I am currently having a timeout on a Hive query over and HBase table, similar to this article. As per the instructions in that article, I intend to increase the HBase timeout, including the RPC timeout. However before going ahead, I would like to understand the potential consequences of this change on HBase and external services that access HBase, since this is a production cluster. If someone could give me an idea of what negative consequences this might have it would help a lot.
>> Region Server will take longer to report failure for master to trigger failover
No, RS does not report failures to Master. Master detects timeout as a listener for Zk events. Every RS, including Master sends periodically pings to ZK (this timeout - zookeeper.session.timeout is different from RPC timeout) and if pings does not for longer than Zk session timeout, Master declares RD dead and starts failover procedure.
In case of very large RPC timeout, client application has no chance to react to outages in any meaningful way. This is the major consequence of an increased RPC timeout.