03-26-2015 01:51 PM
Our SAS 9.3 EBI servers are located in the primary data center in one location and we're asked to build a DR environment for SAS 9.3 EBI servers in a different data center that is geographically separate. The PROD SAS servers and DR SAS servers are on different host machines in different network domains.
I checked with SAS Tech Support about this topic, but was told that that is no official SAS provided way/solution for this purpose. I'm wondering if there is any way to achieve this goal with SAS 9.3, especially for incremental backup/restore purpose?
03-26-2015 08:07 PM
We have a full DR setup similar to your requirement. According to our SAS licence, as long as we only use one of the SAS server locations at a time, then that is OK - we only pay for a primary set of servers. This can be accomplished by using server CNAMEs instead of actual server names.
We have nightly replication of SAS metadata and nightly incremental replication of SAS data using custom scripts and a tool called ROBOCOPY. Not very sophisticated but it works. Remember you have to shutdown your SAS servers so particularly metadata can be correctly copied. Then you have to start SAS services back up again, all in the correct order.
There are no SAS-provided tools to do this automated replication and this is certainly a weakness. Also there is no detailed documentation on what is required so it is very much a case of experience plus trial and error. SAS 9.3 replication is relatively straightforward, but we found it hard to get it right when we recently moved to SAS 9.4. It is a lot more complicated especially in the mid-tier in SAS 9.4.
03-27-2015 02:16 PM
The answer of SAS TS as you noted is a disappointing one. They are selling SAS able to run on some systems.
As a DR and BCP plans are often mandatory for Information technology that is a environment to be supported.
How you are designing and implementing a DR approach is dependent of your in house ICT policies.
One prereq to review Is licensing. In clustered approach all machines are part as real operational. They should all be licensed.
In a cold/hot standby there is some machine that will only be go into life when there is a disaster. To be able that the DR plan is working you should be able to verify that process. http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32009L0024&from=EN (article 5.3 and 6.1-2) are covering the DR testing interoperability (EC). When there is nothing in in the contracts (not supported) it should be permitted by SAS, otherwise they are violating this directive.
So you have a cold DR environment. Tat one should be designed tested and implemented and verified at regular intervals as of regulations..
One thing to do is either:
- isolating that in dedicated network segment allowing using the same DNS names. A dedicated DNS server in the DR environment could be very handy.
- Doing a smart relocation of all data and DNS to another machine. This is described by SAS for 9.3 with LSF orchestrator.
Your data can be as good as nearly real time shadowed (duplicated SAN solutions) or on daily intervals.
The real problematic issue to get the duplicated machine having all needed data of >>ALL<< components.
Even a good Backup/Reststore is not very clear and reliable with SAS solutions. Saskiwi mentioned that already.