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diff --git a/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/loadbalancers.xml b/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/loadbalancers.xml deleted file mode 100644 index eda22cd4..00000000 --- a/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/loadbalancers.xml +++ /dev/null @@ -1,236 +0,0 @@ -<?xml version="1.0" encoding="ISO-8859-1"?> -<!DOCTYPE document [ - <!ENTITY project SYSTEM "project.xml"> -]> -<document url="loadbalancers.html"> - - &project; -<copyright> - Licensed to the Apache Software Foundation (ASF) under one or more - contributor license agreements. See the NOTICE file distributed with - this work for additional information regarding copyright ownership. - The ASF licenses this file to You under the Apache License, Version 2.0 - (the "License"); you may not use this file except in compliance with - the License. You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, software - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. -</copyright> -<properties> -<title>LoadBalancer HowTo</title> -<author email="mturk@apache.org">Mladen Turk</author> -<date>$Date: 2011-03-07 19:04:44 +0100 (Mon, 07 Mar 2011) $</date> -</properties> -<body> -<section name="Introduction"> -<br/> -<p>A load balancer is a worker that does not directly communicate with Tomcat. -Instead it is responsible for the management of several "real" workers, -called members or sub workers of the load balancer.</p> -<p> -This management includes: -</p> -<ul> -<li> -Instantiating the workers in the web server. -</li> -<li> -Using the worker's load-balancing factor, perform weighted load balancing -(distributing load according to defined strengths of the targets). -</li> -<li> -Keeping requests belonging to the same session executing on the same Tomcat -(session stickyness). -</li> -<li> -Identifying failed Tomcat workers, suspending requests to them and instead -falling-back on other workers managed by the load balancer. -</li> -<li> -Providing status and load metrics for the load balancer itself and all -members via the status worker interface. -</li> -<li> -Allowing to dynamically reconfigure load-balancing via the status worker -interface. -</li> -</ul> -<p> -Workers managed by the same load balancer worker are load-balanced -(based on their configured balancing factors and current request or session load) -and also secured against failure by providing failover to other members of the same -load balancer. So a single Tomcat process death will not "kill" the entire site. -</p> -<p>Some of the features provided by a load balancer are even interesting, when -only working with a single member worker (where load balancing is not possible).</p> - -<subsection name="Basic Load Balancer Properties"> -<p>A worker is configured as a load balancer by setting its worker <code>type</code> -to <b>lb</b>. -</p> -<p> -The following table specifies some properties used to configure a load balancer worker: -</p> -<ul> -<li><b>balance_workers</b> is a comma separated list of names of the member workers of the -load balancer. These workers are typically of type <b>ajp13</b>. The member workers do -not need to appear in the <code>worker.list</code> property themselves, adding the -load balancer to it suffices.</li> -<li><b>sticky_session</b> specifies whether requests with SESSION ID's should be routed -back to the same Tomcat instance that created the session. You can set sticky_session to -<b>False</b> when Tomcat is using a session manager which can share session data across -multiple instances of Tomcat - or if your application is stateless. -By default sticky_session is set to <b>True</b>.</li> -<li><b>lbfactor</b> can be added to each member worker to configure individual -strengths for the members. A higher <code>lbfactor</code> will lead to more -requests being balanced to that worker. The factors must be given by integers and the -load will be distributed proportional to the factors given. Higher factors lead to -more requests.</li> -</ul> - -<source> - # The load balancer worker balance1 will distribute - # load to the members worker1 and worker2 - worker.balance1.type=lb - worker.balance1.balance_workers=worker1, worker2 - worker.worker1.type=ajp13 - worker.worker1.host=myhost1 - worker.worker1.port=8009 - worker.worker2.type=ajp13 - worker.worker1.host=myhost2 - worker.worker1.port=8009 -</source> - -<warn> -Session stickyness is not implemented using a tracking table for sessions. -Instead each Tomcat instance gets an individual name and adds its name at -the end of the session id. When the load balancer sees a session id, it -finds the name of the Tomcat instance and sends the request via the correct -member worker. For this to work you must set the name of the Tomcat instances -as the value of the <code>jvmRoute</code> attribute in the Engine element of -each Tomcat's server.xml. The name of the Tomcat needs to be equal to the name -of the corresponding load balancer member. In the above example, Tomcat on host -"myhost1" needs <code>jvmRoute="worker1"</code>, Tomcat on host "myhost2" -needs <code>jvmRoute="worker2"</code>. -</warn> - -<p>For a complete reference of all load balancer configuration -attributes, please consult the worker <a href="../reference/workers.html">reference</a>. -</p> -</subsection> - -<subsection name="Advanced Load Balancer Worker Properties"> -<p>The load balancer supports complex topologies and failover configurations. -Using the member attribute <code>distance</code> you can group members. -The load balancer will always send a request to a member of lowest distance. -Only when all of those are broken, it will balance to the members of the -next higher configured distance. This allows to define priorities between -Tomcat instances in different data center locations. -</p> -<p>When working with shared sessions, either by using session replication -or a persisting session manager (e.g. via a database), one often splits -up the Tomcat farm into replication groups. In case of failure of a member, -the load balancer needs to know, which other members share the session. -This is configured using the <code>domain</code> attribute. All workers -with the same domain are assumed to share the sessions.</p> -<p>For maintenance purposes you can tell the load balancer to not -allow any new sessions on some members, or even not use them at all. -This is controlled by the member attribute <code>activation</code>. -The value <b>Active</b> allows normal use of a member, <b>disabled</b> -will not create new sessions on it, but still allow sticky requests, -and <b>stopped</b> will no longer send any requests to the member. -Switching the activation from "active" to "disabled" some time before -maintenance will drain the sessions on the worker and minimize disruption. -Depending on the usage pattern of the application, draining will take from -minutes to hours. Switching the worker to stopped immediately before -maintenance will reduce logging of false errors by mod_jk.</p> -<p>Finally you can also configure hot spare workers by using -<code>activation</code> set to <b>disabled</b> in combination with -the attribute <code>redirect</code> added to the other workers:</p> - -<source> - # The advanced router LB worker - worker.list=router - worker.router.type=lb - worker.router.balance_workers=worker1,worker2 - - # Define the first member worker - worker.worker1.type=ajp13 - worker.worker1.host=myhost1 - worker.worker1.port=8009 - # Define preferred failover node for worker1 - worker.worker1.redirect=worker2 - - # Define the second member worker - worker.worker2.type=ajp13 - worker.worker2.host=myhost2 - worker.worker2.port=8009 - # Disable worker2 for all requests except failover - worker.worker2.activation=disabled -</source> - -<p> -The <code>redirect</code> flag on worker1 tells the load balancer -to redirect the requests to worker2 in case that worker1 has a problem. -In all other cases worker2 will not receive any requests, thus acting -like a hot standby. -</p> - -<p>A final note about setting <code>activation</code> to <b>disabled</b>: -The session id coming with a request is send either -as part of the request URL (<code>;jsessionid=...</code>) or via a cookie. -When using bookmarks or browsers that are running since a long time, -it is possible to send a request carrying an old and invalid session id -pointing at a disabled member. -Since the load balancer does not have a list of valid sessions, it will -forward the request to the disabled member. Thus draining takes longer than -expected. To handle such cases, you can add a Servlet filter to your web -application, which checks the request attribute <code>JK_LB_ACTIVATION</code>. -This attribute contains one of the strings "ACT", "DIS" or "STP". If you -detect "DIS" and the session for the request is no longer active, delete the -session cookie and redirect using a self-referential URL. The redirected -request will then no longer carry session information and thus the load -balancer will not send it to the disabled worker. The request attribute -<code>JK_LB_ACTIVATION</code> has been added in version 1.2.32.