfile Format) you can use the following directive.
    #
    #CustomLog "logs/access.log" combined
</IfModule>

<IfModule alias_module>
    #
    # Redirect: Allows you to tell clients about documents that used to 
    # exist in your server's namespace, but do not anymore. The client 
    # will make a new request for the document at its new location.
    # Example:
    # Redirect permanent /foo http://192.168.12.242/bar

    #
    # Alias: Maps web paths into filesystem paths and is used to
    # access content that does not live under the DocumentRoot.
    # Example:
    # Alias /webpath /full/filesystem/path
    #
    # If you include a trailing / on /webpath then the server will
    # require it to be present in the URL.  You will also likely
    # need to provide a <Directory> section to allow access to
    # the filesystem path.

    #
    # ScriptAlias: This controls which directories contain server scripts. 
    # ScriptAliases are essentially the same as Aliases, except that
    # documents in the target directory are treated as applications and
    # run by the server when requested rather than as documents sent to the
    # client.  The same rules about trailing "/" apply to ScriptAlias
    # directives as to Alias.
    #
    ScriptAlias /cgi-bin/ "D:/Program Files/Apache Software Foundation/Apache2.2/cgi-bin/"

</IfModule>

<IfModule cgid_module>
    #
    # ScriptSock: On threaded servers, designate the path to the UNIX
    # socket used to communicate with the CGI daemon of mod_cgid.
    #
    #Scriptsock logs/cgisock
</IfModule>

#
# "D:/Program Files/Apache Software Foundation/Apache2.2/cgi-bin" should be changed to whatever your ScriptAliased
# CGI directory exists, if you have that configured.
#
<Directory "D:/Program Files/Apache Software Foundation/Apache2.2/cgi-bin">
    AllowOverride None
    Options None
    Order allow,deny
    Allow from all
</Directory>

#
# DefaultType: the default MIME type the server will use for a document
# if it cannot otherwise determine one, such as from filename extensions.
# If your server contains mostly text or HTML documents, "text/plain" is
# a good value.  If most of your content is binary, such as applications
# or images, you may want to use "application/octet-stream" instead to
# keep browsers from trying to display binary files as though they are
# text.
#
DefaultType text/plain

<IfModule mime_module>
    #
    # TypesConfig points to the file containing the list of mappings from
    # filename extension to MIME-type.
    #
    TypesConfig conf/mime.types

    #
    # AddType allows you to add to or override the MIME configuration
    # file specified in TypesConfig for specific file types.
    #
    #AddType application/x-gzip .tgz
    #
    # AddEncoding allows you to have certain browsers uncompress
    # information on the fly. Note: Not all browsers support this.
    #
    #AddEncoding x-compress .Z
    #AddEncoding x-gzip .gz .tgz
    #
    # If the AddEncoding directives above are commented-out, then you
    # probably should define those extensions to indicate media types:
    #
    AddType application/x-compress .Z
    AddType application/x-gzip .gz .tgz

    #
    # AddHandler allows you to map certain file extensions to "handlers":
    # actions unrelated to filetype. These can be either built into the server
    # or added with the Action directive (see below)
    #
    # To use CGI scripts outside of ScriptAliased directories:
    # (You will also need to add "ExecCGI" to the "Options" directive.)
    #
    #AddHandler cgi-script .cgi

    # For type maps (negotiated resources):
    #AddHandler type-map var

    #
    # Filters allow you to process content before it is sent to the client.
    #
    # To parse .shtml files for server-side includes (SSI):
    # (You will also need to add "Includes" to the "Options" directive.)
    #
    #AddType text/html .shtml
    #AddOutputFilter INCLUDES .shtml
</IfModule>

#
# The mod_mime_magic module allows the server to use various hints from the
# contents of the file itself to determine its type.  The MIMEMagicFile
# directive tells the module where the hint definitions are located.
#
#MIMEMagicFile conf/magic

#
# Customizable error responses come in three flavors:
# 1) plain text 2) local redirects 3) external redirects
#
# Some examples:
#ErrorDocument 500 "The server made a boo boo."
#ErrorDocument 404 /missing.html
#ErrorDocument 404 "/cgi-bin/missing_handler.pl"
#ErrorDocument 402 http://192.168.12.242/subscription_info.html
#

#
# MaxRanges: Maximum number of Ranges in a request before
# returning the entire resource, or 0 for unlimited
# Default setting is to accept 200 Ranges
#MaxRanges 0

#
# EnableMMAP and EnableSendfile: On systems that support it, 
# memory-mapping or the sendfile syscall is used to deliver
# files.  This usually improves server performance, but must
# be turned off when serving from networked-mounted 
# filesystems or if support for these functions is otherwise
# broken on your system.
#
#EnableMMAP off
#EnableSendfile off

# Supplemental configuration
#
# The configuration files in the conf/extra/ directory can be 
# included to add extra features or to modify the default configuration of 
# the server, or you may simply copy their contents here and change as 
# necessary.

