HDFS-14121. Log message about the old hosts file format is misleading (Contributed by Zsolt Venczel via Daniel Templeton)
Change-Id: I7ff548f6c82e0aeb08a7a50ca7c2c827db8726bb Project: http://git-wip-us.apache.org/repos/asf/hadoop/repo Commit: http://git-wip-us.apache.org/repos/asf/hadoop/commit/aa128598 Tree: http://git-wip-us.apache.org/repos/asf/hadoop/tree/aa128598 Diff: http://git-wip-us.apache.org/repos/asf/hadoop/diff/aa128598 Branch: refs/heads/HDFS-13891 Commit: aa1285989092bc253c45b7a83acec2e9bce2c5dc Parents: ca379e1 Author: Zsolt Venczel <[email protected]> Authored: Fri Dec 14 13:02:45 2018 +0100 Committer: Daniel Templeton <[email protected]> Committed: Fri Dec 14 13:54:57 2018 +0100 ---------------------------------------------------------------------- .../hdfs/util/CombinedHostsFileReader.java | 41 ++++++++++++++------ 1 file changed, 29 insertions(+), 12 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/hadoop/blob/aa128598/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/util/CombinedHostsFileReader.java ---------------------------------------------------------------------- diff --git a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/util/CombinedHostsFileReader.java b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/util/CombinedHostsFileReader.java index aa8e4c1..be1f6d0 100644 --- a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/util/CombinedHostsFileReader.java +++ b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/util/CombinedHostsFileReader.java @@ -23,6 +23,7 @@ import com.fasterxml.jackson.databind.JsonMappingException; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.ObjectReader; +import java.io.File; import java.io.FileInputStream; import java.io.InputStreamReader; import java.io.IOException; @@ -61,26 +62,37 @@ public final class CombinedHostsFileReader { private CombinedHostsFileReader() { } + private static final String REFER_TO_DOC_MSG = " For the correct JSON" + + " format please refer to the documentation (https://hadoop.apache"; + + ".org/docs/current/hadoop-project-dist/hadoop-hdfs/HdfsDataNodeAd" + + "minGuide.html#JSON-based_configuration)"; + /** * Deserialize a set of DatanodeAdminProperties from a json file. - * @param hostsFile the input json file to read from + * @param hostsFilePath the input json file to read from * @return the set of DatanodeAdminProperties * @throws IOException */ public static DatanodeAdminProperties[] - readFile(final String hostsFile) throws IOException { + readFile(final String hostsFilePath) throws IOException { DatanodeAdminProperties[] allDNs = new DatanodeAdminProperties[0]; ObjectMapper objectMapper = new ObjectMapper(); + File hostFile = new File(hostsFilePath); boolean tryOldFormat = false; - try (Reader input = - new InputStreamReader(new FileInputStream(hostsFile), "UTF-8")) { - allDNs = objectMapper.readValue(input, DatanodeAdminProperties[].class); - } catch (JsonMappingException jme) { - // The old format doesn't have json top-level token to enclose the array. - // For backward compatibility, try parsing the old format. - tryOldFormat = true; - LOG.warn("{} has invalid JSON format." + - "Try the old format without top-level token defined.", hostsFile); + + if (hostFile.length() > 0) { + try (Reader input = + new InputStreamReader(new FileInputStream(hostFile), + "UTF-8")) { + allDNs = objectMapper.readValue(input, DatanodeAdminProperties[].class); + } catch (JsonMappingException jme) { + // The old format doesn't have json top-level token to enclose + // the array. + // For backward compatibility, try parsing the old format. + tryOldFormat = true; + } + } else { + LOG.warn(hostsFilePath + " is empty." + REFER_TO_DOC_MSG); } if (tryOldFormat) { @@ -89,13 +101,18 @@ public final class CombinedHostsFileReader { JsonFactory jsonFactory = new JsonFactory(); List<DatanodeAdminProperties> all = new ArrayList<>(); try (Reader input = - new InputStreamReader(new FileInputStream(hostsFile), "UTF-8")) { + new InputStreamReader(new FileInputStream(hostsFilePath), + "UTF-8")) { Iterator<DatanodeAdminProperties> iterator = objectReader.readValues(jsonFactory.createParser(input)); while (iterator.hasNext()) { DatanodeAdminProperties properties = iterator.next(); all.add(properties); } + LOG.warn(hostsFilePath + " has legacy JSON format." + REFER_TO_DOC_MSG); + } catch (Throwable ex) { + LOG.warn(hostsFilePath + " has invalid JSON format." + REFER_TO_DOC_MSG, + ex); } allDNs = all.toArray(new DatanodeAdminProperties[all.size()]); } --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
