[ 
https://issues.apache.org/jira/browse/HADOOP-16279?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Gabor Bota updated HADOOP-16279:
--------------------------------
    Description: 
In HADOOP-15621 we implemented TTL for Authoritative Directory Listings and 
added {{ExpirableMetadata}}. {{DDBPathMetadata}} extends {{PathMetadata}} 
extends {{ExpirableMetadata}}, so all metadata entries in ddb can expire, but 
the implementation is not done yet. 

To complete this feature the following should be done:
* Add new tests for metadata entry and tombstone expiry to {{ITestS3GuardTtl}}
* Implement metadata entry and tombstone expiry 

I would like to start a debate on whether we need to use separate expiry times 
for entries and tombstones. My +1 on not using separate settings - so only one 
config name and value.

----

Notes:
* In HADOOP-13649 the metadata TTL is implemented in LocalMetadataStore, using 
an existing feature in guava's cache implementation. Expiry is set with 
{{fs.s3a.s3guard.local.ttl}}.
* This is not the same, and not using the [DDB's TTL 
feature|https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/TTL.html].
 We need stronger consistency guarantees than what ddb promises: [cleaning once 
a day with a background 
job|https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/howitworks-ttl.html]
 is not usable for this feature - although it can be used as a general cleanup 
solution separately and independently from S3Guard.

  was:
In HADOOP-15621 we implemented TTL for Authoritative Directory Listings and 
added {{ExpirableMetadata}}. {{DDBPathMetadata}} extends {{PathMetadata}} 
extends {{ExpirableMetadata}}, so all metadata entries in ddb can expire, but 
the implementation is not done yet. 

To complete this feature the following should be done:
* Add new tests for metadata entry and tombstone expiry to {{ITestS3GuardTtl}}
* Implement metadata entry and tombstone expiry 

I would like to start a debate on whether we need to use separate expiry times 
for entries and tombstones. My +1 on not using separate settings - so only one 
config name and value.

----

Notes:
* In HADOOP-13649 the metadata TTL is implemented in LocalMetadataStore, using 
an existing feature in guava's cache implementation. Expiry is set with 
{{fs.s3a.s3guard.local.ttl}}.
* This is not the same, and not using the DDB's feature of ttl 
[(DOCS)|https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/TTL.html].
 We need stronger consistency guarantees than what ddb promises: [cleaning once 
a day with a background 
job|https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/howitworks-ttl.html]
 is not usable for this feature - although it can be used as a general cleanup 
solution separately and independently from S3Guard.


> S3Guard: Implement time-based (TTL) expiry for entries (and tombstones)
> -----------------------------------------------------------------------
>
>                 Key: HADOOP-16279
>                 URL: https://issues.apache.org/jira/browse/HADOOP-16279
>             Project: Hadoop Common
>          Issue Type: Sub-task
>          Components: fs/s3
>            Reporter: Gabor Bota
>            Priority: Major
>
> In HADOOP-15621 we implemented TTL for Authoritative Directory Listings and 
> added {{ExpirableMetadata}}. {{DDBPathMetadata}} extends {{PathMetadata}} 
> extends {{ExpirableMetadata}}, so all metadata entries in ddb can expire, but 
> the implementation is not done yet. 
> To complete this feature the following should be done:
> * Add new tests for metadata entry and tombstone expiry to {{ITestS3GuardTtl}}
> * Implement metadata entry and tombstone expiry 
> I would like to start a debate on whether we need to use separate expiry 
> times for entries and tombstones. My +1 on not using separate settings - so 
> only one config name and value.
> ----
> Notes:
> * In HADOOP-13649 the metadata TTL is implemented in LocalMetadataStore, 
> using an existing feature in guava's cache implementation. Expiry is set with 
> {{fs.s3a.s3guard.local.ttl}}.
> * This is not the same, and not using the [DDB's TTL 
> feature|https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/TTL.html].
>  We need stronger consistency guarantees than what ddb promises: [cleaning 
> once a day with a background 
> job|https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/howitworks-ttl.html]
>  is not usable for this feature - although it can be used as a general 
> cleanup solution separately and independently from S3Guard.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: common-issues-h...@hadoop.apache.org

Reply via email to