apache/druid · error · IllegalArgumentException

maxTries must be greater than 1

Error message

maxTries must be greater than 1

What it means

RetryingInputStream validates its retry policy in the constructor and requires maxTries to be greater than 1, since with a single try there is no point in the retry wrapper. Values of 0, 1, or negative throw this IllegalArgumentException.

Solutions

1. Set maxTries to at least 2 (Druid's default is RetryUtils.DEFAULT_MAX_TRIES)
2. Leave maxTries null to use the default instead of setting 1
3. Fix ingestion spec fields like http.maxRetry to a valid value >= 2

Example fix

// before
new RetryingInputStream(openFn, retryCond, 1, doWait);
// after
new RetryingInputStream(openFn, retryCond, 3, doWait);

if (maxTries != null && maxTries <= 1) { throw new IllegalArgumentException("maxTries must be > 1"); }

When it happens

Trigger: Constructing RetryingInputStream with maxTries <= 1 (e.g. 0, 1, or negative), often from deserialized inputFormat/split specs where maxRetry or httpMaxRetry was set to 1 or 0.

Common situations: Config authors setting maxRetry: 1 intending 'one attempt', property files with 0 or unset-then-defaulted values, programmatic builders passing Integer constants like 1.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

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AI-assisted analysis of apache/druid@9b90983fd2 (2026-09-07). Data as JSON: /api/errors/86ba415f8498f9f2. Report an issue: GitHub.

Appendix: source

Thrown at processing/src/main/java/org/apache/druid/data/input/impl/RetryingInputStream.java:92

  }

  @VisibleForTesting
  RetryingInputStream(
      T object,
      ObjectOpenFunction<T> objectOpenFunction,
      Predicate<Throwable> retryCondition,
      @Nullable Integer maxTries,
      boolean doWait
  ) throws IOException
  {
    this.object = Preconditions.checkNotNull(object, "object");
    this.objectOpenFunction = Preconditions.checkNotNull(objectOpenFunction, "objectOpenFunction");
    this.retryCondition = Preconditions.checkNotNull(retryCondition, "retryCondition");
    this.maxTries = maxTries == null ? RetryUtils.DEFAULT_MAX_TRIES : maxTries;
    this.doWait = doWait;

    if (this.maxTries <= 1) {
      throw new IAE("maxTries must be greater than 1");
    }
    openWithRetry(0);
  }

  private void openIfNeeded() throws IOException
  {
    if (delegate == null) {
      openWithRetry(startOffset);
    }
  }

  private void openWithRetry(final long offset) throws IOException
  {
    for (int nTry = 0; nTry < maxTries; nTry++) {
      try {
        delegate = new CountingInputStream(objectOpenFunction.open(object, offset));
        break;
      }

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