# Server-pool management (MPM specific)修改連接數(shù)
Include conf/extra/httpd-mpm.conf

# Multi-language error messages
#Include conf/extra/httpd-multilang-errordoc.conf

# Fancy directory listings
#Include conf/extra/httpd-autoindex.conf

# Language settings
#Include conf/extra/httpd-languages.conf

# User home directories
#Include conf/extra/httpd-userdir.conf

# Real-time info on requests and configuration
#Include conf/extra/httpd-info.conf

# Virtual hosts 虛擬主機(jī) 沒有域名不需要設(shè)置
#Include conf/extra/httpd-vhosts.conf

# Local access to the Apache HTTP Server Manual
#Include conf/extra/httpd-manual.conf

# Distributed authoring and versioning (WebDAV)
#Include conf/extra/httpd-dav.conf

# Various default settings
#Include conf/extra/httpd-default.conf

# Secure (SSL/TLS) connections
#Include conf/extra/httpd-ssl.conf
#
# Note: The following must must be present to support
#       starting without SSL on platforms with no /dev/random equivalent
#       but a statically compiled-in mod_ssl.
#
<IfModule ssl_module>
SSLRandomSeed startup builtin
SSLRandomSeed connect builtin
</IfModule>

第三部分：mod_jk代碼講解

mod_jk 分析
1 mod_jk模塊的總體功能
由于tomcat的HTTP處理部分都由Java所寫（5.5.12版本以后出現(xiàn)了native庫，用以
提高其I/O和SSL的性能[1]），在高并發(fā)的情況下負(fù)載較高。而apache對于靜態(tài)文件的處
理能力比tomcat強(qiáng)，所以tomcat開發(fā)組開發(fā)了與apache結(jié)合使用的mod_jk模塊。該協(xié)議
由apache作請求代理，將HTTP協(xié)議的請求轉(zhuǎn)化為AJP協(xié)議包，并傳給后端的
tomcat。mod_jk和apache現(xiàn)在普遍使用AJP1.3協(xié)議[2]。它是一個(gè)二進(jìn)制格式的協(xié)議，比
字符格式的HTTP協(xié)議解析速度要快。
除了性能的提升，mod_jk另外的一個(gè)作用可以實(shí)現(xiàn)apache與tomcat一對多的對應(yīng)，
使后端tomcat負(fù)載均衡。mod_jk也提供apache與tomcat鏈接情況的監(jiān)控。
mod_jk模塊的典型工作流程是這樣的：一個(gè)HTTP請求過來，mod_jk模塊根據(jù)其URI選
擇合適的worker來進(jìn)行處理。如果是lb_worker（負(fù)載均衡的worker），就再根據(jù)各種條
件選擇后臺合適的ajp_worker（處理AJP協(xié)議的worker）。ajp_worker將HTTP協(xié)議的包，
組裝成AJP協(xié)議格式的包，然后選取一條空閑的鏈接，發(fā)送給后臺的tomcat服務(wù)器。等到
后臺將數(shù)據(jù)發(fā)送過來時(shí)，接收并解析AJP協(xié)議，重新組裝成HTTP協(xié)議，然后把結(jié)果發(fā)送給
客戶端。
2 mod_jk模塊的框架
2.1 線程
從宏觀上來講，mod_jk由一個(gè)watchdog線程和一組worker線程(進(jìn)程)組成。
watchdog線程是在apache內(nèi)部新創(chuàng)建的線程，它是一個(gè)維護(hù)線程。每隔
JkWatchdogInterval的時(shí)間（當(dāng)然，所有worker線程也有一個(gè)統(tǒng)一的worker.maintain 時(shí)
間，JkWatchdogInterval應(yīng)該至少大于worker.maintain），它會掃描所有worker線程。
watchdog線程會檢查每個(gè)worker線程的空閑鏈接、負(fù)載情況、與后端的鏈接情況，并使共
享內(nèi)存同步。worker線程是就是一些ajp13，ajp14，jni，lb或status類型的線程，負(fù)責(zé)
所有實(shí)際的工作。
在mod_jk中，線程內(nèi)（外）的同步均是通過線程鎖（pthread_mutex_lock）來實(shí)現(xiàn)的。
而進(jìn)程之間的全局同步，是用文件記錄鎖（flock或fcntl）來實(shí)現(xiàn)。進(jìn)程間的數(shù)據(jù)共享是
用這樣做的：進(jìn)程啟動時(shí)，創(chuàng)建一個(gè)JkShmSize 大小的文件，然后mmap到內(nèi)存，由于各進(jìn)
程mmap到內(nèi)存的是相同的鏡像，所以可以實(shí)現(xiàn)數(shù)據(jù)的共享，但是寫入共享內(nèi)存時(shí)，要做好
互斥。
由于apache的基本處理方式（prefork和worker模式）就是一個(gè)線程/進(jìn)程負(fù)責(zé)一個(gè)
連接，所以mod_jk各線程中對于網(wǎng)絡(luò)IO處理都是阻塞的。
2.2 worker對象