</p> -</subsection> - -<subsection name="Status Worker properties"> -<p> -The status worker does not communicate with Tomcat. -Instead it is responsible for the worker management. It is -especially useful when combined with load balancer workers. -</p> -<source> - # Add the status worker to the worker list - worker.list=jkstatus - # Define a 'jkstatus' worker using status - worker.jkstatus.type=status -</source> -<p>Next thing is to mount the requests to the jkstatus worker. For Apache -web servers use the:</p> -<source> - # Add the jkstatus mount point - JkMount /jkmanager/* jkstatus -</source> -<p>To obtain a higher level of security use the:</p> -<source> - # Enable the JK manager access from localhost only - <Location /jkmanager/> - JkMount jkstatus - Order deny,allow - Deny from all - Allow from 127.0.0.1 - </Location> -</source> - -</subsection> - -</section> - -</body> -</document> diff --git a/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/project.xml b/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/project.xml deleted file mode 100644 index b513a8aa..00000000 --- a/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/project.xml +++ /dev/null @@ -1,81 +0,0 @@ -<?xml version="1.0" encoding="ISO-8859-1"?> -<!-- - Licensed to the Apache Software Foundation (ASF) under one or more - contributor license agreements. See the NOTICE file distributed with - this work for additional information regarding copyright ownership. - The ASF licenses this file to You under the Apache License, Version 2.0 - (the "License"); you may not use this file except in compliance with - the License. You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, software - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. ---> -<project name="Apache Tomcat Connector Documentation - Generic HowTo" - href="http://tomcat.apache.org/"> - - <title>The Apache Tomcat Connector - Generic HowTo</title> - - <logo href="/images/tomcat.gif"> - The Apache Tomcat Connector - Generic HowTo - </logo> -<body> - - <menu name="Links"> - <item name="Docs Home" href="../index.html"/> - </menu> - - <menu name="Reference Guide"> - <item name="workers.properties" href="../reference/workers.html"/> - <item name="uriworkermap.properties" href="../reference/uriworkermap.html"/> - <item name="Status Worker" href="../reference/status.html"/> - <item name="Apache HTTP Server" href="../reference/apache.html"/> - <item name="IIS" href="../reference/iis.html"/> - </menu> - - <menu name="Generic HowTo"> - <item name="For the impatient" href="../generic_howto/quick.html"/> - <item name="All about workers" href="../generic_howto/workers.html"/> - <item name="Timeouts" href="../generic_howto/timeouts.html"/> - <item name="Load Balancing" href="../generic_howto/loadbalancers.html"/> - <item name="Reverse Proxy" href="../generic_howto/proxy.html"/> - </menu> - - <menu name="Webserver HowTo"> - <item name="Apache HTTP Server" href="../webserver_howto/apache.html"/> - <item name="IIS" href="../webserver_howto/iis.html"/> - <item name="Netscape/SunOne/Sun" href="../webserver_howto/nes.html"/> - </menu> - - <menu name="AJP Protocol Reference"> - <item name="AJPv13" href="../ajp/ajpv13a.html"/> - <item name="AJPv13 Extension Proposal" href="../ajp/ajpv13ext.html"/> - </menu> - - <menu name="Miscellaneous Documentation"> - <item name="Frequently asked questions" href="../miscellaneous/faq.html"/> - <item name="Changelog" href="../miscellaneous/changelog.html"/> - <item name="Current Tomcat Connectors bugs" href="http://issues.apache.org/bugzilla/buglist.cgi?query_format=advanced&short_desc_type=allwordssubstr&short_desc=&product=Tomcat+Connectors&long_desc_type=substring&long_desc=&bug_file_loc_type=allwordssubstr&bug_file_loc=&keywords_type=allwords&keywords=&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&emailassigned_to1=1&emailtype1=substring&email1=&emailassigned_to2=1&emailreporter2=1&emailcc2=1&emailtype2=substring&email2=&bugidtype=include&bug_id=&votes=&chfieldfrom=&chfieldto=Now&chfieldvalue=&cmdtype=doit&order=Reuse+same+sort+as+last+time&field0-0-0=noop&type0-0-0=noop&value0-0-0="/> - <item name="Contribute documentation" href="../miscellaneous/doccontrib.html"/> - <item name="JK Status Ant Tasks" href="../miscellaneous/jkstatustasks.html"/> - <item name="Reporting Tools" href="../miscellaneous/reporttools.html"/> - <item name="Old JK/JK2 documentation" href="http://tomcat.apache.org/connectors-doc-archive/jk2/index.html"/> - </menu> - - <menu name="News"> - <item name="2011" href="../news/20110701.html"/> - <item name="2010" href="../news/20100101.html"/> - <item name="2009" href="../news/20090301.html"/> - <item name="2008" href="../news/20081001.html"/> - <item name="2007" href="../news/20070301.html"/> - <item name="2006" href="../news/20060101.html"/> - <item name="2005" href="../news/20050101.html"/> - <item name="2004" href="../news/20041100.html"/> - </menu> - -</body> -</project> diff --git a/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/proxy.xml b/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/proxy.xml deleted file mode 100644 index 69c60fd5..00000000 --- a/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/proxy.xml +++ /dev/null @@ -1,347 +0,0 @@ -<?xml version="1.0" encoding="ISO-8859-1"?> -<!DOCTYPE document [ - <!ENTITY project SYSTEM "project.xml"> -]> -<document url="proxy.html"> - - &project; -<copyright> - Licensed to the Apache Software Foundation (ASF) under one or more - contributor license agreements. See the NOTICE file distributed with - this work for additional information regarding copyright ownership. - The ASF licenses this file to You under the Apache License, Version 2.0 - (the "License"); you may not use this file except in compliance with - the License. You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, software - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. -</copyright> -<properties> -<title>Reverse Proxy HowTo</title> -<author email="rjung@apache.org">Rainer Jung</author> -<date>$Date: 2011-03-07 16:17:11 +0100 (Mon, 07 Mar 2011) $</date> -</properties> -<body> -<section name="Introduction"> -<br/> -<p>The Apache module mod_jk and its ISAPI and NSAPI variants connect -a web server to a backend (typically Tomcat) using the AJP protocol. -The web server receives an HTTP(S) request and the module forwards -the request to the backend. This function is usually called a gateway -or a proxy, in the context of HTTP it is called a reverse proxy. -</p> -</section> -<section name="Typical Problems"> -<br/> -<p>A reverse proxy is not totally transparent to the application on -the backend. For instance the host name and port the original client -(e.g. browser) needs to talk to belong to the web server and not to the -backend, so the reverse proxy talks to a different host name and port. -When the application on the backend returns content including -self-referential URLs using its own backend address and port, the -client will usually not be able to use these URLs. -</p> -<p>Another example is the client IP address, which for the web server is the -source IP of the incoming connection, whereas for the backend the -connection always comes from the web server. This can be a problem, when -the client IP is used by the backend application e.g. for security reasons. -</p> -</section> -<section name="AJP as a Solution"> -<br/> -<p>Most of these problems are automatically handled by the AJP protocol -and the AJP connectors of the backend. The AJP protocol transports -this communication metadata and the backend connector presents this -metadata whenever the application asks for it using Servlet API methods. -</p> -<p>The following list contains the communication metadata handled by AJP -and the ServletRequest/HttpServletRequest API calls which can be used to retrieve them: -<ul> -<li>local name: <code>getLocalName()</code> and <code>getLocalAddr</code>. -This is also equal to <code>getServerName()</code>, unless a <code>Host</code> header -is contained in the request. In this case the server name is taken from that header. -</li> -<li>local port: <code>getLocalPort()</code> -This is also equal to <code>getServerPort()</code>, unless a <code>Host</code> header -is contained in the request. In this case the server port is taken from that header -if it contains an explicit port, or is equal to the default port of the scheme used. -</li> -<li>client address: <code>getRemoteAddr()</code> -</li> -<li>client port: <code>getRemotePort()</code> -The remote port was initially not supported. It is available when using mod_jk 1.2.32 -with Apache or IIS (not for the NSAPI plugin) together with Tomcat version at least -5.5.28, 6.0.20 or 7.0.0. For older versions, <code>getRemotePort()</code> -will incorrectly return 0 or -1. As a workaround you can forward the remote port by setting -<code>JkEnvVar REMOTE_PORT</code> and then either using -<code>request.getAttribute("REMOTE_PORT")</code> instead of <code>getRemotePort()</code> -or wrapping the request using a filter and overriding <code>getRemotePort()</code> with -<code>request.getAttribute("REMOTE_PORT")</code>. -</li> -<li>client host: <code>getRemoteHost()</code> -</li> -<li>authentication type: <code>getAuthType()</code> -</li> -<li>remote user: <code>getRemoteUser()</code>, -if <code>tomcatAuthentication="false"</code> -</li> -<li>protocol: <code>getProtocol()</code> -</li> -<li>HTTP method: <code>getMethod()</code> -</li> -<li>URI: <code>getRequestURI()</code> -</li> -<li>HTTPS used: <code>isSecure()</code>, <code>getScheme()</code> -</li> -<li>query string: <code>getQueryString()</code> -</li> -</ul> -The following additional SSL-related data will be made available by Apache and forwarded by mod_jk only -if you set <code>SSLOptions +StdEnvVars</code>. For the certificate information you also need -to set <code>SSLOptions +ExportCertData</code>. -<ul> -<li>SSL cipher: <code>getAttribute(javax.servlet.request.cipher_suite)</code> -</li> -<li>SSL key size: <code>getAttribute(javax.servlet.request.key_size)</code>. -Can be disabled using <code>JkOptions -ForwardKeySize</code>. -</li> -<li>SSL client certificate: <code>getAttribute(javax.servlet.request.X509Certificate)</code>. -If you want the whole certificate chain, then you need to also set <code>JkOptions ForwardSSLCertChain</code>. -It is likely, that in this case you also need to adjust the maximal AJP packet size -using the worker attribute <a href="../reference/workers.html">max_packet_size</a>. -</li> -<li>SSL session ID: <code>getAttribute(javax.servlet.request.ssl_session)</code>. -This is for Tomcat, it has not yet been standardized. -</li> -</ul> -</p> -</section> -<section name="Fine Tuning"> -<br/> -<p>In some situations this is not enough though. Assume there is another -less clever reverse proxy in front of your web server, for instance an -HTTP load balancer or similar device which also serves as an SSL accelerator. -</p> -<p>Then you are sure that all your clients use HTTPS, but your web server doesn't -know about that. All it can see is requests coming from the accelerator using -plain HTTP. -</p> -<p>Another example would be a simple reverse proxy in front of your web server, -so that the client IP address that your web server sees is always the IP address -of this reverse proxy, and not of the original client. Often such reverse proxies -generate an additional HTTP header, like <code>X-Forwareded-for</code> which -contains the original client IP address (or a list of IP addresses, if there are -more cascading reverse proxies in front). It would be nice, if we could use the -content of such a header as the client IP address to pass to the backend. -</p> -<p>So we might need to manipulate some of the data that AJP sends to the backend. -When using mod_jk inside Apache httpd you can use several httpd environment -variables to let mod_jk know, which data it should forward. These environment variables -can be set by the httpd directives SetEnv or SetEnvIf, but also in a very flexible -way using mod_rewrite (since httpd 2.x it can not only test against environment -variables, but also set them). -</p> -<p>The following list contains all environment variables mod_jk checks, before -sending data to the backend: -<ul> -<li>JK_LOCAL_NAME: the local name -</li> -<li>JK_LOCAL_PORT: the local port -</li> -<li>JK_REMOTE_HOST: the client host -</li> -<li>JK_REMOTE_ADDR: the client address -</li> -<li>JK_AUTH_TYPE: the authentication type -</li> -<li>JK_REMOTE_USER: the remote user -</li> -<li>HTTPS: On (case-insensitive) to indicate, that HTTPS is used -</li> -<li>SSL_CIPHER: the SSL cipher -</li> -<li>SSL_CIPHER_USEKEYSIZE: the SSL key size -</li> -<li>SSL_CLIENT_CERT: the SSL client certificate -</li> -<li>SSL_CLIENT_CERT_CHAIN_: prefix of variable names, containing -the client cerificate chain -</li> -<li>SSL_SESSION_ID: the SSL session ID -</li> -</ul> -</p> -<p>Remember: in general you don't need to set them. The module retrieves the data automatically -from the web server. Only in case you want to change this data, you can overwrite it by -using these variables. -</p> -<p>Some of these variables might also be used by other web server modules. All -variables whose name does not begin with "JK" are set directly by Apache httpd. -If you want to change the data, but do not want to negatively influence the behaviour -of other modules, you can change the names of all variables mod_jk uses to private ones. -For the details see the <a href="../reference/apache.html">Apache reference</a> page. -</p> -<p>All variables, that are not SSL-related have only been introduced in version 1.2.27. -</p> -<p>Finally there is a shortcut to forward the local IP of the web server as the remote IP. -This can be useful, e.g. when using the Tomcat remote address valve for allowing connections -only from registered Apache web servers. This feature is activated by setting -<code>JkOptions ForwardLocalAddress</code>. -</p> -</section> -<section name="Tomcat AJP Connector Settings"> -<br/> -<p>As an alternative to using the environment variables described in the previous section -(which do only exist when using Apache httpd), you can also configure Tomcat to overwrite -some of the communications data forwarded by mod_jk. The AJP connector in Tomcat's <code>server.xml</code> -allows to set the <a href="http://tomcat.apache.org/tomcat-6.0-doc/config/ajp.html#Attributes">following properties</a>: -<ul> -<li>proxyName: server name as returned by <code>getServerName()</code> -</li> -<li>proxyPort: server port as returned by <code>getServerPort()</code> -</li> -<li>scheme: protocol scheme as returned by <code>getScheme()</code> -</li> -<li>secure: set to "true", if you wish <code>isSecure()</code> to return "true". -</li> -</ul> -Remember: in general you don't need to set those. AJP automatically handles all cases -where the web server running mod_jk knows the right data. -</p> -</section> -<section name="URL Handling"> -<br/> -<subsection name="URL Rewriting"> -<p>Sometimes one want to change path components of the URLs under which an application -is available. Especially if a web application is deployed as some context, say <code>/myapp</code>, -marketing prefers short URLs, so want the application to be directly available under -<code>http://www.mycompany.com/</code>. Although you can deploy the application as the so-called -ROOT context, which will be directly available at "/", admins often prefer not to use -the ROOT context, e.g. because only one application can be the root context (per host). -</p> -<p>The procedure to change the URLs in the reverse proxy is tedious, because often -an application produces self-referential URLs, which then include the path components -which you tried to hide to the outside world. Nevertheless, if you absolutely need to do it, -here are the steps. -</p> -<p>Case A: You need to make the application available at a simple URL, but it is OK, if -users proceed using the more complex URLs, as long as they don't have to type them in. -That's the easy case, and if this suffices to you, you're lucky. Use a simply RedirectMatch -for Apache httpd: -</p> -<source> -RedirectMatch ^/$ http://www.mycompany.com/myapp/ -</source> -<p>Your application will then be available under <code>http://www.mycompany.com/</code>, -and each visitor will be immediately redirected to the real URL -<code>http://www.mycompany.com/myapp/</code> -</p> -<p>Case B: You need to hide path components for all requests going to the application. -Here's the recipe for the case, where you want to hide the first path component -<code>/myapp</code>. More complex manipulations are left as an exercise to the reader. -First the solution for the case of Apache httpd: -</p> -<p>1. Use <a href="http://httpd.apache.org/docs/2.2/mod/mod_rewrite.html"><code>mod_rewrite</code></a> -to add <code>/myapp</code> to all requests before forwarding to the backend: -</p> -<source> -# Don't forget the PT flag! (pass through) -RewriteRule ^/(.*) http://www.mycompany.com/myapp/$1 [PT] -</source> -<p>2. Use <a href="http://httpd.apache.org/docs/2.2/mod/mod_headers.html"><code>mod_headers</code></a> -to rewrite any HTTP redirects your application might return. Such redirects typically contain -the path components you want to hide, because by the HTTP standard, redirects always need to include -the full URL, and your application is not aware of the fact, that your clients talk to it via -some shortened URL. An HTTP redirect is done with a special response header named <code>Location</code>. -We rewrite the Location headers of our responses: -</p> -<source> -# Keep protocol, server and port if present, -# but insert our webapp name before the rest of the URL -Header edit Location ^([^/]*//[^/]*)?