XPK Start: Tue Apr 21 16:28:58 UTC 2026 PyTorch was not found. Models won't be available and only tokenizers, configuration and file/data utilities can be used. 2026-04-21 16:29:22.885560: E external/local_xla/xla/stream_executor/cuda/cuda_platform.cc:51] failed call to cuInit: INTERNAL: CUDA error: Failed call to cuInit: UNKNOWN ERROR (303) I0421 16:29:23.419519 136518552889152 max_utils.py:273] Attempting to initialize the jax distributed system... I0421 16:29:32.460307 136518552889152 distributed.py:149] Starting JAX distributed service on [::]:8482 I0421 16:29:32.462526 136518552889152 distributed.py:172] Connecting to JAX distributed service on mt-02-synthetic-aswsf-slice-job-0-0.mt-02-synthetic-aswsf:8482 I0421 16:29:32.969108 136518552889152 max_utils.py:284] Jax distributed system initialized! I0421 16:29:38.041515 136518552889152 max_utils.py:800] System Information: Jax Version: 0.9.2 I0421 16:29:38.041636 136518552889152 max_utils.py:801] System Information: Jaxlib Version: 0.9.2 I0421 16:29:38.041680 136518552889152 max_utils.py:802] System Information: Jax Backend: PJRT C API TFRT TPU v6 lite Built on Mar 4 2026 11:32:08 (1772652728) cl/878335365 I0421 16:29:38.041715 136518552889152 train_utils.py:378] WARNING: Sequence packing is essentially ignored for synthetic data. Please use a real dataset to use sequence packing. I0421 16:29:38.742145 136518552889152 maxtext_utils.py:1718] Num_devices: 32, shape (1, 1, 1, 32, 1, 1, 1, 1, 1, 1, 1, 1, 1) I0421 16:29:38.856113 136518552889152 checkpointing.py:688] Setting up checkpoint logger... I0421 16:29:38.856228 136518552889152 checkpointing.py:234] Creating checkpoint manager with ocdbt=True and zarr3=True I0421 16:29:38.856273 136518552889152 pytree_checkpoint_handler.py:592] save_device_host_concurrent_bytes=None I0421 16:29:38.856471 136518552889152 base_pytree_checkpoint_handler.py:441] Created BasePyTreeCheckpointHandler: use_ocdbt=True, use_zarr3=True, pytree_metadata_options=PyTreeMetadataOptions(support_rich_types=False), array_metadata_store=<orbax.checkpoint._src.metadata.array_metadata_store.Store object at 0x7c28fc3346e0>, enable_pinned_host_transfer=False, save_concurrent_bytes: 96000000000 (89.4 GiB), restore_concurrent_bytes: 96000000000 (89.4 GiB) I0421 16:29:41.742773 136518552889152 checkpointing.py:266] Enabling policy for fixed interval checkpointing. I0421 16:29:41.743049 136518552889152 checkpoint_manager.py:708] [process=0][thread=MainThread] CheckpointManager init: checkpointers=None, item_names=('items',), item_handlers={'items': <orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler object at 0x7c14c425c050>}, handler_registry=None I0421 16:29:41.743299 136518552889152 composite_checkpoint_handler.py:237] Deferred registration for item: "items". Adding handler `<orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler object at 0x7c14c425c050>` for item "items" and save args `<class 'orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeSaveArgs'>` and restore args `<class 'orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeRestoreArgs'>` to `_handler_registry`. I0421 16:29:41.743347 136518552889152 composite_checkpoint_handler.py:237] Deferred registration for item: "metrics". Adding handler `<orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonCheckpointHandler object at 0x7c14c426ed80>` for item "metrics" and save args `<class 'orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonSaveArgs'>` and restore args `<class 'orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonRestoreArgs'>` to `_handler_registry`. I0421 16:29:41.743381 136518552889152 composite_checkpoint_handler.py:505] Initialized registry DefaultCheckpointHandlerRegistry({('items', <class 'orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeSaveArgs'>): <orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler object at 0x7c14c425c050>, ('items', <class 'orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeRestoreArgs'>): <orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler object at 0x7c14c425c050>, ('metrics', <class 'orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonSaveArgs'>): <orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonCheckpointHandler object at 0x7c14c426ed80>, ('metrics', <class 'orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonRestoreArgs'>): <orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonCheckpointHandler object at 0x7c14c426ed80>}). I0421 16:29:41.743721 136518552889152 abstract_checkpointer.py:35] orbax-checkpoint version: 0.11.34 I0421 16:29:41.743793 136518552889152 async_checkpointer.py:192] [process=0][thread=MainThread] Using barrier_sync_fn: <function get_barrier_sync_fn.