Access historical CPU and memory metrics - Xen Orchestra v5

yann

puneet336 olivierlambert the lib is still working, but I'm usually use it with a local connection, running scripts inside dom0, with this code:

def get_xapi_session():
    session = XenAPI.xapi_local()
    try:
        session.xenapi.login_with_password('root', '', '', 'xcp-ng-tests session')
    except Exception as e:
        raise Exception('Cannot get XAPI session: {{}}'.format(e))
    return session

Will check what happens with a remote session.

yann

puneet336 you need to make your connection to your pool master (not your XOA guest), that's where the XAPI endpoint is.

If you did not deploy TLS certificates on your pool, XenAPI.Session(URL) will complain that the SSL certificate is self-signed (which you can workaround by adding ignore_ssl=True as you did above, but don't keep this in production).

You will also find a few guidelines to write a robust XenAPI client at https://xapi-project.github.io/xen-api/usage.html

puneet336

yann i tried running the following script from the xoa server.

#!/usr/bin/env python3
import XenAPI
username = "username"
password = "ldap password"
#url = "https://xoaserver1.example.com"
session = XenAPI.xapi_local()

#session.xenapi.login_with_password('root', '', "", "xcp-ng-tests session")
#session.xenapi.login_with_password(username, password, "1.0", "session_getter")
session.xenapi.login_with_password(username, password, "", "xcp-ng-tests session")


print(session._session)

i see following error :

Traceback (most recent call last):
  File "/home/user1/MC3/test.py", line 10, in <module>
    session.xenapi.login_with_password(username, password, "", "xcp-ng-tests session")
  File "/home/user1/MC3/envs/user1env/lib/python3.12/site-packages/XenAPI/XenAPI.py", line 260, in __call__
    return self.__send(self.__name, args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user1/MC3/envs/user1env/lib/python3.12/site-packages/XenAPI/XenAPI.py", line 145, in xenapi_request
    self._login(methodname, params)
  File "/home/user1/MC3/envs/user1env/lib/python3.12/site-packages/XenAPI/XenAPI.py", line 182, in _login
    raise e
  File "/home/user1/MC3/envs/user1env/lib/python3.12/site-packages/XenAPI/XenAPI.py", line 170, in _login
    getattr(self, 'session.%s' % method)(*params))
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user1/MC3/envs/user1env/lib/python3.12/xmlrpc/client.py", line 1122, in __call__
    return self.__send(self.__name, args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user1/MC3/envs/user1env/lib/python3.12/xmlrpc/client.py", line 1461, in __request
    response = self.__transport.request(
               ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user1/MC3/envs/user1env/lib/python3.12/xmlrpc/client.py", line 1166, in request
    return self.single_request(host, handler, request_body, verbose)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user1/MC3/envs/user1env/lib/python3.12/xmlrpc/client.py", line 1178, in single_request
    http_conn = self.send_request(host, handler, request_body, verbose)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user1/MC3/envs/user1env/lib/python3.12/xmlrpc/client.py", line 1291, in send_request
    self.send_content(connection, request_body)
  File "/home/user1/MC3/envs/user1env/lib/python3.12/xmlrpc/client.py", line 1321, in send_content
    connection.endheaders(request_body)
  File "/home/user1/MC3/envs/user1env/lib/python3.12/http/client.py", line 1331, in endheaders
    self._send_output(message_body, encode_chunked=encode_chunked)
  File "/home/user1/MC3/envs/user1env/lib/python3.12/http/client.py", line 1091, in _send_output
    self.send(msg)
  File "/home/user1/MC3/envs/user1env/lib/python3.12/http/client.py", line 1035, in send
    self.connect()
  File "/home/user1/MC3/envs/user1env/lib/python3.12/site-packages/XenAPI/XenAPI.py", line 99, in connect
    self.sock.connect(path)
FileNotFoundError: [Errno 2] No such file or directory

Did i miss anything while running the script?

yann

puneet336 xapi_local() will only work in the dom0 (it looks for a local socket to the XAPI daemon, which is why you get a FileNotFoundError). If you run it from the XOA appliance (or from anywhere else than the dom0, you'll need XenAPI.Session(URL), but again with a URL to the dom0, not your XOA appliance.

Remember XAPI is a service running in the host's dom0, XOA is just a client connecting to that service.

puneet336

Thank you for the response yann . I was not aware about the dom0 and came across https://stackoverflow.com/questions/19147398/is-xen-dom0-a-guest-or-a-host ,

I believe i ran the python script from within the dom0 VM i.e. the server which hosts the Xen XOA Web UI. When i log in to the server ( which i beleive to be dom0 as of now) i see the following banner :

Is there a way to list out the IP of the dom0 vm ? or
Any method confirm if i am running the scripts from the dom0 VM (presence of any special file or any command which can list out the same)?

puneet336

Hi yann ,
is there way to get the ip of dm0 vm via cli/ Web GUI?

AtaxyaNetwork

puneet336 Hi,

The IP of the dom0 is the IP of the "host" you added in Xen Orchestra. You can find it the settings -> server tab

puneet336

AtaxyaNetwork Thank you for the response,

I was unable to see settings Option from the Web UI,
but using Home>Pools, i saw following :

then i clicked on the 4x pools to get information on the hosts for this pool

I was able to get the name of the master server for this pool (tagged as master), say pool1.master.example.com

when i use hostname=pool1.master.example.com

#!/usr/bin/env python3
import XenAPI
username = "root"
password = "root account password"
url = "https://pool1.master.example.com"
session = XenAPI.Session(url)
session.xenapi.login_with_password(username, password, "1.0", "session_getter")
print(session._session)

i am able to see session tokens

identified uuid of one of the VM being managed by pool master

and i am able to download the data using :

wget -c  "http://pool1.master.example.com/host_rrd?session_id=pool1.master.opaqreftoken&uuid=VM1uuid" --output-document test.xml

puneet336

Hi olivierlambert , yann
I was able to get rrd data using instructions i mentioned in previous comment, But i am not sure if it contains historical data or this is just current metrics snapshot.

wget -c  "http://pool1.master.example.com/host_rrd?session_id=pool1.master.opaqreftoken&uuid=VM1uuid" --output-document test.xml

but the file which i downloaded was just 20MB file and this host has been up since last 1 year.
Not sure if the xml file which i got will have entire year's data as there is just 1 lastupdate tag in the document , i.e. <lastupdate>1718163483</lastupdate>

I am looking to parse the xml for raw data and dump the same in following form for each hosts's xml file
timestamp1, cpu metrics1, memory usage metrics1
timestamp2, cpu metrics2, memory usage metrics2
timestamp3, cpu metrics3, memry usage metrics3
timestamp4, cpu metrics4, memry usage metrics4

Could you please share some information or link which can help me understand the format of xml or,
if you could share information about the tags which i need to look upon ?

Though i am going through the xml document , Any help hint which could help me understand the format or obtain memory and cpu metrics would help.

olivierlambert

Have you read https://xapi-project.github.io/xen-api/metrics.html ? It explains the diff between getting all data and only the diff (delta). It's a must read to understand the way RRDs can be fetch.