/(.*)$ $1/myapp/$2 -</source> -<p>3. Use <code>mod_headers</code> again, to rewrite the paths contained in any cookies, -your application might set. Such cookie paths again might contain -the path components you want to hide. -A cookie is set with the HTTP response header named <code>Set-Cookie</code>. -We rewrite the Set-Cookie headers of our responses: -</p> -<source> -# Fix the cookie path -Header edit Set-Cookie "^(.*; Path=/)(.*)" $1/myapp/$2 -</source> -<p>3. Some applications might contain hard coded absolute links. -In this case check, whether you find a configuration item for your web framework -to configure the base URL. If not, your only chance is to parse all response -content bodies and do search and replace. This is fragile and very resource intensive. -If you really need to do this, you can use -<a href="http://apache.webthing.com/mod_proxy_html/"><code>mod_proxy_html</code></a>, -<a href="http://httpd.apache.org/docs/2.2/mod/mod_substitute.html"><code>mod_substitute</code></a> -or <a href="http://blogs.sun.com/basant/entry/using_mod_sed_to_filter"><code>mod_sed</code></a> -for this task. -</p> -<p>If you are using Microsoft IIS as a web server, the ISAPI plugin provides a way -of doing the first step with a builtin feature. You define a mapping file for simple prefix -changes like this: -</p> -<source> -# Add a context prefix to all requests ... -/=/myapp/ -# ... or change some prefix ... -/oldapp/=/myapp/ -</source> -<p>and then put the name of the file in the <code>rewrite_rule_file</code> entry of the registry or your -<code>isapi_redirect.properties</code> file. In you <code>uriworkermap.properties</code> file, you -still need to map the URLs as they are before rewriting! -</p> -<p>More complex rewrites can be done using the same file, but with regular expressions. A leading -tilde sign '<code>~</code>', indicates, that you are using a regular expression: -</p> -<source> -# Use a regular expression rewrite -~/oldapps([0-9]*)/=/newapps$1/ -</source> -<p>There is no support for Steps 2 (rewriting redirect responses) or 3 (rewriting cookie paths). -</p> -</subsection> -<subsection name="URL Encoding"> -<p>Some types of problems are triggered by the use of encoded URLs -(see <a href="http://en.wikipedia.org/wiki/Percent-encoding">percent encoding</a>). -For the same location there exist -a lot of different URLs which are equivalent. The reverse proxy needs to inspect the URL in order -to apply its own authentication rules and to decide, to which backend it should send the request -(or whether it should handle it itself). Therefore the request URL first is normalized: -percent encoded characters are decoded, <code>/./</code> is replaced by <code>/</code>, -<code>/XXX/../</code> is replaced by <code>/</code> and similar manipulations of the URL are done. -After that, the web server might apply rewrite rules to further change the URL in less obvious ways. -Finally there is no more way to put the resulting URL in an encoding, which is "similar" to -the one which was used for the original URL. -</p> -<p> -For historical reasons, there have been several alternatives, how mod_jk and the ISAPI -plugin encoded the resulting URL before sending it to the backend. They could be chosen via -<code>JkOptions</code> (Apache httpd) or <code>uri_select</code> (ISAPI). None of those historical -encodings are recommended, because they have either negative functionality implications or -pose a security risk. The default encoding since version 1.2.24 is <code>ForwardURIProxy</code> -(Apache httpd) or <code>proxy</code> (ISAPI) and it is strongly recommended to keep the default -and remove all old explicit settings. -</p> -</subsection> -</section> -<section name="Request Attributes"> -<br/> -<p> -You can also add more attributes to any request you are forwarding when using Apache httpd. -For this use the <code>JkEnvVar</code> directive (for details see the -<a href="../reference/apache.html">Apache reference</a> page). Such request attributes can be -retrieved on the Tomcat side via request.getAttribute(attributeName). -Note that their names will not be listed in request.getAttributeNames()! -</p> -</section> -</body> -</document> diff --git a/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/quick.xml b/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/quick.xml deleted file mode 100644 index 68277226..00000000 --- a/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/quick.xml +++ /dev/null @@ -1,170 +0,0 @@ -<?xml version="1.0" encoding="ISO-8859-1"?> -<!DOCTYPE document [ - <!ENTITY project SYSTEM "project.xml"> -]> -<document url="quick.html"> - - &project; -<copyright> - Licensed to the Apache Software Foundation (ASF) under one or more - contributor license agreements. See the NOTICE file distributed with - this work for additional information regarding copyright ownership. - The ASF licenses this file to You under the Apache License, Version 2.0 - (the "License"); you may not use this file except in compliance with - the License. You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, software - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. -</copyright> -<properties> -<title>Quick Start HowTo</title> -<author email="hgomez@apache.org">Henri Gomez</author> -<date>$Date: 2010-03-15 16:26:00 +0100 (Mon, 15 Mar 2010) $</date> -</properties> -<body> -<section name="Introduction"> -<p> - This document describes the configuration files used by JK on the - Web Server side for the 'impatient': - <ul> - <li> - <b>workers.properties</b> is a mandatory file used by the webserver and which - is the same for all JK implementations (Apache/IIS/NES). - </li> - <li> - <b>web server</b> add-ons to be set on the webserver side. - </li> - </ul> -</p> -<p> - We'll give here minimum servers configuration and an example <b>workers.properties</b> - to be able to install and check quickly your configuration. -</p> -</section> - -<section name="Minimum workers.properties"> -<p> - Here is a minimum <b>workers.properties</b>, using just ajp13 to connect your Apache webserver - to the Tomcat engine, complete documentation is available in <a href="workers.html">Workers HowTo</a>. -</p> -<p> -<source> - - # Define 1 real worker using ajp13 - worker.list=worker1 - # Set properties for worker1 (ajp13) - worker.worker1.type=ajp13 - worker.worker1.host=localhost - worker.worker1.port=8009 - -</source> -</p> -</section> - -<section name="Minimum Apache web server configuration"> -<p> - Here is a minimum information about Apache configuration, a - more complete <a href="../webserver_howto/apache.html">separate HowTo for Apache</a> is available. -</p> -<p> - You should first have <b>mod_jk.so</b> (unix) or <b>mod_jk.dll</b> (Windows) installed - in your Apache module directory (see your Apache documentation to locate it). -</p> -<p> - Usual locations for modules directory on Unix: - <ul> - <li>/usr/lib/apache/</li> - <li>/usr/lib/apache2/</li> - <li>/usr/local/apache/libexec/</li> - </ul> -</p> -<p> - Usual locations for modules directory on Windows : - <ul> - <li>C:\Program Files\Apache Group\Apache\modules\</li> - <li>C:\Program Files\Apache Group\Apache2\modules\</li> - </ul> -</p> -<p> - You'll find a link to prebuilt binaries - <a href="http://tomcat.apache.org/download-connectors.cgi/">here</a> -</p> -<p> - Here is the minimum which should be set in <b>httpd.conf</b> directly or - included from another file: -</p> -<p> - Usual locations for configuration directory on Unix: - <ul> - <li>/etc/httpd/conf/</li> - <li>/etc/httpd2/conf/</li> - <li>/usr/local/apache/conf/</li> - </ul> -</p> -<p> - Usual locations for configuration directory on Windows : - <ul> - <li>C:\Program Files\Apache Group\Apache\conf\</li> - <li>C:\Program Files\Apache Group\Apache2\conf\</li> - </ul> -</p> -<p> -<source> - - # Load mod_jk module - # Update this path to match your modules location - LoadModule jk_module libexec/mod_jk.so - # Declare the module for <IfModule directive> (remove this line on Apache 2.x) - AddModule mod_jk.c - # Where to find workers.properties - # Update this path to match your conf directory location (put workers.properties next to httpd.conf) - JkWorkersFile /etc/httpd/conf/workers.properties - # Where to put jk shared memory - # Update this path to match your local state directory or logs directory - JkShmFile /var/log/httpd/mod_jk.shm - # Where to put jk logs - # Update this path to match your logs directory location (put mod_jk.log next to access_log) - JkLogFile /var/log/httpd/mod_jk.log - # Set the jk log level [debug/error/info] - JkLogLevel info - # Select the timestamp log format - JkLogStampFormat "[%a %b %d %H:%M:%S %Y] " - # Send everything for context /examples to worker named worker1 (ajp13) - JkMount /examples/* worker1 - -</source> -</p> -</section> - -<section name="Minimum IIS web server configuration"> -<p> - A separate <a href="../webserver_howto/iis.html">HowTo for the IIS web server</a> is available. -</p> -<todo> -More information to be added! -</todo> -</section> - -<section name="Minimum NES/iPlanet/Sun web server configuration"> -<p> - A separate <a href="../webserver_howto/nes.html">HowTo for the Netscape/iPlanet/Sun web server</a> is available. -<todo> -More information to be added? -</todo> -</p> -</section> - - -<section name="Test your configuration"> -<p> - (Re)start the web server and browse to the <a href="http://localhost/examples/">http://localhost/examples/</a> -</p> - -</section> -</body> -</document> diff --git a/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/timeouts.xml b/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/timeouts.xml deleted file mode 100644 index 12208e1a..00000000 --- a/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/timeouts.xml +++ /dev/null @@ -1,407 +0,0 @@ -<?xml version="1.0" encoding="ISO-8859-1"?