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https://issues.apache.org/jira/browse/HBASE-12853?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14277488#comment-14277488
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Lars Hofhansl commented on HBASE-12853:
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The coprocessors are per region, and you want the "salting" for spreading
across regions. So you mean to have some region server contact other region
server in order to execute a portion of a scan there?
Phoenix does the parallelization on the client and then farms out the work to
the various region servers, which then execute the requests with the help of
per region coprocessors.
Would be nice to completely hide this. We might have to invent something now
for that.
> distributed write pattern to replace ad hoc 'salting'
> -----------------------------------------------------
>
> Key: HBASE-12853
> URL: https://issues.apache.org/jira/browse/HBASE-12853
> Project: HBase
> Issue Type: New Feature
> Reporter: Michael Segel
> Priority: Minor
>
> In reviewing HBASE-11682 (Description of Hot Spotting), one of the issues is
> that while 'salting' alleviated regional hot spotting, it increased the
> complexity required to utilize the data.
> Through the use of coprocessors, it should be possible to offer a method
> which distributes the data on write across the cluster and then manages
> reading the data returning a sort ordered result set, abstracting the
> underlying process.
> On table creation, a flag is set to indicate that this is a parallel table.
> On insert in to the table, if the flag is set to true then a prefix is added
> to the key. e.g. <region server#>- or <region server #|| where the region
> server # is an integer between 1 and the number of region servers defined.
> On read (scan) for each region server defined, a separate scan is created
> adding the prefix. Since each scan will be in sort order, its possible to
> strip the prefix and return the lowest value key from each of the subsets.
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