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| author |   hongbotian <hongbo.tianhongbo@huawei.com> | 2015-11-30 03:10:21 -0500 |
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| committer | hongbotian <hongbo.tianhongbo@huawei.com> | 2015-11-30 03:10:21 -0500 |
| commit | c0b7206652b2852bc574694e7ba07ba1c2acdc00 (patch) | |
| tree | 5cb95cb0e19e03610525903df46279df2c3b7eb1 /rubbos/app/tomcat-connectors-1.2.32-src/docs/generic_howto/loadbalancers.html | |
| parent | b6d3d6e668b793220f2d3af1bc3e828553dc3fe6 (diff) | |
delete app
Change-Id: Id4c572809969ebe89e946e88063eaed262cff3f2
Signed-off-by: hongbotian <hongbo.tianhongbo@huawei.com>
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diff --git a/rubbos/app/tomcat-connectors-1.2.32-src/docs/generic_howto/loadbalancers.html b/rubbos/app/tomcat-connectors-1.2.32-src/docs/generic_howto/loadbalancers.html deleted file mode 100644 index 06a1ee5a..00000000 --- a/rubbos/app/tomcat-connectors-1.2.32-src/docs/generic_howto/loadbalancers.html +++ /dev/null @@ -1,207 +0,0 @@ -<html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>The Apache Tomcat Connector - Generic HowTo - LoadBalancer HowTo</title><meta name="author" value="Mladen Turk"><meta name="email" value="mturk@apache.org"><link href="../style.css" type="text/css" rel="stylesheet"></head><body bgcolor="#ffffff" text="#000000" link="#525D76" alink="#525D76" vlink="#525D76"><table border="0" width="100%" cellspacing="4"><!--PAGE HEADER--><tr><td colspan="2"><!--TOMCAT LOGO--><a href="http://tomcat.apache.org/"><img src="../images/tomcat.gif" align="left" alt="Apache Tomcat" border="0"></a><!--APACHE LOGO--><a href="http://www.apache.org/"><img src="http://www.apache.org/images/asf-logo.gif" align="right" alt="Apache Logo" border="0"></a></td></tr><!--HEADER SEPARATOR--><tr><td colspan="2"><hr noshade size="1"></td></tr><tr><!--LEFT SIDE NAVIGATION--><td width="20%" valign="top" nowrap="true"><p><strong>Links</strong></p><ul><li><a href="../index.html">Docs Home</a></li></ul><p><strong>Reference Guide</strong></p><ul><li><a href="../reference/workers.html">workers.properties</a></li><li><a href="../reference/uriworkermap.html">uriworkermap.properties</a></li><li><a href="../reference/status.html">Status Worker</a></li><li><a href="../reference/apache.html">Apache HTTP Server</a></li><li><a href="../reference/iis.html">IIS</a></li></ul><p><strong>Generic HowTo</strong></p><ul><li><a href="../generic_howto/quick.html">For the impatient</a></li><li><a href="../generic_howto/workers.html">All about workers</a></li><li><a href="../generic_howto/timeouts.html">Timeouts</a></li><li><a href="../generic_howto/loadbalancers.html">Load Balancing</a></li><li><a href="../generic_howto/proxy.html">Reverse Proxy</a></li></ul><p><strong>Webserver HowTo</strong></p><ul><li><a href="../webserver_howto/apache.html">Apache HTTP Server</a></li><li><a href="../webserver_howto/iis.html">IIS</a></li><li><a href="../webserver_howto/nes.html">Netscape/SunOne/Sun</a></li></ul><p><strong>AJP Protocol Reference</strong></p><ul><li><a href="../ajp/ajpv13a.html">AJPv13</a></li><li><a href="../ajp/ajpv13ext.html">AJPv13 Extension Proposal</a></li></ul><p><strong>Miscellaneous Documentation</strong></p><ul><li><a href="../miscellaneous/faq.html">Frequently asked questions</a></li><li><a href="../miscellaneous/changelog.html">Changelog</a></li><li><a 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=">Current Tomcat Connectors bugs</a></li><li><a href="../miscellaneous/doccontrib.html">Contribute documentation</a></li><li><a href="../miscellaneous/jkstatustasks.html">JK Status Ant Tasks</a></li><li><a href="../miscellaneous/reporttools.html">Reporting Tools</a></li><li><a href="http://tomcat.apache.org/connectors-doc-archive/jk2/index.html">Old JK/JK2 documentation</a></li></ul><p><strong>News</strong></p><ul><li><a href="../news/20110701.html">2011</a></li><li><a href="../news/20100101.html">2010</a></li><li><a href="../news/20090301.html">2009</a></li><li><a href="../news/20081001.html">2008</a></li><li><a href="../news/20070301.html">2007</a></li><li><a href="../news/20060101.html">2006</a></li><li><a href="../news/20050101.html">2005</a></li><li><a href="../news/20041100.html">2004</a></li></ul></td><!