Handle missing sar stats gracefully

diff --git a/client/collectors/linux.py b/client/collectors/linux.py
index 9112a10f4bbd9e84c160e97bceba68887e0157b2..605e2c3232af7a2690ce9cb8d5d7278935e9007c 100644 (file)
--- a/client/collectors/linux.py
+++ b/client/collectors/linux.py
@@ -1,3 +1,5 @@
+import os.path
+
 from datetime import datetime, timedelta, time
 from utils.logging import log
 from utils.misc import run_cmd
@@ -23,10 +25,13 @@ class LinuxCollector(object):
        def result(self):
                'build the results'
 
-               r = {
-                       'sar' : self._collect_sar_stats(),
-                       'sysctl' : self._collect_sysctl()
-               }
+               r = {'sysctl' : self._collect_sysctl()}
+
+               # ignore sar if we've not found it
+               sar = self._collect_sar_stats()
+               if sar:
+                       r['sar'] = sar
+
                r.update(self._collect_system_info())
 
                return r
@@ -44,26 +49,36 @@ class LinuxCollector(object):
                        # FIXME maybe skip if the file does not exist
                        filename = '%(path)s/sa%(day)s' % {'path' : self._sar, 'day' : d.strftime('%d')}
 
-                       log("extracting sar data from '%s'" % (filename,))
+                       # if the sar file does not exist, skip it
+                       if os.path.isfile(filename):
+
+                               log("extracting sar data from '%s'" % (filename,))
 
-                       # need to use the right combination of start/end timestamps
-                       s = self._start_ts.strftime('%H:%M:%S')
-                       e = self._end_ts.strftime('%H:%M:%S')
+                               # need to use the right combination of start/end timestamps
+                               s = self._start_ts.strftime('%H:%M:%S')
+                               e = self._end_ts.strftime('%H:%M:%S')
+
+                               if d == self._start_ts.date() and d == self._end_ts.date():
+                                       r = run_cmd(['sar', '-A', '-p', '-s', s, '-e', e, '-f', filename])
+                               elif d == self._start_ts.date():
+                                       r = run_cmd(['sar', '-A', '-p', '-s', s, '-f', filename])
+                               elif d == self._end_ts.date():
+                                       r = run_cmd(['sar', '-A', '-p', '-e', e, '-f', filename])
+                               else:
+                                       r = run_cmd(['sar', '-A', '-p', '-f', filename])
+
+                               sar[str(d)] = r[1]
 
-                       if d == self._start_ts.date() and d == self._end_ts.date():
-                               r = run_cmd(['sar', '-A', '-p', '-s', s, '-e', e, '-f', filename])
-                       elif d == self._start_ts.date():
-                               r = run_cmd(['sar', '-A', '-p', '-s', s, '-f', filename])
-                       elif d == self._end_ts.date():
-                               r = run_cmd(['sar', '-A', '-p', '-e', e, '-f', filename])
                        else:
-                               r = run_cmd(['sar', '-A', '-p', '-f', filename])
 
-                       sar[str(d)] = r[1]
+                               log("file '%s' does not exist, skipping" % (filename,))
 
                        # proceed to the next day
                        d += timedelta(days=1)
 
+               if not sar:
+                       return None
+
                return sar