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https://issues.apache.org/jira/browse/ACCUMULO-1614?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13758610#comment-13758610
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Keith Turner edited comment on ACCUMULO-1614 at 9/5/13 1:23 AM:
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In the percolator prototype I am working on I have a test that randomly
transfers money between bank accounts. In this test the sum of all money in
all bank accounts should never change. Percolator allows this to be done
across rows. Using conditional mutations, this test could easily be done
within rows.
Could have a test that simulates a lot banks and randomly transfer money
between accounts within a bank. Data would look something like the following
row=bank01 cf=acct01 cq=bal val=100,1
row=bank01 cf=acct02 cq=bal val=100,1
row=bank01 cf=acct03 cq=bal val=100,1
The value contains a balance and seq num. The sequence number is a one up
counter that prevents concurrent updates to an account, even if the updates try
to add the same amount to an account.
The random walk test would pick a random bank and then pick two random columns
to transfer money between. Below is an example that uses the sample data above
and shows two threads trying to transfer 10 to acct01.
# Thread 1 : read bank01:acct01:bal
# Thread 1 : read bank01:acct03:bal
# Thread 2 : read bank01:acct01:bal
# Thread 2 : read bank01:acct02:bal
# Thread 1 : Write mutation that sets bank01:acct01:bal=110,2 and
bank01:acct03:bal=90,2 ONLY IF bank01:acct01:bal==100,1 and
bank01:acct03:bal==100,1
# Thread 2 : Write mutation that sets bank01:acct01:bal=110,2 and
bank01:acct02:bal=90,2 ONLY IF bank01:acct01:bal==100,1 and
bank01:acct02:bal==100,1
Thread 1 will succeed and thread 2 will fail.
It should be possible to run an isolated scan over the bank rows at any point
in time and get a predictable result (even in the face of concurrent updates
because only entire mutations are seen). For example the sum of all money in
bank01 should always be 300.
The random walk test could do transfers and verifies. To get concurreny, run
multiple random walkers against the same table.
was (Author: kturner):
Could have a test that simulates a lot banks and randomly transfer money
between accounts within a bank. Data would look something like the following
row=bank01 cf=acct01 cq=bal val=100,1
row=bank01 cf=acct02 cq=bal val=100,1
> Create random walk test that use conditional writer
> ---------------------------------------------------
>
> Key: ACCUMULO-1614
> URL: https://issues.apache.org/jira/browse/ACCUMULO-1614
> Project: Accumulo
> Issue Type: Sub-task
> Components: client, tserver
> Reporter: Keith Turner
> Fix For: 1.6.0
>
>
> Need to create random walk test that use conditional writer or modify
> existing random walk test to use conditional writer.
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