<locals>._fn at 0x7c14c42cd760> timeout: 1200 secs and primary_host=0 for async checkpoint writes I0421 16:29:42.898016 136518552889152 checkpoint_manager.py:1812] Found 0 checkpoint steps in gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints I0421 16:29:43.343517 136518552889152 checkpoint_manager.py:929] [process=0][thread=MainThread] CheckpointManager created, primary_host=0, CheckpointManagerOptions=CheckpointManagerOptions(save_interval_steps=1, max_to_keep=None, keep_time_interval=None, keep_period=None, should_keep_fn=None, best_fn=None, best_mode='max', keep_checkpoints_without_metrics=True, step_prefix=None, step_format_fixed_length=None, step_name_format=None, create=True, cleanup_tmp_directories=False, save_on_steps=frozenset(), single_host_load_and_broadcast=False, todelete_subdir=None, todelete_full_path=None, enable_background_delete=False, read_only=False, enable_async_checkpointing=True, async_options=None, multiprocessing_options=MultiprocessingOptions(primary_host=0, active_processes=None, barrier_sync_key_prefix=None), should_save_fn=None, file_options=FileOptions(path_permission_mode=None), save_root_metadata=True, temporary_path_class=None, save_decision_policy=FixedIntervalPolicy(interval=10), preservation_policy=LatestN(n=None), prevent_write_metrics=False, enable_should_save_is_saving_in_progress_check=True, enable_per_process_directory_creation=False, lightweight_initialize=False), root_directory=gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints: <orbax.checkpoint.checkpoint_manager.CheckpointManager object at 0x7c14c424b9e0> I0421 16:29:43.343724 136518552889152 checkpointing.py:302] Checkpoint manager created! I0421 16:29:44.294751 136518552889152 checkpointing.py:578] checkpoint manager exists so trying to load this run's existing checkpoint I0421 16:29:44.294869 136518552889152 checkpointing.py:676] No existing checkpoints found, not restoring checkpoint. fsdp: 32 I0421 16:29:46.085567 136518552889152 nnx_decoders.py:465] nnx_decoders/carry Logical: bfloat16[32,2048,2048]...................................... ('activation_batch', 'activation_norm_length', 'activation_embed'). I0421 16:29:46.085669 136518552889152 nnx_decoders.py:465] nnx_decoders/carry Physical: bfloat16[32,2048,2048]...................................... ('fsdp', None, None). I0421 16:29:46.091218 136518552889152 nnx_decoders.py:465] Unknown Logical: bfloat16[32,2048,2048]...................................... ('activation_batch', 'activation_norm_length', 'activation_embed'). I0421 16:29:46.091274 136518552889152 nnx_decoders.py:465] Unknown Physical: bfloat16[32,2048,2048]...................................... ('fsdp', None, None). I0421 16:29:46.108054 136518552889152 attentions.py:1088] attentions/inputs_q Logical: bfloat16[32,2048,2048]...................................... ('activation_batch', 'activation_attn_length', 'activation_attn_embed'). I0421 16:29:46.108111 136518552889152 attentions.py:1088] attentions/inputs_q Physical: bfloat16[32,2048,2048]...................................... ('fsdp', None, None). I0421 16:29:46.131030 136518552889152 attentions.py:1089] attentions/inputs_kv Logical: bfloat16[32,2048,2048]...................................... ('activation_batch', 'activation_attn_length', 'activation_attn_embed'). I0421 16:29:46.131129 136518552889152 attentions.py:1089] attentions/inputs_kv Physical: bfloat16[32,2048,2048]...................................... ('fsdp', None, None). I0421 16:29:46.156245 136518552889152 attentions.py:1154] attentions/query Logical: bfloat16[32,2048,16,128].................................... ('activation_kv_batch', 'activation_attn_length', 