Tensorboard log only on local_rank 0

scripts/ppo.py

 import os
+import shutil
 import queue
 import random
 import threading
@@ -527,13 +528,18 @@ if __name__ == "__main__":
     timestamp = int(time.time())
     run_name = f"{args.env_id}__{args.exp_name}__{args.seed}__{timestamp}"
 
+    dummy_writer = SimpleNamespace()
+    dummy_writer.add_scalar = lambda x, y, z: None
+
     tb_log_dir = f"{args.tb_dir}/{run_name}"
+    if args.local_rank == 0:
         writer = SummaryWriter(tb_log_dir)
         writer.add_text(
             "hyperparameters",
             "|param|value|\n|-|-|\n%s" % ("\n".join([f"|{key}|{value}|" for key, value in vars(args).items()])),
         )
-
+    else:
+        writer = dummy_writer
 
     def save_fn(obj, path):
         with open(path, "wb") as f:
@@ -782,8 +788,6 @@ if __name__ == "__main__":
     params_queues = []
     rollout_queues = []
     eval_queue = queue.Queue()
-    dummy_writer = SimpleNamespace()
-    dummy_writer.add_scalar = lambda x, y, z: None
 
     unreplicated_params = flax.jax_utils.unreplicate(agent_state.params)
     for d_idx, d_id in enumerate(args.actor_device_ids):
@@ -875,8 +879,11 @@ if __name__ == "__main__":
             ckpt_name = f"{timestamp}_{M_steps}M.flax_model"
             ckpt_maneger.save(unreplicated_params, ckpt_name)
             if args.gcs_bucket is not None:
+                lastest_path = ckpt_maneger.get_latest()
+                copy_path = lastest_path.with_name("latest" + lastest_path.suffix)
+                shutil.copyfile(lastest_path, copy_path)
                 zip_file_path = "latest.zip"
-                zip_files(zip_file_path, [ckpt_maneger.get_latest(), tb_log_dir])
+                zip_files(zip_file_path, [str(copy_path), tb_log_dir])
                 sync_to_gcs(args.gcs_bucket, zip_file_path)
 
         if learner_policy_version >= args.num_updates:

ygoai/rl/ckpt.py

 import os
-import shutil
 from pathlib import Path
 import zipfile
 
@@ -37,17 +36,13 @@ class ModelCheckpoint(object):
         self._saved.append(path)
         print(f"Saved model to {path}")
 
-        # Copy the lastest checkpoint as latest
-        lastest_path = path.with_name("latest" + path.suffix)
-        shutil.copyfile(path, lastest_path)
-
         if len(self._saved) > self._n_saved:
             path = self._saved.pop(0)
             os.remove(path)
     
     def get_latest(self):
         path = self._saved[-1]
-        return str(path.with_name("latest" + path.suffix))
+        return path
 
 
 def sync_to_gcs(bucket, source, dest=None):