[ https://issues.apache.org/jira/browse/HBASE-8751?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13684933#comment-13684933 ]
Feng Honghua commented on HBASE-8751: ------------------------------------- Showing up in the 'table:cf-list list' doesn't guarantee a CF will be replicated: only CF with replication-scope=1 in the 'table:cf-list list' will be replicated. > Enable peer cluster to choose/change the ColumnFamilies/Tables it really want > to replicate from a source cluster > ---------------------------------------------------------------------------------------------------------------- > > Key: HBASE-8751 > URL: https://issues.apache.org/jira/browse/HBASE-8751 > Project: HBase > Issue Type: Improvement > Components: Replication > Reporter: Feng Honghua > Attachments: HBASE-8751-0.94-V0.patch > > > Consider scenarios (all cf are with replication-scope=1): > 1) cluster S has 3 tables, table A has cfA,cfB, table B has cfX,cfY, table C > has cf1,cf2. > 2) cluster X wants to replicate table A : cfA, table B : cfX and table C from > cluster S. > 3) cluster Y wants to replicate table B : cfY, table C : cf2 from cluster S. > Current replication implementation can't achieve this since it'll push the > data of all the replicatable column-families from cluster S to all its peers, > X/Y in this scenario. > This improvement provides a fine-grained replication theme which enable peer > cluster to choose the column-families/tables they really want from the source > cluster: > A). Set the table:cf-list for a peer when addPeer: > hbase-shell> add_peer '3', "zk:1100:/hbase", "table1; table2:cf1,cf2; > table3:cf2" > B). View the table:cf-list config for a peer using show_peer_tableCFs: > hbase-shell> show_peer_tableCFs "1" > C). Change/set the table:cf-list for a peer using set_peer_tableCFs: > hbase-shell> set_peer_tableCFs '2', "table1:cfX; table2:cf1; table3:cf1,cf2" > In this theme, replication-scope=1 only means a column-family CAN be > replicated to other clusters, but only the 'table:cf-list list' determines > WHICH cf/table will actually be replicated to a specific peer. > To provide back-compatibility, empty 'table:cf-list list' will replicate all > replicatable cf/table. (this means we don't allow a peer which replicates > nothing from a source cluster, we think it's reasonable: if replicating > nothing why bother adding a peer?) > This improvement addresses the exact problem raised by the first FAQ in > "http://hbase.apache.org/replication.html": > "GLOBAL means replicate? Any provision to replicate only to cluster X and > not to cluster Y? or is that for later? > Yes, this is for much later." > I also noticed somebody mentioned "replication-scope" as integer rather than > a boolean is for such fine-grained replication purpose, but I think extending > "replication-scope" can't achieve the same replication granularity > flexibility as providing above per-peer replication configurations. > This improvement has been running smoothly in our production clusters > (Xiaomi) for several months. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira