Hi Mani:
Let me try to answer some of your questions.
1. If the primary node fails, the secondary node becomes primary. Whether it will create another redundant copy depends on your setting of default-recovery-delay. Please refer to the document:
2. If both primary and secondary nodes fail, after they are restarted, it will not automatically reload the data. Since there is no disk persistence in your case. You probably have to use SYSCS_UTIL.IMPORT_TABLE_EX and DDLUtils to load the data.
5. The LRU overflow to disk will work, depending on the eviction settings. Please refer to the document:
When a row is evicted, the primary key value remains in memory while the remaining column data is evicted. The overflowed data will be read from disk when it is queried.
You can also check our Socialcast website for help.
-Jianxia