Merge "Introduce TTL for idle connections"

oslo_messaging/_drivers/base.py

@@ -25,10 +25,13 @@ import six
 from oslo_messaging import exceptions
 
 base_opts = [
-    cfg.IntOpt('rpc_conn_pool_size',
-               default=30,
+    cfg.IntOpt('rpc_conn_pool_size', default=30,
                deprecated_group='DEFAULT',
                help='Size of RPC connection pool.'),
+    cfg.IntOpt('conn_pool_min_size', default=2,
+               help='The pool size limit for connections expiration policy'),
+    cfg.IntOpt('conn_pool_ttl', default=1200,
+               help='The time-to-live in sec of idle connections in the pool')
 ]
 
 

oslo_messaging/_drivers/impl_kafka.py

@@ -50,6 +50,12 @@ kafka_opts = [
 
     cfg.IntOpt('pool_size', default=10,
                help='Pool Size for Kafka Consumers'),
+
+    cfg.IntOpt('conn_pool_min_size', default=2,
+               help='The pool size limit for connections expiration policy'),
+
+    cfg.IntOpt('conn_pool_ttl', default=1200,
+               help='The time-to-live in sec of idle connections in the pool')
 ]
 
 CONF = cfg.CONF
@@ -301,8 +307,13 @@ class KafkaDriver(base.BaseDriver):
         super(KafkaDriver, self).__init__(
             conf, url, default_exchange, allowed_remote_exmods)
 
+        # the pool configuration properties
+        max_size = self.conf.oslo_messaging_kafka.pool_size
+        min_size = self.conf.oslo_messaging_kafka.conn_pool_min_size
+        ttl = self.conf.oslo_messaging_kafka.conn_pool_ttl
+
         self.connection_pool = driver_pool.ConnectionPool(
-            self.conf, self.conf.oslo_messaging_kafka.pool_size,
+            self.conf, max_size, min_size, ttl,
             self._url, Connection)
         self.listeners = []
 

oslo_messaging/_drivers/impl_rabbit.py

@@ -1325,8 +1325,13 @@ class RabbitDriver(amqpdriver.AMQPDriverBase):
         self.prefetch_size = (
             conf.oslo_messaging_rabbit.rabbit_qos_prefetch_count)
 
+        # the pool configuration properties
+        max_size = conf.oslo_messaging_rabbit.rpc_conn_pool_size
+        min_size = conf.oslo_messaging_rabbit.conn_pool_min_size
+        ttl = conf.oslo_messaging_rabbit.conn_pool_ttl
+
         connection_pool = pool.ConnectionPool(
-            conf, conf.oslo_messaging_rabbit.rpc_conn_pool_size,
+            conf, max_size, min_size, ttl,
             url, Connection)
 
         super(RabbitDriver, self).__init__(

oslo_messaging/_drivers/pool.py

@@ -1,4 +1,3 @@
-
 # Copyright 2013 Red Hat, Inc.
 #
 #    Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -19,6 +18,7 @@ import sys
 import threading
 
 from oslo_log import log as logging
+from oslo_utils import timeutils
 import six
 
 from oslo_messaging._drivers import common
@@ -38,28 +38,48 @@ else:
 
 @six.add_metaclass(abc.ABCMeta)
 class Pool(object):
-
     """A thread-safe object pool.
 
     Modelled after the eventlet.pools.Pool interface, but designed to be safe
     when using native threads without the GIL.
 
     Resizing is not supported.
+
     """
 
-    def __init__(self, max_size=4):
+    def __init__(self, max_size=4, min_size=2, ttl=1200, on_expire=None):
         super(Pool, self).__init__()
-
+        self._min_size = min_size
         self._max_size = max_size
+        self._item_ttl = ttl
         self._current_size = 0
         self._cond = threading.Condition()
-
         self._items = collections.deque()
+        self._on_expire = on_expire
+
+    def expire(self):
+        """Remove expired items from left (the oldest item) to
+        right (the newest item).
+        """
+        with self._cond:
+            while len(self._items) > self._min_size:
+                try:
+                    ttl_watch, item = self._items.popleft()
+                    if ttl_watch.expired():
+                        self._on_expire and self._on_expire(item)
+                        self._current_size -= 1
+                    else:
+                        self._items.appendleft((ttl_watch, item))
+                        return
+                except IndexError:
+                    break
 
     def put(self, item):
         """Return an item to the pool."""
         with self._cond:
-            self._items.appendleft(item)
+            ttl_watch = timeutils.StopWatch(duration=self._item_ttl)
+            ttl_watch.start()
+            self._items.append((ttl_watch, item))
             self._cond.notify()
 
     def get(self):
@@ -70,7 +90,9 @@ class Pool(object):
         with self._cond:
             while True:
                 try:
-                    return self._items.popleft()
+                    ttl_watch, item = self._items.pop()
+                    self.expire()
+                    return item
                 except IndexError:
                     pass
 
@@ -90,12 +112,12 @@ class Pool(object):
 
     def iter_free(self):
         """Iterate over free items."""
-        with self._cond:
-            while True:
-                try:
-                    yield self._items.popleft()
-                except IndexError:
-                    break
+        while True:
+            try:
+                _, item = self._items.pop()
+                yield item
+            except IndexError:
+                raise StopIteration
 
     @abc.abstractmethod
     def create(self):
@@ -104,17 +126,20 @@ class Pool(object):
 
 class ConnectionPool(Pool):
     """Class that implements a Pool of Connections."""
-    def __init__(self, conf, rpc_conn_pool_size, url, connection_cls):
+
+    def __init__(self, conf, max_size, min_size, ttl, url, connection_cls):
         self.connection_cls = connection_cls
         self.conf = conf
         self.url = url
-        super(ConnectionPool, self).__init__(rpc_conn_pool_size)
-        self.reply_proxy = None
+        super(ConnectionPool, self).__init__(max_size, min_size, ttl,
+                                             self._on_expire)
 
-    # TODO(comstud): Timeout connections not used in a while
-    def create(self, purpose=None):
-        if purpose is None:
-            purpose = common.PURPOSE_SEND
+    def _on_expire(self, connection):
+        connection.close()
+        LOG.debug("Idle connection has expired and been closed."
+                  " Pool size: %d" % len(self._items))
+
+    def create(self, purpose=common.PURPOSE_SEND):
         LOG.debug('Pool creating new connection')
         return self.connection_cls(self.conf, self.url, purpose)
 

releasenotes/notes/connection_ttl-2cf0fe6e1ab8c73c.yaml

@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    | Idle connections in the pool will be expired and closed.
+    | Default ttl is 1200s. Next configuration params was added
+
+    * *conn_pool_ttl* (defaul 1200)
+    * *conn_pool_min_size* (default 2)