從具體的worker對象的角度來講，mod_jk由ajp_worker、jni_worker、lb_worker和
status_worker組成。這些對象參考了設(shè)計(jì)模式中factory的模型。每類worker都有生產(chǎn)
workers的factory。
在mod_jk中，其中的worker主要在worker.list中列出。其中，lb_worker可以含有
balance_workers，以lb_sub_worker的形式存儲于lb_worker中。lb_sub_worker可以是各
種類型的ajp_worker。所以真正工作的ajp_worker既可以“單干”，也可以由lb_worker
來分配任務(wù)。這主要取決于URI到底映射到哪個(gè)worker上以及該worker是否在
worker.list配置。
lb_worker，lb_sub_worker和ajp_worker一些配置信息都位于其結(jié)構(gòu)體中，而狀態(tài)信
息或在運(yùn)行中可變的參數(shù)則位于共享內(nèi)存中的對應(yīng)結(jié)構(gòu)體中，當(dāng)然也并不絕對，有些參數(shù)是
冗余的。
從正在運(yùn)行的某個(gè)線程的角度上來講，ajp_worker就是對應(yīng)了一個(gè)線程。
3 從HTTP到AJP的處理流程
由于mod_jk模塊是apache的處理模塊，本節(jié)主要是講述mod_jk模塊從客戶端到后端
服務(wù)器的處理流程。中間會涉及一些apache模塊的一些結(jié)構(gòu)。
3.1 mod_jk模塊在apache中的定義
3.1.1 mod_jk定義
/* 這是jk模塊的主要定義結(jié)構(gòu)體*/
module AP_MODULE_DECLARE_DATA jk_module = {
STANDARD20_MODULE_STUFF,
NULL, /* dir config creater */
NULL, /* dir merger --- default is to override */
create_jk_config, /*創(chuàng)建 jk模塊的配置結(jié)構(gòu)體*/
merge_jk_config, /* 初始化及合并 jk模塊的配置結(jié)構(gòu)體*/
jk_cmds, /* 所有在apahce中的命令及操作函數(shù) */
jk_register_hooks /* 具體的操作函數(shù)處理鉤子 */
};
3.1.2 mod_jk模塊的主要處理函數(shù)
/* mod_jk將各處理函數(shù)掛到相應(yīng)的鉤子上，鉤子實(shí)際上就是一些函數(shù)指針。針對某個(gè)HTTP
請求，這些函數(shù)會自上而下執(zhí)行。*/
static void jk_register_hooks(apr_pool_t * p)
{
/* 該函數(shù)在apache讀入配置后運(yùn)行，用以初始化全局互斥鎖，jk日志，全局變量的初
始化，以及讀入 workers.properties、uriworkermap.properties文件，初始化各worker
的屬性，建立worker名稱到worker結(jié)構(gòu)體的映射，uri到worker的映射*/
ap_hook_post_config(jk_post_config, NULL, NULL, APR_HOOK_MIDDLE);
/*該函數(shù)在apache主進(jìn)程fork工作子進(jìn)程后做的初始化工作，主要包括初始化進(jìn)程內(nèi)
互斥鎖，開啟維護(hù)線程，讀入共享內(nèi)存*/
ap_hook_child_init(jk_child_init, NULL, NULL, APR_HOOK_MIDDLE);
/* 將mod_jk的URI到真實(shí)URI，然后URI到worker的映射翻譯過程，用以找到該URI
相應(yīng)的worker_name */
ap_hook_translate_name(jk_translate, NULL, NULL, APR_HOOK_MIDDLE);
#if (MODULE_MAGIC_NUMBER_MAJOR > 20010808)
/* 綁定那些alias_dir的URI到mod_jk的配置，并找到相應(yīng)worker_name */
ap_hook_map_to_storage(jk_map_to_storage, NULL, NULL, APR_HOOK_MIDDLE);
/* 這是mod_jk的主要處理函數(shù) */
ap_hook_handler(jk_handler, NULL, NULL, APR_HOOK_MIDDLE);
#endif
}
3.2 jk_handler函數(shù)
jk_handler函數(shù)是mod_jk的主要處理函數(shù)，它負(fù)責(zé)將HTTP請求從apache發(fā)到tomcat,
再從tomcat接受數(shù)據(jù)，并返回給客戶。
它的處理過程如下：
1. 根據(jù)前面得到的worker_name，找到相應(yīng)的jk_worker（其結(jié)構(gòu)體見4.4）。
2. 初始化服務(wù)結(jié)構(gòu)體jk_ws_service，主要是針對HTTP服務(wù)端的一些設(shè)置及函數(shù)（服務(wù)
的結(jié)構(gòu)體見4.5），與AJP協(xié)議關(guān)系不大。
3. 調(diào)用jk_worker的get_endpoint函數(shù)，獲取具體的jk_endpoint結(jié)構(gòu)體（函數(shù)見
3.3.1和3.4.1，jk_endpoint的結(jié)構(gòu)體定義見4.4）。
4. 調(diào)用上述jk_endpoint的service函數(shù)。
5. 調(diào)用上述jk_endpoint的done函數(shù)，結(jié)束與tomcat的AJP連接。
6. 根據(jù)函數(shù)的結(jié)果處理各種狀態(tài)。
7. 釋放資源。
3.3 lb_worker的處理函數(shù)
3.3.1 lb_worker的get_endpoint
初始化lb_worker的endpoint結(jié)構(gòu)體，掛上其service及done函數(shù)。
3.3.2 lb_worker的service函數(shù)
