openstack-manuals/doc/common/section_nova_cli_usage_statistics.xml
Brad Pokorny dfe6129e7f Document what used_now and used_max mean
The "nova host-describe" documentation in the user-guide
doesn't currently explain what used_now and used_max mean.
This commit adds a short explanation of each one to help
users understand the difference between the two values.

Fixes bug 1236430

Change-Id: Id6ab2ddbd0d21b1cd34881d3881d620dc5e060a7
2013-10-07 16:48:47 +00:00

108 lines
6.8 KiB
XML

<?xml version="1.0" encoding="UTF-8"?>
<section xmlns="http://docbook.org/ns/docbook" xmlns:xi="http://www.w3.org/2001/XInclude"
xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0" xml:id="usage_statistics">
<title>Show usage statistics for hosts and instances</title><para xlink:href="http://graphite.wikidot.com">You can show basic
statistics on resource usage for hosts and instances.</para>
<note> <para xlink:href="http://graphite.wikidot.com">For more sophisticated
monitoring, see the <link
xlink:href="https://launchpad.net/ceilometer"
>Ceilometer</link> project, which is under
development. You can also use tools, such as <link
xlink:href="http://ganglia.info/">Ganglia</link> or
<link xlink:href="http://graphite.wikidot.com/"
>Graphite</link>, to gather more detailed data.</para></note>
<procedure xml:id="host_usage_statistics">
<title>To show host usage statistics</title>
<step><para>List the hosts and the nova-related services that run on
them:</para><screen><prompt>$</prompt> <userinput>nova host-list</userinput>
<computeroutput>+------------------+-------------+----------+
| host_name | service | zone |
+------------------+-------------+----------+
| devstack-grizzly | conductor | internal |
| devstack-grizzly | compute | nova |
| devstack-grizzly | cert | internal |
| devstack-grizzly | network | internal |
| devstack-grizzly | scheduler | internal |
| devstack-grizzly | consoleauth | internal |
+------------------+-------------+----------+</computeroutput></screen>
</step>
<step><para>Get a summary of resource usage of all of the instances running
on the host.</para>
<screen><prompt>$</prompt> <userinput>nova host-describe <replaceable>devstack-grizzly</replaceable></userinput>
<computeroutput>+------------------+----------------------------------+-----+-----------+---------+
| HOST | PROJECT | cpu | memory_mb | disk_gb |
+------------------+----------------------------------+-----+-----------+---------+
| devstack-grizzly | (total) | 2 | 4003 | 157 |
| devstack-grizzly | (used_now) | 3 | 5120 | 40 |
| devstack-grizzly | (used_max) | 3 | 4608 | 40 |
| devstack-grizzly | b70d90d65e464582b6b2161cf3603ced | 1 | 512 | 0 |
| devstack-grizzly | 66265572db174a7aa66eba661f58eb9e | 2 | 4096 | 40 |
+------------------+----------------------------------+-----+-----------+---------+</computeroutput></screen>
<para>The <literal>cpu</literal> column shows the sum of
the virtual CPUs for instances running on the host.</para>
<para>The <literal>memory_mb</literal> column shows the
sum of the memory (in MB) allocated to the instances
that run on the hosts.</para>
<para>The <literal>disk_gb</literal> column shows the sum
of the root and ephemeral disk sizes (in GB) of the
instances that run on the hosts.</para>
<para>The <literal>used_now</literal> row shows the sum
of the resources allocated to the instances
that run on the host plus the resources allocated to
the virtual machine of the host itself.</para>
<para>The <literal>used_max</literal> row shows the sum
of the resources allocated to the instances
that run on the host.</para>
<note> <para>These values are computed by using only information
about the flavors of the instances that run on the
hosts. This command does not query the CPU usage,
memory usage, or hard disk usage of the physical
host.</para> </note> </step> </procedure>
<procedure xml:id="instance_usage_statistics">
<title>To show instance usage statistics</title>
<step>
<para>Get CPU, memory, I/O, and network statistics for an
instance.</para>
<para>First, list instances:</para>
<screen><prompt>$</prompt> <userinput>nova list</userinput>
<computeroutput>+--------------------------------------+----------------------+--------+------------+-------------+------------------+
| ID | Name | Status | Task State | Power State | Networks |
+--------------------------------------+----------------------+--------+------------+-------------+------------------+
| 84c6e57d-a6b1-44b6-81eb-fcb36afd31b5 | myCirrosServer | ACTIVE | None | Running | private=10.0.0.3 |
| 8a99547e-7385-4ad1-ae50-4ecfaaad5f42 | myInstanceFromVolume | ACTIVE | None | Running | private=10.0.0.4 |
+--------------------------------------+----------------------+--------+------------+-------------+------------------+</computeroutput></screen>
<para>Then, get diagnostic statistics:</para>
<screen><prompt>$</prompt> <userinput>nova diagnostics myCirrosServer</userinput>
<computeroutput>+------------------+----------------+
| Property | Value |
+------------------+----------------+
| vnet1_rx | 1210744 |
| cpu0_time | 19624610000000 |
| vda_read | 0 |
| vda_write | 0 |
| vda_write_req | 0 |
| vnet1_tx | 863734 |
| vnet1_tx_errors | 0 |
| vnet1_rx_drop | 0 |
| vnet1_tx_packets | 3855 |
| vnet1_tx_drop | 0 |
| vnet1_rx_errors | 0 |
| memory | 2097152 |
| vnet1_rx_packets | 5485 |
| vda_read_req | 0 |
| vda_errors | -1 |
+------------------+----------------+</computeroutput></screen>
</step>
<step> <para>Get summary statistics for each tenant:</para>
<screen><prompt>$</prompt> <userinput>nova usage-list</userinput>
<computeroutput>Usage from 2013-06-25 to 2013-07-24:
+----------------------------------+-----------+--------------+-----------+---------------+
| Tenant ID | Instances | RAM MB-Hours | CPU Hours | Disk GB-Hours |
+----------------------------------+-----------+--------------+-----------+---------------+
| b70d90d65e464582b6b2161cf3603ced | 1 | 344064.44 | 672.00 | 0.00 |
| 66265572db174a7aa66eba661f58eb9e | 3 | 671626.76 | 327.94 | 6558.86 |
+----------------------------------+-----------+--------------+-----------+---------------+</computeroutput></screen>
</step>
</procedure>
</section>