BIND 10 #1648: Abstract pool/lease store: design

[BIND 10 Development]

#1648: Abstract pool/lease store: design
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                   Reporter:  tomek  |                 Owner:  UnAssigned
                       Type:  task   |                Status:  reviewing
                   Priority:         |             Milestone:  DHCP-
  medium                             |  Sprint-20120611
                  Component:  data   |            Resolution:
  source                             |             Sensitive:  0
                   Keywords:         |           Sub-Project:  DHCP
            Defect Severity:  N/A    |  Estimated Difficulty:  0
Feature Depending on Ticket:         |           Total Hours:  0
        Add Hours to Ticket:  0      |
                  Internal?:  0      |
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Comment (by marcin):

 '''Pool removal and DB consistency'''
 The description on wiki page says:
 ''I propose following mechanism: once the lease is marked for removal, it
 is removed immediately, if the number of active leases is 0. Otherwise it
 is marked for removal. No new leases are allowed and existing leases are
 not extended. This will allow for gentle lease removal.''

 Shouldn't that be?
 ''I propose following mechanism: once the '''pool''' is marked for
 removal, it is removed immediately, if the number of active leases is 0.
 Otherwise it is marked for removal. No new leases are allowed and existing
 leases are not extended. This will allow for gentle '''pool''' removal.''

 In general I like the idea not to remove things immediately but are there
 possible any corner cases like "infinite leases"? If so, is there any way
 to assign finite expiration time to make sure we will be finally able to
 remove it and parent pool?

 '''Q4: Do we want to store information in human readable form?'''
 ''...e.g. 10.25.0.0 sorts after 10.192.0.0....''

 Does sorting issue really matter? If we decide to store values in a binary
 form what would be the benefit of correctly sorting if values are not
 human readable?

 On the other hand, it will be probably better for performance if it is
 stored in binary form.

 '''Q6: Do we want to specify fixed values or ranges for timers like t1,
 t2, preferred or valid lifetimes?'''
 Is this meant to be per/pool configuration or it is global for the server?

 '''Q9: Reserved leases?'''
 If we have leases within pools we will not be actually able to remove
 pools as there will be fixed leases referencing this pool in DB. This will
 support idea to split them.

-- 
Ticket URL: <http://bind10.isc.org/ticket/1648#comment:5>
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