Your real-world situation is not a single-threaded application, is it?
You will have multiple threads which are all updating Phoenix concurrently.

Given the semantics that your application needs from the requirements
you stated, I'm not sure what else you can do differently. You can get
low-latency out of HBase, but that's at the cost of throughput (not a
unique characteristic of HBase).

Denormalizing your tables will reduce the amount of work each update
will have to execute. Every secondary index is another update that needs
to be executed to satisfy your UPSERT.

Updates in HBase go in memory and to the WAL. New updates to HBase are
blocked when the memstore fills up and needs to flush to disk. Thus, it
is optimal to keep flush-times short so that you don't have many threads
blocked. However, you are still fighting yourself when you have threads
all trying to grab the same lock to write their data.

You can also try reaching out to your vendor (EMR) to see what other
tunings they recommend. I don't know what this architecture looks like.

On 7/11/18 11:33 AM, alchemist wrote: