| 1 | NAME |
1 | NAME |
| 2 | AnyEvent::SNMP - adaptor to integrate Net::SNMP into Anyevent. |
2 | AnyEvent::SNMP - adaptor to integrate Net::SNMP into AnyEvent. |
| 3 | |
3 | |
| 4 | SYNOPSIS |
4 | SYNOPSIS |
| 5 | use AnyEvent::SNMP; |
5 | use AnyEvent::SNMP; |
| 6 | use Net::SNMP; |
6 | use Net::SNMP; |
| 7 | |
7 | |
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| 20 | # ... do something else until the result is required |
20 | # ... do something else until the result is required |
| 21 | my @result = $cv->wait; |
21 | my @result = $cv->wait; |
| 22 | |
22 | |
| 23 | DESCRIPTION |
23 | DESCRIPTION |
| 24 | This module implements an alternative "event dispatcher" for Net::SNMP, |
24 | This module implements an alternative "event dispatcher" for Net::SNMP, |
| 25 | using AnyEvent as a backend. |
25 | using AnyEvent as a backend. This integrates Net::SNMP into AnyEvent. |
| 26 | |
26 | That means you can make non-blocking Net::SNMP calls and as long as |
| 27 | This integrates Net::SNMP into AnyEvent: You can make non-blocking |
27 | other parts of your program also use AnyEvent (or some event loop |
| 28 | Net::SNMP calls and as long as other parts of your program also use |
28 | supported by AnyEvent), they will run in parallel. |
| 29 | AnyEvent (or some event loop supported by AnyEvent), they will run in |
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| 30 | parallel. |
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| 31 | |
29 | |
| 32 | Also, the Net::SNMP scheduler is very inefficient with respect to both |
30 | Also, the Net::SNMP scheduler is very inefficient with respect to both |
| 33 | CPU and memory usage. Most AnyEvent backends (including the pure-perl |
31 | CPU and memory usage. Most AnyEvent backends (including the pure-perl |
| 34 | backend) fare much better than the Net::SNMP dispatcher. |
32 | backend) fare much better than the Net::SNMP dispatcher. |
| 35 | |
33 | |
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34 | Another major added fetaure of this module over Net::SNMP is automatic |
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35 | rate-adjustments: Net::SNMP is so slow that firing a few thousand |
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36 | requests can cause many timeouts simply because Net::SNMP cannot process |
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37 | the replies in time. This module automatically adapts the send rate to |
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38 | avoid false timeouts caused by slow reply processing. |
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39 | |
| 36 | A potential disadvantage is that replacing the dispatcher is not at all |
40 | A potential disadvantage of this module is that replacing the dispatcher |
| 37 | a documented thing to do, so future changes in Net::SNP might break this |
41 | is not at all a documented thing to do, so future changes in Net::SNP |
| 38 | module (or the many similar ones). |
42 | might break this module (or the many similar ones). |
| 39 | |
43 | |
| 40 | This module does not export anything and does not require you to do |
44 | This module does not export anything and does not require you to do |
| 41 | anything special apart from loading it *before doing any non-blocking |
45 | anything special apart from loading it *before doing any non-blocking |
| 42 | requests with Net::SNMP*. It is recommended but not required to load |
46 | requests with Net::SNMP*. It is recommended but not required to load |
| 43 | this module before "Net::SNMP". |
47 | this module before "Net::SNMP". |
| 44 | |
48 | |
| 45 | GLOBAL VARIABLES |
49 | GLOBAL VARIABLES |
| 46 | $AnyEvent::SNMP::MAX_OUTSTANDING (default: 50, dynamic) |
50 | $AnyEvent::SNMP::MAX_OUTSTANDING (default: 50, dynamic) |
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51 | AnyEvent::SNMP::set_max_outstanding $new_value |
| 47 | Use this package variable to restrict the number of outstanding SNMP |
52 | Use this package variable to restrict the number of outstanding SNMP |
| 48 | requests at any point in time. |
53 | requests at any point in time. |
| 49 | |
54 | |
| 50 | Net::SNMP is very fast at creating and sending SNMP requests, but |
55 | Net::SNMP is very fast at creating and sending SNMP requests, but |
| 51 | much slower at parsing (big, bulk) responses. This makes it easy to |
56 | much slower at parsing (big, bulk) responses. This makes it easy to |
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| 62 | |
67 | |
| 63 | Unfortunately, this number depends not only on processing speed and |
68 | Unfortunately, this number depends not only on processing speed and |
| 64 | load of the machine running Net::SNMP, but also on the network |
69 | load of the machine running Net::SNMP, but also on the network |
| 65 | latency and the speed of your SNMP agents. |
70 | latency and the speed of your SNMP agents. |
| 66 | |
71 | |
| 67 | AnyEvent::SNMP tries to dynamically adjust this number dynamically |
72 | AnyEvent::SNMP tries to dynamically adjust this number upwards and |
| 68 | upwards and downwards. |
73 | downwards. |
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74 | |
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75 | Increasing $MAX_OUTSTANDING will not automatically use the extra |
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76 | request slots. To increase $MAX_OUTSTANDING and make |
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77 | "AnyEvent::SNMP" make use of the extra paralellity, call |
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78 | "AnyEvent::SNMP::set_max_outstanding" with the new value, e.g.: |
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79 | |
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80 | AnyEvent::SNMP::set_max_outstanding 500; |
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81 | |
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82 | Although due to the dynamic adjustment, this might have little |
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83 | lasting effect. |
| 69 | |
84 | |
| 70 | Note that you can use Net::SNMP::XS to speed up parsing of responses |
85 | Note that you can use Net::SNMP::XS to speed up parsing of responses |
| 71 | considerably. |
86 | considerably. |
| 72 | |
87 | |
| 73 | $AnyEvent::SNMP::MIN_RECVQUEUE (default: 4) |
88 | $AnyEvent::SNMP::MIN_RECVQUEUE (default: 8) |
| 74 | $AnyEvent::SNMP::MAX_RECVQUEUE (default: 64) |
89 | $AnyEvent::SNMP::MAX_RECVQUEUE (default: 64) |
| 75 | These values specify the minimum and maximum receive queue length |
90 | These values specify the minimum and maximum receive queue length |
| 76 | (in units of one response packet). |
91 | (in units of one response packet). |
| 77 | |
92 | |
| 78 | When AnyEvent::SNMP handles $MAX_RECVQUEUE or more packets per |
93 | When AnyEvent::SNMP handles $MAX_RECVQUEUE or more packets per |
