Package org.epics.archiverappliance.etl

Interface ETLSource

All Known Implementing Classes:

MergeDedupStoragePlugin, PlainPBStoragePlugin

public interface ETLSource

An ETL source is data source that can act as a source for ETL. There are the methods that an ETL source needs to implement

Author:

mshankar

Method Summary

Modifier and Type	Method	Description
boolean	consolidateOnShutdown()	Should ETL move data from this source to the destination on shutdown.
String	getDescription()
List<ETLInfo>	getETLStreams(String pv, Timestamp currentTime, ETLContext context)	Given a pv and a time, this method returns all the streams that are ready for ETL.
PartitionGranularity	getPartitionGranularity()
void	markForDeletion(ETLInfo info, ETLContext context)	Delete the ETLStream identifier by info when you can as it has already been consumed by the ETL destination.

Method Detail

getETLStreams

List<ETLInfo> getETLStreams(String pv,
                            Timestamp currentTime,
                            ETLContext context)
                     throws IOException

Given a pv and a time, this method returns all the streams that are ready for ETL. For example, if the partition granularity of a source is an hour, then this method returns all the streams that are in this source for the previous hours. Ideally, these streams must be closed for writing and should not change. The ETL process will consolidates these streams into the ETL destination, which is expected to be at a longer time granularity.

Parameters:

pv - The name of PV.

currentTime - The time that is being used as the cutoff. If we pass in a timestamp way out into the future, we should return all the streams available.

context - ETLContext

Returns:

List ETLinfo

Throws:

IOException -  

markForDeletion

void markForDeletion(ETLInfo info,
                     ETLContext context)

Delete the ETLStream identifier by info when you can as it has already been consumed by the ETL destination. You can delete it later or immediately.

Parameters:

info - ETLInfo

context - ETLContext

getPartitionGranularity

PartitionGranularity getPartitionGranularity()

getDescription

String getDescription()

consolidateOnShutdown

boolean consolidateOnShutdown()

Should ETL move data from this source to the destination on shutdown. For example, if you are using a ramdisk for the STS and you have a UPS, you can minimize any data loss but turning this bit on for data stores that are on the ramdisk. On shutdown, ETL will try to move the data out of this store into the next lifetime store.

Returns:

boolean True or False