org.apache.hadoop.hbase.client.Consistency Maven / Gradle / Ivy
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package org.apache.hadoop.hbase.client;
import org.apache.yetus.audience.InterfaceAudience;
/**
* Consistency defines the expected consistency level for an operation.
*/
@InterfaceAudience.Public
public enum Consistency {
// developer note: Do not reorder. Client.proto#Consistency depends on this order
/**
* Strong consistency is the default consistency model in HBase, where reads and writes go through
* a single server which serializes the updates, and returns all data that was written and ack'd.
*/
STRONG,
/**
* Timeline consistent reads might return values that may not see the most recent updates. Write
* transactions are always performed in strong consistency model in HBase which guarantees that
* transactions are ordered, and replayed in the same order by all copies of the data. In timeline
* consistency, the get and scan requests can be answered from data that may be stale.
* The client may still observe transactions out of order if the requests are responded from
* different servers.
*/
TIMELINE,
}