它的處理過程如下：
1. 獲取共享內(nèi)存中記錄的worker狀態(tài)。
2. 如果需要綁定sessionID，獲取sessionID。
3. 調(diào)用get_most_suitable_worker函數(shù)，獲取相應(yīng)的lb_sub_worker(也即
ajp_worker)。
4. 調(diào)用ajp_worker的get_endpoint函數(shù)。
5. 調(diào)用上述endpoint的service函數(shù)。
6. 調(diào)用上述endpoint的done函數(shù)。
7. 根據(jù)service的返回結(jié)果，更新各種記錄狀態(tài)。
3.3.3 get_most_suitable_worker函數(shù)
它的處理過程如下：
1. 如果需要綁定sessionID，就根據(jù)sessionID找到工作正常的最佳worker。
2. 如果找不到，則調(diào)用find_best_worker函數(shù)。其處理過程如下：
i. 又調(diào)用find_best_byvalue函數(shù)。其處理過程如下：按照Round Robin的方式在
本lb_worker中找到第一個(gè)不在錯(cuò)誤狀態(tài)、也沒有停止、沒有disabled 、也不
busy的lb_sub_worker。
ii.如果find_best_byvalue返回錯(cuò)誤，說明本lb_worker的lb_sub_worker都處于
非正常工作狀態(tài)，需要調(diào)用find_failover_worker函數(shù)，通過
redirect、route、domain指令來進(jìn)行查找[3]。
3.4 ajp_worker的處理函數(shù)
3.4.1 ajp_worker的get_endpoint函數(shù)
它的主要功能是：找到與后端tomcat的一個(gè)空閑連接。
3.4.2 ajp_worker的ajp_service函數(shù)
該函數(shù)主要分為 ajp_send_request和and ajp_get_reply兩個(gè)函數(shù)。
它的處理過程如下：
1. 獲取共享內(nèi)存中的狀態(tài)。
2. 分配AJP請求包、恢復(fù)包、POST包的內(nèi)存。
3. 調(diào)用ajp_marshal_into_msgb函數(shù)，將HTTP請求包轉(zhuǎn)化為AJP包。
4. 將當(dāng)前ajp_worker的狀態(tài)更新。
5. 調(diào)用ajp_send_request函數(shù)。
6. 如果發(fā)送成功，調(diào)用ajp_get_reply函數(shù)，等待并接受AJP包。
7. 如果成功，更新當(dāng)前狀態(tài)。
3.4.2 ajp_worker的ajp_send_request函數(shù)
它的處理過程如下：
1. 調(diào)用jk_is_socket_connected函數(shù)，檢查即將發(fā)送的socket是否有效。它的檢查過
程是運(yùn)用select函數(shù)，等1微妙，如果成功返回說明，該socket的文件描述符至少
在內(nèi)核中還有效。
2. 如果上一次發(fā)送超時(shí)，則調(diào)用ajp_handle_cping_cpong函數(shù)來判斷后端連接是否有
效。該函數(shù)主要是發(fā)出了一個(gè)AJP13_CPING_REQUEST類型的AJP包，如果tomcat收
到，應(yīng)返回一個(gè)AJP13_CPONG_REPLY的包。
3. 如果上述的測試都成功，調(diào)用ajp_connection_tcp_send_message，發(fā)送AJP包。
3.4.3 ajp_worker的ajp_get_reply函數(shù)
它的處理過程如下：
1. 調(diào)用jk_is_input_event，用select等待接受數(shù)據(jù)，直到socket有接受數(shù)據(jù)。
2. 調(diào)用ajp_connection_tcp_get_message，接受AJP包，并檢查協(xié)議頭。
3. 調(diào)用ajp_process_callback，對該AJP包進(jìn)行解析處理。其處理過程如下：
i. 如果是JK_AJP13_SEND_HEADERS包，將其解包成HTTP包頭。如果沒有錯(cuò)誤，就調(diào)
用jk_ws_service->start_response（）函數(shù)發(fā)送HTTP回復(fù)的head。返回
JK_AJP13_SEND_HEADERS。
ii.如果是JK_AJP13_SEND_BODY_CHUNK包，調(diào)用jk_ws_service->write發(fā)送HTTP回
復(fù)的body。返回JK_AJP13_NO_RESPONSE。
iii.如果是JK_AJP13_GET_BODY_CHUNK包，說明還有數(shù)據(jù)要發(fā)送到tomcat，調(diào)用
ajp_read_into_msg_buff，繼續(xù)發(fā)送數(shù)據(jù)。返回JK_AJP13_HAS_RESPONSE。
iv.如果是JK_AJP13_END_RESPONSE包，就說明tomcat的回復(fù)已經(jīng)完成。返回
JK_AJP13_END_RESPONSE。
3.5 jk_ws_service的一些處理函數(shù)
3.5.1 jk_ws_service 的 ws_start_response函數(shù)
該函數(shù)主要是構(gòu)建HTTP回復(fù)包的頭部。
3.5.2 jk_ws_service 的 ws_write函數(shù)
調(diào)用 apache的ap_rwrite函數(shù)，發(fā)送整個(gè)HTTP包。
3.5.3 jk_ws_service 的 ws_read函數(shù)
調(diào)用apache的ap_get_client_block讀入全部的request body數(shù)據(jù)。
4 mod_jk的主要數(shù)據(jù)結(jié)構(gòu)
4.1 lb_worker
lb_worker是負(fù)載均衡worker。主要負(fù)責(zé)調(diào)配其名下的一些lb_sub_worker 。

