summaryrefslogtreecommitdiff
path: root/TAO/ChangeLog-99c
diff options
context:
space:
mode:
Diffstat (limited to 'TAO/ChangeLog-99c')
-rw-r--r--TAO/ChangeLog-99c118
1 files changed, 118 insertions, 0 deletions
diff --git a/TAO/ChangeLog-99c b/TAO/ChangeLog-99c
index 7251d8e1484..bcce0206571 100644
--- a/TAO/ChangeLog-99c
+++ b/TAO/ChangeLog-99c
@@ -1,3 +1,121 @@
+Mon Jul 19 18:06:00 1999 Kirthika Parameswaran <kirthika@cs.wustl.edu>
+
+ Connection Caching Feature
+ --------------------------
+
+ Motivation:
+
+ In TAO, connections opened on a request are stored in a
+ connection cache and reused for the subsequent requests between
+ the same client and server , since establishing TCP connections
+ per request is expensive.
+
+ Every connection needs a connection endpoint which has to obtained
+ from the OS. The OS can allot only a fixed number of file
+ descriptors to a process. This can become a issue in case of
+ clients and servers with multiple connections open who may not be
+ allowed to make a new connection as the process has run out of
+ file descriptors.
+
+ Aim:
+
+ Clients and servers should be able to to continue making new
+ connections and not be hindered due to running out of file
+ descriptors.
+
+ Solution:
+
+ Auto-purging .
+
+ The connections are stored in a cache. The connections arent
+ closed as soon as they are used as it is expensive to establish a
+ TCP connection per request.
+
+ So on the client side,
+
+ When ever the connect call fails due to the process running out
+ of descriptors to create a new socket, auto-purging will occur
+ and those connections which are unused will be removed from the
+ connection cache.
+
+ On the server side,
+
+ The acceptor in TAO will tackle the issue of the process running
+ out of descriptors by requesting the peer connector in the
+ process to clear its connection cache. TAO_Accept_Strategy has
+ been added for this purpose.
+
+ Caching Strategy:
+
+ This is the entity which will decide which entries of the
+ connection cache shoudl be removed. Least Recently Used,
+ Least Frequently Used , FIrst In First Out and Null (do-nothing)
+ strategies have been implemented. LRU is the default one.
+
+ Purge_Percent:
+
+ Denotes the percentage of total entries to be removed.
+
+ Advantages:
+
+ Large number of connections can be supported on the client and server
+ side overcoming the problem of inadequate resources.
+
+ Disadvantages.
+
+ Latency could arise since the purging would eat up some memory cycles.
+
+ ( I look at it being something like the garbage collection feature in
+ Java! )
+
+ ---------------------------------------------------------------------
+
+ * tao/Resource_Factory.{h, cpp}:
+ * tao/ORB_Core.{h, cpp}:
+ * tao/default_resource.{h,cpp}:
+
+ Added connection_caching_strategy and purge_percent options.
+ This will enable the user to choose the kind of caching strategy
+ he wants to implement which will be part of the connection
+ strategy. This strategy will be used when entries need to be
+ removed from the connector's connection cache. The purge_percent
+ denotes the percentage of entries to discrad on demand.
+
+ * tao/IIOP_Connector.h:
+ * tao/UIOP_Connector.h:
+
+ Changed the TAO_CACHED_CONNECT_STRATEGY to
+ Cached_Connect_Strategy_Ex which provides an advanced way of
+ caching and purging entries from the connection cache depending
+ on the different caching_strategies plugged in at run-time.
+
+ * tao/IIOP_Connector.cpp (make_connection_caching_strategy):
+ * tao/UIOP_Connector.cpp (make_connection_caching_strategy):
+
+ Creation of the appropriate caching strategy according to the
+ -ORBConnectionCachingStrategy option specified.
+
+ * tao/Acceptor_Impl.{h, cpp} (TAO_Accept_Strategy):
+
+ Added TAO_Accept_Strategy which does the open and accepting of
+ connections. If connections fail because the process runs out of
+ descriptors, then the unused connections from the connection
+ cache are purged. Both the open () as well as teh
+ accept_svc_handler () tackle thsi problem.
+
+ * tao/IIOP_Acceptor.cpp (open_i):
+ * tao/UIOP_Acceptor.cpp (open_i):
+
+ Added accept_strategy during the creation of the
+ TAO_ACCEPTOR_BASE.
+
+ * tao/IIOP_Acceptor.cpp (~TAO_IIOP_Acceptor):
+ * tao/UIOP_Acceptor.cpp (~TAO_UIOP_Acceptor):
+
+ Added the deletion of the accept_strategy.
+
+ Thanks to Irfan of the DOC group for helping me out with this.
+
Fri Jul 16 16:31:50 1999 Jeff Parsons <parsons@cs.wustl.edu>
* TAO_IDL/be_include/be_visitor_array/cdr_op_ci.h: