Hi The purpose of assign() api is to assign a region to an RS as you have understood correctly.
The purpose of unassign() api is to unassign a region from an RS that was serving it. In Hbase while the balancer tries to balance the regions then the overall purpose is to assign a region R1 served by RS1 to another server RS2. So as part of this first unassign() will be called to remove the R1 from RS1 and assign will be called to assign R1 to RS2. Similarly there is a functionality called disabling a table. It means all the regions pertaining to a table will be closed. In that case also unassign() will be called. You can also do unassign() manually to unassign or close a region. Am i clear on this ? Regards Ram -----Original Message----- From: 吴宗远 [mailto:zongyuan.w...@alibaba-inc.com] Sent: Thursday, September 08, 2011 12:37 PM To: user@hbase.apache.org Subject: a question about assgin() Hi all, I was confused with the difference between “assign()” and “unassign()” method, because both of them cause the region to be assign to a region. can somebody give a clear explanation? And what is the suitable scenario to use assign() ? Thanks, Zongyuan ________________________________ This email (including any attachments) is confidential and may be legally privileged. If you received this email in error, please delete it immediately and do not copy it or use it for any purpose or disclose its contents to any other person. Thank you. 本电邮(包括任何附件)可能含有机密资料并受法律保护。如您不是正确的收件人，请您 立即删除本邮件。请不要将本电邮进行复制并用作任何其他用途、或透露本邮件之内 容。谢谢。
