[jira] [Created] (PHOENIX-2941) Alternative means of propagating schema changes

["Nick Dimiduk (JIRA)" <ji...@apache.org>]

Nick Dimiduk created PHOENIX-2941:
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             Summary: Alternative means of propagating schema changes
                 Key: PHOENIX-2941
                 URL: https://issues.apache.org/jira/browse/PHOENIX-2941
             Project: Phoenix
          Issue Type: Improvement
            Reporter: Nick Dimiduk


The current approach to propagating schema changes (ie, add column) involves maintaining a [GlobalCache|https://github.com/apache/phoenix/blob/10909ae502095bac775d98e6d92288c5cad9b9a6/phoenix-core/src/main/java/org/apache/phoenix/cache/GlobalCache.java] of table schema on both clients and in RS coprocessors. This schema information is versioned, and query timestamp is used to determine when the cache is considered stale and needs updated. This causes problems for users who specify a timestamp either via connection settings (ie, PHOENIX-2607) or using the ROW_TIMESTAMP feature. Presumably this will also negatively impact users of the Tephra transaction system as it uses the cell timestamp to store transaction id.

We need some other means of propagating schema changes throughout the cluster. One approach might be a ZK node for each table that can notify coprocessors (and clients?) that their cache is stale.



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