Commit | Line | Data |
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6ce1669f H |
1 | /proc/sys/net/ipv4/vs/* Variables: |
2 | ||
3 | am_droprate - INTEGER | |
4 | default 10 | |
5 | ||
6 | It sets the always mode drop rate, which is used in the mode 3 | |
7 | of the drop_rate defense. | |
8 | ||
9 | amemthresh - INTEGER | |
10 | default 1024 | |
11 | ||
12 | It sets the available memory threshold (in pages), which is | |
13 | used in the automatic modes of defense. When there is no | |
14 | enough available memory, the respective strategy will be | |
15 | enabled and the variable is automatically set to 2, otherwise | |
16 | the strategy is disabled and the variable is set to 1. | |
17 | ||
7e777dd4 SH |
18 | conntrack - BOOLEAN |
19 | 0 - disabled (default) | |
20 | not 0 - enabled | |
21 | ||
22 | If set, maintain connection tracking entries for | |
23 | connections handled by IPVS. | |
24 | ||
25 | This should be enabled if connections handled by IPVS are to be | |
26 | also handled by stateful firewall rules. That is, iptables rules | |
27 | that make use of connection tracking. It is a performance | |
28 | optimisation to disable this setting otherwise. | |
29 | ||
30 | Connections handled by the IPVS FTP application module | |
31 | will have connection tracking entries regardless of this setting. | |
32 | ||
40cb1f9b | 33 | Only available when IPVS is compiled with CONFIG_IP_VS_NFCT enabled. |
7e777dd4 | 34 | |
6ce1669f H |
35 | cache_bypass - BOOLEAN |
36 | 0 - disabled (default) | |
37 | not 0 - enabled | |
38 | ||
39 | If it is enabled, forward packets to the original destination | |
40 | directly when no cache server is available and destination | |
41 | address is not local (iph->daddr is RTN_UNICAST). It is mostly | |
42 | used in transparent web cache cluster. | |
43 | ||
44 | debug_level - INTEGER | |
45 | 0 - transmission error messages (default) | |
46 | 1 - non-fatal error messages | |
47 | 2 - configuration | |
48 | 3 - destination trash | |
49 | 4 - drop entry | |
50 | 5 - service lookup | |
51 | 6 - scheduling | |
52 | 7 - connection new/expire, lookup and synchronization | |
53 | 8 - state transition | |
54 | 9 - binding destination, template checks and applications | |
55 | 10 - IPVS packet transmission | |
56 | 11 - IPVS packet handling (ip_vs_in/ip_vs_out) | |
57 | 12 or more - packet traversal | |
58 | ||
40cb1f9b | 59 | Only available when IPVS is compiled with CONFIG_IP_VS_DEBUG enabled. |
6ce1669f H |
60 | |
61 | Higher debugging levels include the messages for lower debugging | |
62 | levels, so setting debug level 2, includes level 0, 1 and 2 | |
63 | messages. Thus, logging becomes more and more verbose the higher | |
64 | the level. | |
65 | ||
66 | drop_entry - INTEGER | |
67 | 0 - disabled (default) | |
68 | ||
69 | The drop_entry defense is to randomly drop entries in the | |
70 | connection hash table, just in order to collect back some | |
71 | memory for new connections. In the current code, the | |
72 | drop_entry procedure can be activated every second, then it | |
73 | randomly scans 1/32 of the whole and drops entries that are in | |
74 | the SYN-RECV/SYNACK state, which should be effective against | |
75 | syn-flooding attack. | |
76 | ||
77 | The valid values of drop_entry are from 0 to 3, where 0 means | |
78 | that this strategy is always disabled, 1 and 2 mean automatic | |
79 | modes (when there is no enough available memory, the strategy | |
80 | is enabled and the variable is automatically set to 2, | |
81 | otherwise the strategy is disabled and the variable is set to | |
82 | 1), and 3 means that that the strategy is always enabled. | |
83 | ||
84 | drop_packet - INTEGER | |
85 | 0 - disabled (default) | |
86 | ||
87 | The drop_packet defense is designed to drop 1/rate packets | |
88 | before forwarding them to real servers. If the rate is 1, then | |
89 | drop all the incoming packets. | |
90 | ||
91 | The value definition is the same as that of the drop_entry. In | |
92 | the automatic mode, the rate is determined by the follow | |
93 | formula: rate = amemthresh / (amemthresh - available_memory) | |
94 | when available memory is less than the available memory | |
95 | threshold. When the mode 3 is set, the always mode drop rate | |
96 | is controlled by the /proc/sys/net/ipv4/vs/am_droprate. | |
97 | ||
98 | expire_nodest_conn - BOOLEAN | |
