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https://issues.apache.org/jira/browse/HBASE-13686?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14566975#comment-14566975
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Guanghao Zhang commented on HBASE-13686:
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refill in AverageIntervalRateLimiter.
{code}
if (nextRefillTime == -1) {
// Till now no resource has been consumed.
nextRefillTime = EnvironmentEdgeManager.currentTimeMillis();
return limit;
}
{code}
If set the RateLimiter is 10 res per minute. In the first minute, we can
consume 30 res (10 from avail, 10 from above "return limit", 10 from refill).
nextRefillTime should be one property of RateLimiter and initialized when new
RateLimiter.
> 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-v2.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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