optional random seed specification for random assignment

xtreemfs_client/OSDManager.py

@@ -307,7 +307,7 @@ class OSDManager(object):
         self.__write_configuration()
 
     def copy_folders(self, folders, environment='LOCAL', remote_source=None, sshfs_mount_dir='/tmp/sshfs_tmp_mnt',
-                     apply_layout=True, execute_copy=True, random_osd_assignment=False):
+                     apply_layout=True, execute_copy=True, random_osd_assignment=False, random_seed=None):
         """
         copy a list of given folders into the managed folder, assigning OSDs to new folders and updating
         self.dataDistribution
@@ -369,7 +369,8 @@ class OSDManager(object):
         if self.debug:
             print("OSDManager: random_osd_assignment: " + str(random_osd_assignment))
 
-        new_assignments = self.distribution.add_folders(new_folders, random_osd_assignment=random_osd_assignment)
+        new_assignments = self.distribution.add_folders(new_folders, random_osd_assignment=random_osd_assignment,
+                                                        random_seed=random_seed)
         if apply_layout:
             self.apply_osd_assignments(new_assignments)
         elif self.debug:

xtreemfs_client/das.py

@@ -38,6 +38,7 @@ parser.add_argument("--remote-source", "-r", nargs=1,
                          'The remote host must be reachable via ssh without password.')
 parser.add_argument("--random-layout", "-x", action='store_const', const=True, default=False)
 parser.add_argument("--random-osd-assignment", action='store_const', const=True, default=False)
+parser.add_argument("--random-seed", nargs=1)
 parser.add_argument("--environment", "-e", choices=['LOCAL', 'SLURM', 'HU_CLUSTER'], default='LOCAL')
 
 parser.add_argument("--print", "-p", action='store_const', const=True, default=False,
@@ -90,7 +91,7 @@ if args.copy:
         folders = args.source_folders[0].split(',')
         x_man.copy_folders(folders, environment=args.environment, apply_layout=(not args.random_layout),
                            remote_source=args.remote_source[0], random_osd_assignment=args.random_osd_assignment,
-                           execute_copy=(not args.dont_execute_copy))
+                           random_seed=args.random_seed[0], execute_copy=(not args.dont_execute_copy))
 
 elif args.new_folders:
     if len(args.source_folders) == 0:

xtreemfs_client/dataDistribution.py

@@ -208,7 +208,8 @@ class DataDistribution(object):
                     ignore_osd_capacities=True,
                     random_osd_assignment=False,
                     ignore_folder_sizes=False,
-                    debug=False):
+                    debug=False,
+                    random_seed=None):
         """
         adds a list of folders to the data distribution.
         if not specified otherwise, the assignments are calculated using the LPT algorithm.
@@ -242,6 +243,9 @@ class DataDistribution(object):
         # this information must be returned
         osds_for_new_folders = []
 
+        if random_osd_assignment:
+            random.seed(random_seed)
+
         # totally random OSD assignment, ignoring OSD capacities
         # (might lead to I/O errors when too many groups are assigned to an OSD)
         if random_osd_assignment and ignore_osd_capacities and not ignore_folder_sizes: