Should I install Phoenix Query Server on all HBase region server nodes? What is the best practice and consideration?

[#1 · Accepted solution]

Currently The PQS does not have any failover capabilities. the plan is to have all queries be stateless, so multiple servers can be load-balanced using regular HTTP balancers.

today you can have as many as you want but a client will only talk to a given query server. Having multiple could be interesting if you do your own balancing, or when the failover mechanism come.

Concerning where to put the PQS remember they are called from "outside" so you may not want to have to open access to all you RS in a more secured env.

[#2]

Ambari does push towards installing PQS on each region server. The only "security consideration" I see is a single port opened to clients on each node, so I wouldn't worry too much about this presently.

Some concrete results on stateless queries behind a generic load balancer should be landing within the year (2015).