--RIGHT SIDE MAIN BODY--><td width="80%" valign="top" align="left"><table border="0" width="100%" cellspacing="4"><tr><td align="left" valign="top"><h1>The Apache Tomcat Connector - Generic HowTo</h1><h2>LoadBalancer HowTo</h2></td><td align="right" valign="top" nowrap="true"><small><a href="printer/loadbalancers.html"><img src="../images/printer.gif" border="0" alt="Printer Friendly Version"><br>print-friendly<br>version - </a></small></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Introduction"><strong>Introduction</strong></a></font></td></tr><tr><td><blockquote> -<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> - -<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Basic Load Balancer Properties"><strong>Basic Load Balancer Properties</strong></a></font></td></tr><tr><td><blockquote> -<p>A worker is configured as a load balancer by setting its worker <b class="code">type</b> -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 <b class="code">worker.list</b> 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 <b class="code">lbfactor</b> 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> - -<div class="example"><pre> - # 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 -</pre></div> - -<p><font color="#ff0000"> -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 <b class="code">jvmRoute</b> 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 <b class="code">jvmRoute="worker1"</b>, Tomcat on host "myhost2" -needs <b class="code">jvmRoute="worker2"</b>. -</font></p> - -<p>For a complete reference of all load balancer configuration -attributes, please consult the worker <a href="../reference/workers.html">reference</a>. -</p> -</blockquote></td></tr></table> - -<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Advanced Load Balancer Worker Properties"><strong>Advanced Load Balancer Worker Properties</strong></a></font></td></tr><tr><td><blockquote> -<p>The load balancer supports complex topologies and failover configurations. -Using the member attribute <b class="code">distance</b> 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 <b class="code">domain</b> 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 <b class="code">activation</b>. -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 -<b class="code">activation</b> set to <b>disabled</b> in combination with -the attribute <b class="code">redirect</b> added to the other workers:</p> - -<div class="example"><pre> - # 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 -</pre></div> - -<p> -The <b class="code">redirect</b> 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 <b class="code">activation</b> to <b>disabled</b>: -The session id coming with a request is send either -as part of the request URL (<b class="code">;jsessionid=...</b>) 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 <b class="code">JK_LB_ACTIVATION</b>. -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 -<b class="code">JK_LB_ACTIVATION</b> has been added in version 1.2.32.</p> -</blockquote></td></tr></table> - -<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Status Worker properties"><strong>Status Worker properties</strong></a></font></td></tr><tr><td><blockquote> -<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> -<div class="example"><pre> - # Add the status worker to the worker list - worker.list=jkstatus - # Define a 'jkstatus' worker using status - worker.jkstatus.type=status -</pre></div> -<p>Next thing is to mount the requests to the jkstatus worker. For Apache -web servers use the:</p> -<div class="example"><pre> - # Add the jkstatus mount point - JkMount /jkmanager/* jkstatus -</pre></div> -<p>To obtain a higher level of security use the:</p> -<div class="example"><pre> - # 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> -</pre></div> - -</blockquote></td></tr></table> - -</blockquote></td></tr></table></td></tr><!--FOOTER SEPARATOR--><tr><td colspan="2"><hr noshade size="1"></td></tr><!--PAGE FOOTER--><tr><td colspan="2"><div align="center"><font color="#525D76" size="-1"><em> - Copyright © 1999-2011, Apache Software Foundation - </em></font></div></td></tr></table></body></html>
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