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Revision: 1.6
Committed: Sat May 17 21:47:29 2008 UTC (16 years ago) by root
Branch: MAIN
CVS Tags: rel-1_1, rel-1_11
Changes since 1.5: +1 -1 lines
Log Message:
*** empty log message ***

File Contents

# Content
1 NAME
2 AnyEvent::FastPing - quickly ping a large number of hosts
3
4 SYNOPSIS
5 use AnyEvent::FastPing;
6
7 DESCRIPTION
8 This module was written for a single purpose only: sending ICMP ECHO
9 REQUEST packets as quickly as possible to a large number of hosts
10 (thousands to millions).
11
12 It employs a sending thread and is fully event-driven (using AnyEvent),
13 so you have to run an event model supported by AnyEvent to use this
14 module.
15
16 FUNCTIONS
17 AnyEvent::FastPing::ipv4_supported
18 Returns true if IPv4 is supported in this module and on this system.
19
20 AnyEvent::FastPing::ipv6_supported
21 Returns true if IPv6 is supported in this module and on this system.
22
23 AnyEvent::FastPing::icmp4_pktsize
24 Returns the number of bytes each IPv4 ping packet has.
25
26 AnyEvent::FastPing::icmp6_pktsize
27 Returns the number of bytes each IPv4 ping packet has.
28
29 AnyEvent::FastPing::icmp_ping [ranges...], $send_interval, $payload,
30 \&callback
31 Ping the given IPv4 address ranges. Each range is an arrayref of the
32 form "[lo, hi, interval]", where "lo" and "hi" are octet strings
33 with either 4 octets (for IPv4 addresses) or 16 octets (for IPV6
34 addresses), representing the lowest and highest address to ping (you
35 can convert a dotted-quad IPv4 address to this format by using
36 "inet_aton $address". The range "interval" is the minimum time in
37 seconds between pings to the given range. If omitted, defaults to
38 $send_interval.
39
40 The $send_interval is the minimum interval between sending any two
41 packets and is a way to make an overall rate limit. If omitted,
42 pings will be send as fast as possible.
43
44 The $payload is a 32 bit unsigned integer given as the ICMP ECHO
45 REQUEST ident and sequence numbers (in unspecified order :).
46
47 The request will be queued and all requests will be served by a
48 background thread in order. When all ranges have been pinged, the
49 "callback" will be called.
50
51 Algorithm: Each range has an associated "next time to send packet"
52 time. The algorithm loops as long as there are ranges with hosts to
53 be pinged and always serves the range with the most urgent packet
54 send time. It will at most send one packet every $send_interval
55 seconds.
56
57 This will ensure that pings to the same range are nicely interleaved
58 with other ranges - this can help reduce per-subnet bandwidth while
59 maintaining an overall high packet rate.
60
61 The algorithm to send each packet is O(log n) on the number of
62 ranges, so even a large number of ranges (many thousands) is
63 managable.
64
65 No storage is allocated per address.
66
67 Performance: On my 2 GHz Opteron system with a pretty average nvidia
68 gigabit network card I can ping around 60k to 200k adresses per
69 second, depending on routing decisions.
70
71 Example: ping 10.0.0.1-10.0.0.15 with at most 100 packets/s, and
72 11.0.0.1-11.0.255.255 with at most 1000 packets/s. Do not, however,
73 exceed 1000 packets/s overall:
74
75 my $done = AnyEvent->condvar;
76
77 AnyEvent::FastPing::icmp_ping
78 [
79 [v10.0.0.1, v10.0.0.15, .01],
80 [v11.0.0.1, v11.0.255.255, .001],
81 ],
82 .001, 0x12345678,
83 sub {
84 warn "all ranges pinged\n";
85 $done->broadcast;
86 }
87 ;
88
89 $done->wait;
90
91 AnyEvent::FastPing::register_cb \&cb
92 Register a callback that is called for every received ping reply
93 (regardless of whether a ping is still in process or not and
94 regardless of whether the reply is actually a reply to a ping sent
95 earlier).
96
97 The code reference gets a single parameter - an arrayref with an
98 entry for each received packet (replies are beign batched for
99 greater efficiency). Each packet is represented by an arrayref with
100 three members: the source address (an octet string of either 4
101 (IPv4) or 16 (IPv6) octets length), the payload as passed to
102 "icmp_ping" and the round trip time in seconds.
103
104 Example: a single ping reply with payload of 1 from "::1" gets
105 passed like this:
106
107 [ [
108 "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\1",
109 "0.000280141830444336",
110 1
111 ] ]
112
113 Example: ping replies for 127.0.0.1 and 127.0.0.2, with a payload of
114 0x12345678:
115
116 [
117 [
118 "\177\0\0\1",
119 "0.00015711784362793",
120 305419896
121 ],
122 [
123 "\177\0\0\2",
124 "0.00090184211731",
125 305419896
126 ]
127 ]
128
129 AnyEvent::FastPing::unregister_cb \&cb
130 Unregister the callback again (make sure you pass the same
131 codereference as to "register_cb").
132
133 AUTHOR
134 Marc Lehmann <schmorp@schmorp.de>
135 http://home.schmorp.de/
136
137 AUTHOR
138 This software is distributed under the GENERAL PUBLIC LICENSE, version 2
139 or any later version or, at your option, the Artistic License.
140