load-balancing: inbound: T3116: Support back-end L4 load balancing

[jack9603301]

Change Summary

Support back-end L4 load balancing

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Code style update (formatting, renaming)
• [ ] Refactoring (no functional changes)
• [ ] Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• [ ] Other (please describe):

Related Task(s)

https://phabricator.vyos.net/T3116

Component(s) name

load-balancing

Proposed changes

Support back-end L4 load balancing

How to test

Checklist:

• [x] I have read the CONTRIBUTING document
• [x] I have linked this PR to one or more Phabricator Task(s)
• [x] My commit headlines contain a valid Task id
• [x] My change requires a change to the documentation
• [ ] I have updated the documentation accordingly

[github-actions[bot]]

This pull request has conflicts, please resolve those before we can evaluate the pull request.

[sever-sever]

Update make file. It has some conflicts. For the rest, I approve.

[github-actions[bot]]

Conflicts have been resolved. A maintainer will review the pull request shortly.

[helixzz]

Hi there, I was wondering that when will this PR merge to main branch? @jack9603301 @c-po Just found the implement was done half year ago.

Really looking forward to see LVS (inbound load balancing) cound be a built-in feature in VyOS! =)

[c-po]

Well depending on your usecase, therebis already support for http inbound load balancind (through keepalived)

[andamasov]

@dmbaturin can you review this

[jack9603301]

Well depending on your usecase, therebis already support for http inbound load balancind (through keepalived)

It's not just HTTP, in fact it can perform load balancing on the four-layer protocol, and LVS is one of the well-known open source implementations, and keepalived is only hot backup in nature

The implementation is basically awaiting review, would love to see it become a built-in feature of vyos

[sever-sever]

keepalived is only hot backup in nature

It is not only "backup" it also uses a load-balancing feature, I guess it also uses LVS as a backend https://github.com/vyos/vyos-1x/blob/a09359828e38c5b51a4579af16b5ea263a98233f/interface-definitions/high-availability.xml.in#L286 https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/load_balancer_administration/ch-initial-setup-vsa#s3-initial-setup-conf-file-virt-VSA https://keepalived.readthedocs.io/en/latest/terminology.html

[jack9603301]

keepalived is only hot backup in nature

It is not only "backup" it also uses a load-balancing feature, I guess it also uses LVS as a backend

https://github.com/vyos/vyos-1x/blob/a09359828e38c5b51a4579af16b5ea263a98233f/interface-definitions/high-availability.xml.in#L286

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/load_balancer_administration/ch-initial-setup-vsa#s3-initial-setup-conf-file-virt-VSA https://keepalived.readthedocs.io/en/latest/terminology.html

ok, this could be another wrapper around ipvs, maybe it would be better if we could use ipvs directly?

And I seem to find an interesting place, that is, the implementation time of keepalived's load balancing function is later than LVS

[roedie]

Keepalived and ipvsadm both use the IPVS framework. ipvsadm is the original tool to configure IPVS (just like iptables is the netfilter config tool). Keepalived has some advantage because you can make your Loadbalancer HA, do backend service health checks (remove dead IPVS backends for example) and configure IPVS in one place.

ipvsadmonly had advantage if you want to use IPVS but not make your loadbalancer HA. AFAIK you have to create your own backend checks.

Will it stil be possible to use both?

[jack9603301]

Keepalived and ipvsadm both use the IPVS framework. ipvsadm is the original tool to configure IPVS (just like iptables is the netfilter config tool). Keepalived has some advantage because you can make your Loadbalancer HA, do backend service health checks (remove dead IPVS backends for example) and configure IPVS in one place.

ipvsadmonly had advantage if you want to use IPVS but not make your loadbalancer HA. AFAIK you have to create your own backend checks.

Will it stil be possible to use both?

you mean?

[dmbaturin]

There are now implementations in 1.4 based on both Keepalived/LVS and HAProxy, so this is redundant, unfortunately.