Add option to evict keys LRU from the sharded redis tables (#3499)

* wip

* wip

* format

* wip

* note

* lint

* fix

* flag

* typo

* raise timeout

* fix

* optional get

* fix flag

* increase timeout in test

* update docs

* format

python/ray/scripts/scripts.py

@@ -116,6 +116,22 @@ def cli(logging_level, logging_format):
     type=int,
     help="the maximum amount of memory (in bytes) to allow the "
     "object store to use")
+@click.option(
+    "--redis-max-memory",
+    required=False,
+    type=int,
+    help=("The max amount of memory (in bytes) to allow redis to use, or None "
+          "for no limit. Once the limit is exceeded, redis will start LRU "
+          "eviction of entries. This only applies to the sharded "
+          "redis tables (task and object tables)."))
+@click.option(
+    "--collect-profiling-data",
+    default=True,
+    type=bool,
+    help=("Whether to collect profiling data. Note that "
+          "profiling data cannot be LRU evicted, so if you set "
+          "redis_max_memory then profiling will also be disabled to prevent "
+          "it from consuming all available redis memory."))
 @click.option(
     "--num-workers",
     required=False,
@@ -202,11 +218,11 @@ def cli(logging_level, logging_format):
 def start(node_ip_address, redis_address, redis_port, num_redis_shards,
           redis_max_clients, redis_password, redis_shard_ports,
           object_manager_port, node_manager_port, object_store_memory,
-          num_workers, num_cpus, num_gpus, resources, head, no_ui, block,
-          plasma_directory, huge_pages, autoscaling_config,
-          no_redirect_worker_output, no_redirect_output,
-          plasma_store_socket_name, raylet_socket_name, temp_dir,
-          internal_config):
+          redis_max_memory, collect_profiling_data, num_workers, num_cpus,
+          num_gpus, resources, head, no_ui, block, plasma_directory,
+          huge_pages, autoscaling_config, no_redirect_worker_output,
+          no_redirect_output, plasma_store_socket_name, raylet_socket_name,
+          temp_dir, internal_config):
     # Convert hostnames to numerical IP address.
     if node_ip_address is not None:
         node_ip_address = services.address_to_ip(node_ip_address)
@@ -262,6 +278,8 @@ def start(node_ip_address, redis_address, redis_port, num_redis_shards,
             redis_port=redis_port,
             redis_shard_ports=redis_shard_ports,
             object_store_memory=object_store_memory,
+            redis_max_memory=redis_max_memory,
+            collect_profiling_data=collect_profiling_data,
             num_workers=num_workers,
             cleanup=False,
             redirect_worker_output=not no_redirect_worker_output,