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-$Header: /cvsroot/pgsql/doc/src/sgml/ref/postmaster.sgml,v 1.7 1999/10/12 13:59:45 thomas Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/ref/postmaster.sgml,v 1.8 2000/03/26 07:04:54 tgl Exp $
Postgres documentation
-->
<date>1999-07-20</date>
</refsynopsisdivinfo>
<synopsis>
-postmaster [ -B <replaceable class="parameter">nBuffers</replaceable> ] [ -D <replaceable class="parameter">DataDir</replaceable> ] [ -i ] [ -l ]
-postmaster [ -B <replaceable class="parameter">nBuffers</replaceable> ] [ -D <replaceable class="parameter">DataDir</replaceable> ] [ -N <replaceable class="parameter">nBackends</replaceable> ] [ -S ]
- [ -d [ <replaceable class="parameter">DebugLevel</replaceable> ] [ -i ] [ -l ] [ -o <replaceable class="parameter">BackendOptions</replaceable> ] [ -p <replaceable class="parameter">port</replaceable> ]
-postmaster [ -n | -s ] ...
+postmaster [ -B <replaceable class="parameter">nBuffers</replaceable> ] [ -D <replaceable class="parameter">DataDir</replaceable> ] [ -N <replaceable class="parameter">maxBackends</replaceable> ] [ -S ]
+ [ -d <replaceable class="parameter">DebugLevel</replaceable> ] [ -i ] [ -l ]
+ [ -o <replaceable class="parameter">BackendOptions</replaceable> ] [ -p <replaceable class="parameter">port</replaceable> ] [ -n | -s ]
</synopsis>
<refsect2 id="R2-APP-POSTMASTER-1">
<term>-B <replaceable class="parameter">nBuffers</replaceable></term>
<listitem>
<para>
- The number of shared-memory buffers for the
+ Sets the number of shared-memory disk buffers for the
<application>postmaster</application>
- to allocate and manage for the backend server processes that it
+ to allocate for use by the backend server processes that it
starts. This value defaults to 64 buffers, where each buffer is 8k bytes
- (or whatever BLCKSZ is set to in config.h).
+ (or whatever BLCKSZ is set to in src/include/config.h).
</para>
</listitem>
</varlistentry>
</varlistentry>
<varlistentry>
- <term>-N <replaceable class="parameter">nBackends</replaceable></term>
+ <term>-N <replaceable class="parameter">maxBackends</replaceable></term>
<listitem>
<para>
- The maximum number of backend server processes that this postmaster
- is allowed to start. In the default configuration, this value
- is usually set
- to 32, and can be set as high as 1024 if your system will support that
- many processes. Both the default and upper limit values can be altered
- when building <productname>Postgres</productname> (see src/include/config.h).
+ Sets the maximum number of backend server processes that this postmaster
+ is allowed to start. By default, this value is 32, but it can be set
+ as high as 1024 if your system will support that many processes.
+ (Note that -B is required to be at least twice -N, so you'll need to
+ increase -B if you increase -N.)
+ Both the default and upper limit values for -N can be altered
+ when building <productname>Postgres</productname>
+ (see src/include/config.h).
</para>
</listitem>
</varlistentry>
<para>
Specifies that the <application>postmaster</application>
process should start up in silent mode. That is, it will disassociate
- from the user's (controlling) tty and start its own process group.
- This should not be used in combination with debugging options because
- any messages printed to standard output and standard error are
- discarded.
+ from the user's (controlling) tty, start its own process group, and
+ redirect its standard output and standard error to
+ <filename>/dev/null</filename>.
+ </para>
+ <para>
+ <emphasis>Note</emphasis> that using this switch makes it very
+ difficult to troubleshoot problems, since all tracing and logging
+ output that would normally be generated by this postmaster and its
+ child backends will be discarded.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term>-d [ <replaceable class="parameter">DebugLevel</replaceable> ]</term>
+ <term>-d <replaceable class="parameter">DebugLevel</replaceable></term>
<listitem>
<para>
- This argument <replaceable class="parameter">DebugLevel</replaceable>
- determines the amount of debugging output the backend servers will
+ Determines the amount of debugging output the backend servers will
produce.