99 | 0 - disabled (default) | |
100 | not 0 - enabled | |
101 | ||
102 | The default value is 0, the load balancer will silently drop | |
103 | packets when its destination server is not available. It may | |
104 | be useful, when user-space monitoring program deletes the | |
105 | destination server (because of server overload or wrong | |
106 | detection) and add back the server later, and the connections | |
107 | to the server can continue. | |
108 | ||
109 | If this feature is enabled, the load balancer will expire the | |
110 | connection immediately when a packet arrives and its | |
111 | destination server is not available, then the client program | |
112 | will be notified that the connection is closed. This is | |
113 | equivalent to the feature some people requires to flush | |
114 | connections when its destination is not available. | |
115 | ||
116 | expire_quiescent_template - BOOLEAN | |
117 | 0 - disabled (default) | |
118 | not 0 - enabled | |
119 | ||
120 | When set to a non-zero value, the load balancer will expire | |
121 | persistent templates when the destination server is quiescent. | |
122 | This may be useful, when a user makes a destination server | |
123 | quiescent by setting its weight to 0 and it is desired that | |
124 | subsequent otherwise persistent connections are sent to a | |
125 | different destination server. By default new persistent | |
126 | connections are allowed to quiescent destination servers. | |
127 | ||
128 | If this feature is enabled, the load balancer will expire the | |
129 | persistence template if it is to be used to schedule a new | |
130 | connection and the destination server is quiescent. | |
131 | ||
132 | nat_icmp_send - BOOLEAN | |
133 | 0 - disabled (default) | |
134 | not 0 - enabled | |
135 | ||
136 | It controls sending icmp error messages (ICMP_DEST_UNREACH) | |
137 | for VS/NAT when the load balancer receives packets from real | |
138 | servers but the connection entries don't exist. | |
139 | ||
140 | secure_tcp - INTEGER | |
141 | 0 - disabled (default) | |
142 | ||
325aadc8 SH |
143 | The secure_tcp defense is to use a more complicated TCP state |
144 | transition table. For VS/NAT, it also delays entering the | |
145 | TCP ESTABLISHED state until the three way handshake is completed. | |
6ce1669f | 146 | |
325aadc8 | 147 | The value definition is the same as that of drop_entry and |
6ce1669f H |
148 | drop_packet. |
149 | ||
150 | sync_threshold - INTEGER | |
151 | default 3 | |
152 | ||
153 | It sets synchronization threshold, which is the minimum number | |
154 | of incoming packets that a connection needs to receive before | |
155 | the connection will be synchronized. A connection will be | |
156 | synchronized, every time the number of its incoming packets | |
157 | modulus 50 equals the threshold. The range of the threshold is | |
158 | from 0 to 49. | |
7e777dd4 SH |
159 | |
160 | snat_reroute - BOOLEAN | |
161 | 0 - disabled | |
162 | not 0 - enabled (default) | |
163 | ||
164 | If enabled, recalculate the route of SNATed packets from | |
165 | realservers so that they are routed as if they originate from the | |
166 | director. Otherwise they are routed as if they are forwarded by the | |
167 | director. | |
168 | ||
169 | If policy routing is in effect then it is possible that the route | |
170 | of a packet originating from a director is routed differently to a | |
171 | packet being forwarded by the director. | |
172 | ||
173 | If policy routing is not in effect then the recalculated route will | |
174 | always be the same as the original route so it is an optimisation | |
175 | to disable snat_reroute and avoid the recalculation. | |
176 | ||
177 | sync_version - INTEGER | |
178 | default 1 | |
179 | ||
180 | The version of the synchronisation protocol used when sending | |
181 | synchronisation messages. | |
182 | ||
183 | 0 selects the original synchronisation protocol (version 0). This | |
184 | should be used when sending synchronisation messages to a legacy | |
185 | system that only understands the original synchronisation protocol. | |
186 | ||
187 | 1 selects the current synchronisation protocol (version 1). This | |
188 | should be used where possible. | |
189 | ||
190 | Kernels with this sync_version entry are able to receive messages | |
191 | of both version 1 and version 2 of the synchronisation protocol. |