Bug 1230018

+++ This bug was initially created as a clone of Bug #1218060 +++

Description of problem:
=======================
Initialising snap_scheduler from all nodes at the same time should fail with proper error message - "Another snap scheduler command is running"

Version-Release number of selected component (if applicable):
==============================================================
glusterfs 3.7.0beta1 built on May  1 2015

How reproducible:
=================
always

Steps to Reproduce:
===================
1.Create a dist rep volume and mount it.

2.Create another shared storage volume and mount it under /var/run/gluster/shared_storage

3.Initialise snap scheduler at the same time from all nodes 

NOde1: 
~~~~~
snap_scheduler.py init
snap_scheduler: Successfully inited snapshot scheduler for this node

Node2, Node3, Node4 : 
~~~~~~~~~~~~~~~~~~~~
snap_scheduler.py init
Traceback (most recent call last):
  File "/usr/sbin/snap_scheduler.py", line 574, in <module>
    sys.exit(main())
  File "/usr/sbin/snap_scheduler.py", line 544, in main
    os.makedirs(LOCK_FILE_DIR)
  File "/usr/lib64/python2.6/os.py", line 157, in makedirs
    mkdir(name, mode)
OSError: [Errno 17] File exists: '/var/run/gluster/shared_storage/snaps/lock_files/'

It should fail with error : 
snap_scheduler: Another snap_scheduler command is running. Please try again after some time.

Actual results:


Expected results:


Additional info:

--- Additional comment from  on 2015-05-20 01:17:37 EDT ---

Same issue seen while checking snap_scheduler.py status from all nodes at the same time 

Node1:
======
snap_scheduler.py status
snap_scheduler: Snapshot scheduling status: Disabled

Node2,Node3, Node4:
===================
 snap_scheduler.py status
Traceback (most recent call last):
  File "/usr/sbin/snap_scheduler.py", line 575, in <module>
    sys.exit(main())
  File "/usr/sbin/snap_scheduler.py", line 545, in main
    os.makedirs(LOCK_FILE_DIR)
  File "/usr/lib64/python2.6/os.py", line 157, in makedirs
    mkdir(name, mode)
OSError: [Errno 17] File exists: '/var/run/gluster/shared_storage/snaps/lock_files/'

--- Additional comment from Anand Avati on 2015-06-04 07:48:45 EDT ---

REVIEW: http://review.gluster.org/11087 (snapshot/scheduler: Handle OSError in os. callbacks) posted (#1) for review on master by Avra Sengupta (asengupt)

--- Additional comment from Anand Avati on 2015-06-10 02:40:59 EDT ---

COMMIT: http://review.gluster.org/11087 committed in master by Krishnan Parthasarathi (kparthas) 
------
commit d835219a30327ede60e4ef28210914ab30bd0712
Author: Avra Sengupta <asengupt>
Date:   Thu Jun 4 17:17:13 2015 +0530

    snapshot/scheduler: Handle OSError in os. callbacks
    
    Handle OSError and not IOError in os. callbacks.
    
    Change-Id: I2b5bfb629bacbd2d2e410d96034b4e2c11c4931e
    BUG: 1218060
    Signed-off-by: Avra Sengupta <asengupt>
    Reviewed-on: http://review.gluster.org/11087
    Tested-by: Gluster Build System <jenkins.com>
    Tested-by: NetBSD Build System <jenkins.org>
    Reviewed-by: Aravinda VK <avishwan>
    Reviewed-by: Krishnan Parthasarathi <kparthas>