Files
ray/python/ray/experimental/gcs_flush_policy.py
T
Zongheng Yang 8190ff1fd0 Experimental: enable automatic GCS flushing with configurable policy. (#2266)
* build_credis.sh: use an up-to-date credis commit.

* build_credis.sh: leveldb is updated, so update build cmds for it

* WIP: make monitor.py issue flush; switch gcs client to use credis

* Experimental: enable automatic GCS flushing with configurable policy.

* Fix linux compilation error

* Fix leveldb build

* Use optimized build for credis

* Address comments

* Attempt to fix tests
2018-06-20 14:40:57 -07:00

92 lines
3.0 KiB
Python

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import os
import time
import ray
import ray.cloudpickle as pickle
class GcsFlushPolicy(object):
"""Experimental: a policy to control GCS flushing.
Used by Monitor to enable automatic control of memory usage.
"""
def should_flush(self, redis_client):
"""Returns a bool, whether a flush request should be issued."""
pass
def num_entries_to_flush(self):
"""Returns an upper bound for number of entries to flush next."""
pass
def record_flush(self):
"""Must be called after a flush has been performed."""
pass
class SimpleGcsFlushPolicy(GcsFlushPolicy):
"""A simple policy with constant flush rate, after a warmup period.
Example policy values:
flush_when_at_least_bytes 2GB
flush_period_secs 10s
flush_num_entries_each_time 10k
This means
(1) If the GCS shard uses less than 2GB of memory, no flushing would take
place. This should cover most Ray runs.
(2) The GCS shard will only honor a flush request, if it's issued after 10
seconds since the last processed flush. In particular this means it's
okay for the Monitor to issue requests more frequently than this param.
(3) When processing a flush, the shard will flush at most 10k entries.
This is to control the latency of each request.
Note, flush rate == (flush period) * (num entries each time). So
applications that have a heavier GCS load can tune these params.
"""
def __init__(self,
flush_when_at_least_bytes=(1 << 31),
flush_period_secs=10,
flush_num_entries_each_time=10000):
self.flush_when_at_least_bytes = flush_when_at_least_bytes
self.flush_period_secs = flush_period_secs
self.flush_num_entries_each_time = flush_num_entries_each_time
self.last_flush_timestamp = time.time()
def should_flush(self, redis_client):
if time.time() - self.last_flush_timestamp < self.flush_period_secs:
return False
used_memory = redis_client.info("memory")["used_memory"]
assert used_memory > 0
return used_memory >= self.flush_when_at_least_bytes
def num_entries_to_flush(self):
return self.flush_num_entries_each_time
def record_flush(self):
self.last_flush_timestamp = time.time()
def serialize(self):
return pickle.dumps(self)
def set_flushing_policy(flushing_policy):
"""Serialize this policy for Monitor to pick up."""
if "RAY_USE_NEW_GCS" not in os.environ:
raise Exception(
"set_flushing_policy() is only available when environment "
"variable RAY_USE_NEW_GCS is present at both compile and run time."
)
ray.worker.global_worker.check_connected()
redis_client = ray.worker.global_worker.redis_client
serialized = pickle.dumps(flushing_policy)
redis_client.set("gcs_flushing_policy", serialized)