# ‘Worker’ object has no attribute ‘core\_worker’ **URL:** \ **Category:** Uncategorized\ **Created:** [November 12, 2024, 5:16pm UTC](https://discuss.ray.io/t/worker-object-has-no-attribute-core-worker/20556 "2024-11-12T17:16:04Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![James\_Maxwell](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/james_maxwell/32/7293_2.png) [@James\_Maxwell](https://discuss.ray.io/u/James_Maxwell)\ **Post date:** [November 12, 2024, 5:16pm UTC](https://discuss.ray.io/t/worker-object-has-no-attribute-core-worker/20556/1 "2024-11-12T17:16:04Z")
### What happened + What you expected to happen I am attempting to use the ray.data.read\_parquet method to read data from an Azure Storage account. However, I encounter the following error when trying to call to\_pandas on the Ray dataset: I have created my own ray cluster using docker-compose for local development and testing. 2024-11-11 16:58:13,900 ERROR exceptions.py:81 – Full stack trace: Traceback (most recent call last): File “/Users/.venv/lib/python3.11/site-packages/ray/data/exceptions.py”, line 49, in handle\_trace return fn(\*args, \*\*kwargs) ^^^^^^^^^^^^^^^^^^^ File “/Users/.venv/lib/python3.11/site-packages/ray/data/\_internal/plan.py”, line 423, in execute\_to\_iterator bundle\_iter = execute\_to\_legacy\_bundle\_iterator(executor, self) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File “/Users/.venv/lib/python3.11/site-packages/ray/data/\_internal/execution/legacy\_compat.py”, line 51, in execute\_to\_legacy\_bundle\_iterator bundle\_iter = executor.execute(dag, initial\_stats=stats) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File “/Users/.venv/lib/python3.11/site-packages/ray/data/\_internal/execution/streaming\_executor.py”, line 124, in execute self.\_topology, \_ = build\_streaming\_topology(dag, self.\_options) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File “/Users/.venv/lib/python3.11/site-packages/ray/data/\_internal/execution/streaming\_executor\_state.py”, line 382, in build\_streaming\_topology setup\_state(dag) File “/Users/.venv/lib/python3.11/site-packages/ray/data/\_internal/execution/streaming\_executor\_state.py”, line 373, in setup\_state parent\_state = setup\_state(parent) ^^^^^^^^^^^^^^^^^^^ File “/Users/.venv/lib/python3.11/site-packages/ray/data/\_internal/execution/streaming\_executor\_state.py”, line 379, in setup\_state op.start(options) File “/Users/.venv/lib/python3.11/site-packages/ray/data/\_internal/execution/operators/input\_data\_buffer.py”, line 48, in start self.\_input\_data = self.\_input\_data\_factory( ^^^^^^^^^^^^^^^^^^^^^^^^^ File “/Users/.venv/lib/python3.11/site-packages/ray/data/\_internal/planner/plan\_read\_op.py”, line 85, in get\_input\_data cleaned\_metadata(read\_task, read\_task\_ref), ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File “/Users/.venv/lib/python3.11/site-packages/ray/data/\_internal/planner/plan\_read\_op.py”, line 35, in cleaned\_metadata locations = get\_local\_object\_locations([read\_task\_ref]) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File “/Users/.venv/lib/python3.11/site-packages/ray/experimental/locations.py”, line 75, in get\_local\_object\_locations core\_worker = ray.\_private.worker.global\_worker.core\_worker AttributeError: ‘Worker’ object has no attribute ‘core\_worker’ Running 0: 0.00 row [00:00, ? row/s] ray.data.exceptions.SystemException The above exception was the direct cause of the following exception: Traceback (most recent call last): File “/Users/fme\_tms\_ldm\_ray\_cluster/sample\_code/src/sample\_code/deltalake\_test.py”, line 39, in df = ds.to\_pandas() ^^^^^^^^^^^^^^ File “/Users/.venv/lib/python3.11/site-packages/ray/data/dataset.py”, line 4588, in to\_pandas bundles = self.iter\_internal\_ref\_bundles() ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File “/Users/.venv/lib/python3.11/site-packages/ray/data/dataset.py”, line 4845, in iter\_internal\_ref\_bundles iter\_ref\_bundles, \_, \_ = self.