Tutorial: Sentora Panel in a HA / Clustered Environment - ADVANCED USERS ONLY

[sincitycloud]

So I was able to easily (for me) to make Sentora work in a HA in a clustered environment just like I did with Zpanel in May 2014 (my old zpanel forum name was lcsunshine).

Sentora's new rewritten code handles sessions and mysql connections much better where as zpanel when talking to a Percona MySQL 5.5 cluster via a haproxy load balancer wouldn't display modules forcing a refresh.

Just as a quick disclosure I don't want to come off as a jerk but this is for the advanced / expert users/admins/sys engineers, if you don't know how to or what Percona XtraDB Cluster / MySQL Clustering, HAProxy, iSCSI/NFS SANs, Hypervisor are etc... STOP NOW and do not try this tutorial; read up on them, play with them first, and teach your self before you tackle this tutorial.

For this tutorial we are going to do this over the course of the next couple of days and use 1 pair of HAProxy Load balancers with keepalive and VRRP w/ virtual/floating IP address; for the Load Balancer builds I will just link to another tutorial which will show you how to do that, I will also just link to the Percona XtraDB 5.5 Instructions as well, I have no affiliation with these other sites I just feel they are the best directions with illustrations I found.

Besides not having a single point of failure, a benefit of clustering Sentora is the the ability to grow / expand in a shared hosting environment, this is essential the foundation for shared grid hosting over multiple nodes! The major paid server control panel vendors are behind the ball on this, and still have the mind set of: "1 server / 1 panel all my eggs in one basket".

So if you want to build a multi node HA Cluster for Sentora here is everything you are going to need.

1. Your choice of cloud hypervisor: VMWare, Xen, HyperV, KVM etc
   
2. One iSCSI/NFS SAN (clustered or single your choice; since we are trying to avoid a single point of failure a cluster iSCSI/NFS SAN is best)
   
3. Six Virtual Servers (2 for Database Cluster we prefer Percona XtraDB v5.5, 2 for Load Balancers, 2 for the Sentora Panel Server & Services) running Centos 6.6 / 7 (For this tutorial I will use Centos 6.6)
   

Install Centos 6.6 on 2 VMs and Build your Percona XtraDB Cluster v5.5.X as outlined here unless you have your own method:
http://www.percona.com/doc/percona-xtradb-cluster/5.5/
http://www.percona.com/doc/percona-xtrad...ation.html

Install Centos 6.6 on 2 VMs and Build your HAProxy Cluster as outlined hereunless you have your own method:
Keepalived: http://tecadmin.net/ip-failover-setup-us...-redhat-6/
HAProxy: http://www.serverlab.ca/tutorials/linux/...-centos-6/

Install Centos 6.6 on 2 VMs  and run the Sentora install as outlined here:
http://docs.sentora.org/?node=7

We will continue this post tomorrow afternoon / night with the next steps......

Feel Free to ask questions in the mean time.

---
Donald DAvanzo
Chief Technology Officer
www.SinCityCloud.com

[Me.B]

Did you try using DRDB with this setup?

remember your old post.

[sincitycloud]

Did you try using DRDB with this setup?

remember your old post.

No haven't worked with DRDB, but I know it is ver similar to what Legato Replistor did when I worked with it 10 years back for DR setups/builds in the banking, finance, and hedge fund sectors which were all SEC regulated when it came to IT and infrastructure.

I used to work at a very large datacenter in New York who hosted & managed very high profile clients prior to taking my position as the CTO for SinCityCloud.com; for this project I am trying to stick with what has been used/tested, and is "tried and true" in a production environment.

But DRDB is on my radar for a few other projects we are testing in our Lab.

[j.waibel]

On my testing maschine i replaced mysql, after the installation been compleded, by a MariaDB galera setup.
This worked without any changes to the sentora setup and could be used for a ha/failover clustering of the database to.

J.

[Me.B]

Mysql support failover without an issue. Also in centos 7 you got mariaDB as default DB engine.

M B

[sincitycloud]

On my testing maschine i replaced mysql, after the installation been compleded, by a MariaDB galera setup.
This worked without any changes to the sentora setup and could be used for a ha/failover clustering of the database to.

J.

So you kept your MySQL DB local and then replicate it an external DB server?

Only issue with not changing the config files is that they resolve to localhost (127.0.0.1), so if your DB fails locally for whatever reason Sentora, Apps / Services etc won't know to look at the second external DB server.

But if you go through a load balancer it would detect that MariaDB1 failed and send all SQL requests to MariaDB2

But please correct me if I am misunderstanding your setup.

[Me.B]

On my testing maschine i replaced mysql, after the installation been compleded, by a MariaDB galera setup.
This worked without any changes to the sentora setup and could be used for a ha/failover clustering of the database to.

J.

So you kept your MySQL DB local and then replicate it an external DB server?

Only issue with not changing the config files is that they resolve to localhost (127.0.0.1), so if your DB fails locally for whatever reason Sentora, Apps / Services etc won't know to look at the second external DB server.

But if you go through a load balancer it would detect that MariaDB1 failed and send all SQL requests to MariaDB2

But please correct me if I am misunderstanding your setup.

if you user a DNS for MySQL with short TTL that get updated in case of failure that would do the trick.

We can also set a php test if server fails switch to backup server but that means too changing some how the default config.