BIND 10 #3089: Integrate NameTransaction management into D2UpdateMgr

[BIND 10 Development]

#3089: Integrate NameTransaction management into D2UpdateMgr
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            Reporter:  tmark         |                        Owner:
                Type:  enhancement   |  UnAssigned
            Priority:  medium        |                       Status:
           Component:  dhcp-ddns     |  reviewing
            Keywords:  Task# 6.5     |                    Milestone:  DHCP-
           Sensitive:  0             |  Kea1.0-alpha
         Sub-Project:  DHCP          |                   Resolution:
Estimated Difficulty:  0             |                 CVSS Scoring:
         Total Hours:  0             |              Defect Severity:  N/A
                                     |  Feature Depending on Ticket:
                                     |          Add Hours to Ticket:  0
                                     |                    Internal?:  0
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Changes (by tmark):

 * owner:  tmark => UnAssigned
 * status:  assigned => reviewing


Comment:

 Until now, D2UpdateMgr has created instances of !NameChangeTransaction
 when building transactions.  This allowed the D2UpdateMgr to be developed
 and tested ahead of the lower order classes.  Now that both
 !NameAddTransaction and !NameRemoveTransaction have been implemented, this
 ticket updates D2UpdateMgr to use them accordingly.   This basic change is
 in D2UpdateMgr::makeTransaction().

 Since the transaction classes are fully functional, the unit tests added
 to D2UpdateMgr with this ticket are relatively rich. In these tests the
 transactions build real update requests which are actually sent via
 !DNSClient to a !FauxServer which provides real responses back.

 During this testing numerous small changes were identified and made:

 * added toText method !DnsServerInfo for better logging.
 * added debug level log messages for DNS request send and response
 received
 * altered D2UpdateMgr::checkFinishedTransactions() to use !isModelDone()
 to rather than NameChangeRequest::status to identify transaction
 completeness
 * DNSClient was modified to store a reference to the caller's message
 pointer (see DNSClient::response_).  This circumvents an issue in lib/dns
 whereby a Message can only be rendered "fromWire" once.
 * NameChangeTransaction::startTransaction, sets the NCR status to
 ST_PENDING. This had been overlooked.
 * NameChangeTransaction::clearDnsUpdateRequest, now clears
 update_attempts_. The value was not being reset prior to starting a new
 request.
 * NameChangeTransaction::DNS_UPDATE_DEFAULT_TIMEOUT has been temporarily
 shortened until it is made configurable.  This is to keep unit test times
 to reasonable limits.
 * several new convenience methods, accessors were added for testing
 purposes

 Several new tests were added to d2_update_mgr_unittests.cc:

 * TEST_F(D2UpdateMgrTest, addTransaction)
 * TEST_F(D2UpdateMgrTest, removeTransaction)
 * TEST_F(D2UpdateMgrTest, errorTransaction)
 * TEST_F(D2UpdateMgrTest, multiTransaction)
 * TEST_F(D2UpdateMgrTest, multiTransactionTimeout)

 A new class, !TimedIO was added to nc_test_utils, which provides the means
 to conduct !IOService based tests backed with a "safety" timer.

 !FauxServer was modified to be able to reschedule it's next receive. This
 allows
 it to endlessly receive and respond, once initially started.

 Sadly there are no new classes or state diagrams.  The following ChangeLog
 is proposed:

 {{{
 7xx.    [func]      [tmark]

     b10-dhcp-ddns D2UpdateMgr now uses the newly implemented
     NameAddTransaction and NameRemoveTransaction classes.  This allows
     it conduction actual DNS update exchanges based upon queued
     NameChangeRequests.
     (Trac# 3089     git TBD)
 }}}

-- 
Ticket URL: <http://bind10.isc.org/ticket/3089#comment:5>
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