\_plan.execute\_to\_iterator() ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File “/Users/.venv/lib/python3.11/site-packages/ray/data/exceptions.py”, line 89, in handle\_trace raise e.with\_traceback(None) from SystemException() AttributeError: ‘Worker’ object has no attribute ‘core\_worker’ ### Versions / Dependencies ray = 2.38.0 python = 3.11.10 Os = macos ### Reproduction script raytest image ```auto FROM python:3.11.10-slim RUN pip install --no-cache-dir -U 'ray[default,data]' adlfs fsspec tqdm deltalake deltaray ``` envs ```auto HOST=localhost RAY_IMAGE=raytest REDISPORT=6345 DASHBOARDPORT=8265 HEADNODEPORT=20001 REDISPASSWORD=yourpassword NUM_WORKERS=4 NUM_CPU_WORKER=1 ``` docker compose ```auto version: "3" services: ray-head: image: ${RAY_IMAGE} ports: - "${REDISPORT}:${REDISPORT}" - "${DASHBOARDPORT}:${DASHBOARDPORT}" - "${HEADNODEPORT}:${HEADNODEPORT}" env_file: - .env command: bash -c "ray start --head --ray-client-server-port=${HEADNODEPORT} --dashboard-port=${DASHBOARDPORT} --port=${REDISPORT} --dashboard-host=0.0.0.0 --redis-password=${REDISPASSWORD} --block" shm_size: 2g deploy: resources: limits: cpus: '1' memory: '2g' networks: - ray_net ray-worker: image: ${RAY_IMAGE} depends_on: - ray-head env_file: - .env command: bash -c "ray start --address=ray-head:${REDISPORT} --redis-password=${REDISPASSWORD} --num-cpus=${NUM_CPU_WORKER} --block" shm_size: 2g deploy: mode: replicated replicas: ${NUM_WORKERS} resources: limits: cpus: ${NUM_CPU_WORKER} memory: '2g' networks: - ray_net networks: ray_net: ipam: driver: default config: - subnet: 172.63.0.0/16 ``` python script ```python import ray from deltalake import DeltaTable from ray.data import read_parquet from ray.data.datasource import ParquetMetadataProvider from fsspec import filesystem ray.init(address='ray://localhost:20001') access_key = "mykey" account_name = "myaccountname" storage_options = { "account_name": account_name, "account_key": access_key, } fs = filesystem("abfs", **storage_options) partition_filters = [("customer_id", "in", ["abc"])] dt = DeltaTable("abfs://mypath", storage_options=storage_options) ds = read_parquet( paths=dt.file_uris(partition_filters=partition_filters), filesystem=fs, columns=None, parallelism=-1, ray_remote_args=None, tensor_column_schema=None, meta_provider=ParquetMetadataProvider(), ) df = ds.to_pandas() print(df) ``` ### Issue Severity High: It blocks me from completing my task. ---
**Author:** ![mowen](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/mowen/32/7309_2.png) [@mowen](https://discuss.ray.io/u/mowen)\ **Post date:** [November 13, 2024, 7:33pm UTC](https://discuss.ray.io/t/worker-object-has-no-attribute-core-worker/20556/2 "2024-11-13T19:33:05Z")
I think this issue stems from how you are initializing ray with `ray.init(address='ray://localhost:20001')`. This will use ray in Client Mode which has some limitations for various libraries (more on ray Client Mode [here](https://docs.ray.io/en/latest/cluster/running-applications/job-submission/ray-client.html)). In this case the driver doesn’t have access to the `core_worker` attribute because it’s not a full Ray worker, and the error `AttributeError: 'Worker' object has no attribute 'core_worker'` occurs because the function `get_local_object_locations` tries to access `ray._private.worker.global_worker.core_worker`, which doesn’t exist in client mode. I would try this again without using Client Mode and see if that fixes your problem. More on how to call ray init [here](https://docs.ray.io/en/latest/ray-core/api/doc/ray.init.html).