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ramkrishna.s.vasudevan commented on HBASE-5510: ----------------------------------------------- @Ted The rationale is like, I have set of regions S1...Sn and R1...Rn...In this i expect S1-R1, S2-R2 ...to be colocated in the same RS. S1...Sn are balanced by one LB. There is a custom LB which will balance R1..Rn. Now this LB should get the assignment done by first LB and based on that it will assign R1..Rn. Finally ensuring the colocation. Am i clear Ted? > Change in LB.randomAssignment(List<ServerName> servers) API > ----------------------------------------------------------- > > Key: HBASE-5510 > URL: https://issues.apache.org/jira/browse/HBASE-5510 > Project: HBase > Issue Type: Improvement > Affects Versions: 0.92.0 > Reporter: Anoop Sam John > Assignee: ramkrishna.s.vasudevan > > In LB there is randomAssignment(List<ServerName servers>) API which will be > used by AM to assign > a region from a down RS. [This will be also used in other cases like call to > assign() API from client] > I feel it would be better to pass the HRegionInfo also into this method. > When the LB making a choice for a region > assignment, when one RS is down, it would be nice that the LB knows for > which region it is doing this server selection. > +Scenario+ > While one RS down, we wanted the regions to get moved to other RSs but a set > of regions stay together. We are having custom load balancer but with the > current way of LB interface this is not possible. Another way is I can allow > a random assignment of the regions at the RS down time. Later with a cluster > balance I can balance the regions as I need. But this might make regions > assign 1st to one RS and then again move to another. Also for some time > period my business use case can not get satisfied. > Also I have seen some issue in JIRA which speaks about making sure that Root > and META regions always sit in some specific RSs. With the current LB API > this wont be possible in future. -- 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