04-14-2009 11:00 PM
Hi,
I have ACE module and 2 servers the problem i am facing is only one server is been serviced by ACE the other server is not getting much traffic at all.
One server gets hit most of the time like 3 pkts goes to server 1 and 1 pkt goes to server 2.
Could anyone tell me why is this issue that unequal load balancing is occoring on my device.
Thanks in advance.
04-14-2009 11:14 PM
Hi,
Did you configure a weight for each server?
What loadbalancing method are you using? Round-robin (default), least conns?
Can you post your config and the output of "show service-policy name_of_policy" and "show serverfarm name_of_serverfarm"
04-22-2009 05:35 AM
Hi,
I've got the same issue with the ACE module. All the outputs show that the load is evenly distributed, but the load of the first server is twofold from the second. Here's the configuration.
access-list ALL line 10 extended permit ip any any
probe dns DNS_PROBE
domain http://www.online.kz
expect address 89.218.40.131
probe icmp ICMP_PROBE
interval 10
rserver host DNS-118-1
ip address 10.0.0.1
inservice
rserver host DNS-118-2
ip address 10.0.0.2
inservice
serverfarm host DNS
probe DNS_PROBE
rserver DNS-118-1
inservice
rserver DNS-118-2
inservice
class-map match-any CLASS_MAP
2 match virtual-address 10.0.0.3 tcp eq domain
3 match virtual-address 10.0.0.3 udp eq domain
policy-map type loadbalance first-match L7_LOADB
class class-default
serverfarm DNS
policy-map multi-match L3L4_LOADB
class CLASS_MAP
loadbalance vip inservice
loadbalance policy L7_LOADB
loadbalance vip icmp-reply active
loadbalance vip advertise active
nat dynamic 1 vlan 118
service-policy input L3L4_LOADB
interface vlan 118
bridge-group 118
no icmp-guard
access-group input ALL
access-group output ALL
nat-pool 1 10.0.0.3 10.0.0.3 netmask 255.255.255.255 pat
no shutdown
interface bvi 118
ip address 10.0.0.4 255.255.255.240
alias 10.0.0.5 255.255.255.240
peer ip address 10.0.0.6 255.255.255.240
no shutdown
ft interface vlan 120
ip address 10.245.10.33 255.255.255.248
peer ip address 10.245.10.34 255.255.255.248
no shutdown
ft peer 1
heartbeat interval 300
heartbeat count 10
ft-interface vlan 120
ft group 1
peer 1
priority 150
associate-context Admin
inservice
ip route 0.0.0.0 0.0.0.0 10.0.0.254
04-22-2009 05:37 AM
here's the output of
sh serverfarm det
serverfarm : DNS, type: HOST
total rservers : 2
active rservers: 2
description : -
state : ACTIVE
predictor : ROUNDROBIN
failaction : -
back-inservice : 0
partial-threshold : 0
num times failover : 0
num times back inservice : 0
total conn-dropcount : 0
Probe(s) :
DNS_PROBE, type = DNS
---------------------------------
----------connections-----------
real weight state current total failures
---+---------------------+------+------------+----------+----------+---------
rserver: DNS-118-1
10.0.0.1:0 8 OPERATIONAL 206 127901 1
max-conns : - , out-of-rotation count : -
min-conns : -
conn-rate-limit : - , out-of-rotation count : -
bandwidth-rate-limit : - , out-of-rotation count : -
retcode out-of-rotation count : -
load value : 0
rserver: DNS-118-2
10.0.0.2:0 8 OPERATIONAL 230 212332 4
max-conns : - , out-of-rotation count : -
min-conns : -
conn-rate-limit : - , out-of-rotation count : -
bandwidth-rate-limit : - , out-of-rotation count : -
retcode out-of-rotation count : -
load value : 0
here's the output of
sh service-policy L3L4_LOADB detail
Status : ACTIVE
Description: -----------------------------------------
Context Global Policy:
service-policy: L3L4_LOADB
class: CLASS_MAP
nat:
nat dynamic 1 vlan 118
curr conns : 325 , hit count : 340457
dropped conns : 5
client pkt count : 2697687 , client byte count: 179735431
server pkt count : 2694477 , server byte count: 535957631
conn-rate-limit : 0 , drop-count : 0
bandwidth-rate-limit : 0 , drop-count : 0
VIP Address: Protocol: Port:
10.0.0.3 tcp eq 53
10.0.0.3 udp eq 53
loadbalance:
L7 loadbalance policy: L7_LOADB
VIP Route Metric : 77
VIP Route Advertise : ENABLED-WHEN-ACTIVE
VIP ICMP Reply : ENABLED-WHEN-ACTIVE
VIP State: INSERVICE
curr conns : 325 , hit count : 340462
dropped conns : 5
client pkt count : 2697687 , client byte count: 179735431
server pkt count : 2694477 , server byte count: 535957631
conn-rate-limit : 0 , drop-count : 0
bandwidth-rate-limit : 0 , drop-count : 0
L7 Loadbalance policy : L7_LOADB
class/match : class-default
LB action: :
primary serverfarm: DNS
state: UP
backup serverfarm : -
hit count : 340457
dropped conns : 0
04-22-2009 05:43 AM
Hi,
both your servers are serving at the moment of the output more or less equally used:
real weight state current total failures
---+---------------------+------+------------+----------+----------+---------
rserver: DNS-118-1
10.0.0.1:0 8 OPERATIONAL 206 127901 1
rserver: DNS-118-2
10.0.0.2:0 8 OPERATIONAL 230 212332 4
server DNS-118-1 has 206 current connections, server DNS-118-2 has 230 current connections.
try clearing the counters and see if they remain more or less equal.
clear serverfarm DNS
HTH,
Dario
04-22-2009 05:48 AM
I tried to clear counters. They always remain equal, but the actual information is nothing compared to the output. Servers' logs show that one of them is twice as loaded as the first one.
04-22-2009 05:55 AM
Before I upgraded ACE software to 3.0(0)A2(1.4a) the situation was even worse. The load of the second server was 10x of the first one along with the same configuration.
08-11-2009 12:52 AM
I have resolved this issue. In my realisation there are 2 DNS servers - so the ACE deals with UDP flows. ACE can inadequately interpret UDP flows and assign multiple flows to one for some reason. This leads to uneven loadbalancing.
I configured Layer 7 loadbalancing policy for my serverfarm as "generic". Then I applied class this Layer 7 policy inside Layer 4 policy along with "loadbalance vip udp-fast-age". This command seems to correct the issue.
08-12-2009 07:43 AM
Thank you for posting what solved the issue. This is very good for the forum that we have the possibility of learning from what other people have dealt with.
Rgds, Ingolf
02-07-2010 12:18 AM
02-07-2010 12:44 PM
Hi Jimmy,
i think it have no sense to put fast age and timeout conn of 120 seconds (is the default).
Try to remove conn map and say us if you have resolved issue.
BR
Danilo
02-08-2010 01:44 AM
Hi Danilo,
Thanks for the reply. I have tried to remove that connection parameter, but it still showing the same symptom.
I've tried to change the topology to L3 too, but still, same result.
Thanks.
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