apache/beam · error · RuntimeException

Invalid host/port in BigtableConfig

Error message

Invalid host/port in BigtableConfig 

What it means

When a Bigtable emulator host:port is configured, buildBigtableDataSettings parses it as host and port. If the string after the last ':' is not a valid integer port (or the string has no host part at all), the NumberFormatException/IndexOutOfBoundsException is rethrown as this RuntimeException.

Solutions

1. Fix the emulator address to 'host:port' format, e.g. "localhost:8086", in your BigtableConfig/executor config.
2. Validate the endpoint before building: split on ':' and check Integer.parseInt succeeds.
3. If you meant a real Bigtable instance, remove the emulator host/port so the code takes the BigtableDataSettings.newBuilder() path.

Example fix

// before
builder.setHostAndPort("localhost"); // throws
// after
builder.setHostAndPort("localhost:8086");

String[] parts = hostAndPort.split(":");
if (parts.length != 2 || parts[0].isEmpty()) throw new IllegalArgumentException("Emulator must be host:port");
int port = Integer.parseInt(parts[1]); // throws clear NumberFormatException

boolean isValidHostPort(String s) { int i = s.lastIndexOf(':'); if (i <= 0) return false; try { Integer.parseInt(s.substring(i + 1)); return true; } catch (NumberFormatException e) { return false; } }

try { settings = translator.buildBigtableDataSettings(config, options); } catch (RuntimeException e) { if (e.getMessage().contains("Invalid host/port")) { ... } throw e; }

When it happens

Trigger: Setting the Bigtable config's hostAndPort (emulator target) to a malformed value like "localhost" (no port), "localhost:notaport", or "::bad" and then translating the config into BigtableDataSettings.

Common situations: Typo in emulator endpoint; environment variable for the emulator host missing its port; copy-paste dropping the :8086; wrong variable interpolated into the config.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• Allow list file does not exist
• Ambiguous expression type (perhaps missing quoting?)
• Approximate Nearest Neighbor Search (ANNS) field must be…
• BigQuery temp location expected a valid 'gs://' path, but…
• Bigtable location must be in the following format…

AI-assisted analysis of apache/beam@12126d8942 (2026-09-13). Data as JSON: /api/errors/b6d1ebf7459430dc. Report an issue: GitHub.

Appendix: source

Thrown at sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigtable/BigtableConfigTranslator.java:118

    return buildBigtableDataSettings(config, pipelineOptions).build();
  }

  private static BigtableDataSettings.Builder buildBigtableDataSettings(
      BigtableConfig config, PipelineOptions pipelineOptions) throws IOException {
    BigtableDataSettings.Builder dataBuilder;
    boolean emulator = false;
    if (!Strings.isNullOrEmpty(config.getEmulatorHost())) {
      emulator = true;
      String hostAndPort = config.getEmulatorHost();
      try {
        int lastIndexOfCol = hostAndPort.lastIndexOf(":");
        int port = Integer.parseInt(hostAndPort.substring(lastIndexOfCol + 1));
        dataBuilder =
            BigtableDataSettings.newBuilderForEmulator(
                hostAndPort.substring(0, lastIndexOfCol), port);
      } catch (NumberFormatException | IndexOutOfBoundsException ex) {
        throw new RuntimeException("Invalid host/port in BigtableConfig " + hostAndPort);
      }
    } else {
      dataBuilder = BigtableDataSettings.newBuilder();
    }

    // Configure target
    dataBuilder
        .setProjectId(Objects.requireNonNull(config.getProjectId().get()))
        .setInstanceId(Objects.requireNonNull(config.getInstanceId().get()));
    if (config.getAppProfileId() != null
        && !Strings.isNullOrEmpty(config.getAppProfileId().get())) {
      dataBuilder.setAppProfileId(Objects.requireNonNull(config.getAppProfileId().get()));
    }

    // Skip resetting the credentials if it's connected to an emulator
    if (!emulator) {
      if (pipelineOptions.as(GcpOptions.class).getGcpCredential() != null) {
        dataBuilder

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