[jira] [Updated] (PHOENIX-5998) Paged server side operations

["Kadir OZDEMIR (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/PHOENIX-5998?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Kadir OZDEMIR updated PHOENIX-5998:
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    Description: Phoenix provides the option of performing upsert select and delete query operations on the client or server side.  This is decided by the Phoenix optimizer based on configuration parameters. For the server side option, the table operation (upsert select/delete query) is parallelized such that multiple table regions are scanned and the mutations derived from these scans can also be executed in parallel on the server side. However, currently there is no paging capability and the server side operation can take long enough lead to HBase client timeouts. When this happens, Phoenix can return failure to its applications and the rest of the parallel scans and mutations on the server side can still continue since  Phoenix has no mechanism in place to stop these operations before returning failure to applications. This can create unexpected race conditions between these left-over operations and the new operations issued by applications. Putting a limit on the number of rows to be processed within a single RPC call (i.e., the next operation on the scanner) on the server side using a Phoenix level paging is highly desirable and a required step to prevent the possible race conditions. This paging mechanism has been already implemented for index rebuild and verification operations and proven to be effective to prevent timeouts. This paging can be implemented for all server side operations including aggregates, upsert selects, delete queries and so on.

> Paged server side operations 
> -----------------------------
>
>                 Key: PHOENIX-5998
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-5998
>             Project: Phoenix
>          Issue Type: Improvement
>         Environment: Phoenix provides the option of performing upsert select and delete query operations on the client or server side.  This is decided by the Phoenix optimizer based on configuration parameters. For the server side option, the table operation (upsert select/delete query) is parallelized such that multiple table regions are scanned and the mutations derived from these scans can also be executed in parallel on the server side. However, currently there is no paging capability and the server side operation can take long enough lead to HBase client timeouts. When this happens, Phoenix can return failure to its applications and the rest of the parallel scans and mutations on the server side can still continue since  Phoenix has no mechanism in place to stop these operations before returning failure to applications. This can create unexpected race conditions between these left-over operations and the new operations issued by applications. Putting a limit on the number of rows to be processed within a single RPC call (i.e., the next operation on the scanner) on the server side using a Phoenix level paging is highly desirable and a required step to prevent the possible race conditions. This paging mechanism has been already implemented for index rebuild and verification operations and proven to be effective to prevent timeouts. This paging can be implemented for all server side operations including aggregates, upsert selects, delete queries and so on.
>            Reporter: Kadir OZDEMIR
>            Priority: Major
>             Fix For: 4.x
>
>
> Phoenix provides the option of performing upsert select and delete query operations on the client or server side.  This is decided by the Phoenix optimizer based on configuration parameters. For the server side option, the table operation (upsert select/delete query) is parallelized such that multiple table regions are scanned and the mutations derived from these scans can also be executed in parallel on the server side. However, currently there is no paging capability and the server side operation can take long enough lead to HBase client timeouts. When this happens, Phoenix can return failure to its applications and the rest of the parallel scans and mutations on the server side can still continue since  Phoenix has no mechanism in place to stop these operations before returning failure to applications. This can create unexpected race conditions between these left-over operations and the new operations issued by applications. Putting a limit on the number of rows to be processed within a single RPC call (i.e., the next operation on the scanner) on the server side using a Phoenix level paging is highly desirable and a required step to prevent the possible race conditions. This paging mechanism has been already implemented for index rebuild and verification operations and proven to be effective to prevent timeouts. This paging can be implemented for all server side operations including aggregates, upsert selects, delete queries and so on.



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