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https://issues.apache.org/jira/browse/HBASE-13686?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14554253#comment-14554253
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Ashish Singhi commented on HBASE-13686:
---------------------------------------

Updated the patch as per the comments and uploaded the same on RB.
In this {{RateLimiter}} is an abstract class and {{AverageIntervalRateLimiter}} 
 and {{FixedIntervalRateLimiter}} are extending it.
[~zghaobac] I did not keep the AverageIntervalRateLimiter  as 
BurstAllowedRateLimiter, as I felt the former was straight forward name to get 
a hint what the class will do. Hope you don't mind.

> Fail to limit rate in RateLimiter
> ---------------------------------
>
>                 Key: HBASE-13686
>                 URL: https://issues.apache.org/jira/browse/HBASE-13686
>             Project: HBase
>          Issue Type: Bug
>    Affects Versions: 2.0.0, 1.1.0
>            Reporter: Guanghao Zhang
>            Assignee: Ashish Singhi
>             Fix For: 2.0.0, 1.2.0, 1.1.1
>
>         Attachments: HBASE-13686-v1.patch, HBASE-13686.patch
>
>
> While using the patch in HBASE-11598 , I found that RateLimiter can't to 
> limit the rate right.
> {code} 
>  /**
>    * given the time interval, are there enough available resources to allow 
> execution?
>    * @param now the current timestamp
>    * @param lastTs the timestamp of the last update
>    * @param amount the number of required resources
>    * @return true if there are enough available resources, otherwise false
>    */
>   public synchronized boolean canExecute(final long now, final long lastTs, 
> final long amount) {
>     return avail >= amount ? true : refill(now, lastTs) >= amount;
>   }
> {code}
> When avail >= amount, avail can't be refill. But in the next time to call 
> canExecute, lastTs maybe update. So avail will waste some time to refill. 
> Even we use smaller rate than the limit, the canExecute will return false. 



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