server-tags.xtp

RESIN 3.2 最新源码

        <server id="c" address="192.168.0.12" server-port="6800">
          <http port="8080"/>
        </server>

        <host id="">
          ...
    </cluster>
</resin>
</example>

<p>Main configuration for the server, configuring ports,
threads and virtual hosts.</p>

<ul>
<li>Common resources for all virtual hosts and web-apps.</li>
<li>Thread pooling</li>
<li>HTTP and SRUN/Cluster ports</li>
<li>Caching</li>
<li>virtual host configuration and common web-app-default</li>
</ul>

<p>The &lt;server&gt; will generally contain a &lt;class-loader&gt; configuration
which loads the resin/lib jars dynamically, allowing for system-wide jars
to be dropped into resin/lib.  &lt;server&gt; configures
the main dynamic environment.  Database pools common to all virtual hosts,
for example, should be configured in the &lt;server&gt; block.</p>

<p>The &lt;server&gt; configures the &lt;thread-pool&gt; and a set
of &lt;http&gt; and &lt;srun&gt; ports which share the thread pool.
Requests received on those ports will use worker threads from the
thread pool.</p>

<deftable-childtags>
<tr><td>alternate-session-url-prefix</td>
    <td>a prefix to add the session to the beginning of the URL as a path
        prefix instead of the standard ;jsessionid= suffix. For clients like
        mobile devices with limited memory, this will allow careful web
        designers to minimize the page size.</td>
    <td>null</td></tr>
<tr><td>keepalive-max</td>
    <td>the maximum number of keepalive connections</td>
    <td>512</td></tr>
<tr><td>keepalive-thread-timeout</td>
    <td>the maximum time a connection is maintained in the keepalive state</td>
    <td>120s</td></tr>
</deftable-childtags>

<example title="alternate-session-url-prefix">
&lt;server&gt;
  ...
  &lt;alternate-session-url-prefix&gt;/~J=&lt;/alternate-session-url-prefix&gt;
  ...
</example>

<s2 name="server-el" title="EL variables and functions">
<deftable title="EL variables defined by &lt;server&gt;">
<tr><th>variable</th>
    <th>corresponding API</th></tr>
<tr><td>serverId</td>
    <td><i>server</i>.getServerId()</td></tr>
<tr><td>root-dir</td>
    <td><i>server</i>.getRootDirectory()</td></tr>
<tr><td>server-root</td><td><i>server</i>.getRootDirectory()</td></tr>
</deftable>

<deftable title="EL functions defined by &lt;server&gt;">
<tr><th>function</th>
    <th>corresponding API</th></tr>
<tr><td>jndi</td>
    <td><a href="javadoc|com.caucho.naming.Jndi|lookup(String)">Jndi.lookup(String)</a></td></tr>
</deftable>

</s2>

</defun>

<defun title="&lt;server-default>" version="Resin 3.1">
<parents>cluster</parents>

<p>&lt;server-default> defines default values for
all &lt;server&gt; instances.  Since most &lt;server> configuration
is identical for all server instances, the shared configuration belongs
in a &lt;server-default>.  For example, &lt;http> ports, timeouts,
JVM arguments, and keepalives are typically identical for all
server instances and therefore belong in a server-default.</p>

<example title="server">
&lt;resin xmlns="http://caucho.com/ns/resin"&gt;
    &lt;cluster id="web-tier"&gt;
        &lt;server-default&gt;
           &lt;thread-max>512&lt;/thread-max>

           &lt;jvm-arg>-Xmx512m -Xss1m&lt;/jvm-arg>

           &lt;http port="8080"/&gt;
        &lt;/server-default&gt;

        &lt;server id="a" address="192.168.0.10" port="6800"/&gt;
        &lt;server id="b" address="192.168.0.11" port="6800"/&gt;
        &lt;server id="c" address="192.168.0.12" port="6800"/&gt;

        &lt;host id=""&gt;
          ...
    &lt;/cluster&gt;
&lt;/resin&gt;
</example>

</defun>

<defun title="&lt;shutdown-wait-max>" version="Resin 3.0">
<parents>server</parents>