'activation_kv_heads', 'activation_kv_head_dim'). I0421 16:29:46.156313 136518552889152 attentions.py:1154] attentions/query Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0421 16:29:46.172770 136518552889152 attentions.py:1155] attentions/key Logical: bfloat16[32,2048,16,128].................................... ('activation_kv_batch', 'activation_attn_length', 'activation_kv_heads', 'activation_kv_head_dim'). I0421 16:29:46.172832 136518552889152 attentions.py:1155] attentions/key Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0421 16:29:46.189127 136518552889152 attentions.py:1156] attentions/value Logical: bfloat16[32,2048,16,128].................................... ('activation_kv_batch', 'activation_attn_length', 'activation_kv_heads', 'activation_kv_head_dim'). I0421 16:29:46.189187 136518552889152 attentions.py:1156] attentions/value Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0421 16:29:46.219773 136518552889152 attentions.py:1197] attentions/out Logical: bfloat16[32,2048,16,128].................................... ('activation_batch', 'activation_attn_length', 'activation_heads', 'activation_kv'). I0421 16:29:46.219844 136518552889152 attentions.py:1197] attentions/out Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0421 16:29:46.240610 136518552889152 linears.py:525] linears/x Logical: bfloat16[32,2048,7168]...................................... ('activation_batch', 'activation_length', 'activation_mlp'). I0421 16:29:46.240673 136518552889152 linears.py:525] linears/x Physical: bfloat16[32,2048,7168]...................................... ('fsdp', None, None). I0421 16:29:57.675289 136518552889152 max_utils.py:791] Total memory size: 1.5 GB, Output size: 0.4 GB, Temp size: 1.1 GB, Argument size: 0.4 GB, Host temp size: 0.0 GB. I0421 16:29:57.684376 136518552889152 metric_logger.py:301] number parameters: 1.104 billion I0421 16:30:09.137356 136518552889152 checkpointing.py:794] Waiting for step 0 to finish before checkpoint... I0421 16:30:09.289963 136518552889152 checkpointing.py:798] Waited 0.15259313583374023 seconds for step 0 to finish before starting checkpointing. I0421 16:30:09.292326 136518552889152 checkpoint_manager.py:2009] [process=0][thread=MainThread][wait_until_finished] No Save Finalize thread to wait for. Returning. I0421 16:30:09.294074 136518552889152 checkpoint_manager.py:1512] [process=0] Saving checkpoint at step 0 I0421 16:30:09.295400 136518552889152 event_tracking.py:70] [process=0] [async] Started save checkpoint @ gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/0. I0421 16:30:09.629076 136518552889152 signaling_client.py:364] Using JaxDistributedSignalingClient I0421 16:30:09.648308 136518552889152 jax_array_handlers.py:360] Scheduling D2H of 69 prioritized jax.Array. I0421 16:30:09.648377 136518552889152 replica_slices.py:424] Transferring arrays to host memory with options: use_replica_parallel=True, min_slice_bytes_for_replica_parallel=None, max_replicas_for_replica_parallel=None, enable_pinned_host_transfer=False I0421 16:30:09.920555 136518552889152 base_pytree_checkpoint_handler.py:154] [process=0][thread=MainThread] Initiated "orbax.checkpoint._src.serialization.jax_array_handlers.ArrayHandler".serialize. Time taken: 0.273654s I0421 16:30:09.921413 136518552889152 base_pytree_checkpoint_handler.py:130] [process=0] /jax/orbax/write/blocking_gbytes_per_sec: 5.422 GiB/s (total gbytes: 1.5 GiB) (time elapsed: 0.28452515602111816 s) (per-host) I0421 16:30:09.921489 136518552889152 base_pytree_checkpoint_handler.py:768] [process=0][thread=MainThread] Initiated Pytree async_save. Time taken: 0.284624s (batch_requests_ready=0.003051s, total_serialization_initiated=0.280796s, others=0.000777s) I0421 16:30:09.921589 136518552889152 composite_checkpoint_handler.py:715] [process=0][thread=MainThread] Initiated CompositeCheckpointHandler.async_save. Time taken: 0.288509s (all_items=0.000017s, per_item={'items': '0.00001693'}, temp_paths=0.288492) I0421 16:30:09.922331 136518552889152 event_tracking.py:125] [process=0] [async] Finished blocking save in 0.63 seconds. Continuing save @ gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/0. I0421 16:30:09.922674 136390298138368 async_checkpointer.py:76] [process=0][thread=async_save] Background save thread started. Deadline for this save operation is 2026-04-21 16:50:09.922637 I0421 16:30:09.929366 136390276790016 atomicity.py:140] Creating tmp directory gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/0 I0421 16:30:09.937182 136518552889152 checkpoint_manager.py:1560] [process=0][thread=MainThread][step=0] Starting CheckpointManager Save Finalize thread=save_finalize I0421 16:30:09.937454 136388108334848 async_checkpointer.py:280] [process=0][thread=save_finalize] Waiting for background save thread=async_save. I0421 16:30:09.937601 136518552889152 standard_logger.py:34] {'step': 0, 'event_type': 'save', 'directory': 'gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints', 'reached_preemption': False, 'preemption_received_at': None, 'synchronous': False, 'wait_for_prev_start_time': 1776789009.292307, 'wait_for_prev_duration_secs': 6.079673767089844e-05, 'time_between_consecutive_saves_sec': None, 'checkpointer_blocking_start_time': 1776789009.294119, 'checkpointer_blocking_duration_secs': 0.6287012100219727, 'get_old_steps_start_time': 1776789009.9228446, 'get_old_steps_duration_secs': 3.0994415283203125e-05, 'checkpoint_manager_blocking_start_time': 1776789009.2903728, 'checkpoint_manager_blocking_duration_secs': 0.6471767425537109} I0421 16:30:09.937711 136518552889152 checkpointing.py:409] Started an asynchronous checkpoint save for step 0 I0421 16:30:09.937778 136518552889152 max_utils.py:750] Memstats: After params initialized: I0421 16:30:09.937828 136518552889152 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_0(process=0,(0,0,0,0)) I0421 16:30:09.937861 136518552889152 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_1(process=0,(1,0,0,0)) I0421 16:30:09.937887 136518552889152 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_4(process=0,(0,1,0,0)) I0421 16:30:09.937912 136518552889152 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_5(process=0,(1,1,0,0)) I0421 16:30:10.362455 136518552889152 metric_logger.py:196] completed step: 0, seconds: 11.127, TFLOP/s/device: 1.221, Tokens/s/device: 184.061, total_weights: 65536, loss: 10.874, lm_loss: 10.874, perplexity: 52786.469 I0421 16:30:10.365489 136518552889152 metric_logger.py:281] To see full metrics 'tensorboard --logdir=gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/tensorboard/' I0421 16:30:10.799693 136518552889152 metric_logger.py:196] completed step: 1, seconds: 1.221, TFLOP/s/device: 11.124, Tokens/s/device: 1676.792, total_weights: 65536, loss: 10.874, lm_loss: 10.874, perplexity: 52786.469 I0421 16:30:10.941512 136518552889152 metric_logger.py:196] completed step: 2, seconds: 0.438, TFLOP/s/device: 31.008, Tokens/s/device: 4673.857, total_weights: 65536, loss: 10.262, lm_loss: 10.262, perplexity: 28632.133 I0421 16:30:11.089184 136518552889152 metric_logger.py:196] completed step: 3, seconds: 0.013, TFLOP/s/device: 1066.410, Tokens/s/device: 160740.915, total_weights: 65536, loss: 9.732, lm_loss: 9.732, perplexity: 16855.789 I0421 16:30:11.740139 136390260004608 atomicity.py:140] Creating tmp directory gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/0/items I0421 16:30:11.908754 136387571005184 checkpoint.py:188] Wrote Metadata={'item_handlers': None, 'metrics': {}, 'performance_metrics': {}, 'init_timestamp_nsecs': 1776789011471457103, 'commit_timestamp_nsecs': None, 'custom_metadata': {}}, json={"item_handlers": null, "metrics": {}, "performance_metrics": {}, "init_timestamp_nsecs": 1776789011471457103, "commit_timestamp_nsecs": null, "custom_metadata": {}} to gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/0/_CHECKPOINT_METADATA I0421 16:30:12.850089 2862 google_auth_provider.cc:181] Running on GCE, using service account 562977990677-compute@developer.gserviceaccount.com I0421 16:30:14.643023 136388125120256 array_metadata_store.py:203] [process=0][thread=array_type_handler] Wrote 69 array_metadata.ArrayMetadata to gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/0/items/array_metadatas/process_0 I0421 16:30:33.710146 136518552889152 metric_logger.py:196] completed step: 4, seconds: 0.143, TFLOP/s/device: 94.997, Tokens/s/device: 14318.975, total_weights: 65536, loss: 9.274, lm_loss: 9.274, perplexity: 10661.594 I0421 16:30:33.720867 136518552889152 metric_logger.py:196] completed step: 5, seconds: 0.148, TFLOP/s/device: 91.897, Tokens/s/device: 13851.783, total_weights: 65536, loss: 8.888, lm_loss: 8.888, perplexity: 7245.978 I0421 16:30:33.865633 136518552889152 metric_logger.py:196] completed step: 6, seconds: 22.619, TFLOP/s/device: 0.601, Tokens/s/device: 90.543, total_weights: 65536, loss: 8.589, lm_loss: 8.589, perplexity: 5371.156 I0421 16:30:34.013036 136518552889152 metric_logger.py:196] completed step: 7, seconds: 0.008, TFLOP/s/device: 1693.100, Tokens/s/device: 255202.492, total_weights: 65536, loss: 8.380, lm_loss: 8.380, perplexity: 4360.465 I0421 16:30:34.160821 136518552889152 metric_logger.py:196] completed step: 8, seconds: 0.146, TFLOP/s/device: 92.770, Tokens/s/device: 13983.245, total_weights: 65536, loss: 8.251, lm_loss: 8.251, perplexity: 3831.256 I0421 16:30:34.309298 136518552889152 checkpointing.py:794] Waiting for step 9 to finish before checkpoint... I0421 16:30:34.310098 136518552889152 checkpointing.py:798] Waited 0.0008106231689453125 seconds for step 9 to finish before starting checkpointing. I0421 16:30:34.312109 136518552889152 checkpoint_manager.py:2020] [process=0][thread=MainThread][step=0][wait_until_finished] Waiting for Save Finalize thread (save_finalize) to complete. I0421 16:30:49.455473 136388116727552 base_pytree_checkpoint_handler.py:1282] [process=0][thread=write_metadata_after_commits] Commit + Array metadata written. Time taken: 36.615151s (commit=35.365692s, array_metadata_write=1.249459s) I0421 16:30:49.456706 136390298138368 base_pytree_checkpoint_handler.py:130] [process=0] /jax/orbax/write/gbytes_per_sec: 39.669 MiB/s (total gbytes: 1.5 GiB) (time elapsed: 39.819791316986084 s) (per-host) I0421 16:30:49.456864 136390298138368 async_checkpointer.py:90] [process=0][thread=async_save] 3 Handler Commit operations completed. Time taken: 39.534077s. I0421 16:30:50.167967 136390298138368 checkpoint.py:228] Read Metadata={'item_handlers': None, 'metrics': {}, 'performance_metrics': {}, 'init_timestamp_nsecs': 1776789011471457103, 'commit_timestamp_nsecs': None, 'custom_metadata': {}} from gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/0/_CHECKPOINT_METADATA I0421 16:30:51.293756 136390298138368 array_metadata_store.py:411] [process=0][thread=async_save] Validated ArrayMetadata from all 8 hosts. Time taken: 0.000433s. I0421 16:30:51.355527 136387571005184 checkpoint.py:247] Updated Metadata={'item_handlers': {'items': 'orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler'}, 'metrics': {}, 'performance_metrics': {}, 'init_timestamp_nsecs': 1776789011471457103, 'commit_timestamp_nsecs': None, 'custom_metadata': {}} to gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/0/_CHECKPOINT_METADATA I0421 16:30:51.540316 136390298138368 ocdbt_utils.py:49] Param validation support for Zarr3 will be added later (b/362328389). I0421 16:30:52.476304 136390298138368 base_pytree_checkpoint_handler.py:1406] [process=0][thread=async_save] Pytree save finalize (merge_ocdbt + ArrayMetadata validation) completed. Time taken: 2.184142s. use_zarr3=True, enable_post_merge_validation=True, directory=gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/0/items I0421 16:30:52.477898 136390298138368 atomicity.py:666] Finalizing gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/0/items I0421 16:30:53.008714 136390298138368 atomicity.py:666] Finalizing gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/0 I0421 16:30:54.493539 136390298138368 atomicity.py:847] [process=0][thread=async_save] Finished saving checkpoint (finalized tmp dir) to `gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/0`. I0421 16:30:54.494397 136390298138368 event_tracking.py:138] [process=0] [async] Finished save (blocking + background) in 45.20 seconds @ gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/0 I0421 16:30:54.495996 136390298138368 async_checkpointer.py:160] [process=0][thread=async_save] Background save thread done. Time taken: 44.573209s. I0421 16:30:54.496203 136388108334848 async_checkpointer.py:288] [process=0][thread=save_finalize] Done with waiting for background save thread=async_save. I0421 16:30:54.496341 136388108334848 async_checkpointer.py:298] [process=0][thread=save_finalize] No errors found in background save thread=async_save. I0421 16:30:54.496411 136388108334848 checkpoint_manager.py:2137] [process=0][thread=save_finalize][step=0] CheckpointManager Save Finalize is syncing with other hosts... I0421 16:30:54.498565 136388108334848 checkpoint_manager.py:2146] [process=0][thread=save_finalize][step=0] CheckpointManager Save Finalize is done on all hosts. I0421 16:30:54.498769 136518552889152 checkpoint_manager.py:2032] [process=0][thread=MainThread][step=0][wait_until_finished] Done waiting for Save Finalize thread (save_finalize) running at step=0. W0421 16:30:54.498906 136518552889152 checkpoint_manager.py:1452] Waiting for previous save to complete took 20.186802 seconds. If this number is high, consider checkpointing less frequently. I0421 16:30:54.500602 136518552889152 checkpoint_manager.py:1512] [process=0] Saving checkpoint at step 9 I0421 16:30:54.502635 136518552889152 event_tracking.py:70] [process=0] [async] Started save checkpoint @ gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/9. I0421 16:30:55.227564 136518552889152 jax_array_handlers.py:360] Scheduling D2H of 69 prioritized jax.Array. I0421 16:30:55.227678 136518552889152 replica_slices.py:424] Transferring arrays to host memory with options: use_replica_parallel=True, min_slice_bytes_for_replica_parallel=None, max_replicas_for_replica_parallel=None, enable_pinned_host_transfer=False I0421 16:30:55.254864 136518552889152 base_pytree_checkpoint_handler.py:154] [process=0][thread=MainThread] Initiated "orbax.checkpoint._src.serialization.jax_array_handlers.ArrayHandler".serialize. Time taken: 0.028766s I0421 16:30:55.255755 136518552889152 base_pytree_checkpoint_handler.py:130] [process=0] /jax/orbax/write/blocking_gbytes_per_sec: 40.931 GiB/s (total gbytes: 1.5 GiB) (time elapsed: 0.037687063217163086 s) (per-host) I0421 16:30:55.255837 136518552889152 base_pytree_checkpoint_handler.py:768] [process=0][thread=MainThread] Initiated Pytree async_save. Time taken: 0.037790s (batch_requests_ready=0.002636s, total_serialization_initiated=0.034344s, others=0.000810s) I0421 16:30:55.255932 136518552889152 composite_checkpoint_handler.py:715] [process=0][thread=MainThread] Initiated CompositeCheckpointHandler.async_save. Time taken: 0.041744s (all_items=0.000016s, per_item={'items': '0.00001645'}, temp_paths=0.041727) I0421 16:30:55.256758 136518552889152 event_tracking.py:125] [process=0] [async] Finished blocking save in 0.76 seconds. Continuing save @ gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/9. I0421 16:30:55.257122 136388108334848 async_checkpointer.py:76] [process=0][thread=async_save] Background save thread started. Deadline for this save operation is 2026-04-21 16:50:55.257085 I0421 16:30:55.263590 136518552889152 checkpoint_manager.py:1560] [process=0][thread=MainThread][step=9] Starting CheckpointManager Save Finalize thread=save_finalize I0421 16:30:55.263849 136388662810368 async_checkpointer.py:280] [process=0][thread=save_finalize] Waiting for background save thread=async_save. I0421 16:30:55.263997 136518552889152 standard_logger.py:34] {'step': 9, 'event_type': 'save', 'directory': 'gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints', 'reached_preemption': False, 'preemption_received_at': None, 'synchronous': False, 'wait_for_prev_start_time': 1776789034.3120701, 'wait_for_prev_duration_secs': 20.18680167198181, 'time_between_consecutive_saves_sec': None, 'checkpointer_blocking_start_time': 1776789054.5006409, 'checkpointer_blocking_duration_secs': 0.7566165924072266, 'get_old_steps_start_time': 1776789055.2572818, 'get_old_steps_duration_secs': 3.266334533691406e-05, 'checkpoint_manager_blocking_start_time': 1776789034.310369, 'checkpoint_manager_blocking_duration_secs': 20.953594207763672} I0421 16:30:55.264112 136518552889152 checkpointing.py:409] Started an asynchronous checkpoint save for step 9 I0421 16:30:55.264156 