[ https://issues.apache.org/jira/browse/HIVE-16452?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16008706#comment-16008706 ]
Vihang Karajgaonkar commented on HIVE-16452: -------------------------------------------- Yes, I will update the wiki. It adds a new Thrift API for the metastore. > Database UUID for metastore DB > ------------------------------ > > Key: HIVE-16452 > URL: https://issues.apache.org/jira/browse/HIVE-16452 > Project: Hive > Issue Type: New Feature > Components: Metastore > Reporter: Vihang Karajgaonkar > Assignee: Vihang Karajgaonkar > > In cloud environments it is possible that a same database instance is used as > the long running metadata persistence layer and multiple HMS access this > database. These HMS instances could be running the same time or in case of > transient workloads come up on an on-demand basis. HMS is used by multiple > projects in the Hadoop eco-system as the de-facto metadata keeper for various > SQL engines on the cluster. Currently, there is no way to uniquely identify > the database instance which is backing the HMS. For example, if there are two > instances of HMS running on top of same metastore DB, there is no way to > identify that data received from both the metastore clients is coming from > the same database. Similarly, if there in case of transient workloads > multiple HMS services come up and go, a external application which is > fetching data from a HMS has no way to identify that these multiple instances > of HMS are in fact returning the same data. > We can potentially use the combination of javax.jdo.option.ConnectionURL, > javax.jdo.option.ConnectionDriverName configuration of each HMS instance but > this is approach may not be very robust. If the database is migrated to > another server for some reason the ConnectionURL can change. Having a UUID in > the metastore DB which can be queried using a Thrift API can help solve this > problem. This way any application talking to multiple HMS instances can > recognize if the data is coming the same backing database. -- This message was sent by Atlassian JIRA (v6.3.15#6346)