<p>&lt;shutdown-wait-max> configures the maximum time the server
will wait for the graceful shutdown before forcing an exit.</p>

<default>60s</default>

</defun>

<defun title="&lt;socket-timeout>" version="Resin 3.1">
<parents>http, cluster-port, protocol, server</parents>

<p>&lt;socket-timeout> is the maximum time
a socket <a href="resin-clustering.xtp">load balancer</a>
and <a href="config-sessions.xtp">distributed sessions</a> will wait for
a read or write to a cluster socket.</p>

<p>Crashed servers may never respond to a read request or accept a write.
The socket-timeout lets Resin recover from these kinds of crashes.</p>

<p>Lower values can detect crashes more quickly, but too-low values may
report bogus failures when the server machine is just a little slow.</p>

<default>60s</default>

<example title="socket-timeout">
&lt;resin xmlns="http://caucho.com/ns/resin"&gt;
    &lt;cluster id="app-tier"&gt;
        &lt;server-default>
          &lt;socket-timeout>60s&lt;/socket-timeout>
        &lt;/server-default>

        &lt;server id="a" address="192.168.0.10" port="6800"/&gt;
        &lt;server id="b" address="192.168.0.11" port="6800"/&gt;

        &lt;host id=""&gt;
          ...
    &lt;/cluster&gt;
&lt;/resin&gt;
</example>

</defun>

<defun title="&lt;thread-idle-max>" version="Resin 3.1">
<parents>server</parents>

<p>&lt;thread-idle-max> configures the maximum number of idle
threads in the thread pool.  &lt;thread-idle-max> works
with &lt;thread-idle-min> to maintain a steady number of idle
threads, avoiding the creation or destruction threads when possible.</p>

<p>&lt;thread-idle-max> should be set high enough beyond
&lt;thread-idle-min> so a spiky load will avoid
creating a thread and then  immediately destroying it.</p>

<default>10</default>

<example title="thread-idle-max in resin.xml">
&lt;resin xmlns="http://caucho.com/ns/resin"&gt;
  &lt;cluster id="web-tier"&gt;
    &lt;server-default&gt;
      &lt;thread-max>512&lt;/thread-max>

      &lt;thread-idle-min>10&lt;/thread-idle-min>
      &lt;thread-idle-max>20&lt;/thread-idle-max>

      &lt;jvm-arg>-Xss1m -Xmx1024m&lt;/jvm-arg>
    &lt;/server-default&gt;

    &lt;server id="web-a" address="192.168.0.10"/>
        ...
  &lt;/cluster>
&lt;/resin>
</example>

</defun>

<defun title="&lt;thread-idle-min>" version="Resin 3.1">
<parents>server</parents>

<p>&lt;thread-idle-min> configures the minimum number of idle
threads in the thread pool.  &lt;thread-idle-min> helps spiky loads,
avoiding delays for thread requests by keeping threads ready for future
requests.  When the number of idle threads drops
below &lt;thread-idle-min>, Resin creates a new thread.</p>

<p>&lt;thread-idle-min> should be set high enough to deal with load
spikes.  Since idle threads are relatively inexpensive in modern operating
systems, having a number of idle threads is not a major resource hog,
especially since these threads are idle, waiting for a new job.</p>

<p>&lt;thread-idle-min> works together with &lt;thread-idle-max> to
avoid thread allocation thrashing, i.e. avoiding creating a new thread
because of &lt;thread-idle-min> and then quickly destroying it
because of &lt;thread-idle-max>.</p>

<default>5</default>

<example title="thread-idle-min in resin.xml">
&lt;resin xmlns="http://caucho.com/ns/resin"&gt;
  &lt;cluster id="web-tier"&gt;
    &lt;server-default&gt;
      &lt;thread-max>512&lt;/thread-max>

      &lt;thread-idle-min>10&lt;/thread-idle-min>
      &lt;thread-idle-max>20&lt;/thread-idle-max>

