apache/hadoop · error · IllegalArgumentException

Capacity ratio config is not with correct format: {}

Error message

Capacity ratio config is not with correct format: {}

What it means

Each comma-separated entry of dfs.datanode.same.disk.tiering.capacity.ratio.percentage must match the regex ^\[([0-9.]*)\](.+)$ - a bracketed number followed by a volume path. Any entry that does not match (missing brackets, missing path, stray characters) makes StorageLocation.parseCapacityRatio() throw IllegalArgumentException with the whole config string.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/StorageLocation.java:187

    Map<URI, Double> result = new HashMap<>();
    capacityRatioConf = capacityRatioConf.replaceAll("\\s", "");
    if (capacityRatioConf.isEmpty()) {
      return result;
    }
    String[] capacityRatios = capacityRatioConf.split(",");
    for (String ratio : capacityRatios) {
      Matcher matcher = CAPACITY_RATIO_REGEX.matcher(ratio);
      if (matcher.matches()) {
        String capacityString = matcher.group(1).trim();
        String location = matcher.group(2).trim();
        double capacityRatio = Double.parseDouble(capacityString);
        if (capacityRatio > 1 || capacityRatio < 0) {
          throw new IllegalArgumentException("Capacity ratio" + capacityRatio
              + " is not between 0 to 1: " + ratio);
        }
        result.put(new Path(location).toUri(), capacityRatio);
      } else {
        throw new IllegalArgumentException(
            "Capacity ratio config is not with correct format: "
                + capacityRatioConf
        );
      }
    }
    return result;
  }

  @Override
  public String toString() {
    return "[" + storageType + "]" + baseURI.normalize();
  }

  @Override
  public boolean equals(Object obj) {
    if (!(obj instanceof StorageLocation)) {
      return false;
    }

View on GitHub (pinned to 2add963021)

Solutions

1. Format every entry as [fraction]/absolute/path - e.g. [0.3]/disk1/archive,[0.2]/disk2/archive
2. Remove trailing/empty comma-separated entries
3. Validate locally before deploy: every token must match Pattern \\[(\\d+\\.\\d*)\\](.+)

Example fix

# before (hdfs-site.xml)
<property>
  <name>dfs.datanode.same.disk.tiering.capacity.ratio.percentage</name>
  <value>0.3:/disk1/archive,0.2:/disk2/archive</value>
</property>

# after
<property>
  <name>dfs.datanode.same.disk.tiering.capacity.ratio.percentage</name>
  <value>[0.3]/disk1/archive,[0.2]/disk2/archive</value>
</property>

static boolean isValidCapacityRatioEntry(String entry) {
  return entry.matches("^\\[[0-9.]+\\]/.+"); // ratio in brackets + absolute-ish path
}
// validate every comma token of the config before DN startup

When it happens

Trigger: Setting dfs.datanode.same.disk.tiering.capacity.ratio.percentage to e.g. '0.5:/disk1' (colon instead of [num]/path), 'disk1' (no ratio), '[0.5]' (no path), or leaving a trailing comma producing an empty entry; whitespace is stripped before matching, but structure must be exact.

Common situations: First-time same-disk-tiering configuration using URI-ish 'key=value' habits instead of the [ratio]/path syntax; copy-paste from docs that lost the brackets; trailing separators after edits.

Related errors

• Capacity ratio{} is not between 0 to 1: {}
• URI: {} is not in the expected format
• Xceiver count {} exceeds the limit of concurrent xceivers: {
• Cannot create directory {rootPath}
• Incompatible node types: storageType={storageType} but Stora

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/695e52d39b29ee78. Report an issue: GitHub.