[pgpool-general: 7777] Re: Virtual IP not reachable after if_up_cmd setup

[Bo Peng]

Hello,

The settings of delegate_IP, if_up_cmd,if_down_cmd and arping_cmd are used for on-premises.
If you are running your cluster on AWS, you need to configure 
wd_escalation_command and wd_de_escalation_command.

There are several ways to setup virtual IP on AWS.

For example:
- use an elastic ip
– configure Route53
– create route tabale for a private VIP

The following documetation is using an "elastic ip".

  https://www.pgpool.net/docs/latest/en/html/example-aws.html

On Tue, 12 Oct 2021 20:26:04 +0300
Nirav Bhatt <niravbhatt.cpp at gmail.com> wrote:

> Hello,
> 
> Inside my AWS cloud, I have following 3 servers
> 
> (all 3 can reach each other very fine using ping server1, ping server2,
> ping server3 as well as IP address.):
> 
> 10.192.10.10 server1
> 10.192.11.20 server2
> 10.192.12.30 server3
> 
> 10.192.10.40 Virtual IP (I want this to be private, not elastic which is
> public)
> 
> I was testing the following  if_up_cmd command on server1:
> 
> /usr/bin/sudo /sbin/ip addr add 10.192.10.40/32 dev ens5 label ens5:0
> 
> I could see new IP in the ifconfig result:
> 
> ens5: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9001
>         inet 10.192.10.10  netmask 255.255.255.0  broadcast 10.192.10.255
>         inet6 fe80::4b0:29ff:fe38:3399  prefixlen 64  scopeid 0x20<link>
>         ether 06:b0:29:38:33:99  txqueuelen 1000  (Ethernet)
>         RX packets 67233  bytes 67464992 (67.4 MB)
>         RX errors 0  dropped 0  overruns 0  frame 0
>         TX packets 22922  bytes 5116469 (5.1 MB)
>         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
> 
> ens5:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9001
>         inet 10.192.10.40  netmask 255.255.255.255  broadcast 10.192.10.255
>         ether 06:b0:29:38:33:99  txqueuelen 1000  (Ethernet)
> 
> lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
>         inet 127.0.0.1  netmask 255.0.0.0
>         inet6 ::1  prefixlen 128  scopeid 0x10<host>
>         loop  txqueuelen 1000  (Local Loopback)
>         RX packets 39948  bytes 13976834 (13.9 MB)
>         RX errors 0  dropped 0  overruns 0  frame 0
>         TX packets 39948  bytes 13976834 (13.9 MB)
>         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
> 
> However, after running the ip addr add, I can not ping the new elastic IP
> 10.192.10.40 from other servers. Only server1 has successful ping.
> 
> I tried running arping past the above, but that is also failing.
> 
> arping -U 10.192.10.40 -w 1 -I ens5:1
> 
> I tried adding and deleting several times, with different IP combinations
> also to suit different AWS subnets, but no result. Server2 and server3
> can't simply reach it.
> 
> My system is Ubuntu, the AMI is following, in case it helps:
> ubuntu/images/hvm-ssd/ubuntu-focal-20.04-arm64-server-20211001
> 
> Thanks for the support!
> -Nirav


-- 
Bo Peng <pengbo at sraoss.co.jp>
SRA OSS, Inc. Japan
http://www.sraoss.co.jp/