136518552889152 checkpoint_manager.py:2020] [process=0][thread=MainThread][step=9][wait_until_finished] Waiting for Save Finalize thread (save_finalize) to complete. I0421 16:30:55.893641 136390298138368 atomicity.py:140] Creating tmp directory gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/9 I0421 16:30:57.664131 136388691355392 atomicity.py:140] Creating tmp directory gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/9/items I0421 16:31:00.527701 136388679595776 array_metadata_store.py:203] [process=0][thread=array_type_handler] Wrote 69 array_metadata.ArrayMetadata to gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/9/items/array_metadatas/process_0 I0421 16:31:41.131563 136388671203072 base_pytree_checkpoint_handler.py:1282] [process=0][thread=write_metadata_after_commits] Commit + Array metadata written. Time taken: 42.347404s (commit=41.090585s, array_metadata_write=1.256819s) I0421 16:31:41.132745 136388108334848 base_pytree_checkpoint_handler.py:130] [process=0] /jax/orbax/write/gbytes_per_sec: 34.403 MiB/s (total gbytes: 1.5 GiB) (time elapsed: 45.91464710235596 s) (per-host) I0421 16:31:41.132893 136388108334848 async_checkpointer.py:90] [process=0][thread=async_save] 3 Handler Commit operations completed. Time taken: 45.875659s. I0421 16:31:43.161511 136388108334848 array_metadata_store.py:411] [process=0][thread=async_save] Validated ArrayMetadata from all 8 hosts. Time taken: 0.000339s. I0421 16:31:43.308276 136388108334848 ocdbt_utils.py:49] Param validation support for Zarr3 will be added later (b/362328389). I0421 16:31:44.240226 136388108334848 base_pytree_checkpoint_handler.py:1406] [process=0][thread=async_save] Pytree save finalize (merge_ocdbt + ArrayMetadata validation) completed. Time taken: 2.145162s. use_zarr3=True, enable_post_merge_validation=True, directory=gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/9/items I0421 16:31:44.241995 136388108334848 atomicity.py:666] Finalizing gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/9/items I0421 16:31:44.776910 136388108334848 atomicity.py:666] Finalizing gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/9 I0421 16:31:46.639219 136388108334848 atomicity.py:847] [process=0][thread=async_save] Finished saving checkpoint (finalized tmp dir) to `gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/9`. I0421 16:31:46.639964 136388108334848 event_tracking.py:138] [process=0] [async] Finished save (blocking + background) in 52.14 seconds @ gs://lance-maxtext/nnx_ckpt_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900/nnx_xpk_feat_nnx_trainstate_and_training_loop_20260421_161900_02_synthetic/checkpoints/9 I0421 16:31:46.642106 136388108334848 async_checkpointer.py:160] [process=0][thread=async_save] Background save thread done. Time taken: 51.384871s. I0421 16:31:46.642223 136388662810368 async_checkpointer.py:288] [process=0][thread=save_finalize] Done with waiting for background save thread=async_save. I0421 16:31:46.642284 136388662810368 async_checkpointer.py:298] [process=0][thread=save_finalize] No errors found in background save thread=async_save. I0421 16:31:46.642351 136388662810368 checkpoint_manager.py:2137] [process=0][thread=save_finalize][step=9] CheckpointManager Save Finalize is syncing with other hosts... I0421 16:31:46.645298 136388662810368 checkpoint_manager.py:2146] [process=0][thread=save_finalize][step=9] CheckpointManager Save Finalize is done on all hosts. I0421 16:31:46.645466 136518552889152 checkpoint_manager.py:2032] [process=0][thread=MainThread][step=9][wait_until_finished] Done waiting for Save Finalize thread (save_finalize) running at step=9. I0421 16:31:46.645654 136518552889152 checkpoint_manager.py:2009] [process=0][thread=MainThread][wait_until_finished] No Save Finalize thread to wait for. Returning. I0421 16:31:46.646655 136518552889152 metric_logger.py:196] completed step: 9, seconds: 0.147, TFLOP/s/device: 92.464, Tokens/s/device: 13937.187, total_weights: 65536, loss: 8.175, lm_loss: 8.175, perplexity: 3551.438 Per train step: Total TFLOPs: 13.59 split as 93.93% learnable weight flops and 6.07% attention flops XPK End: Tue Apr 21 16:31:54 UTC 2026 EXIT_CODE=0