blob: 7a460182c4a374e1ae7e71d64d3f0660098c6fa4 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
|
Connection Purging Test By: Kirthika Parameswaran <kirthika@cs.wustl.edu>
======================= Irfan Pyarali <irfan@cs.wustl.edu>
This is a test which stress tests the connection management and checks
whether cached handlers are purged effectively when the process runs
out of descriptors.
In detail:
---------
Connection Caching Feature
--------------------------
Motivation:
In TAO, open connections are stored in a connection cache and
reused for the subsequent requests between the same client and
server. This is done to avoid the cost of establishing new
connections. Every connection needs a OS handle which has to
obtained from the OS. The OS can allot only a fixed number of
handles to a process. This can become a issue in case of
clients and servers with multiple handles open who may not be
allowed to establish a new connection as the process has run out
of handles.
Aim:
Clients and servers should be able to to continue making new
connections by tearing down "old" connections.
Solution: Auto-purging
The connections are stored in a cache. When ever the connect
call fails due to the process running out of handles,
auto-purging will kick in and some "old" connections will be
removed from the connection cache. The decision about which
connections are "old" is made by the caching strategies. The
percentage of existing connections to be purged is controlled by
a purge percent.
ACE classes: Caching_Utility, Cleanup_Stratgies, and
Caching_Strategies have been used. Simple examples are
available in $ACE_ROOT/tests/Cached_Accept_Conn_Test.cpp and
$ACE_ROOT/tests/Cached_Conn_Test.cpp.
Note that the users can also purge handles used by the ORB
explicitly through TAO_Connector_Registry::purge_connections().
This can enable them to open new handles for their application.
Test:
----
This test creates the number of "server" ORBs specified by the
-i option and has a client ORB which invokes remote methods on
these ORBs.
Two possible cases:
1. When the process runs out of handles during "connect", the
Connector removes handlers from its connection cache depending
upon the kind of connection caching strategy followed. (by
default: Least Recently Used) set by the
ORBConnectionCachingStrategy option.
2. When the "accept" or "open" calls made by the Acceptors in the
same process fail, request is made on all the Connectors of all
the ORBs in the system to perform purging depending on the
ORBPurgePercentage value provided.
Note: This test does not use the Collocation optimisations since
we want to use up handles and test the connection caching as well
as purging.
Options:
-------
i: Number of iteration which equals the number of server orbs.
d: Debugging ON
a: Number of handles to be kept free. The Handle Gobbler will
eat up the max_handles specified for the OS but leave
behind the handles requested. This helps in testing more
effectively. Please remember to set this value judiciously.
r: Number of remote call invocations to be made by the client
on the servant.
?: help!
Options Using svc.conf:
-----------------------
Through options to the Resource_Factory :-
-ORBConnectionCachingStrategy <lru/lfu/fifo/null>
-ORBPurgePercent <percentage>
Execution:
---------
Simply run the ./run_test.pl !
else
./Connection_Purging -ORBCollocation no
with options specified per need.
|