dist/common/jk_lb_worker.h
struct lb_worker
{
/* jk模塊通用worker結(jié)構(gòu)體。包含一些回調(diào)函數(shù)，不同的worker有不同的函數(shù)實(shí)現(xiàn)
*/
jk_worker_t worker;
/* Shared memory worker data */
jk_shm_lb_worker_t *s;
char name[JK_SHM_STR_SIZ+1];
/* Sequence counter starting at 0 and increasing
* every time we change the config
*/
volatile unsigned int sequence;
jk_pool_t p;
jk_pool_atom_t buf[TINY_POOL_SIZE];
JK_CRIT_SEC cs;
/*其名下的workers*/
lb_sub_worker_t *lb_workers;
unsigned int num_of_workers;
int sticky_session;
int sticky_session_force;
int recover_wait_time;
int max_reply_timeouts;
int retries;
int retry_interval;
int lbmethod;
int lblock;
int maintain_time;
unsigned int max_packet_size;
unsigned int next_offset;
/* Session cookie */
char session_cookie[JK_SHM_STR_SIZ+1];
/* Session path */
char session_path[JK_SHM_STR_SIZ+1];
};
lb_sub_worker是由lb_worker支配的ajp_worker。當(dāng)然lb_sub_worker有不同的類型。
它們的實(shí)際類型存儲在ajp_worker中。
dist/common/jk_lb_worker.h
struct lb_sub_worker
{
/* 包含ajp_worker的回調(diào)函數(shù)及其ajp_worker結(jié)構(gòu)體*/
jk_worker_t *worker;
/* Shared memory worker data */
jk_shm_lb_sub_worker_t *s;
char name[JK_SHM_STR_SIZ+1];
/* Sequence counter starting at 0 and increasing
* every time we change the config
*/
volatile unsigned int sequence;
/* route */
char route[JK_SHM_STR_SIZ+1];
/* worker domain */
char domain[JK_SHM_STR_SIZ+1];
/* worker redirect route */
char redirect[JK_SHM_STR_SIZ+1];
/* worker distance */
int distance;
/* current activation state (config) of the worker */
int activation;
/* Current lb factor */
int lb_factor;
/* Current worker index */
int i;
/* Current lb reciprocal factor */
jk_uint64_t lb_mult;
};
typedef struct lb_sub_worker lb_sub_worker_t;
4.2 ajp_worker
ajp_worker是具體工作的worker，對應(yīng)后端一個(gè)tomcat應(yīng)用服務(wù)。
dist/common/jk_ajp_common.c
struct ajp_worker
{
/* 包含ajp_worker的回調(diào)函數(shù)*/
jk_worker_t worker;
/* Shared memory worker data */
jk_shm_ajp_worker_t *s;
char name[JK_SHM_STR_SIZ+1];
/* Sequence counter starting at 0 and increasing
* every time we change the config
*/
volatile unsigned int sequence;
jk_pool_t p;
jk_pool_atom_t buf[TINY_POOL_SIZE];
JK_CRIT_SEC cs;
struct sockaddr_in worker_inet_addr; /* Contains host and port */
unsigned connect_retry_attempts;
const char *host;
int port;
int maintain_time;
/*
* Open connections cache...
*
* 1. Critical section object to protect the cache.
* 2. Cache size.
* 3. An array of "open" endpoints.
*/
unsigned int ep_cache_sz;
unsigned int ep_mincache_sz;
unsigned int ep_maxcache_sz;
int cache_acquire_timeout;
ajp_endpoint_t **ep_cache;
int proto; /* PROTOCOL USED AJP13/AJP14 */
jk_login_service_t *login;
/* Weak secret similar with ajp12, used in ajp13 */
const char *secret;
/*
* Post physical connect handler.
* AJP14 will set here its login handler
*/
int (*logon) (ajp_endpoint_t * ae, jk_logger_t *l);
/*
* Handle Socket Timeouts
*/
int socket_timeout;
int socket_connect_timeout;
int keepalive;
int socket_buf;
/*
* Handle Cache Timeouts
*/
int cache_timeout;
/*
* Handle Connection/Reply Timeouts
*/
int connect_timeout; /* connect cping/cpong delay in ms (0 means
disabled) */
int reply_timeout; /* reply timeout delay in ms (0 means disabled) */
int prepost_timeout; /* before sending a request cping/cpong timeout
delay in ms (0 means disabled) */
int conn_ping_interval; /* interval for sending keepalive cping packets on
* unused connection */
int ping_timeout; /* generic cping/cpong timeout. Used for keepalive
packets or
* as default for boolean valued connect and
prepost timeouts.
*/
unsigned int ping_mode; /* Ping mode flags (which types of cpings should
be used) */
/*
* Recovery options
*/
unsigned int recovery_opts;
/*
* Public property to enable the number of retry attempts
* on this worker.
*/
int retries;
unsigned int max_packet_size; /* Maximum AJP Packet size */
int retry_interval; /* Number of milliseconds to sleep before
doing a retry */
/*
* HTTP status that will cause failover (0 means disabled)
*/
unsigned int http_status_fail_num;
int http_status_fail[JK_MAX_HTTP_STATUS_FAILS];
};
4.3 status_worker
status_worker用于產(chǎn)生一些狀態(tài)的統(tǒng)計(jì)信息。
dist/common/jk_statuc.c
struct status_worker
{
jk_pool_t p;
jk_pool_atom_t buf[TINY_POOL_SIZE];
const char *name;
const char *css;
const char *ns;
const char *xmlns;
const char *doctype;
const char *prefix;
int read_only;
char **user_names;
