Sergey Soldatov created HBASE-16857:

             Summary: RateLimiter may fails during parallel scan execution
                 Key: HBASE-16857
             Project: HBase
          Issue Type: Bug
    Affects Versions: 1.1.2
         Environment: hbase.quota.enabled=true 
            Reporter: Sergey Soldatov
            Assignee: Sergey Soldatov

Steps to reproduce using phoenix (that's the easiest way to run a lot of 
parallel scans):
1. Create table:
create table "abc" (id bigint not null primary key, name varchar) 
2. set quota from hbase shell:
set_quota TYPE => THROTTLE, TABLE => 'abc', LIMIT => '10G/sec' 
3. in phoenix run 
 select * from "abc"; 
It will fail with ThrottlingException.
Sometimes it requires to run it several times to reproduce.
That happens because the logic in DefaultOperationQuota. First we run 
limiter.checkQuota where we may change available to Long.MAX_VALUE, after that 
we run limiter.grabQuota where we reduce available for 1000 (is it scan 
overhead or what?) and in close() we adding this 1000 back. 
When number of parallel scans are executing there is a chance that one of the 
threads run limiter.checkQuota right before the second run close(). We get 
overflow and as the result available value becomes negative, so during the next 
check we just fail. 
This behavior was introduced in HBASE-13686.

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