In [1]: import ray
ray
In [2]: ray.init(object_store_memory_mb=50*1000)
WARNING: Not updating worker name since `setproctitle` is not installed. Install this with `pip install setproctitle` (or ray[debug]) to enable monitoring of worker processes.
Process STDOUT and STDERR is being redirected to /tmp/ray/session_2018-12-31_23-58-25_28453/logs.
Waiting for redis server at 127.0.0.1:14322 to respond...
Waiting for redis server at 127.0.0.1:24609 to respond...
WARNING: The object store is using /tmp instead of /dev/shm because /dev/shm has only 33008.238592MB available. This may slow down performance! You may be able to free up space by deleting files in /dev/shm or terminating any running plasma_store_server processes. If you are inside a Docker container, you may need to pass an argument with the flag '--shm-size' to 'docker run'.
Starting the Plasma object store with 50.0GB memory using /tmp.
E1231 23:58:25.641736 28607 io.cc:167] Connection to IPC socket failed for pathname /tmp/ray/session_2018-12-31_23-58-25_28453/sockets/plasma_store, retrying 50 more times

In [3]: ray.utils.get_system_memory_bytes() // 10**9
Out[3]: 66

~$ ray/build/external/arrow-install/bin/plasma_store_server -s /tmp/store -m 50000000000 -d /tmp
I0101 00:02:24.788489 28722 store.cc:994] Allowing the Plasma store to use up to 50GB of memory.
I0101 00:02:24.788723 28722 store.cc:1024] Starting object store with directory /tmp and huge page support disabled
F0101 00:02:24.788743 28722 store.cc:1039] System memory request exceeds memory available in /tmp. The request is for 50000000000 bytes, and the amount available is 42490683392 bytes. You may be able to free up space by deleting files in /dev/shm. If you are inside a Docker container, you may need to pass an argument with the flag '--shm-size' to 'docker run'.
*** Check failure stack trace: ***
    @           0x44212c  google::LogMessage::Fail()
    @           0x442070  google::LogMessage::SendToLog()
    @           0x4419b2  google::LogMessage::Flush()
    @           0x4417ad  google::LogMessage::~LogMessage()
    @           0x43e5e0  arrow::util::ArrowLog::~ArrowLog()
    @           0x415b04  main
    @     0x7f5039fa4830  __libc_start_main
    @           0x415f09  _start
    @              (nil)  (unknown)
Aborted (core dumped)

E1231 23:58:30.547828 28607 io.cc:167] Connection to IPC socket failed for pathname /tmp/ray/session_2018-12-31_23-58-25_28453/sockets/plasma_store, retrying 1 more times
E1231 23:58:30.549942 28453 io.cc:167] Connection to IPC socket failed for pathname /tmp/ray/session_2018-12-31_23-58-25_28453/sockets/plasma_store, retrying 1 more times
F1231 23:58:30.647966 28607 object_store_notification_manager.cc:22]  Check failed: _s.ok() Bad status: IOError: Could not connect to socket /tmp/ray/session_2018-12-31_23-58-25_28453/sockets/plasma_store
*** Check failure stack trace: ***
    @           0x5d7cd0  google::LogMessage::Fail()
    @           0x5d7c14  google::LogMessage::SendToLog()
    @           0x5d7556  google::LogMessage::Flush()
    @           0x5d7351  google::LogMessage::~LogMessage()
    @           0x5c5c50  arrow::util::ArrowLog::~ArrowLog()
    @           0x5770e7  ray::ObjectStoreNotificationManager::ObjectStoreNotificationManager()
    @           0x526cfa  ray::ObjectManager::ObjectManager()
    @           0x4c0e67  ray::raylet::Raylet::Raylet()
    @           0x4ae3c9  main
    @     0x7fc2edc6d830  __libc_start_main
    @           0x4b3d19  _start
    @              (nil)  (unknown)
---------------------------------------------------------------------------
ArrowIOError                              Traceback (most recent call last)
<ipython-input-2-f09714301df8> in <module>()
----> 1 ray.init(object_store_memory_mb=50*1000)

~/ray/python/ray/worker.py in init(redis_address, num_cpus, num_gpus, resources, object_store_memory, object_store_memory_mb, redis_max_memory, redis_max_memory_mb, collect_profiling_data, node_ip_address, object_id_seed, num_workers, local_mode, driver_mode, redirect_worker_output, redirect_output, ignore_reinit_error, num_redis_shards, redis_max_clients, redis_password, plasma_directory, huge_pages, include_webui, driver_id, configure_logging, logging_level, logging_format, plasma_store_socket_name, raylet_socket_name, temp_dir, _internal_config, use_raylet)
   1619         _internal_config=_internal_config,
   1620     )
-> 1621     ret = _init(ray_params, driver_id=driver_id)
   1622     for hook in _post_init_hooks:
   1623         hook()

~/ray/python/ray/worker.py in _init(ray_params, driver_id)
   1428         mode=ray_params.driver_mode,
   1429         worker=global_worker,
-> 1430         driver_id=driver_id)
   1431     return ray_params.address_info
   1432 

~/ray/python/ray/worker.py in connect(ray_params, info, mode, worker, driver_id)
   1975     # Create an object store client.
   1976     worker.plasma_client = thread_safe_client(
-> 1977         plasma.connect(info["store_socket_name"]))
   1978 
   1979     raylet_socket = info["raylet_socket_name"]

~/ray/python/ray/pyarrow_files/pyarrow/_plasma.pyx in pyarrow._plasma.connect()

~/ray/python/ray/pyarrow_files/pyarrow/error.pxi in pyarrow.lib.check_status()

ArrowIOError: Could not connect to socket /tmp/ray/session_2018-12-31_23-58-25_28453/sockets/plasma_store