Hi, Can you please give some feedback on the below?
________________________________ From: Mahesh Renduchintala <[email protected]> Sent: Tuesday, November 3, 2020 8:20 AM To: [email protected] <[email protected]> Subject: ReadFromBackup, Primary_SYNC, Backups Hi I have a large SQL table (12 million records) in cacheMode partitioned. This table is distributed over two server nodes -1- When running a large SELECT from a thick client node, could data be fetched from the backup instead of primary partitions? Below is the configuration. <property name="cacheMode" value="PARTITIONED"/> <property name="backups" value="2"/> <property name="atomicityMode" value="TRANSACTIONAL"/> <property name="writeSynchronizationMode" value="PRIMARY_SYNC"/> <property name="rebalanceMode" value="ASYNC"/> <property name="statisticsEnabled" value="true"/> <property name="readFromBackup" value="true"/> <property name="queryParallelism" value="2"/> /> We are seeing some performance improvement, since we made regardFromBackup= False and a few other things. -2- in a two server system, if readFromBackup = False for a cache, and if one server fails, would 2nd server stop serving client requests since some partition data is in the backup? -3- is it possible that readFromBackup=True and Primary_Sync mode for a cache could give inconsistent data for cacheMode Replicated in a 2 server node? -4- if I increase backup= 10, in a 2 server system, would it mean that there are 10 backups. I am guessing, ignite would keep a single back up on each server, not 5 and 5 on each server. a new backup is created for that cache for any new node joining the cluster. is this right understanding? Strong regards mahesh
