org.apache.hadoop.hbase.snapshot.CorruptedSnapshotException: Couldn't read snapshot info from:file:/tmp/hbase-cloudera/hbase - mapreduce

Question

Hi I am trying to Export Hbase table snapshot to my local hdfs so that i can run mapreduce on that .
I have taken the snapshot of the Hbase table using below command
snapshot 'FundamentalAnalytic','FundamentalAnalyticSnapshot'
Also when i ran list_snapshots command i can see my snapshot also .
I have exported my Hbase table snapshot to my local HDFS directory using below command and copied successfully .
hbase org.apache.hadoop.hbase.snapshot.ExportSnapshot -snapshot FundamentalAnalyticSnapshot -copy-to /tmp -mappers 16
Finally i have to run map reduce on the snapshot so below is my driver code to configure that job .
TableMapReduceUtil.initTableSnapshotMapperJob(snapshotName, // input table
scan, // Scan instance to control CF and attribute selection
DefaultMapper.class, // mapper class
NullWritable.class, // mapper output key
Text.class, // mapper output value
job,
true,
new Path("/home/cloudera/archive/data/default/FundamentalAnalytic/bc95715f67e52547e86b5b096a1f1cb5/cf/d29205a44623434eba2d100a94d8ebfb_SeqId_4_"));
This is where i get error .
I dont know which path i have to give as last arg in initTableSnapshotMapperJob method.
When i run this code i get below error .
org.apache.hadoop.hbase.snapshot.CorruptedSnapshotException: Couldn't read snapshot info from:file:/tmp/hbase-cloudera/hbase/.hbase-snapshot/FundamentalAnalyticSnapshot/.snapshotinfo
at org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils.readSnapshotInfo(SnapshotDescriptionUtils.java:294)
at org.apache.hadoop.hbase.snapshot.RestoreSnapshotHelper.copySnapshotForScanner(RestoreSnapshotHelper.java:818)
at org.apache.hadoop.hbase.mapreduce.TableSnapshotInputFormatImpl.setInput(TableSnapshotInputFormatImpl.java:355)
at org.apache.hadoop.hbase.mapreduce.TableSnapshotInputFormat.setInput(TableSnapshotInputFormat.java:204)
at org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil.initTableSnapshotMapperJob(TableMapReduceUtil.java:335)
at com.thomsonretuers.hbase.HBaseToFileDriver.run(HBaseToFileDriver.java:128)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
at com.thomsonretuers.hbase.HBaseToFileDriver.main(HBaseToFileDriver.java:75)
Caused by: java.io.FileNotFoundException: File file:/tmp/hbase-cloudera/hbase/.hbase-snapshot/FundamentalAnalyticSnapshot/.snapshotinfo does not exist
One quick Question about Snapshot.
I want to take snapshot and run full table scan ,in that case scan
on snapshot will impact the region server performance?

Answer 1

I solved it after using correct path
Create snapshot
snapshot 'FundamentalAnalytic','FundamentalAnalyticSnapshot'
Export Snapshot to local hdfs
hbase org.apache.hadoop.hbase.snapshot.ExportSnapshot -snapshot FundamentalAnalyticSnapshot -copy-to /tmp -mappers 16
Driver Job Configuration to rum mapreduce on Hbase snapshot
String snapshotName="FundamentalAnalyticSnapshot";
Path restoreDir = new Path("hdfs://quickstart.cloudera:8020/tmp");
String hbaseRootDir = "hdfs://quickstart.cloudera:8020/hbase";
TableMapReduceUtil.initTableSnapshotMapperJob(snapshotName, // Snapshot name
scan, // Scan instance to control CF and attribute selection
DefaultMapper.class, // mapper class
NullWritable.class, // mapper output key
Text.class, // mapper output value
job,
true,
restoreDir);
Also running mapreduce on Hbase snapshot will skip scan on Hbase table and also there will be no impact on region server.