> -<!DOCTYPE document [ - <!ENTITY project SYSTEM "project.xml"> -]> -<document url="timeouts.html"> - - &project; -<copyright> - Licensed to the Apache Software Foundation (ASF) under one or more - contributor license agreements. See the NOTICE file distributed with - this work for additional information regarding copyright ownership. - The ASF licenses this file to You under the Apache License, Version 2.0 - (the "License"); you may not use this file except in compliance with - the License. You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, software - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. -</copyright> -<properties> -<title>Timeouts HowTo</title> -<author email="rjung@apache.org">Rainer Jung</author> -<date>$Date: 2009-03-22 00:11:39 +0100 (Sun, 22 Mar 2009) $</date> -</properties> -<body> -<section name="Introduction"> -<br/> -<p>Setting communication timeouts is very important to improve the -communication process. They help to detect problems and stabilise -a distributed system. JK can use several different timeout types, which -can be individually configured. For historical reasons, all of them are -disabled by default. This HowTo explains their use and gives -hints how to find appropriate values. -</p> -<p>All timeouts can be configured in the workers.properties file. -For a complete reference of all worker configuration -items, please consult the worker <a href="../reference/workers.html">reference</a>. -This page assumes, that you are using at least version 1.2.16 of JK. -Dependencies on newer versions will be mentioned where necessary. -</p> -<warn> -Do not set timeouts to extreme values. Very small timeouts will likely -be counterproductive. -</warn> -<warn> -Long Garbage Collection pauses on the backend do not make a good -fit with some timeouts. Try to optimise your Java memory and GC settings. -</warn> -</section> - -<section name="JK Timeout Attributes"> -<br/> -<subsection name="CPing/CPong"> -<p> -CPing/CPong is our notion for using small test packets to check the -status of backend connections. JK can use such test packets directly after establishing -a new backend connection (connect mode) and also directly before each request gets -send to a backend (prepost mode). -Starting with version 1.2.27 it can also be used when a connection was idle -for a long time (interval mode). -The maximum waiting time (timeout) for a CPong answer to a CPing and the idle -time in interval mode can be configured. -</p> -<p> -The test packets will be answered by the backend very fast with a minimal amount of -needed processing resources. A positive answer tells us, that the backend can be reached -and is actively processing requests. It does not detect, if some context is deployed -and working. The benefit of CPing/CPong is a fast detection of a communication -problem with the backend. The downside is a slightly increased latency. -</p> -<p> -The worker attribute <b>ping_mode</b> can be set to a combination of characters -to determine, in which situations test packets are used: -<ul> -<li><b>C</b>: connect mode, timeout <b>ping_timeout</b> overwritten by <b>connect_timeout</b></li> -<li><b>P</b>: prepost mode, timeout <b>ping_timeout</b> overwritten by <b>prepost_timeout</b></li> -<li><b>I</b>: interval mode, timeout <b>ping_timeout</b>, idle time <b>connection_ping_interval</b></li> -<li><b>A</b>: all modes</li> -</ul> -</p> -<p> -Multiple values must be concatenated without any separator characters. -We recommend using all CPing tests. If your application is very latency sensitive, then -you should only use the combination of connect and interval mode. -</p> -<p> -Activating the CPing probing via <b>ping_mode</b> has been added in version 1.2.27. -For older versions only the connect and prepost modes exist and must be activated by -explicitely setting <b>connect_timeout</b> and <b>prepost_timeout</b>. -</p> -<p> -The worker attribute <b>ping_timeout</b> sets the default wait timeout -in milliseconds for CPong for all modes. By default the value is "10000" -milliseconds. The value only gets used, if you activate CPing/Cpong probes -via <b>ping_mode</b>. The default value should be fine, except if you experience -very long Java garbage collection pauses. -Depending on your network latency and stability, good custom values -often are between 5000 and 15000 milliseconds. -You can overwrite the timeout used for connect and prepost mode with -<b>connect_timeout</b> and <b>prepost_timeout</b>. -Remember: don't use extremely small values. -</p> -<p> -The worker attribute <b>connect_timeout</b> sets the wait timeout -in milliseconds for CPong during connection establishment. You can use it -if you want to overwrite the general timeout set with <b>ping_timeout</b>. -To use connect mode CPing, you need to enable it via <b>ping_mode</b>. -Since JK usually uses persistent connections, opening new connections is a -rare event. We therefore recommend activating connect mode. -Depending on your network latency and stability, good values often -are between 5000 and 15000 milliseconds. -Remember: don't use extremely small values. -</p> -<p> -The worker attribute <b>prepost_timeout</b> sets the wait timeout -in milliseconds for CPong before request forwarding. You can use it -if you want to overwrite the general timeout set with <b>ping_timeout</b>. -To use prepost mode CPing, you need to enable it via <b>ping_mode</b>. -Activating this type of CPing/CPong adds a small latency to each -request. Usually this is small enough and the benefit of CPing/CPong is more important. -So in general we also recommend using <b>prepost_timeout</b>. -Depending on your network latency and stability, good values often -are between 5000 and 10000 milliseconds. -Remember: don't use extremely small values. -</p> -<p> -Until version 1.2.27 <b>ping_mode</b> and <b>ping_timeout</b> did not -exist and to enable connect or prepost mode CPing you had to set <b>connect_timeout</b> -respectively <b>prepost_timeout</b> to some reasonable positive value. -</p> -</subsection> - -<subsection name="Low-Level TCP Timeouts"> -<p> -Some platforms allow to set timeouts for all operations on TCP sockets. -This is available for Linux and Windows, other platforms do not support this, -e.g. Solaris. If your platform supports TCP send and receive timeouts, -you can set them using the worker attribute <b>socket_timeout</b>. -You can not set the two timeouts to different values. -</p> -<p> -JK will accept this attribute even if your platform does not support -socket timeouts. In this case setting the attribute will have no effect. -By default the value is "0" and the timeout is disabled. -You can set the attribute to some seconds value (not: milliseconds). -JK will then set the send and the receive timeouts of the backend -connections to this value. The timeout is low-level, it is -used for each read and write operation on the socket individually. -</p> -<p> -Using this attribute will make JK react faster to some types of network problems. -Unfortunately socket timeouts have negative side effects, because for most -platforms, there is no good way to recover from such a timeout, once it fired. -For JK there is no way to decide, if this timeout fired because of real network -problems, or only because it didn't receive an answer packet from a backend in time. -So remember: don't use extremely small values. -</p> -<p> -For the general case of connection establishment you can use -<b>socket_connect_timeout</b>. It takes a millisecond value and works -on most platforms, even if <b>socket_timeout</b> is not supported. -We recommend using <b>socket_connect_timeout</b> because