Hello - is it possible for me to be removed from this mailing list, I am not sure how I got on it. Pls advise, thanks
On 3/16/15 9:20 PM, "Anuj Wadehra" <anujw_2...@yahoo.co.in> wrote: >Hi, > >We are trying to Decouple our Reporting DB from OLTP. Need urgent help on >the feasibility of proposed solution for PRODUCTION. > >Use Case: Currently, our OLTP and Reporting application and DB are same. >Some CF are used for both OLTP and Reporting while others are solely used >for Reporting.Every business transaction synchronously updates the main >OLTP CF and asynchronously updates other Reporting CFs. > >Problem Statement: >1. Decouple Reporting and OLTP such that Reporting load can't impact >OLTP performance. >2. Scaling of Reporting and OLTP modules must be independent >3. OLTP client should not update all Reporting CFs. We generate Data >Records on File sytem/shared disk.Reporting should use these Records to >create Reporting DB. >4. Small customers may do OLTP and Reporting on same 3-node cluster. >Bigger customers can be given an option to have dedicated OLTP and >Reporting nodes. So, standard Hardware box should be usable for 3 >deployments (OLTP,Reporting or OLTP+Reporting) > >Note: Reporting is ad-hoc, may involve full table scans and does not >involve Analytics. Data size is huge 2TB (OLTP+Reporting) per node. > >Hardware : Standard deployment -3 node cluster with each node having 24 >cores, 64GB RAM, 400GB * 6 SSDs in RAID5 > >Proposed Solution: >1. Split OLTP and Reporting clients into two application components. >2. For small deployments where more than 3 nodes are not required: > A. Install 2 Cassandra instances on each node one for OLTP and other >for Reporting > B. To distribute I/O load in 2:1 --Remove RAID5 (as Cassandra offers >replication) and assign 4 disks as JBod for OLTP and 2 disks for Reporting > C. RAM is abundant and often under-utilized , so assign 8GB each for >2 Cassandra instance > D. To make sure that Reporting is not able to overload CPU, tune >concurrent_reads,concurrent_writes > OLTP client will only write to OLTP DB and generate DB record. Reporting >client will poll FS and populate Reporting DB in required format. >3. Larger customers can have Reporting clients and DB on dedicated >physical nodes with all resources. > >Key Questions: >Is it ok to run 2 Cassandra instances on one node in Production system >and limit CPU Usage,Disk I/O and RAM as suggested above? >Any other solution for above mentioned problem statement? > > > >Thanks >Anuj
