Create default log directory if not exists

cassandra/mp.py

@@ -33,6 +33,7 @@
 from cassandra.constants import TAG_CONFIG, SUPERVISOR_RANK
 from cassandra.compfactory import create_component
 import logging
+import os
 
 
 def bootstrap_mp(argvals):
@@ -52,21 +53,21 @@ def bootstrap_mp(argvals):
 
     if argvals.logdir is None:
         logdir = 'logs'
+        os.makedirs(logdir, exist_ok=True)
     else:
         logdir = argvals.logdir
 
     logging.basicConfig(filename=f'{logdir}/cassandra-{rank}.log', level=argvals.loglvl,
                         filemode='w')
-    # print the location of the logs so that it will appear in the
-    # output file of batch jobs.
-    print(f'\nThis is Cassandra version {__version__}.  Log output will be written to {logdir}.')
-
+
     if rank == SUPERVISOR_RANK:
+        # Print the location of the logs so that it will appear in the
+        # output file of batch jobs.
+        print(f'\nThis is Cassandra version {__version__}.  Log output will be written to {logdir}.')
         my_assignment = distribute_assignments_supervisor(argvals)
     else:
         my_assignment = distribute_assignments_worker(argvals)
 
-
     # my_assignment will be a dictionary of configuration sections assigned to
     # this process.  We need to create and initialize the components assigned to
     # us.  We also need to create a RAB.
@@ -78,7 +79,7 @@ def bootstrap_mp(argvals):
         component = create_component(section, cap_tbl)
         component.params.update(conf)
         component.finalize_parsing()
-        comps.append(component) 
+        comps.append(component)
 
     # Next we need to compile a table of remote capabilities.  To do this, each
     # component needs to distribute its local capability table to all the other
@@ -126,7 +127,7 @@ def distribute_assignments_worker(argvals):
 def distribute_assignments_supervisor(argvals):
     """Parse config file and distribute component assignments
 
-    :param argvals: Arguments structure parsed by argparse.  
+    :param argvals: Arguments structure parsed by argparse.
     :return: Dictionary of component definitions for components assigned to this
                     process (i.e., the supervisor).
 
@@ -150,15 +151,15 @@ def distribute_assignments_supervisor(argvals):
 
     config = ConfigObj(argvals.ctlfile)
 
-    # Get list of section names 
+    # Get list of section names
     section_names = list(config.keys())
     try:
         # Global section goes to everyone.  Also, it's required, so check for it
         # here
         section_names.remove('Global')
     except ValueError as e:
         raise RuntimeError("Config file must have a '[Global]' section") from e
-    
+
     section_weights = [config[s].get('mp.weight', 1.0) for s in section_names]
     name_weight = zip(section_names, section_weights)
     section_names = [s[0] for s in sorted(name_weight, key=lambda x:x[1], reverse=True)]
@@ -169,10 +170,10 @@ def distribute_assignments_supervisor(argvals):
 
     assignments = []
     for i in range(nproc):
-        assignments.append({'Global':config['Global']})
+        assignments.append({'Global': config['Global']})
     for section in section_names:
         assignments[nextrank][section] = config[section]
-        nextrank = (nextrank+1)%nproc
+        nextrank = (nextrank+1) % nproc
 
     # Distribute these assignments to the workers
     for r in range(nproc):
@@ -183,7 +184,7 @@ def distribute_assignments_supervisor(argvals):
     logging.debug(f'supervisor assignment: {assignments[SUPERVISOR_RANK]}')
     return assignments[SUPERVISOR_RANK]
 
-    
+
 def finalize(rab, thread):
     """Finalization procedure for mp calculations.
 
@@ -200,11 +201,10 @@ def finalize(rab, thread):
     """
 
     logging.debug(f'{rab.comm.Get_rank()} entering finalize.')
-    
+
     rab.comm.barrier()
 
     rab.shutdown()
     thread.join()
 
 # End of finalize()
-