Example usage for org.apache.hadoop.hdfs DistributedFileSystem deleteSnapshot

Introduction

In this page you can find the example usage for org.apache.hadoop.hdfs DistributedFileSystem deleteSnapshot.

Prototype

@Override
    public void deleteSnapshot(final Path snapshotDir, final String snapshotName) throws IOException 

Source Link

Usage

From source file:org.apache.falcon.snapshots.retention.HdfsSnapshotEvictor.java

License:Apache License

protected static void evictSnapshots(DistributedFileSystem fs, String dirName, String ageLimit,
        int numSnapshots) throws FalconException {
    try {//www.  j  a  v a2 s.  c o m
        LOG.info("Started evicting snapshots on dir {}{} using policy {}, agelimit {}, numSnapshot {}",
                fs.getUri(), dirName, ageLimit, numSnapshots);

        long evictionTime = System.currentTimeMillis() - EvictionHelper.evalExpressionToMilliSeconds(ageLimit);

        dirName = StringUtils.removeEnd(dirName, Path.SEPARATOR);
        String snapshotDir = dirName + Path.SEPARATOR + HdfsSnapshotUtil.SNAPSHOT_DIR_PREFIX + Path.SEPARATOR;
        FileStatus[] snapshots = fs.listStatus(new Path(snapshotDir));
        if (snapshots.length <= numSnapshots) {
            // no eviction needed
            return;
        }

        // Sort by last modified time, ascending order.
        Arrays.sort(snapshots, new Comparator<FileStatus>() {
            @Override
            public int compare(FileStatus f1, FileStatus f2) {
                return Long.compare(f1.getModificationTime(), f2.getModificationTime());
            }
        });

        for (int i = 0; i < (snapshots.length - numSnapshots); i++) {
            // delete if older than ageLimit while retaining numSnapshots
            if (snapshots[i].getModificationTime() < evictionTime) {
                fs.deleteSnapshot(new Path(dirName), snapshots[i].getPath().getName());
            }
        }

    } catch (ELException ele) {
        LOG.warn("Unable to parse retention age limit {} {}", ageLimit, ele.getMessage());
        throw new FalconException("Unable to parse retention age limit " + ageLimit, ele);
    } catch (IOException ioe) {
        LOG.warn("Unable to evict snapshots from dir {} {}", dirName, ioe);
        throw new FalconException("Unable to evict snapshots from dir " + dirName, ioe);
    }

}

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