apache/druid · error · IllegalArgumentException

Cannot define both uri and fileRegex

Error message

Cannot define both uri and fileRegex

What it means

fileRegex (a filename filter pattern) can only be used with uriPrefix-based loading, where multiple files are listed and filtered. When a single `uri` is given together with a fileRegex, the constructor throws this IAE because a regex makes no sense for a single explicitly named file.

Source

Thrown at extensions-core/lookups-cached-global/src/main/java/org/apache/druid/query/lookup/namespace/UriExtractionNamespace.java:125

      throw new IAE("Either uri xor uriPrefix required");
    }
    this.namespaceParseSpec = Preconditions.checkNotNull(namespaceParseSpec, "namespaceParseSpec");
    if (pollPeriod == null) {
      // Warning because if UriExtractionNamespace is being used for lookups, any updates to the database will not
      // be picked up after the node starts. So for use casses where nodes start at different times (like streaming
      // ingestion with peons) there can be data inconsistencies across the cluster.
      LOG.warn("No pollPeriod configured for UriExtractionNamespace - entries will be loaded only once at startup");
      this.pollPeriod = Period.ZERO;
    } else {
      this.pollPeriod = pollPeriod;
    }
    this.fileRegex = fileRegex == null ? versionRegex : fileRegex;
    if (fileRegex != null && versionRegex != null) {
      throw new IAE("Cannot specify both versionRegex and fileRegex. versionRegex is deprecated");
    }

    if (uri != null && this.fileRegex != null) {
      throw new IAE("Cannot define both uri and fileRegex");
    }

    if (this.fileRegex != null) {
      try {
        Pattern.compile(this.fileRegex);
      }
      catch (PatternSyntaxException ex) {
        throw new IAE(ex, "Could not parse `fileRegex` [%s]", this.fileRegex);
      }
    }
    this.maxHeapPercentage = maxHeapPercentage == null ? DEFAULT_MAX_HEAP_PERCENTAGE : maxHeapPercentage;
  }

  public String getFileRegex()
  {
    return fileRegex;
  }

View on GitHub (pinned to 9b90983fd2)

Solutions

1. Remove the `fileRegex` field from the lookup config when using `uri`.
2. If filtering is actually needed, switch from `uri` to `uriPrefix` and keep the regex.
3. Fix generators/templates to emit fileRegex only for prefix-based lookups.
4. For the deprecated path, also ensure versionRegex is not set, since it maps onto fileRegex.

Example fix

// before
{"uri":"file:///data/l.csv", "fileRegex":".*csv"}
// after
{"uri":"file:///data/l.csv"}

// java
if (cfg.hasNonNull("uri") && cfg.hasNonNull("fileRegex")) {
  throw new IllegalArgumentException("fileRegex requires uriPrefix, not uri");
}

// java
try { mapper.readValue(json, UriExtractionNamespace.class); }
catch (IllegalArgumentException e) {
  if (e.getMessage().equals("Cannot define both uri and fileRegex")) { /* remove one */ }
}

When it happens

Trigger: Constructing UriExtractionNamespace with `uri` set (non-null) and a non-null fileRegex (or deprecated versionRegex, which is folded into fileRegex).

Common situations: Configs that previously used uriPrefix switched to a single uri without removing fileRegex; users adding a filter "just in case" to a single-file lookup; generated configs that always emit fileRegex.

Related errors

• Either uri xor uriPrefix required
• Cannot specify both versionRegex and fileRegex. versionRegex
• Could not parse `fileRegex` [%s]
• Set only one of 'key' or 'sharedAccessStorageToken' or 'useA
• Invalid pod adapter [%s], only pod adapter [%s] can be speci

AI-assisted analysis of apache/druid@9b90983fd2 (2026-09-07). Data as JSON: /api/errors/9bec3dc007f8ab23. Report an issue: GitHub.