[hbase] Changes to support secured HBase cluster

[bijugs]

Changes in this pull request include

For hbase098

• Use HBase connection object to create table object
• Changes to make YCSB hbase tests run against a kerberized hbase cluster
• Update to README.txt to document the new parameters

For hbase10

• Changes to make YCSB hbase tests run against a kerberized hbase cluster

If users like to use kerberos keytab to make the connection to secure hbase cluster instead of using the user-id of the user running the test they can be passed using principal=keytab-principal-name and keytab=keytab=file properties.

Update: After the conversation in issue #322 , changes were made to hbase098 and hbase10 to use single HBase connection across all the threads when running a multi-thread test.

[busbey]

please start commit messages with just then name of the module impacted (i.e. "[hbase098]" rather than "changes to hbase098"

[busbey]

For hbase098

• Use a single HBase connection object across all the threads which is recommended

Do you have some perf numbers to show the actual impact?

Why only do this change in the 0.98 driver?

[busbey]

If you're going to add properties for the principal and keytab, please document them

• In the relevant binding README
• In the workload template file

Are these changes needed to run on a kerberos cluster? I was under the impression the one merely needed to kinit before running YCSB and the hbase driver would correctly use the cached tickets?

[busbey]

where does this get closed? should either ref count or register a shutdown hook

[busbey]

Note also that #350 has been waiting for verification of essentially the same keytab functionality.

[bijugs]

Thanks @busbey for the review and feedback.

• please start commit messages with just then name of the module impacted (i.e. "[hbase098]" rather than "changes to hbase098"
  • Will change the commit message to start with module name.
• Why only do this change in the 0.98 driver?
  • hbase10 is already using connection object to create table objects and I don't have a 0.94 environment to test the changes.
• If you're going to add properties for the principal and keytab, please document them
  • Will document them in the module specific readme
• Are these changes needed to run on a kerberos cluster?
  • We are testing against a Kerberized cluster from a node outside the cluster. These changes should not impact the current behavior
• Do you have some perf numbers to show the actual impact? & where does this get closed?
  • Since core/Client.java calls _db.cleanup(), at this time single connection object will not work. To complete this PR will close the connection on the cleanup() method. Will raise another request to update the core/Client.java so that DBs which can work with single connection object shared among multiple threads will be able to leverage it.

[risdenk]

@busbey and @bijugs There is a related issue #322 for HBase single connection object. Just wanted to cross reference it here.

[bijugs]

@busbey Changes were made for the review comments.

@risdenk Thanks for pointing out the existing issue. Will update with my comments there so that we can have a conversation on the proposed change.

[cmatser]

👍 from me

[busbey]

Thanks for the contribution!