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From: Dmitry Minkovsky <dminkovsky@gmail.com>
Date: Fri, 17 Jul 2015 09:36:05 -0400
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 <CADyNd1T9igfh4U8NmreqjcA+aYptER+6TWC2hAC4gvTn50hQ_A@mail.gmail.com>
Subject: How can I tell when a client is connected and ready to go?
To: user@hbase.apache.org
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I am using HBase 1.1.0 and create HBase client connections like this:

try {
    Configuration config = HBaseConfiguration.create();
    connection = ConnectionFactory.createConnection(config);
}
catch (IOException e) {
    logger.info("Error {}", e);
}

However, I noticed that when ZooKeeper and HBase Master/Region servers are
down, the catch clause is never reached. The code runs as if the connection
is made, and connection.isClosed() returns false. So:

- What happens when I use this connection? Are the RPC calls buffered and
retried at some interval in background?

- How can I tell whether the connection is actually ready for use? Should I
try to do this, or just use it? My inclination is not to run a client
service without the underlying datastores all actually ready, but perhaps
this is not the idea with the new HBase API.

- Under what conditions is the IOException catch actually reached?


My goal is to be able to fail fast. Is that the wrong idea with this client?


Thanks,
Dmitry

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