unsigned int num_of_users;
int user_case_insensitive;
jk_uint32_t good_mask;
jk_uint32_t bad_mask;
jk_worker_t worker;
jk_worker_env_t *we;
};
4.4 jk_worker和 jk_endpoint
jk_worker是所有worker通用結(jié)構(gòu)體名稱, 主要包含的是一些函數(shù)指針。它是一個(gè)類
似java中抽象類的概念，各成員函數(shù)在從factory函數(shù)生產(chǎn)時(shí)初始化。
dist/common/jk_service.h
struct jk_worker
{
/*
* A 'this' pointer which is used by the subclasses of this class to
* point to data/functions which are specific to a given protocol
* (e.g. ajp12 or ajp13 or ajp14).
*/
void *worker_private;/* 指向ajp_worker，lb_worker結(jié)構(gòu)體 ...*/
int type;
/*
* For all of the below (except destroy), the first argument is
* essentially a 'this' pointer.
*/
/* 先于init函數(shù)調(diào)用，用于分配各類worker結(jié)構(gòu)體的內(nèi)存，作必要的初始化
* Given a worker which is in the process of being created, and a list
* of configuration options (or 'properties'), check to see if it the
* options are. This will always be called before the init() method.
* The init/validate distinction is a bit hazy to me.
* See jk_ajp13_worker.c/jk_ajp14_worker.c and jk_worker.c-
>wc_create_worker()
*/
int (JK_METHOD * validate) (jk_worker_t *w,
jk_map_t *props,
jk_worker_env_t *we, jk_logger_t *l);
/*
* Update worker either from jk_status or reloading from workers.properties
*/
int (JK_METHOD * update) (jk_worker_t *w,
jk_map_t *props,
jk_worker_env_t *we, jk_logger_t *l);
/*
* Do whatever initialization needs to be done to start this worker up.
* Configuration options are passed in via the props parameter.
*/
int (JK_METHOD * init) (jk_worker_t *w,
jk_map_t *props,
jk_worker_env_t *we, jk_logger_t *l);
/*
* Obtain an endpoint to service a particular request. A pointer to
* the endpoint is stored in pend.
*/
int (JK_METHOD * get_endpoint) (jk_worker_t *w,
jk_endpoint_t **pend, jk_logger_t *l);
/*
* Shutdown this worker. The first argument is not a 'this' pointer,
* but rather a pointer to 'this', so that the object can be free'd (I
* think -- though that doesn't seem to be happening. Hmmm).
*/
int (JK_METHOD * destroy) (jk_worker_t **w, jk_logger_t *l);
/*
* Maintain this worker.
*/
int (JK_METHOD * maintain) (jk_worker_t *w, time_t now, jk_logger_t *l);
};
/* jk_endpoint可以稱之為通用終端服務(wù)結(jié)構(gòu)體，各類worker可能有自己的endpoint結(jié)構(gòu)
體。比如ajp_worker, 該終端是用來做具體工作的，比如發(fā)出請求，接收AJP數(shù)據(jù)等等。如
果是lb_worker，該終端是的作用是找出合適ajp_worker, 把任務(wù)交給它。* /
struct jk_endpoint
{
jk_uint64_t rd;
jk_uint64_t wr;
/*
* Flag to pass back recoverability status from
* a load balancer member to the load balancer itself.
* Depending on the configuration and request status
* recovery is not allowed.
*/
int recoverable;
/*
* A 'this' pointer which is used by the subclasses of this class to
* point to data/functions which are specific to a given protocol
* (e.g. ajp12 or ajp13 or ajp14).
*/
void *endpoint_private;
/* 該函數(shù)是具體的服務(wù)函數(shù)
* Forward a request to the servlet engine. The request is described
* by the jk_ws_service_t object.
* is_error is either 0 meaning recoverable or set to
* the HTTP error code.
*/
int (JK_METHOD * service) (jk_endpoint_t *e,
jk_ws_service_t *s,
jk_logger_t *l, int *is_error);
/*
* Called when this particular endpoint has finished processing a
* request. For some protocols (e.g. ajp12), this frees the memory
* associated with the endpoint. For others (e.g. ajp13/ajp14), this can
* return the endpoint to a cache of already opened endpoints.
*
* Note that the first argument is *not* a 'this' pointer, but is
* rather a pointer to a 'this' pointer. This is necessary, because
* we may need to free this object.
*/
int (JK_METHOD * done) (jk_endpoint_t **p, jk_logger_t *l);
};
4.5 jk_ws_service
該結(jié)構(gòu)體是與apache相關(guān)的一些參數(shù)或函數(shù)，面向HTTP協(xié)議，與AJP協(xié)議不太相關(guān)。
dist/common/jk_service.h
struct jk_ws_service
{
/*
* A 'this' pointer which is used by the subclasses of this class to
* point to data which is specific to a given web server platform
* (e.g. Apache or IIS).
*/
void *ws_private;
/*
* Provides memory management. All data specific to this request is
* allocated within this pool, which can then be reclaimed at the end
* of the request handling cycle.
*
* Alive as long as the request is alive.
*/
jk_pool_t *pool;
/*
* CGI Environment needed by servlets
*/
const char *method;
const char *protocol;
char *req_uri;
const char *remote_addr;
const char *remote_host;
const char *remote_user;
const char *auth_type;