      &lt;jvm-arg>-Xss1m -Xmx1024m&lt;/jvm-arg>
    &lt;/server-default&gt;

    &lt;server id="web-a" address="192.168.0.10"/>
        ...
  &lt;/cluster>
&lt;/resin>
</example>

</defun>

<defun title="&lt;thread-max>" version="Resin 3.1">
<parents>server</parents>

<p>&lt;thread-max> configures the maximum number of threads
managed by Resin's thread pool.  Resin's thread pool is used
for connection threads, timers, and Resin worker threads for JMS, JCA
and EJB.  Since Resin's thread pool only manages Resin threads,
the actual number of threads in the JVM will be higher.</p>

<p>Modern operating systems can handle a fairly large number of threads,
so values of 512 or 1024 are often reasonable values for thread-max.  The
main limitation for thread-max is virtual memory.  Since each thread
takes up stack space (configured with -Xss), a 32-bit system
might have a thread limit based on virtual memory.</p>

<p>For example, on Linux the user space is only 2G.  If the heap memory
is 1024m (-Xmx1024m) and the stack size is 1m (-Xss1m), the maximum
number of threads is somewhat less than 1024.</p>

<p>In general, JVMs do not handle running out of threads very well, either
freezing or throwing out of memory errors.  Although it may be necessary
to limit the number of threads to avoid running out of memory,
&lt;thread-max> should generally be set to a high value.</p>

<example title="thread-max in resin.xml">
&lt;resin xmlns="http://caucho.com/ns/resin"&gt;
  &lt;cluster id="web-tier"&gt;
    &lt;server-default&gt;
      &lt;thread-max>512&lt;/thread-max>

      &lt;jvm-arg>-Xss1m -Xmx1024m&lt;/jvm-arg>
    &lt;/server-default&gt;

    &lt;server id="web-a" address="192.168.0.10"/>
        ...
  &lt;/cluster>
&lt;/resin>
</example>

<default>4096</default>

</defun>

<defun title="&lt;user-name>" version="Resin 3.1">
<parents>server</parents>

<p>&lt;user-name> configures the operating system user Resin should
run as.  Since the HTTP port 80 is protected in Unix, the web server
needs to start as root to bind to port 80.  For security, Resin should
switch to a non-root user after binding to port 80.</p>

<example title="resin.xml with user-name">
&lt;resin xmlns="http://caucho.com/ns/resin">
  &lt;cluster id="app-tier">

    &lt;server-default>
      &lt;http port="80"/>

      &lt;user-name>resin&lt;/user-name>
    &lt;/server-default>

    &lt;server id="web-a"/>
    ...
  &lt;/cluster>
&lt;/resin>
</example>

</defun>

<defun title="&lt;watchdog-arg>" version="Resin 3.1">
<parents>server</parents>

<p>The &lt;watchdog-arg> configures arguments for the
watchdog process.  The watchdog improves reliability by
monitoring the Resin instance, restarting it if necessary.</p>

<p>The &lt;watchdog-arg> typically is used to enable <g>jconsole</g>
for the watchdog JVM.</p>

<example title="resin.xml">
&lt;resin xmlns="http://caucho.com/ns/resin">
  &lt;cluster id="app-tier">
    &lt;server-default>

      &lt;watchdog-arg>-Dcom.sun.management.jmxremote&lt;/watchdog-arg>

    &lt;/server-default>

    ...
       
  &lt;/cluster>
&lt;/resin>
</example>

</defun>

<defun title="&lt;watchdog-port>" version="Resin 3.1">
<parents>server</parents>

<p>&lt;watchdog-port> configures the administration port for the
watchdog JVM.  The watchdog launches the server JVM and monitors its
health, restarting the JVM when necessary to improve site reliability.
The command line arguments use the watchdog-port for
the "start" and "stop" commands to tell the watchdog to start and
stop the server JVM.  The administration also uses the watchdog port
for watchdog administration.</p>

<p>The watchdog port will use the same &lt;address> as the server, so it
will always be an internal network address, never an external internet
address.</p>

<default>6700</default>

</defun>

</body>
</document>