Restoring from Amazon EMR WAL
Because the Amazon EMR WAL for your original cluster is retained for 30 days, you can restore and reuse the WAL for a newly-created cluster within that 30-day period. When you launch a new cluster from the same S3 root directory, Amazon EMR keeps the WAL instances from your old cluster. If you terminate this new cluster, the 30-day clock restarts from the time of when you terminate.
Use the following procedure to restore an existing WAL with a new cluster. This process assumes that you created your original cluster with Amazon EMR WAL enabled.
-
Within 30 days of creating a WAL-enabled cluster, create a new cluster in the same AWS Region as the original cluster. The new cluster can be in the same AZ or in a different AZ within the same Region that the original cluster was created.
Configure the object properties to specify the storage mode and the root directory location in Amazon S3. The Amazon S3 location that you specify should be in the same Region as your EMR cluster, but only one active cluster can use the same HBase root directory in S3 at a time.
For console steps to create a cluster, and a detailed
create-clusterexample that uses the AWS CLI, see Creating a cluster with HBase. -
To use the existing Amazon EMR WAL for the new cluster, set the
hbase.emr.wal.enabledproperty totrue. The following JSON snippet shows an example configuration object.
[
{
"Classification": "hbase-site",
"Properties": {
"hbase.rootdir": "s3://amzn-s3-demo-bucket/MyHBaseStore"
}
},
{
"Classification": "hbase",
"Properties": {
"hbase.emr.storageMode": "s3",
"hbase.emr.wal.enabled": "true"
}
}
] 