const char *query_string;
const char *server_name;
unsigned server_port;
char *server_software;
jk_uint64_t content_length; /* 64 bit integer that represents the content */
/* length should be 0 if unknown. */
unsigned is_chunked; /* 1 if content length is unknown (chunked rq) */
unsigned no_more_chunks; /* 1 if last chunk has been read */
jk_uint64_t content_read; /* number of bytes read */
/*
* SSL information
*
* is_ssl - True if request is in ssl connection
* ssl_cert - If available, base64 ASN.1 encoded client certificates.
* ssl_cert_len - Length of ssl_cert, 0 if certificates are not available.
* ssl_cipher - The ssl cipher suite in use.
* ssl_session - The ssl session string
*
* In some servers it is impossible to extract all this information, in this
* case, we are passing NULL.
*/
int is_ssl;
char *ssl_cert;
unsigned ssl_cert_len;
char *ssl_cipher;
char *ssl_session;
/*
* SSL extra information for Servlet 2.3 API
*
* ssl_key_size - ssl key size in use
*/
int ssl_key_size;
/*
* Headers, names and values.
*/
char **headers_names; /* Names of the request headers */
char **headers_values; /* Values of the request headers */
unsigned num_headers; /* Number of request headers */
/*
* Request attributes.
*
* These attributes that were extracted from the web server and are
* sent to Tomcat.
*
* The developer should be able to read them from the ServletRequest
* attributes. Tomcat is required to append org.apache.tomcat. to
* these attribute names.
*/
char **attributes_names; /* Names of the request attributes */
char **attributes_values; /* Values of the request attributes */
unsigned num_attributes; /* Number of request attributes */
/*
* The route is in use when the adapter load balance among
* several workers. It is the ID of a specific target in the load balance
* group. We are using this variable to implement target session
* affinity
*/
const char *route;
/* Temp solution for auth. For native1 it'll be sent on each request,
if an option is present. For native2 it'll be sent with the first
request. On java side, both cases will work. For tomcat3.2 or
a version that doesn't support secret - don't set the secret,
and it'll work.
*/
const char *secret;
/*
* Area to get POST data for fail-over recovery in POST
*/
jk_msg_buf_t *reco_buf;
int reco_status;
/*
* If set call flush after each write
*/
int flush_packets;
/*
* If set call flush after AJP13_SEND_HEADERS.
*/
int flush_header;
/*
* service extensions
*/
svc_extension_t extension;
/*
* JK_TRUE if response headers have been sent back
*/
int response_started;
/*
* JK_TRUE if response should not be send to the client
*/
int response_blocked;
/*
* HTTP status sent from container.
*/
int http_response_status;
/* Uri worker map. Added for virtual host support
*/
jk_uri_worker_map_t *uw_map;
/* 下面這些回調(diào)函數(shù)實(shí)現(xiàn)都可以在mod_jk.c找到
* Callbacks into the web server. For each, the first argument is
* essentially a 'this' pointer. All return JK_TRUE on success
* and JK_FALSE on failure.
*/
/*
* Send the response headers to the browser.
*/
int (JK_METHOD * start_response) (jk_ws_service_t *s,
int status,
const char *reason,
const char *const *header_names,
const char *const *header_values,
unsigned num_of_headers);
/*
* Read a chunk of the request body into a buffer. Attempt to read len
* bytes into the buffer. Write the number of bytes actually read into
* actually_read.
*/
int (JK_METHOD * read) (jk_ws_service_t *s,
void *buffer,
unsigned len, unsigned *actually_read);
/*
* Write a chunk of response data back to the browser.
*/
int (JK_METHOD * write) (jk_ws_service_t *s,
const void *buffer, unsigned len);
/*
* Flush a chunk of response data back to the browser.
*/
void (JK_METHOD * flush) (jk_ws_service_t *s);
/*
* Done with sending response back to the browser.
*/
void (JK_METHOD * done) (jk_ws_service_t *s);
/*
* If set do not reuse socket after each full response
*/
int disable_reuse;
/*
* Add more data to log facilities.
*/
void (JK_METHOD * add_log_items) (jk_ws_service_t *s,
const char *const *log_names,
const char *const *log_values,
unsigned num_of_items);
/*
* Iterate through all vhosts
*/
void *(JK_METHOD * next_vhost) (void *d);
/*
* String representation of a vhost
*/
void (JK_METHOD * vhost_to_text) (void *d, char *buf, size_t len);
/*
* Get uw_map associated with a vhost
*/
jk_uri_worker_map_t *(JK_METHOD * vhost_to_uw_map) (void *d);
};