in some network -failure situations failure detection during connection establishment -can take several minutes due to TCP retransmits. Depending on the quality -of your network a timeout somewhere between 1000 and 5000 milliseconds -should be fine. Note that <code>socket_timeout</code> is in seconds, and -<code>socket_connect_timeout</code> in milliseconds. -</p> -</subsection> - -<subsection name="Connection Pools and Idle Timeouts"> -<p> -JK handles backend connections in a connection pool per web server process. -The connections are used in a persistent mode. After a request completed -successfully we keep the connection open and wait for the next -request to forward. The connection pool is able to grow according -to the number of threads that want to forward requests in parallel. -</p> -<p> -Most applications have a varying load depending on the hour of the day -or the day of the month. Other reasons for a growing connection pool -would be temporary slowness of backends, leading to an increasing -congestion of the frontends like web servers. Many backends use a dedicated -thread for each incoming connection they handle. So usually one wants the -connection pool to shrink, if the load diminishes. -</p> -<p> -JK allows connections in the pool to get closed after some idle time. -This maximum idle time can be configured with the attribute -<b>connection_pool_timeout</b> which is given in units of seconds. -The default value is "0", which disables closing idle connections. -</p> -<p> -We generally recommend values around 10 minutes, so setting -<b>connection_pool_timeout</b> to 600 (seconds). If you use this attribute, -please also set the attribute <b>connectionTimeout</b> in the AJP -Connector element of your Tomcat server.xml configuration file to -an analogous value. <b>Caution</b>: connectionTimeout is in milliseconds. -So if you set JK connection_pool_timeout to 600, you should set Tomcat -connectionTimeout to 600000. -</p> -<p> -JK connections do not get closed immediately after the timeout passed. -Instead there is an automatic internal maintenance task -running every 60 seconds, that checks the idle status of all connections. -The 60 seconds interval -can be adjusted with the global attribute worker.maintain. We do not -recommend to change this value, because it has a lot of side effects. -Until version 1.2.26, the maintenance task only runs, if requests get -processed. So if your web server has processes that do not receive any -requests for a long time, there is no way to close the idle connections -in its pool. Starting with version 1.2.27 you can configure an independent -watchdog thread when using Apache 2.x with threaded APR or IIS. -</p> -<p> -The maximum connection pool size can be configured with the -attribute <b>connection_pool_size</b>. We generally do not recommend -to use this attribute in combination with Apache httpd. For -Apache httpd we automatically detect the number of threads per -process and set the maximum pool size to this value. For IIS we use -a default value of 250 (before version 1.2.20: 10), -for the Sun Web Server the default is "1". -We strongly recommend adjusting this value for IIS and the Sun Web Server -to the number of requests one web server process should -be able to send to a backend in parallel. You should measure how many connections -you need during peak hours without performance problems, and then add some -percentage depending on your growth rate etc. Finally you should check, -whether your web server processes are able to use at least as many threads, -as you configured as the pool size. -</p> -<p> -The JK attribute <b>connection_pool_minsize</b> defines, -how many idle connections remain when the pool gets shrunken. -By default this is half of the maximum pool size. -</p> -</subsection> - -<subsection name="Firewall Connection Dropping"> -<p> -One particular problem with idle connections comes from firewalls, that -are often deployed between the web server layer and the backend. -Depending on their configuration, they will silently drop -connections from their status table if they are idle for to long. -</p> -<p> -From the point of view of JK and of the web server, the other side -simply doesn't answer any traffic. Since TCP is a reliable protocol -it detects the missing TCP ACKs and tries to resend the packets for -a relatively long time, typically several minutes. -</p> -<p> -Many firewalls will allow connection closing, even if they dropped -the connection for normal traffic. Therefore you should always use -<a href="#Connection Pools and Idle Timeouts">connection_pool_timeout and -connection_pool_minsize</a> on the JK side -and connectionTimeout on the Tomcat side. -</p> -<p> -Furthermore using the boolean attribute <b>socket_keepalive</b> you can -set a standard socket option, that automatically sends TCP keepalive packets -after some idle time on each connection. By default this is set to "False". -If you suspect idle connection drops by firewalls you should set this to -"True". -</p> -<p> -Unfortunately the default intervals and algorithms for these packets -are platform specific. You might need to inspect TCP tuning options for -your platform on how to control TCP keepalive. -Often the default intervals are much longer than the firewall timeouts -for idle connections. Nevertheless we recommend talking to your firewall -administration and your platform administration in order to make them agree -on good configuration values for the firewall and the platform TCP tuning. -</p> -<p> -In case none of our recommendations help and you are definitively having -problems with idle connection drops, you can disable the use of persistent -connections when using JK together with Apache httpd. For this you set -"JkOptions +DisableReuse" in your Apache httpd configuration. -This will have a huge negative performance impact! -</p> -</subsection> - -<subsection name="Reply Timeout"> -<p> -JK can also use a timeout on request replies. This timeout does not -measure the full processing time of the response. Instead it controls, -how much time between consecutive response packets is allowed. -</p> -<p> -In most cases, this is what one actually wants. Consider for example -long running downloads. You would not be able to set an effective global -reply timeout, because downloads could last for many minutes. -Most applications though have limited processing time before starting -to return the response. For those applications you could set an explicit -reply timeout. Applications that do not harmonise with reply timeouts -are batch type applications, data warehouse and reporting applications -which are expected to observe long processing times. -</p> -<warn> -If JK aborts waiting for a response, because a reply timeout fired, -there is no way to stop processing on the backend. Although you free -processing resources in your web server, the request -will continue to run on the backend - without any way to send back a -result once the reply timeout fired. -</warn> -<p> -JK uses the worker attribute <b>reply_timeout</b> to set reply timeouts. -The default value is "0" (timeout disabled) and you can set it to any -millisecond value. -</p> -<p> -In combination with Apache httpd, you can also set a more flexible reply_timeout -using an httpd environment variable. If you set the variable JK_REPLY_TIMEOUT -to some integer value, this value will be used instead of the value in -the worker configuration. This way you can set reply timeouts more flexible -with mod_setenvif and mod_rewrite depending on URI, query string etc. -If the environment variable JK_REPLY_TIMEOUT is not set, or is set to a -negative value, the default reply timeout of the worker will be used. If -JK_REPLY_TIMEOUT contains the value "0", then the reply timeout will be disabled -for the request. -</p> -<p> -In combination with a load balancing worker, JK will disable a member -worker of the load balancer if a reply timeout fires. The worker will then -no longer be used until it gets recovered during the next automatic -maintenance task. Starting with JK 1.2.24 you can improve this behaviour using -<b><a href="../reference/workers.html">max_reply_timeouts</a></b>. This -attribute will allow occasional long running requests without disabling the -worker. Only if those requests happen to often, the worker gets disabled by the -load balancer. -</p> -</subsection> -</section> - -<section name="Load Balancer Error Detection"> -<br/> -<subsection name="Local and Global Error States"> -<p> -A load balancer worker does not only have the ability to balance load. -It also handles stickyness and failover of requests in case of errors. -When a load balancer detects an error on one of its members, it needs to -decide, whether the error is serious, or only a temporary error or maybe -only related to the actual request that was