[ 
https://issues.apache.org/jira/browse/HIVE-16452?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16036608#comment-16036608
 ] 

Lefty Leverenz commented on HIVE-16452:
---------------------------------------

[~vihangk1], do you need anything more from me for this?  Putting the 
information in the wiki is more important than finding the best location -- we 
can always move it later.

> 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
>             Fix For: 3.0.0
>
>
> 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)

Reply via email to