/** * Download <code>fsimage</code> and <code>edits</code> files from the name-node. * * @return true if a new image has been downloaded and needs to be loaded * @throws IOException */ private boolean downloadCheckpointFiles(CheckpointSignature sig) throws IOException { checkpointImage.cTime = sig.cTime; checkpointImage.checkpointTime = sig.checkpointTime; boolean downloadImage = true; String fileid; File[] srcNames; if (sig.imageDigest.equals(checkpointImage.imageDigest)) { downloadImage = false; LOG.info("Image has not changed. Will not download image."); } else { // get fsimage srcNames = checkpointImage.getImageFiles(); assert srcNames.length > 0 : "No checkpoint targets."; fileid = "getimage=1"; TransferFsImage.getFileClient(fsName, fileid, srcNames, false); checkpointImage.imageDigest = sig.imageDigest; LOG.info( "Downloaded file " + srcNames[0].getName() + " size " + srcNames[0].length() + " bytes."); } // get edits file fileid = "getedit=1"; srcNames = checkpointImage.getEditsFiles(); assert srcNames.length > 0 : "No checkpoint targets."; TransferFsImage.getFileClient(fsName, fileid, srcNames, false); LOG.info( "Downloaded file " + srcNames[0].getName() + " size " + srcNames[0].length() + " bytes."); checkpointImage.checkpointUploadDone(null); return downloadImage; }