We designed a below proposed plan of DCRUM HA/FO.
Need your valuable advice to enhance and implement the plan.
Especially I am looking for the VIP to connect to the databases, whether it will work or not.
Seeking for your advices.
Answer by Avner S. ·
Hi Babar, For the database HA I believe you can use the Windows/SQL cluster feature. In this case you will have your Primary CAS/ADS connected to one Database instance (DB_server1\Instance1\Primary_CAS_DB, for example) that is on one host and your secondary CAS/ADS connected to other Database instance (DB_server2\Instance2\Secondary_CAS_DB, for example), located in other host. Using the Windows/SQL Cluster feature, in case one of the hosts goes down, the SQL will be responsable for migrate the DB instance from one host to other. Your configuration will be something like:
Hope that helps,
Answer by Babar Q. ·
Once again we came back with the same requirements of HA/FO/LB for the Dynatrace Data Center RUM 2017 May SP3.
In the below screenshot only the RUM Console database is replicating with the Failover Zone and there is no such illustration for the CAS/ADS databases.
We will have independent databases virtual machines for the CASes/ADSes so how the data will be replicated between databases and what will be the status of the reporting services (e.g. Enabled/Disabled same like RUM Console)?
I am looking forward for your expert advises for the successful implementation.
Answer by Chris V. ·
Not SQL Clustering is not supported in DCRUM. See response to my query by Kris Z. here:
CAS and ADS failover/HA is provided by the DCRUM clustering functionality, but it requires doubling up on databases.
Answer by Babar Q. ·
The below is the feedback from the support team.
"The VIP idea - I don't see it working.
As for the" Is this logical to go with my selected scenario without facing any capacity issues in future?
question - there's no possibility to tell that any hardware won't face capacity issues - it all depends on the users' configuration and traffic - it may be enough for next few years, but it also may not suffice for next week. But I assume you have a steady baseline of 400/800GB DBs. It's in the upper limits of what we usually see. I'd say that a standalone SQL server would be enough for each DB. Both DBs on the same server - I'm not sure. I'd focus on the I/O, especially that you want to virtualize the servers and use external storage. Both will introduce additional load/delay on the SQL. It's not a design we have tested and can share some numbers, unfortunately. For a standard solution (CAS+SQL on the same host) I've seen SQL hitting max 16000-17000 IOPS with an average of 1000-1200 IOPS. This also shows that CAS and ADS use DB in a rather uncommon way - they put a heavy load on it every 5 minutes (default interval) and then idle until next processing interval. So using average load to do any performance comparisons may be misleading.
After this information we are back to square one. It means I should go with my proposed design just to remove the VIP part, so there will be no IOPS issues with the dedicated SQL server for each CAS and ADS.
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