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https://issues.apache.org/jira/browse/PHOENIX-2520?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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James Taylor updated PHOENIX-2520:
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Description:
On the client-side, Phoenix pings the server when a query is compiled to
confirm that the client has the most up-to-date metadata for the table being
queried. For some tables that are known to not change, this RPC is wasteful.
We can allow a property such as {{UPDATE_CACHE_FREQUENCY}} to be specified a
time to wait before checking with the server to see if the metadata has
changed. This could be specified in the CREATE TABLE call and stored in the
SYSTEM.CATALOG table header row. By default the value could be 0 which would
keep the current behavior. Tables that never change could use Long.MAX_VALUE.
Potentially we could allow 'ALWAYS' and 'NEVER' values for convenience.
Proposed implementation:
- add {{public long getAge()}} method to {{PTableRef}}.
- when setting lastAccessTime, also store System.currentMillis() to new
{{setAccessTime}} private member variable
- the getAge() would return {{System.currentMillis() - setAccessTime}}
- code in MetaDataClient would prevent call to server if age <
{{UPDATE_CACHE_FREQUENCY}}
was:
On the client-side, Phoenix pings the server when a query is compiled to
confirm that the client has the most up-to-date metadata for the table being
queried. For some tables that are known to not change, this RPC is wasteful.
We can allow a property such as {{UPDATE_METADATA_CACHE_FREQUENCY_MS}} to be
specified a time to wait before checking with the server to see if the metadata
has changed. This could be specified in the CREATE TABLE call and stored in the
SYSTEM.CATALOG table header row. By default the value could be 0 which would
keep the current behavior. Tables that never change could use Long.MAX_VALUE.
Potentially we could allow 'ALWAYS' and 'NEVER' values for convenience.
Proposed implementation:
- add {{public long getAge()}} method to {{PTableRef}}.
- when setting lastAccessTime, also store System.currentMillis() to new
{{setAccessTime}} private member variable
- the getAge() would return {{System.currentMillis() - setAccessTime}}
- code in MetaDataClient would prevent call to server if age <
{{UPDATE_METADATA_CACHE_FREQUENCY_MS}}
> Create DDL property for metadata update frequency
> -------------------------------------------------
>
> Key: PHOENIX-2520
> URL: https://issues.apache.org/jira/browse/PHOENIX-2520
> Project: Phoenix
> Issue Type: Improvement
> Reporter: James Taylor
> Assignee: James Taylor
> Fix For: 4.7.0
>
> Attachments: PHOENIX-2520.patch, PHOENIX-2520_v2.patch,
> PHOENIX-2520_wip.patch, preferMetaCache.patch
>
>
> On the client-side, Phoenix pings the server when a query is compiled to
> confirm that the client has the most up-to-date metadata for the table being
> queried. For some tables that are known to not change, this RPC is wasteful.
> We can allow a property such as {{UPDATE_CACHE_FREQUENCY}} to be specified a
> time to wait before checking with the server to see if the metadata has
> changed. This could be specified in the CREATE TABLE call and stored in the
> SYSTEM.CATALOG table header row. By default the value could be 0 which would
> keep the current behavior. Tables that never change could use Long.MAX_VALUE.
> Potentially we could allow 'ALWAYS' and 'NEVER' values for convenience.
> Proposed implementation:
> - add {{public long getAge()}} method to {{PTableRef}}.
> - when setting lastAccessTime, also store System.currentMillis() to new
> {{setAccessTime}} private member variable
> - the getAge() would return {{System.currentMillis() - setAccessTime}}
> - code in MetaDataClient would prevent call to server if age <
> {{UPDATE_CACHE_FREQUENCY}}
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