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-$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.45 2000/12/30 15:03:09 petere Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.46 2001/01/08 21:01:54 petere Exp $
-->
<Chapter Id="runtime">
<varlistentry>
- <term>FreeBSD</>
+ <term>FreeBSD</term>
+ <term>OpenBSD</term>
<listitem>
<para>
The options <varname>SYSVSHM</> and <varname>SYSVSEM</> need
the option <varname>SHMMAXPGS</> (in pages). The following
shows an example of how to set the various parameters:
<programlisting>
-options SYSVSHM
-options SHMMAXPGS=4096
-options SHMSEG=256
-
-options SYSVSEM
-options SEMMNI=256
-options SEMMNS=512
-options SEMMNU=256
+options SYSVSHM
+options SHMMAXPGS=4096
+options SHMSEG=256
+
+options SYSVSEM
+options SEMMNI=256
+options SEMMNS=512
+options SEMMNU=256
options SEMMAP=256
</programlisting>
</para>
</variablelist>
- <note>
- <para>
- If your platform is not listed here, please consider
- contributing some information.
- </para>
- </note>
</para>
</sect2>
-<!--
- Other fun things to write about one day:
- * number of processes per user and system-wide (soft/hard limit)
- * open files/inodes per user and system-wide (soft/hard limit)
- (Think about this both ways: Increasing it to allow Postgres to
- open more files, and decreasing it to prevent Postgres from taking
- up all file descriptors.)
- * stack and data segment size, plain-old memory limit
--->
+
+ <sect2>
+ <title>Resource Limits</title>
+
+ <para>
+ Unix-like operating systems enforce various kinds of resource
+ limits that might interfere with the operation of your
+ <productname>Postgres</productname> server. Of importance are
+ especially the limits on the number of processes per user, the
+ number of open files per process, and the amount of memory
+ available to a process. Each of these have a <quote>hard</quote>
+ and a <quote>soft</quote> limit. The soft limit is what actually
+ counts but it can be changed by the user up to the hard limit.
+ The hard limit can only be changed by the root user. The system
+ call <function>setrlimit</function> is responsible for setting
+ these parameters. The shell the built-in command
+ <command>ulimit</command> (Bourne shells) or
+ <command>limit</command> (csh) is used to control the resource
+ limits from the command line. On BSD-derived systems the file
+ <filename>/etc/login.conf</filename> controls what values the
+ various resource limits are set to upon login. See
+ <citerefentry><refentrytitle>login.conf</refentrytitle>
+ <manvolnum>5</manvolnum></citerefentry> for details. The relevant
+ parameters are <varname>maxproc</varname>,
+ <varname>openfiles</varname>, and <varname>datasize</varname>.
+ For example:
+<programlisting>
+default:\
+...
+ :datasize-cur=256M:\
+ :maxproc-cur=256:\
+ :openfiles-cur=256:\
+...
+</programlisting>
+ (<literal>-cur</literal> is the soft limit. Append
+ <literal>-max</literal> to set the hard limit.)
+ </para>
+
+ <para>
+ Kernels generally also have an implementation-dependent
+ system-wide limit on some resources.
+ <simplelist>
+ <member>
+ On <productname>Linux</productname>
+ <filename>/proc/sys/fs/file-max</filename> determines the
+ maximum number of files that the kernel will allocate. It can
+ be changed by writing a different number into the file or by
+ adding an assignment in <filename>/etc/sysctl.conf</filename>.
+ The maximum limit of files per process is fixed at the time the
+ kernel is compiled; see
+ <filename>/usr/src/linux/Documentation/proc.txt</filename> for
+ more information.
+ </member>
+ </simplelist>
+ </para>
+
+ <para>
+ The <productname>Postgres</productname> server uses one process
+ per connection so you should provide for at least as many processes
+ as allowed connections, in addition to what you need for the rest
+ of your system. This is usually not a problem but if you run
+ several servers on one machine things might get tight.
+ </para>
+
+ <para>
+ The factory default limit on open files is often set to
+ <quote>socially friendly</quote> values that allow many users to
+ coexist on a machine without using an inappropriate fraction of
+ the system resources. If you run many servers on a machine this
+ is perhaps what you want, but on dedicated servers you may want to
+ raise this limit.
+ </para>
+ </sect2>
</sect1>
can be started with the argument <option>-l</> (ell) to enable
SSL connections. When starting in SSL mode, the postmaster will look
for the files <filename>server.key</> and <filename>server.crt</> in
- the data directory (pointed to by <envar>PGDATA</envar>).
- These files should contain the server private key
+ the data directory. These files should contain the server private key
and certificate respectively. These files must be set up correctly
before an SSL-enabled server can start. If the private key is protected
with a passphrase, the postmaster will prompt for the passphrase and will
- not start until it has been provided.
+ not start until it has been entered.
</para>
<para>
The postmaster will listen for both standard and SSL connections
on the same TCP/IP port, and will negotiate with any connecting
client whether or not to use SSL.
- See <xref linkend="client-authentication">
+ See <xref linkend="client-authentication">
about how to force on the server side the use of SSL for certain
connections.
</para>
by a CA (either one of the global CAs or a local one) should be used in
production so the client can verify the servers identity. To create
a quick self-signed certificate, use the following OpenSSL command:
- openssl req -new -text -out cert.req
- </programlisting>
+<programlisting>
+openssl req -new -text -out cert.req
+</programlisting>
Fill out the information that openssl asks for. Make sure that you enter
the local host name as Common Name; the challenge password can be
- left blank. The script will generate a key that is passphrase protected;
- it will not accept a pass phrase that is less than four characters long.
- To remove the passphrase (as you must if you want automatic start-up of
- the postmaster), run the commands
- mv privkey.pem cert.pem.pw
- openssl rsa -in cert.pem.pw -out cert.pem
- </programlisting>
+ left blank. The script will generate a key that is passphrase protected;
+ it will not accept a pass phrase that is less than four characters long.
+ To remove the passphrase (as you must if you want automatic start-up of
+ the postmaster), run the commands
+<programlisting>
+mv privkey.pem cert.pem.pw
+openssl rsa -in cert.pem.pw -out cert.pem
+</programlisting>
Enter the old passphrase to unlock the existing key. Now do
- openssl req -x509 -in cert.req -text -key cert.pem -out cert.cert
- cp cert.pem $PGDATA/server.key
- cp cert.cert $PGDATA/server.crt
- </programlisting>
+<programlisting>
+openssl req -x509 -in cert.req -text -key cert.pem -out cert.cert
+cp cert.pem <replaceable>$PGDATA</replaceable>/server.key
+cp cert.cert <replaceable>$PGDATA</replaceable>/server.crt
+</programlisting>
to turn the certificate into a self-signed certificate and to copy the
- key and certificate to where the postmaster will look for them.
+ key and certificate to where the postmaster will look for them.
</para>
</sect1>
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