processed. Temporary errors -are called local errors, serious errors will be called global errors. -</p> -<p> -If the load balancer decides that a backend should be put into the global error -state, then the web server will not send any more requests there. If no session -replication is used, this means that all user sessions located on the respective -backend are no longer available. The users will be send to another backend -and will have to login again. So the global error state is not transparent to the -users. The application is still available, but users might loose some work. -</p> -<p> -In some cases the decision between local error and global error is easy. -For instance if there is an error sending back the response to the client (browser), -then it is very unlikely that the backend is broken. -So this situation is a typical example of a local error. -</p> -<p> -Some situations are harder to decide though. If the load balancer can't establish -a new connection to a backend, it could be because of a temporary overload situation -(so no more free threads in the backend), or because the backend isn't alive any more. -Depending on the details, the right state could either be local error or global error. -</p> -</subsection> -<subsection name="Error Escalation Time"> -<p> -Until version 1.2.26 most errors were interpreted as global errors. -Starting with version 1.2.27 many errors which were previously interpreted as global -were switched to being local whenever the backend is still busy. Busy means, that -other concurrent requests are send to the same backend (successful or not). -</p> -<p> -In many cases there is no perfect way of making the decision -between local and global error. The load balancer simply doesn't have enough information. -In version 1.2.28 you can now tune, how fast the load balancer switches from local error to -global error. If a member of a load balancer stays in local error state for too long, -the load balancer will escalate it into global error state. -</p> -<p> -The time tolerated in local error state is controlled by the load balancer attribute -<b>error_escalation_time</b> (in seconds). The default value is half of <b>recover_time</b>, -so unless you changed <b>recover_time</b> the default is 30 seconds. -</p> -<p> -Using a smaller value for <b>error_escalation_time</b> will make the load balancer react -faster to serious errors, but also carries the risk of more often loosing sessions -in not so serious situations. You can lower <b>error_escalation_time</b> down to 0 seconds, -which means all local errors which are potentially serious are escalated to global errors -immediately. -</p> -<p> -Note that without good basic error detection the whole escalation procedure is useless. -So you should definitely use <b>socket_connect_timeout</b> and activate CPing/CPong -with <b>ping_mode</b> and <b>ping_timeout</b> before thinking about also tuning -<b>error_escalation_time</b>. -</p> -</subsection> -</section> - -</body> -</document> diff --git a/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/workers.xml b/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/workers.xml deleted file mode 100644 index 0c97d0c1..00000000 --- a/rubbos/app/tomcat-connectors-1.2.32-src/xdocs/generic_howto/workers.xml +++ /dev/null @@ -1,445 +0,0 @@ -<?xml version="1.0" encoding="ISO-8859-1"?> -<!DOCTYPE document [ - <!ENTITY project SYSTEM "project.xml"> -]> -<document url="workers.html"> - - &project; -<copyright> - Licensed to the Apache Software Foundation (ASF) under one or more - contributor license agreements. See the NOTICE file distributed with - this work for additional information regarding copyright ownership. - The ASF licenses this file to You under the Apache License, Version 2.0 - (the "License"); you may not use this file except in compliance with - the License. You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, software - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. -</copyright> -<properties> -<title>Workers HowTo</title> -<author email="hgomez@apache.org">Henri Gomez</author> -<author email="shachor@il.ibm.com">Gal Shachor</author> -<author email="mturk@apache.org">Mladen Turk</author> -<date>$Date: 2010-01-28 20:47:58 +0100 (Thu, 28 Jan 2010) $</date> -</properties> -<body> -<section name="Introduction"> -<p> -A Tomcat worker is a Tomcat instance that is waiting to execute servlets on behalf of some web server. -For example, we can have a web server such as Apache forwarding servlet requests to a -Tomcat process (the worker) running behind it. -</p> -<p> -The scenario described above is a very simple one; -in fact one can configure multiple Tomcat workers to serve servlets on -behalf of a certain web server. -The reasons for such configuration can be: -</p> -<ul> -<li> -We want different contexts to be served by different Tomcat workers to provide a -development environment where all the developers share the same web server but own a Tomcat worker of their own. -</li> -<li> -We want different virtual hosts served by different Tomcat processes to provide a -clear separation between sites belonging to different companies. -</li> -<li> -We want to provide load balancing, meaning run multiple Tomcat workers each on a -machine of its own and distribute the requests between them. -</li> -</ul> - -<p> -There are probably more reasons for having multiple workers but I guess that this list is enough... -Tomcat workers are defined in a properties file dubbed workers.properties and this tutorial -explains how to work with it. -</p> - -<p> -This document was originally part of <b>Tomcat: A Minimalistic User's Guide</b> written by Gal Shachor, -but has been split off for organisational reasons. -</p> -</section> - -<section name="Defining Workers"> -<p> -Defining workers to the Tomcat web server plugin can be done using a properties file -(a sample file named workers.properties is available in the conf/ directory). -</p> - -<p> -the file contains entries of the following form: -</p> - -<p> -<b>worker.list</b>=<a comma separated list of worker names> -</p> - -<source> - # the list of workers - worker.list= worker1, worker2 -</source> - -<p> -When starting up, the web server plugin will instantiate the workers whose name appears in the -<b>worker.list</b> property, these are also the workers to whom you can map requests. The directive can be used multiple times. -</p> - -<subsection name="Workers Type"> -<p> -Each named worker should also have a few entries to provide additional information on his behalf. -This information includes the worker's type and other related worker information. -Currently the following worker types that exists are (JK 1.2.5): -</p> - -<table> - <tr><th>Type</th><th>Description</th></tr> - <tr><td>ajp12</td><td>This worker knows how to forward requests to out-of-process Tomcat workers using the ajpv12 protocol.</td></tr> - <tr><td>ajp13</td><td>This worker knows how to forward requests to out-of-process Tomcat workers using the ajpv13 protocol.</td></tr> - <tr><td>jni</td><td>DEPRECATED: This worker knows how to forward requests to in-process Tomcat workers using JNI.</td></tr> - <tr><td>lb</td><td>This is a load-balancing worker; it knows how to provide round-robin based sticky load balancing with a certain level of fault-tolerance.</td></tr> - <tr><td>status</td><td>This is a status worker for managing load balancers.</td></tr> -</table> - -<p> -Defining workers of a certain type should be done with the following property format: -</p> - -<p> -<b>worker</b>.<b>worker name</b>.<b>type</b>=<worker type> -Where worker name is the name assigned to the worker and the worker type is one of the four types defined -in the table (a worker name may only contain any space the characters [a-zA-Z0-9\-_]). -</p> - -<source> - # Defines a worker named "local" that uses the ajpv12 protocol to forward requests to a Tomcat process. - worker.local.type=ajp12 - # Defines a worker named "remote" that uses the ajpv13 protocol to forward requests to a Tomcat process. - worker.remote.type=ajp13 - # Defines a worker named "loadbalancer" that loadbalances several Tomcat processes transparently. - worker.loadbalancer.type=lb -</source> - -</subsection> - -</section> - -<section name="Setting Worker Properties"> -<p> -After defining the workers you can also specify properties for them. -Properties can be specified in the following manner: -</p> - -<p> -worker.<worker name>.