[
https://issues.apache.org/jira/browse/IGNITE-19887?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Vladislav Pyatkov updated IGNITE-19887:
---------------------------------------
Summary: Transfer observable timestamp to read-only transaction (was: Add
internal API to pass read timestamp to read-only transaction)
> Transfer observable timestamp to read-only transaction
> ------------------------------------------------------
>
> Key: IGNITE-19887
> URL: https://issues.apache.org/jira/browse/IGNITE-19887
> Project: Ignite
> Issue Type: Improvement
> Reporter: Vladislav Pyatkov
> Priority: Major
> Labels: ignite-3
>
> *Motivation*
> RO transaction has timestamp which determine a moment when data will be read.
> To avoid waiting, safe time is supposed to provide the timestamp in the past.
> The timestamp is determined by the latest observation timestamp and current
> time in order to be available to retrieve all data which is locally viewed.
> *Implementation notes*
> * The latest observable timestamp would be provided externally (from client,
> from local context for server node).
> * Read timestamp is determined as {{max(lastObservableTs, now() -
> safeTimePropagationFrequency)}}
> * Add a new method to start read only transaction with specific timestamp:
> {code}
> /**
> * Starts a readonly transaction with last observable timestamp.
> *
> * @param lastObservableTs Read timestamp.
> * @return Reade only transaction.
> */
> public ReadOnlyTransactionImpl begin(HybridTimestamp lastObservableTs)
> {code}
> *Definition of done*
> API for RO transaction in past is implemented. The read transaction timestamp
> should evaluate by formula: {{max(lastObservableTs, now() -
> safeTimePropagationFrequency)}} and available through
> {{ReadOnlyTransactionImpl .readTimestamp()}}
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
