perfSONAR User Q&A and Other Discussion

[Andrew Lake <>]

Hi,

Any chance you have anything else setup that uses mond_wsgi (e.g. globus/gridftp) on that host? or does /etc/httpd/conf.d/apache-esmond.conf exists and what are its contents if so (it shouldn't exists so if it does that might be a pointer to the problem)?

To answer your question more fully yes, on CentOS 6 there are two versions of python used by perfSONAR, the stock python 2.6 that is the system default and a version of python 2.7 that it from the CentOS SCL repo. SCL stansd for Software Collections and is repo where slightly newer version of software is provided that require some special steps to use. The Python 2.7 version is needed for esmond, which in turn pulls in some other SCL requirements like the python 2.7 version of mod_wsgi. For this reason, we quarantine esmond, python27 and python27-mod_wsgi off into httpd24 instead of the stock httpd where everything else runs. This is actually the default CentOS SCL setup for running these types of things. We then have the stock httpd process act as a reverse proxy to the httpd24 instance for all /esmond requests. Not ideal, but what we have to do to get the right versions for the tools. One advantage of moving to CentOS 7 is that all this nonsense goes away. It ships with python 2.7 as the default and everything uses that.

Hope that helps,

Andy

On April 24, 2017 at 10:53:32 AM, Liu, Dengfeng (NIH/CIT) [C] () wrote:

Seems the python home is using /usr/lib/esmond, which is 2.7, but for pscheduler is using 2.6.6.

Dengfeng

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From: Liu, Dengfeng (NIH/CIT) [C]
Sent: Monday, April 24, 2017 9:49 AM
To: Mark Feit;
Cc: Andrew Lake
Subject: Re: [perfsonar-user] Wsgi pscheduler module and logger modules

 

also which version of python this wsgi is using? Seems for centos 6, python has multiple version come with perfsonar.

Dengfeng Liu

NIH/CIT/NSS
3014967328(o)
3018302642(c)

---

From: <> on behalf of Liu, Dengfeng (NIH/CIT) [C] <>
Sent: Friday, April 21, 2017 5:12 PM
To: Mark Feit;
Cc: Andrew Lake
Subject: Re: [perfsonar-user] Wsgi pscheduler module and logger modules

 

seems ok, rpm -V python-libs gives no output.

if comment out the import logging, error will show in log:

Traceback (most recent call last):
  File "/var/www/pscheduler-server/pscheduler-api-server.wsgi", line 10, in <module>
    from pschedulerapiserver import application
  File "./pschedulerapiserver/__init__.py", line 5, in <module>
ImportError: No module named pscheduler
Traceback (most recent call last):
  File "/var/www/pscheduler-server/pscheduler-api-server.wsgi", line 10, in <module>
    from pschedulerapiserver import application
  File "./pschedulerapiserver/__init__.py", line 5, in <module>
ImportError: No module named pscheduler

Dengfeng Liu

NIH/CIT/NSS
3014967328(o)
3018302642(c)

---

From: Mark Feit <>
Sent: Friday, April 21, 2017 4:59 PM
To: Liu, Dengfeng (NIH/CIT) [C];
Cc: Andrew Lake
Subject: Re: [perfsonar-user] Wsgi pscheduler module and logger modules

 

Liu, Dengfeng (NIH/CIT) [C] writes:

 

My upgrade shows error:

  File "/var/www/pscheduler-server/pscheduler-api-server.wsgi", line 5, in <module>
    import logging
ImportError: No module named logging

that gives http access problem.

Anyone saw this issue?

 

That sounds like something is missing from your system. 

 

The logging module is part of the standard Python library, and it might be that pScheduler is the first part of perfSONAR to use it.  If you’re on a CentOS system, this module would be in the python-libs RPM; you can run “rpm -V python-libs” to verify that everything in that module is in place.

 

--Mark