[core] Option to fallback to LRU on OutOfMemory (#7410)

* Add a test for LRU fallback

* Update error message

* Upgrade arrow to master

* Integrate with arrow

* Revert "Bazel mirrors (#7385)"

This reverts commit 44aded5272.

* Don't LRU evict

* Revert "Revert "Bazel mirrors (#7385)""

This reverts commit b6359fea78d1bd3925452ca88ac71e0c9e5c7dd3.

* Add lru_evict flag

* fix internal config

* Fix

* upgrade arrow

* debug

* Set free period in config for lru_evict, override max retries to fix
test

* Fix test?

* fix test

* Revert "debug"

This reverts commit 98f01c63a267f38218f5047b1866e4c1c8280017.

* fix exception str

* Fix ref count test

* Shorten travis test?

python/ray/node.py

@@ -2,7 +2,6 @@ import atexit
 import collections
 import datetime
 import errno
-import json
 import os
 import logging
 import signal
@@ -91,8 +90,7 @@ class Node:
         self._resource_spec = None
         self._ray_params = ray_params
         self._redis_address = ray_params.redis_address
-        self._config = (json.loads(ray_params._internal_config)
-                        if ray_params._internal_config else None)
+        self._config = ray_params._internal_config
 
         if head:
             redis_client = None