qa/tasks: use list comprehension for checking the length

instead of using filter(), use `sum()` for counting its
length, as in Python3, `filter()` actually returns a `filter` object
instead of a list.

in this change, `filter()` calls are replaced with `sum()`
for Python3 compatibility.

Signed-off-by: Kyr Shatskyy <kyrylo.shatskyy@suse.com>
(cherry picked from commit 726c59be58473cfe53fa3ea63cf35b58ed797886)

diff --git a/qa/tasks/mds_thrash.py b/qa/tasks/mds_thrash.py
index 55d2565ecfda036dbd7525f4caee4444ec33194a..f3a3962d20d4363e0ded9db5c8037081553bdc3b 100644 (file)
--- a/qa/tasks/mds_thrash.py
+++ b/qa/tasks/mds_thrash.py
@@ -291,10 +291,11 @@ class MDSThrasher(Greenlet):
             status = self.fs.status()
             max_mds = status.get_fsmap(self.fs.id)['mdsmap']['max_mds']
             ranks = list(status.get_ranks(self.fs.id))
-            stopping = filter(lambda info: "up:stopping" == info['state'], ranks)
-            actives = filter(lambda info: "up:active" == info['state'] and "laggy_since" not in info, ranks)
+            stopping = sum(1 for _ in ranks if "up:stopping" == _['state'])
+            actives = sum(1 for _ in ranks
+                          if "up:active" == _['state'] and "laggy_since" not in _)
 
-            if not bool(self.config.get('thrash_while_stopping', False)) and len(stopping) > 0:
+            if not bool(self.config.get('thrash_while_stopping', False)) and stopping > 0:
                 if itercount % 5 == 0:
                     self.log('cluster is considered unstable while MDS are in up:stopping (!thrash_while_stopping)')
             else:
@@ -306,13 +307,14 @@ class MDSThrasher(Greenlet):
                             return status
                     except:
                         pass # no rank present
-                    if len(actives) >= max_mds:
+                    if actives >= max_mds:
                         # no replacement can occur!
-                        self.log("cluster has %d actives (max_mds is %d), no MDS can replace rank %d".format(len(actives), max_mds, rank))
+                        self.log("cluster has {actives} actives (max_mds is {max_mds}), no MDS can replace rank {rank}".format(
+                            actives=actives, max_mds=max_mds, rank=rank))
                         return status
                 else:
-                    if len(actives) == max_mds:
-                        self.log('mds cluster has {count} alive and active, now stable!'.format(count = len(actives)))
+                    if actives == max_mds:
+                        self.log('mds cluster has {count} alive and active, now stable!'.format(count = actives))
                         return status, None
             if itercount > 300/2: # 5 minutes
                  raise RuntimeError('timeout waiting for cluster to stabilize')