org.apache.accumulo.master.replication

Class StatusMaker

java.lang.Object

org.apache.accumulo.master.replication.StatusMaker

public class StatusMaker
extends Object

Reads replication records from the metadata table and creates status records in the replication table. Deletes the record from the metadata table when it's closed.

Constructor Summary

Constructors

Constructor and Description
StatusMaker(AccumuloClient client, VolumeManager fs)

Method Summary

Modifier and Type	Method and Description
protected boolean	addOrderRecord(org.apache.hadoop.io.Text file, Table.ID tableId, Replication.Status stat, Value value) Create a record to track when the file was closed to ensure that replication preference is given to files that have been closed the longest and allow the work assigner to try to replicate in order that data was ingested (avoid replay in different order)
protected boolean	addStatusRecord(org.apache.hadoop.io.Text file, Table.ID tableId, Value v) Create a status record in the replication table
protected void	deleteStatusRecord(Key k) Because there is only one active Master, and thus one active StatusMaker, the only safe time that we can issue the delete for a Status which is closed is immediately after writing it to the replication table.
void	run()
void	setSourceTableName(String table) Not for public use -- visible only for testing

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StatusMaker

public StatusMaker(AccumuloClient client,
                   VolumeManager fs)

Method Detail

setSourceTableName

public void setSourceTableName(String table)

Not for public use -- visible only for testing

Used to read records from a table other than 'metadata'

Parameters:

table - The table to read from

run

public void run()

addStatusRecord

protected boolean addStatusRecord(org.apache.hadoop.io.Text file,
                                  Table.ID tableId,
                                  Value v)

Create a status record in the replication table

addOrderRecord

protected boolean addOrderRecord(org.apache.hadoop.io.Text file,
                                 Table.ID tableId,
                                 Replication.Status stat,
                                 Value value)

Create a record to track when the file was closed to ensure that replication preference is given to files that have been closed the longest and allow the work assigner to try to replicate in order that data was ingested (avoid replay in different order)

Parameters:

file - File being replicated

tableId - Table ID the file was used by

stat - Status msg

value - Serialized version of the Status msg

deleteStatusRecord

protected void deleteStatusRecord(Key k)

Because there is only one active Master, and thus one active StatusMaker, the only safe time that we can issue the delete for a Status which is closed is immediately after writing it to the replication table.

If we try to defer and delete these entries in another thread/process, we will have no assurance that the Status message was propagated to the replication table. It is easiest, in terms of concurrency, to do this all in one step.

Parameters:

k - The Key to delete