apache/hadoop · error · IOException

Unable to parse relative time value of {}: unknown time unit

Error message

Unable to parse relative time value of {}: unknown time unit {}

What it means

DFSUtil.parseRelativeTime only accepts the lowercase unit suffixes s, m, h and d. If the string parses as a number but its last character is none of these, it throws 'unknown time unit <c>'. Note that a bare number like '100' lands here too, and uppercase units ('7D') are rejected because the endsWith checks are case-sensitive.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSUtil.java:1702

    }
    String ttlString = relTime.substring(0, relTime.length()-1);
    long ttl;
    try {
      ttl = Long.parseLong(ttlString);
    } catch (NumberFormatException e) {
      throw new IOException("Unable to parse relative time value of " + relTime
          + ": " + ttlString + " is not a number");
    }
    if (relTime.endsWith("s")) {
      // pass
    } else if (relTime.endsWith("m")) {
      ttl *= 60;
    } else if (relTime.endsWith("h")) {
      ttl *= 60*60;
    } else if (relTime.endsWith("d")) {
      ttl *= 60*60*24;
    } else {
      throw new IOException("Unable to parse relative time value of " + relTime
          + ": unknown time unit " + relTime.charAt(relTime.length() - 1));
    }
    return ttl*1000;
  }

  /**
   * Load HTTPS-related configuration.
   */
  public static Configuration loadSslConfiguration(Configuration conf) {
    Configuration sslConf = new Configuration(false);

    sslConf.addResource(conf.get(
        DFSConfigKeys.DFS_SERVER_HTTPS_KEYSTORE_RESOURCE_KEY,
        DFSConfigKeys.DFS_SERVER_HTTPS_KEYSTORE_RESOURCE_DEFAULT));

    final String[] reqSslProps = {
        DFSConfigKeys.DFS_SERVER_HTTPS_TRUSTSTORE_LOCATION_KEY,
        DFSConfigKeys.DFS_SERVER_HTTPS_KEYSTORE_LOCATION_KEY,

View on GitHub (pinned to 2add963021)

Solutions

1. Use a supported lowercase unit: s, m, h or d (e.g. 10w -> 70d or 168h)
2. Append a unit to bare numbers (100 -> 100s)
3. Lowercase the suffix (7D -> 7d)

Example fix

// before
hdfs cacheadmin -addDirective -ttl 7D
// after
hdfs cacheadmin -addDirective -ttl 7d

import java.util.regex.*;

private static final Pattern REL_TIME = Pattern.compile("^([0-9]+)([smhd])$");

static Long parseTtlSafely(String s) {
  Matcher m = REL_TIME.matcher(s == null ? "" : s);
  if (!m.matches()) return null; // caller reports a friendly error
  long v = Long.parseLong(m.group(1));
  switch (m.group(2)) {
    case "m": return v * 60 * 1000;
    case "h": return v * 3600 * 1000;
    case "d": return v * 86400 * 1000;
    default:  return v * 1000;
  }
}

static boolean isParsableRelativeTime(String s) {
  return s != null && s.matches("[0-9]+[smhd]");
}

catch (IOException e) around DFSUtil.parseRelativeTime; on 'unknown time unit' surface the accepted suffix list (s, m, h, d, lowercase) to the user.

When it happens

Trigger: TTL strings ending in an unsupported character: '10w', '7D', or unitless '100' (its last char '0' is treated as the unit). Reached from `hdfs cacheadmin -addDirective -ttl` and AdminHelper max-ttl parsing.

Common situations: Weeks ('w') or years ('y') entered as units that HDFS does not support; uppercase suffixes; bare integers without any suffix.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• Unable to parse relative time value of {}: too short
• Unable to parse relative time value of {}: {} is not a numbe
• Illegal option {}
• Not enough arguments: expected {} but got {}
• Too many arguments: expected {} but got {}

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/bec399bdb4e27412. Report an issue: GitHub.