<property>=<property value> -</p> - -Each worker has a set of properties that you can set as specified in the following subsections: - -<subsection name="ajp12 Worker properties"> -<p><warn> -The <b>ajp12</b> has been <b>deprecated</b> with Tomcat 3.3.x and you should use instead -<b>ajp13</b> which is the only ajp protocol known by Tomcat 4.x and 5 and 5.5 and Tomcat 6. -</warn></p> -<p> -The ajp12 typed workers forward requests to out-of-process Tomcat workers -using the ajpv12 protocol over TCP/IP sockets. -</p> - -<p> -the ajp12 worker properties are : -</p> - -<p> -<b>host</b> property sets the host where the Tomcat worker is listening for ajp12 requests. -</p> - -<p> -<b>port</b> property sets the port where the Tomcat worker is listening for ajp12 requests -</p> - -<p> -<b>lbfactor</b> property is used when working with a load balancer worker, this is the load-balancing factor for the worker. -We'll see more on this in the <a href="../generic_howto/loadbalancers.html">lb worker</a> section. -</p> - -<source> - # worker "worker1" will talk to Tomcat listening on machine www.x.com at port 8007 using 2 lb factor - worker.worker1.host=www.x.com - worker.worker1.port=8007 - worker.worker1.lbfactor=2 -</source> - -<p> -Notes: In the ajpv12 protocol, connections are created, used and then closed at each request. -The default port for ajp12 is 8007 -</p> - -</subsection> - -<subsection name="ajp13 Worker properties"> -<p> -The ajp13 typed workers forward requests to out-of-process Tomcat workers using the ajpv13 protocol over TCP/IP sockets. -The main difference between ajpv12 and ajpv13 are that: -<ul> -<li> -ajpv13 is a more binary protocol and it tries to compress some of the request data by coding -frequently used strings as small integers. -</li> -<li> -ajpv13 reuses open sockets and leaves them open for future requests (remember when you've got a Firewall between your -web server and Tomcat). -</li> -<li> -ajpv13 has special treatment for SSL information so that the container can implement -SSL related methods such as isSecure(). -</li> -</ul> - -</p> - -<p> -You should note that Ajp13 is now the only out-process protocol supported by Tomcat 4.0.x, 4.1.x, 5.0.x, 5.5.x and 6. -</p> - - -<source> - # worker "worker2" will talk to Tomcat listening on machine www2.x.com at port 8009 using 3 lb factor - worker.worker2.host=www2.x.com - worker.worker2.port=8009 - worker.worker2.lbfactor=3 - # worker "worker2" uses connections, which will stay no more than 10mn in the connection pool - worker.worker2.connection_pool_timeout=600 - # worker "worker2" ask operating system to send KEEP-ALIVE signal on the connection - worker.worker2.socket_keepalive=1 - # mount can be used as an alternative to the JkMount directive - worker.worker2.mount=/contexta /contexta/* /contextb /contextb/* -</source> - -<p> -Notes: In the ajpv13 protocol, the default port is 8009 -</p> - -</subsection> - -<subsection name="lb Worker properties"> -<p> -The load-balancing worker does not really communicate with Tomcat workers. -Instead it is responsible for the management of several "real" workers. -This management includes: -</p> - -<ul> -<li> -Instantiating the workers in the web server. -</li> -<li> -Using the worker's load-balancing factor, perform weighed-round-robin load balancing where -high lbfactor means stronger machine (that is going to handle more requests) -</li> -<li> -Keeping requests belonging to the same session executing on the same Tomcat worker. -</li> -<li> -Identifying failed Tomcat workers, suspending requests to them and instead falling-back on -other workers managed by the lb worker. -</li> -</ul> - -<p> -The overall result is that workers managed by the same lb worker are load-balanced (based on their lbfactor and current user session) and also fall-backed so a single Tomcat process death will not "kill" the entire site. -The following table specifies some properties that the lb worker can accept: -<ul> -<li><b>balance_workers</b> is a comma separated list of workers that the load balancer need to manage. -As long as these workers should only be used via the load balancer worker, -there is no need to also put them into the worker.list property. -This directive can be used multiple times for the same load balancer.</li> -<li><b>sticky_session</b> specifies whether requests with SESSION ID's should be routed back to the same -Tomcat worker. Set sticky_session to False when Tomcat is using a Session Manager which -can persist session data across multiple instances of Tomcat. By default sticky_session is set to True.</li> -</ul> -</p> - -<source> - # The worker balance1 while use "real" workers worker1 and worker2 - worker.balance1.balance_workers=worker1, worker2 -</source> - -</subsection> - -<subsection name="Status Worker properties"> -<p> -The status worker does not communicate with Tomcat. -Instead it is responsible for the load balancer management. -</p> -<source> - # Add the status worker to the worker list - worker.list=jkstatus - # Define a 'jkstatus' worker using status - worker.jkstatus.type=status -</source> -<p>Next thing is to mount the requests to the jkstatus worker. For Apache -web servers use the:</p> -<source> - # Add the jkstatus mount point - JkMount /jkmanager/* jkstatus -</source> -<p>To obtain a higher level of security use the:</p> -<source> - # Enable the JK manager access from localhost only - <Location /jkmanager/> - JkMount jkstatus - Order deny,allow - Deny from all - Allow from 127.0.0.1 - </Location> -</source> - -</subsection> - -<subsection name="Property file macros"> -<p> -You can define "macros" in the property files. -These macros let you define properties and later on use them while -constructing other properties. -</p> - -<source> - # property example, like a network base address - mynet=194.226.31 - # Using the above macro to simplify the address definitions - # for a farm of workers. - worker.node1.host=$(mynet).11 - worker.node2.host=$(mynet).12 - worker.node3.host=$(mynet).13 -</source> - -</subsection> - -<subsection name="Hierarchical property configuration"> -<p> -Workers can reference configurations of other workers. -If worker "x" references worker "y", then it inherits all -configuration parameters from "y", except for the ones -that have explicitly been set for "x". -</p> - -<source> - # worker toe defines some default settings - worker.toe.type=ajp13 - worker.toe.socket_keepalive=true - worker.toe.connect_timeout=10000 - worker.toe.recovery_options=7 - # workers tic and tac inherit those values - worker.tic.reference=worker.toe - worker.tac.reference=worker.toe -</source> - -<p> -Please note, that the reference contains -the full prefix to the referenced configuration attributes, -not only the name of the referenced worker. -</p> - -<p> -References can be nested. Be careful to avoid loops! -</p> - -<p> -Attributes which are allowed multiple times for a single worker -can not be merged from a worker and a reference. An attribute -is only inherited from a reference, if it is not already set -for the referring worker. -</p> - -<p> -References are especially useful, when configuring load balancers. -Try to understand the following two stage references: -</p> - -<source> - # We only use one load balancer - worker.list=lb - # Let's define some defaults - worker.basic.port=8009 - worker.basic.type=ajp13 - worker.basic.socket_keepalive=true - worker.basic.connect_timeout=10000 - worker.basic.recovery_options=7 - # And we use them in two groups - worker.lb1.domain=dom1 - worker.lb1.distance=0 - worker.lb1.reference=worker.basic - worker.lb2.domain=dom2 - worker.lb2.distance=1 - worker.lb2.reference=worker.basic - # Now we configure the load balancer - worker.lb.type=lb - worker.lb.method=B - worker.lb.balanced_workers=w11,w12,w21,w22 - worker.w11.host=myhost11 - worker.w11.reference=worker.lb1 - worker.w12.host=myhost12 - worker.w12.reference=worker.lb1 - worker.w21.host=myhost21 - worker.w21.reference=worker.lb2 - worker.w22.host=myhost22 - worker.w22.reference=worker.lb2 -</source> - -</subsection> - -</section> - -<section name="A sample worker.properties"> -<p> -Since coping with worker.properties on your own is not an easy thing to do, -a sample worker.properties file is bundled along JK. -</p> - -<p> -You could also find here a sample workers.properties defining : -</p> - -<ul> -<li> -An ajp12 worker that used the host localhost and the port 8007 -</li> -<li> -An ajp13 worker that used the host localhost and the port 8008 -</li> -<li> -An lb worker that load balance the ajp12 and ajp13 workers -</li> -</ul> - -<source> - # Define 3 workers, 2 real workers using ajp12, ajp13, the last one being a loadbalancing worker - worker.list=worker1, worker2, worker3 - # Set properties for worker1 (ajp12) - worker.worker1.type=ajp12 - worker.worker1.host=localhost - worker.worker1.port=8007 - worker.worker1.lbfactor=1 - # Set properties for worker2 (ajp13) - worker.worker2.type=ajp13 - worker.worker2.host=localhost - worker.worker2.port=8009 - worker.worker2.lbfactor=1 - worker.worker2.connection_pool_timeout=600 - worker.worker2.socket_keepalive=1 - worker.worker2.socket_timeout=60 - # Set properties for worker3 (lb) which use worker1 and worker2 - worker.worker3.balance_workers=worker1,worker2 -</source> - -</section> -</body> -</document> |