+<?xml version="1.0" encoding="utf-8"?>
<database title="Open vSwitch Configuration Database">
<p>A database with this schema holds the configuration for one Open
vSwitch daemon. The root of the configuration for the daemon is
<column name="statistics">
<p>
- Key-value pairs that report statistics about a running Open_vSwitch
- daemon. The current implementation updates these counters
- periodically. In the future, we plan to, instead, update them only
- when they are queried (e.g. using an OVSDB <code>select</code>
- operation) and perhaps at other times, but not on any regular
- periodic basis.</p>
- <p>
- The currently defined key-value pairs are listed below. Some Open
- vSwitch implementations may not support some statistics, in which
- case those key-value pairs are omitted.</p>
+ Key-value pairs that report statistics about a system running an Open
+ vSwitch. These are updated periodically (currently, every 5
+ seconds). Key-value pairs that cannot be determined or that do not
+ apply to a platform are omitted.
+ </p>
+
<dl>
- <dt><code>load-average</code></dt>
+ <dt><code>cpu</code></dt>
+ <dd>
+ <p>
+ Number of CPU processors, threads, or cores currently online and
+ available to the operating system on which Open vSwitch is
+ running, as an integer. This may be less than the number
+ installed, if some are not online or if they are not available to
+ the operating system.
+ </p>
+ <p>
+ Open vSwitch userspace processes are not multithreaded, but the
+ Linux kernel-based datapath is.
+ </p>
+ </dd>
+
+ <dt><code>load_average</code></dt>
+ <dd>
+ <p>
+ A comma-separated list of three floating-point numbers,
+ representing the system load average over the last 1, 5, and 15
+ minutes, respectively.
+ </p>
+ </dd>
+
+ <dt><code>memory</code></dt>
+ <dd>
+ <p>
+ A comma-separated list of integers, each of which represents a
+ quantity of memory in kilobytes that describes the operating
+ system on which Open vSwitch is running. In respective order,
+ these values are:
+ </p>
+
+ <ol>
+ <li>Total amount of RAM allocated to the OS.</li>
+ <li>RAM allocated to the OS that is in use.</li>
+ <li>RAM that can be flushed out to disk or otherwise discarded
+ if that space is needed for another purpose. This number is
+ necessarily less than or equal to the previous value.</li>
+ <li>Total disk space allocated for swap.</li>
+ <li>Swap space currently in use.</li>
+ </ol>
+
+ <p>
+ On Linux, all five values can be determined and are included. On
+ other operating systems, only the first two values can be
+ determined, so the list will only have two values.
+ </p>
+ </dd>
+
+ <dt><code>process_</code><var>name</var></dt>
<dd>
- System load average multiplied by 100 and rounded to the nearest
- integer.</dd>
+ <p>
+ One such key-value pair will exist for each running Open vSwitch
+ daemon process, with <var>name</var> replaced by the daemon's
+ name (e.g. <code>process_ovs-vswitchd</code>). The value is a
+ comma-separated list of integers. The integers represent the
+ following, with memory measured in kilobytes and durations in
+ milliseconds:
+ </p>
+
+ <ol>
+ <li>The process's virtual memory size.</li>
+ <li>The process's resident set size.</li>
+ <li>The amount of user and system CPU time consumed by the
+ process.</li>
+ <li>The number of times that the process has crashed and been
+ automatically restarted by the monitor.</li>
+ <li>The duration since the process was started.</li>
+ <li>The duration for which the process has been running.</li>
+ </ol>
+
+ <p>
+ The interpretation of some of these values depends on whether the
+ process was started with the <option>--monitor</option>. If it
+ was not, then the crash count will always be 0 and the two
+ durations will always be the same. If <option>--monitor</option>
+ was given, then the crash count may be positive; if it is, the
+ latter duration is the amount of time since the most recent crash
+ and restart.