4.6 共享內(nèi)存中一些數(shù)據(jù)結(jié)構(gòu)
共享內(nèi)存中的數(shù)據(jù)結(jié)構(gòu)基本上都是記錄之用。有些參數(shù)在運(yùn)行中會實(shí)時(shí)變化。

dist/common/jk_shm.h
/** jk shm generic worker record structure */
struct jk_shm_worker_header
{
int id;
int type;
/* worker name */
char name[JK_SHM_STR_SIZ+1];
/* Sequence counter starting at 0 and increasing
* every time we change the config
*/
volatile unsigned int sequence;
};
typedef struct jk_shm_worker_header jk_shm_worker_header_t;
/** jk shm ajp13/ajp14 worker record structure */
struct jk_shm_ajp_worker
{
jk_shm_worker_header_t h;
/* Configuration data mirrored from ajp_worker */
int cache_timeout;
int connect_timeout;
int reply_timeout;
int prepost_timeout;
unsigned int recovery_opts;
int retries;
int retry_interval;
unsigned int max_packet_size;
/* current error state (runtime) of the worker */
volatile int state;
/* Statistical data */
/* Number of currently busy channels */
volatile int busy;
/* Maximum number of busy channels
該參數(shù)并非我們的maxbusy，它是該worker自程序運(yùn)行以來busy的最大值 */
volatile int max_busy;
volatile time_t error_time;
/* Number of bytes read from remote */
volatile jk_uint64_t readed;
/* Number of bytes transferred to remote */
volatile jk_uint64_t transferred;
/* Number of times the worker was used */
volatile jk_uint64_t used;
/* Number of times the worker was used - snapshot during maintenance */
volatile jk_uint64_t used_snapshot;
/* Number of non 200 responses */
volatile jk_uint32_t errors;
/* Decayed number of reply_timeout errors */
volatile jk_uint32_t reply_timeouts;
/* Number of client errors */
volatile jk_uint32_t client_errors;
/* Last reset time */
volatile time_t last_reset;
volatile time_t last_maintain_time;
};
typedef struct jk_shm_ajp_worker jk_shm_ajp_worker_t;
/** jk shm lb sub worker record structure */
struct jk_shm_lb_sub_worker
{
jk_shm_worker_header_t h;
/* route */
char route[JK_SHM_STR_SIZ+1];
/* worker domain */
char domain[JK_SHM_STR_SIZ+1];
/* worker redirect route */
char redirect[JK_SHM_STR_SIZ+1];
/* Number of currently busy channels */
volatile int busy;
/* worker distance */
volatile int distance;
/* current activation state (config) of the worker */
volatile int activation;
/* current error state (runtime) of the worker */
volatile int state;
/* Current lb factor */
volatile int lb_factor;
/* 我們的參數(shù)加在這里*/
volatile int maxbusy;
/* Current lb reciprocal factor */
volatile jk_uint64_t lb_mult;
/* Current lb value */
volatile jk_uint64_t lb_value;
/* Statistical data */
volatile time_t error_time;
/* Number of times the worker was elected - snapshot during maintenance */
volatile jk_uint64_t elected_snapshot;
/* Number of non 200 responses */
volatile jk_uint32_t errors;
};
typedef struct jk_shm_lb_sub_worker jk_shm_lb_sub_worker_t;
/** jk shm lb worker record structure */
struct jk_shm_lb_worker
{
jk_shm_worker_header_t h;
/* Number of currently busy channels，該值是其名下ajp_worker的busy值之和*/
volatile int busy;
/* Maximum number of busy channels，該值是其名下ajp_worker的max_busy值之和
*/
volatile int max_busy;
int sticky_session;
int sticky_session_force;
int recover_wait_time;
int max_reply_timeouts;
int retries;
int retry_interval;
int lbmethod;
int lblock;
unsigned int max_packet_size;
/* Last reset time */
volatile time_t last_reset;
volatile time_t last_maintain_time;
/* Session cookie */
char session_cookie[JK_SHM_STR_SIZ+1];
/* Session path */
char session_path[JK_SHM_STR_SIZ+1];
};
typedef struct jk_shm_lb_worker jk_shm_lb_worker_t;