[rllib] Fix DQN checkpoint/restore and enable test in jenkins (#1063)

* fix dqn restore and add test

* Update .gitignore

* Update test_checkpoint_restore.py

* add checkpoint restore

python/ray/rllib/dqn/dqn.py

@@ -224,7 +224,8 @@ class Actor(object):
             self.episode_rewards,
             self.episode_lengths,
             self.saved_mean_reward,
-            self.obs]
+            self.obs,
+            self.replay_buffer]
 
     def restore(self, data):
         self.beta_schedule = data[0]
@@ -233,6 +234,7 @@ class Actor(object):
         self.episode_lengths = data[3]
         self.saved_mean_reward = data[4]
         self.obs = data[5]
+        self.replay_buffer = data[6]
 
 
 @ray.remote
@@ -367,7 +369,7 @@ class DQNAgent(Agent):
             global_step=self.num_iterations)
         extra_data = [
             self.actor.save(),
-            self.replay_buffer,
+            ray.get([w.save.remote() for w in self.workers]),
             self.cur_timestep,
             self.num_iterations,
             self.num_target_updates,
@@ -376,10 +378,12 @@ class DQNAgent(Agent):
         return checkpoint_path
 
     def _restore(self, checkpoint_path):
-        self.saver.restore(self.sess, checkpoint_path)
+        self.saver.restore(self.actor.sess, checkpoint_path)
         extra_data = pickle.load(open(checkpoint_path + ".extra_data", "rb"))
         self.actor.restore(extra_data[0])
-        self.replay_buffer = extra_data[1]
+        ray.get([
+            w.restore.remote(d) for (d, w)
+            in zip(extra_data[1], self.workers)])
         self.cur_timestep = extra_data[2]
         self.num_iterations = extra_data[3]
         self.num_target_updates = extra_data[4]

python/ray/rllib/test/test_checkpoint_restore.py

@@ -11,7 +11,6 @@ import random
 from ray.rllib.dqn import (DQNAgent, DEFAULT_CONFIG as DQN_CONFIG)
 from ray.rllib.ppo import (PPOAgent, DEFAULT_CONFIG as PG_CONFIG)
 from ray.rllib.a3c import (A3CAgent, DEFAULT_CONFIG as A3C_CONFIG)
-
 # from ray.rllib.es import (ESAgent, DEFAULT_CONFIG as ES_CONFIG)
 
 
@@ -26,11 +25,13 @@ ray.init()
 for (cls, default_config) in [
         (DQNAgent, DQN_CONFIG),
         (PPOAgent, PG_CONFIG),
-        # TODO(ekl) this fails with multiple ES instances in a process
+        (A3CAgent, A3C_CONFIG),
+        # https://github.com/ray-project/ray/issues/1062
         # (ESAgent, ES_CONFIG),
-        (A3CAgent, A3C_CONFIG)]:
+        ]:
     config = default_config.copy()
     config["num_sgd_iter"] = 5
+    config["use_lstm"] = False  # for a3c
     config["episodes_per_batch"] = 100
     config["timesteps_per_batch"] = 1000
     alg1 = cls("CartPole-v0", config)
@@ -49,4 +50,4 @@ for (cls, default_config) in [
         a1 = get_mean_action(alg1, obs)
         a2 = get_mean_action(alg2, obs)
         print("Checking computed actions", alg1, obs, a1, a2)
-        assert(abs(a1-a2) < .05)
+        assert abs(a1-a2) < .1, (a1, a2)