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From "Keith Turner (JIRA)" <j...@apache.org>
Subject [jira] [Created] (ACCUMULO-2204) Add delete client to continuous ingest
Date Thu, 16 Jan 2014 15:40:19 GMT
Keith Turner created ACCUMULO-2204:
--------------------------------------

             Summary: Add delete client to continuous ingest
                 Key: ACCUMULO-2204
                 URL: https://issues.apache.org/jira/browse/ACCUMULO-2204
             Project: Accumulo
          Issue Type: Sub-task
            Reporter: Keith Turner


Adding the linked list operation of deleting nodes would detect deleted data coming back.
Could create something similar to the walker that does the following.

 # selects a random node X
 # follows the linked list for a random number of times and stops at node Y
 # makes X point Y
 # deletes all nodes that were between X and Y in the list

For example given the following linked list 

{noformat}
   7->5->29->13->19->23->17
{noformat}

If 5 were picked as the first node and 23 as the last node, then the following operations
would be done.

 # write 5->23
 # flush
 # delete 29
 # flush
 # delete 13
 # flush
 # delete 19
 # flush
 # do batch read and/or scan to verify deletes 

If 29 or 13 should come back, then the nodes they point to would not exist and verification
would catch this.  I think the operations above are done in such a way that the delete client
could be killed at any time.

Since continuous ingest works w/ random number there is a small chance that the delete client
could delete a node just written by another client.  With 63 bit random numbers this chance
is exceedingly small.  Should it occur the person debugging should be able to sort it out
when looking at the  write ahead logs.  Therefore I do not think its worthwhile taking any
action in the test.



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