+ </p>
+
+ <p>
+ There will be one key-value pair for each file in Open vSwitch's
+ ``run directory'' (usually <code>/var/run/openvswitch</code>)
+ whose name ends in <code>.pid</code>, whose contents are a
+ process ID, and which is locked by a running process. The
+ <var>name</var> is taken from the pidfile's name.
+ </p>
+
+ <p>
+ Currently Open vSwitch is only able to obtain all of the above
+ detail on Linux systems. On other systems, the same key-value
+ pairs will be present but the values will always be the empty
+ string.
+ </p>
+ </dd>
+
+ <dt><code>file_systems</code></dt>
+ <dd>
+ <p>
+ A space-separated list of information on local, writable file
+ systems. Each item in the list describes one file system and
+ consists in turn of a comma-separated list of the following:
+ </p>
+
+ <ol>
+ <li>Mount point, e.g. <code>/</code> or <code>/var/log</code>.
+ Any spaces or commas in the mount point are replaced by
+ underscores.</li>
+ <li>Total size, in kilobytes, as an integer.</li>
+ <li>Amount of storage in use, in kilobytes, as an integer.</li>
+ </ol>
+
+ <p>
+ This key-value pair is omitted if there are no local, writable
+ file systems or if Open vSwitch cannot obtain the needed
+ information.
+ </p>
+ </dd>
</dl>
</column>
</group>
compliance with the IEEE 802.1D specification for bridges.
Default is enabled, set to <code>false</code> to disable.</dd>
</dl>
+ <dl>
+ <dt><code>header_cache</code></dt>
+ <dd>Optional. Enable caching of tunnel headers and the output
+ path. This can lead to a significant performance increase
+ without changing behavior. In general it should not be
+ necessary to adjust this setting. However, the caching can
+ bypass certain components of the IP stack (such as IP tables)
+ and it may be useful to disable it if these features are
+ required or as a debugging measure. Default is enabled, set to
+ <code>false</code> to disable.</dd>
+ </dl>
</dd>
<dt><code>capwap</code></dt>
<dd>Ethernet tunneling over the UDP transport portion of CAPWAP
compliance with the IEEE 802.1D specification for bridges.
Default is enabled, set to <code>false</code> to disable.</dd>
</dl>
+ <dl>
+ <dt><code>header_cache</code></dt>
+ <dd>Optional. Enable caching of tunnel headers and the output
+ path. This can lead to a significant performance increase
+ without changing behavior. In general it should not be
+ necessary to adjust this setting. However, the caching can
+ bypass certain components of the IP stack (such as IP tables)
+ and it may be useful to disable it if these features are
+ required or as a debugging measure. Default is enabled, set to
+ <code>false</code> to disable.</dd>
+ </dl>
</dd>
<dt><code>patch</code></dt>
<dd>
</dl>
</column>
+ <column name="other_config">
+ Key-value pairs for rarely used interface features. Currently,
+ the only keys are for configuring GRE-over-IPsec, which is only
+ available through the <code>openvswitch-ipsec</code> package for
+ Debian. The currently defined key-value pairs are:
+ <dl>
+ <dt><code>ipsec_local_ip</code></dt>
+ <dd>Required key for GRE-over-IPsec interfaces. Additionally,
+ the <ref column="type"/> must be <code>gre</code> and the
+ <code>ipsec_psk</code> <ref column="other_config"/> key must
+ be set. The <code>in_key</code>, <code>out_key</code>, and
+ <code>key</code> <ref column="options"/> must not be
+ set.</dd>
+ <dt><code>ipsec_psk</code></dt>
+ <dd>Required key for GRE-over-IPsec interfaces. Specifies a
+ pre-shared key for authentication that must be identical on
+ both sides of the tunnel. Additionally, the
+ <code>ipsec_local_ip</code> key must also be set.</dd>
+ </dl>
+ </column>
+
<column name="statistics">
<p>
Key-value pairs that report interface statistics. The current