Solved

Redundancy / Synchronization

Posted on 2014-09-05
3
164 Views
Last Modified: 2014-09-12
I am running a number of Xen PV machines on CentOS 6 (using SolusVM) on a number of physical machines in 3 datacenters.
My client is asking my to provide a redundant solution that his machine is in realtime sync with another at a different datacenter that if his Virtual Machine goes down for any reason the other Virtual machine in a different datacenter is available.
I am not sure how to proceed and will be very thankful for any help.
0
Comment
Question by:sysautomation
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 12

Expert Comment

by:Kent W
ID: 40307224
The biggest hurdle here is "what is he syncing"?
Files, database(s)?
Basically you can sync files on a schedule with rsync, databases a few different methods, but step one is get what's needed replicated.
Next you want either a load balancer (haproxy is great and open source), or a DNS failover service like dnsmadeasy.
I use both.
I'd start with DNSME, it's cheap and works great.
If you do a load balancer you would want it to be either at your failover Dc or an independent dc.  Not the same place as your primary server is the key.
With an LB, you also get the benefit of using both servers to double your handling capacity if you want, or just config one as a backup that only gets traffic if your primary is down.
0
 

Author Comment

by:sysautomation
ID: 40307246
Thanks for the help. The server is running Oracle Express Edition 11g and that's the primary thing to be synced. This version of Oracle does not support sync but some expensive version supports. That's why I thought doing this at VM/OS level. The biggest issue is the customer needs it in real-time and would it be really possible doing it with rsync because of real-time?
0
 
LVL 12

Accepted Solution

by:
Kent W earned 500 total points
ID: 40307258
For real time no.  Rsync would not do it.   Unless you were ok with minutes behind.  It's sure cheap if a few minutes aren't a deal breaker.  
DRDB offers block level replication, open source.  Real time replication with buffers / quorum cost quite a bit. Xosoft is thousands.
Neverfail is about the same.
Unless he has a big budget, then block level rep, aside from DRDB, isn't going to be cheap.
If it's *just* the database you need synced, and I'm not big on oracle,  if your version allows it, most databases support the equivalent of master / slave replication.
If that is possible, then you can simply replicate the data to your slave backup, use DNSME or a load balancer for failure detection and failover.
0

Featured Post

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Citrix policies are the most efficient method to configure and tune XenDesktop environments, allowing organizations to control connection, security and bandwidth settings based on various combinations of users, devices or connection types.  Citrix …
In this article, I will show you HOW TO: Perform a Physical to Virtual (P2V) Conversion the easy way from a computer backup (image).
Learn several ways to interact with files and get file information from the bash shell. ls lists the contents of a directory: Using the -a flag displays hidden files: Using the -l flag formats the output in a long list: The file command gives us mor…
Connecting to an Amazon Linux EC2 Instance from Windows Using PuTTY.

710 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question