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Zhihong Yu commented on HBASE-5877: ----------------------------------- @N: I think the following validation in real cluster would illustrate the benefit of this feature: For given table, select a region server and note the row key ranges hosted by one region on the region server. Direct client load to this region. Issue the following command in shell: {code} hbase> move 'ENCODED_REGIONNAME', 'SERVER_NAME' {code} at time T. Difference in client response to region migration around time T with and without the patch would be interesting. > When a query fails because the region has moved, let the regionserver return > the new address to the client > ---------------------------------------------------------------------------------------------------------- > > Key: HBASE-5877 > URL: https://issues.apache.org/jira/browse/HBASE-5877 > Project: HBase > Issue Type: Improvement > Components: client, master, regionserver > Affects Versions: 0.96.0 > Reporter: nkeywal > Assignee: nkeywal > Priority: Minor > Fix For: 0.96.0 > > Attachments: 5877.v1.patch > > > This is mainly useful when we do a rolling restart. This will decrease the > load on the master and the network load. > Note that a region is not immediately opened after a close. So: > - it seems preferable to wait before retrying on the other server. An > optimisation would be to have an heuristic depending on when the region was > closed. > - during a rolling restart, the server moves the regions then stops. So we > may have failures when the server is stopped, and this patch won't help. > The implementation in the first patch does: > - on the region move, there is an added parameter on the regionserver#close > to say where we are sending the region > - the regionserver keeps a list of what was moved. Each entry is kept 100 > seconds. > - the regionserver sends a specific exception when it receives a query on a > moved region. This exception contains the new address. > - the client analyses the exeptions and update its cache accordingly... -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira