ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/AnyEvent-FastPing/README
Revision: 1.7
Committed: Tue Nov 17 21:38:07 2009 UTC (14 years, 6 months ago) by root
Branch: MAIN
CVS Tags: rel-1_12
Changes since 1.6: +7 -7 lines
Log Message:
1.12

File Contents

# User Rev Content
1 root 1.3 NAME
2 root 1.5 AnyEvent::FastPing - quickly ping a large number of hosts
3 root 1.3
4     SYNOPSIS
5 root 1.5 use AnyEvent::FastPing;
6 root 1.3
7     DESCRIPTION
8 root 1.6 This module was written for a single purpose only: sending ICMP ECHO
9 root 1.3 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 root 1.5 AnyEvent::FastPing::ipv4_supported
18 root 1.3 Returns true if IPv4 is supported in this module and on this system.
19    
20 root 1.5 AnyEvent::FastPing::ipv6_supported
21 root 1.3 Returns true if IPv6 is supported in this module and on this system.
22    
23 root 1.5 AnyEvent::FastPing::icmp4_pktsize
24 root 1.3 Returns the number of bytes each IPv4 ping packet has.
25    
26 root 1.5 AnyEvent::FastPing::icmp6_pktsize
27 root 1.3 Returns the number of bytes each IPv4 ping packet has.
28    
29 root 1.5 AnyEvent::FastPing::icmp_ping [ranges...], $send_interval, $payload,
30     \&callback
31 root 1.3 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 root 1.7 pings will be sent as fast as possible.
43 root 1.3
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 root 1.5 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 root 1.3 .001, 0x12345678,
83     sub {
84     warn "all ranges pinged\n";
85     $done->broadcast;
86     }
87     ;
88    
89     $done->wait;
90    
91 root 1.5 AnyEvent::FastPing::register_cb \&cb
92 root 1.3 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 root 1.5 regardless of whether the reply is actually a reply to a ping sent
95 root 1.3 earlier).
96    
97     The code reference gets a single parameter - an arrayref with an
98 root 1.7 entry for each received packet (replies are being batched for
99 root 1.3 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 root 1.5 AnyEvent::FastPing::unregister_cb \&cb
130 root 1.3 Unregister the callback again (make sure you pass the same
131     codereference as to "register_cb").
132    
133     AUTHOR
134 root 1.7 Marc Lehmann <schmorp@schmorp.de>
135     http://home.schmorp.de/
136 root 1.3
137 root 1.7 LICENSE
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 root 1.3