apache/hadoop · error · IllegalArgumentException

numRetries = ${numRetries} < 0

Error message

numRetries = ${numRetries} < 0

What it means

MultipleLinearRandomRetry.Pair holds one rung of a piecewise retry schedule — (numRetries, sleepMillis), e.g. '6 retries 10s apart, then 10 retries 60s apart'. The Pair constructor rejects negative numRetries: a schedule with a negative count is meaningless and always points to a parsing or configuration error upstream.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/retry/RetryPolicies.java:395

  /**
   * Given pairs of number of retries and sleep time (n0, t0), (n1, t1), ...,
   * the first n0 retries sleep t0 milliseconds on average,
   * the following n1 retries sleep t1 milliseconds on average, and so on.
   * 
   * For all the sleep, the actual sleep time is randomly uniform distributed
   * in the close interval [0.5t, 1.5t], where t is the sleep time specified.
   *
   * The objects of this class are immutable.
   */
  public static class MultipleLinearRandomRetry implements RetryPolicy {
    /** Pairs of numRetries and sleepSeconds */
    public static class Pair {
      final int numRetries;
      final int sleepMillis;
      
      public Pair(final int numRetries, final int sleepMillis) {
        if (numRetries < 0) {
          throw new IllegalArgumentException("numRetries = " + numRetries+" < 0");
        }
        if (sleepMillis < 0) {
          throw new IllegalArgumentException("sleepMillis = " + sleepMillis + " < 0");
        }

        this.numRetries = numRetries;
        this.sleepMillis = sleepMillis;
      }
      
      @Override
      public String toString() {
        return numRetries + "x" + sleepMillis + "ms";
      }
    }

    private final List<Pair> pairs;
    private String myString;

View on GitHub (pinned to 2add963021)

Solutions

1. Validate the spec string at config-load time and fail with the offending token and property name.
2. Fix the negative number in the policy spec.
3. If counts are computed, floor them at 0 before constructing Pair.

Example fix

// before
new MultipleLinearRandomRetry.Pair(-3, 5000);

// after
Preconditions.checkArgument(numRetries >= 0, "bad retry spec token: %s", raw);
new MultipleLinearRandomRetry.Pair(numRetries, sleepMillis);

Preconditions.checkArgument(numRetries >= 0,
    "retry count must be >= 0, got %s (spec token: %s)", numRetries, rawToken);

When it happens

Trigger: Building Pair from parsed retry-spec strings (dfs.client.retry.policy.spec, format like '10000,6,60000,10') where a negative number was typed, or from arithmetic that underflows before construction.

Common situations: Hand-edited retry policy specs in site XML with a stray minus sign ('-3,5000'); tooling writing negative defaults; token pairs misaligned so a sleep lands in the count slot.

Related errors

• maxRetries = ${maxRetries} < 0
• sleepTime = ${sleepTime} < 0
• sleepMillis = ${sleepMillis} < 0
• pairs must be neither null nor empty.
• min sleep time must be positive number and max sleep time mu

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/f43bb29782cef220. Report an issue: GitHub.