If <replaceable class="parameter">DebugLevel</replaceable>
- is one, the postmaster will trace all connection traffic,
- and nothing else.
- For levels two and higher,
- debugging is turned on in the backend process and the postmaster
- displays more information,
+ is one, the postmaster will trace all connection traffic.
+ Levels two and higher turn on increasing amounts of debug output
+ from the backend processes, and the postmaster
+ displays more information
including the backend environment and process traffic.
- Note that if no file is specified for backend servers to
- send their debugging output then this output will appear on the
- controlling tty of the
ir parent <application>postmaster</application>.
+ Note that unless the postmaster's standard output and standard error
+ are redirected into a log file, all this output will appear on the
+ controlling tty of the <application>postmaster</application>.
</para>
</listitem>
</varlistentry>
<term>-i</term>
<listitem>
<para>
- This enables TCP/IP or Internet domain socket communication.
- Without this option, only local Unix domain socket communication is
- possible.
+ Allows clients to connect via TCP/IP (Internet domain) connections.
+ Without this option, only local Unix domain socket connections are
+ accepted.
</para>
</listitem>
</varlistentry>
<term>-l</term>
<listitem>
<para>
- This enables SSL socket communication. The <option>-i</option> option
+ Enables secure connections using SSL. The <option>-i</option> option
is also required.
- You have to have compiled with SSL enabled to use this option.
+ You must have compiled with SSL enabled to use this option.
</para>
</listitem>
</varlistentry>
<para>
The
<literal>postgres</literal>
- options specified in
+ option(s) specified in
<replaceable class="parameter">BackendOptions</replaceable>
are passed to all backend server processes started by this
<application>postmaster</application>.
</para>
<para>
- A few command line options are available for debugging in the case
- when a backend dies abnormally.
+ Two additional command line options are available for debugging problems
+ that cause a backend to die abnormally.
These options control the behavior of the
<application>postmaster</application> in this situation, and
<emphasis>neither option is intended for use in
<listitem>
<para>
<application>postmaster</application>
- will not reinitialize shared data structures. A knowledgable system
- programmer can then use the
- <application>shmemdoc</application>
- program to examine shared memory and semaphore state.
+ will not reinitialize shared data structures. A knowledgeable system
+ programmer can then use a debugger
+ to examine shared memory and semaphore state.
</para>
</listitem>
</varlistentry>
<para>
If you see this message, you should run the
<application>ipcclean</application>
- command. After doing this, try starting
+ command. After doing so, try starting
<application>postmaster</application>
again. If this still doesn't work, you probably need to configure
your kernel for shared memory and semaphores as described in the
You may be able to postpone
reconfiguring your kernel by decreasing -B to reduce
<productname>Postgres</productname>' shared memory
- consumption, or by reducing -N to reduce Postgres' semaphore
+ consumption, and/or by reducing -N to reduce Postgres' semaphore
consumption.
</para>
</tip>
</computeroutput></term>
<listitem>
<para>
- If you see this message, you should be certain that there is no other
- <application>postmaster</application>
- process already running. The easiest way to determine this is by
- using the command
+ If you see this message, you should make certain that there is no
+
other <application>postmaster</application>
+ process already running on the same port number. The easiest way to
+ determine this is by using the command
<programlisting>
% ps -ax | grep postmaster
</programlisting>
will prevent <application>postmaster</application>
from freeing the system resources (e.g., shared memory and semaphores)
- that it holds before dying. This prevents you from having to deal with
- the problem with shared memory described earlier.
+ that it holds before dying. Use <literal>SIGTERM</literal> instead
+ to avoid having to clean up manually (as described earlier).
</para>
<para>
</para>
<para>
- To start <application>postmaster</application> with a specific port
- and executable name:
+ To start <application>postmaster</application> with a specific port:
<programlisting>
% nohup postmaster -p 1234 &
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