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https://issues.apache.org/jira/browse/HBASE-13686?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Ashish Singhi updated HBASE-13686:
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Release Note:
As per this jira contribution. We now support two kinds of RateLimiter.
1) org.apache.hadoop.hbase.quotas.AverageIntervalRateLimiter : This limiter
will refill resources at every TimeUnit/resources interval.
Example: For a limiter configured with 10resources/second, then 1resource will
be refilled after every 100ms.
2) org.apache.hadoop.hbase.quotas.FixedIntervalRateLimiter: This limiter will
refill resources only after a given fixed interval of time.
Client can configure anyone of this rate limiter for the cluster by setting the
value for the property "hbase.quota.rate.limiter" in the hbase-site.xml.
org.apache.hadoop.hbase.quotas.AverageIntervalRateLimiter is the default value.
Note: Client needs to restart the cluster for the configuration to take into
effect.
> 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
> Labels: multitenancy, quota
> Fix For: 2.0.0, 1.2.0, 1.1.1
>
> Attachments: HBASE-13686-branch-1.patch, 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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