OD 10.1 Active Active High Availability implementation

[fbucchi]

Hi, I was reading the topic about the subject

http://www.odusergroup.org/forums/index.php?topic=2226.0

Has anyone implemented this solution? I have some doubts that may be someone can help me

Zookeeper
The three ZooKeeper servers should be on different machines than CMOD Servers? or could be run in the same machine?

DB2
We use DB2,  and in the first step, we need to migrate to DB2 pureScale to have shared database accesible from at least two CMOD Servers (we need to define if will have two or more OD servers)

arscache
I guess that if we have a shared file system accesible from CMOD servers, should be OK. Is correct ?

TSM
What's about TSM Server, we can keep only TSM Server?

if we load the information in only one CMOD server, should be accessible from the second CMOD Server?

Thanks in advance
Federico Bucchi

[Justin Derrick]

I don't know anyone who has rolled out this implementation yet -- mostly because of the huge cost in terms of servers.  A multi-terabyte server is going to require about 11 VMs in order to operate properly...  3 x AZK, 2 x DB2, 2 x NAS (for arscache), 2 x TSM, 2 x CMOD.  Now, with Rob Russel's article on IBM CMOD Docker Containers, it might make some of this easier to deploy, but it's still a little crazy in terms of infrastructure for what is already a very reliable service.

I still recommend Independent-Redundant configs for large CMOD customers who have a requirement for greater than three-nines (99.9%) uptime.

-JD.

[fbucchi]

Hi Justin! thanks for your answer! justly, we have other customer with these architecture (two independient CMOD servers) and we don't have problems! but we need to expose both options to the other customer!

Regards

[SV]

I did a POC. Not deployed to test / or prod
Zookeeper: can run on cmod servers
arscache: should be on shared file system
TSM: can always be on it own server or can use one of the cmod server; And CMOD accesses TS via TSM client. so yes.
yes when you losad from any one of the CMOD server, you can access from any other cmod server in this active/active configuration.

[fbucchi]

Thanks for reply SV! we are analyzing this Active Active option, or Active Pasive with HADR or HACMP!

[Justin Derrick]

HACMP isn't really that useful anymore.  It's so rare to get a hardware failure that I don't think it's worth the added expense.  The cost of having a whole other server, sitting, idle, waiting for that one in a billion chance...  Just seems wasteful.  If I'm going to have two servers, run two servers independently and split the load -- so you can serve twice as many users.

-JD.

[fbucchi]

Thanks Justin!!

[Alessandro Perucchi]

An additional question, must DB2 also be in HADR mode? Or if we have a "simple" DB2 is also ok?
I know this is not what you want for prod, but for testing or doing a quick prototype.

[fbucchi]

Hi Alessandro...as you said, in Prod we need to have HA in all  products for audit requirements (DB2, CMOD, TSM) but for license and hardware costs, in dev we'll have a simple installation. I guess that we'll test in Lab and then apply in Prod, but before we need to define with the customer the architecture (HADR for DB2 or DB2pureScale, etc, etc)
Thanks and regards