aeron-io/aeron · error · ConfigurationException

liveStreamId must be set

Error message

liveStreamId must be set

What it means

PersistentSubscription.Builder.conclude() validates that liveStreamId was set and throws ConfigurationException("liveStreamId must be set") when it equals Aeron.NULL_VALUE. A persistent subscription needs the live stream id to follow the live stream once the recording's replay catches up.

Solutions

1. Call builder.liveStreamId(streamId) with a valid stream id before conclude()
2. Wire the same streamId used for the recording into the persistent subscription builder
3. Validate config/CLI inputs so a missing stream id fails at parse time, not at conclude()
4. Check builder call order — ensure no early return skips liveStreamId(...) setup

Example fix

// before
b.recordingId(recordingId).liveChannel(liveChannel);
b.conclude(); // liveStreamId missing

// after
b.recordingId(recordingId).liveChannel(liveChannel).liveStreamId(streamId);
b.conclude();

if (liveStreamId == Aeron.NULL_VALUE) {
    throw new IllegalArgumentException("liveStreamId must be resolved before building PersistentSubscription");
}

boolean hasLiveStreamId(int streamId) { return streamId != Aeron.NULL_VALUE; }

try {
    builder.conclude();
} catch (ConfigurationException e) {
    if (e.getMessage().equals("liveStreamId must be set")) {
        throw new IllegalStateException("liveStreamId is required for a persistent subscription", e);
    }
}

When it happens

Trigger: conclude() invoked on a builder where liveStreamId() was never called or set to Aeron.NULL_VALUE — recordingId and liveChannel may be fine, but the live follow stream id is missing.

Common situations: Builders configured from partial config files where only channel was provided and streamId was omitted; assuming liveStreamId has a default; copying builder setup code and dropping the liveStreamId line.

Understand the failure class

Background: "is required", "must be set", "missing required field": configuration validation errors across open-source libraries — this error's family across 36 libraries.

Related errors

• recordingId must be set
• invalid fileIoMaxLength=
• catalogFileSyncLevel
• Archive.Context.controlChannel must be set
• Archive.Context.controlChannel must be UDP media: uri=

AI-assisted analysis of aeron-io/aeron@6d60124e15 (2026-09-12). Data as JSON: /api/errors/6c6840cd4077cace. Report an issue: GitHub.

Appendix: source

Thrown at aeron-archive/src/main/java/io/aeron/archive/client/PersistentSubscription.java:1687

        /**
         * Conclude configuration by setting up defaults when specifics are not provided.
         */
        @SuppressWarnings("MethodLength")
        public void conclude()
        {
            if ((boolean)IS_CONCLUDED_VH.getAndSet(this, true))
            {
                throw new ConcurrentConcludeException();
            }

            if (Aeron.NULL_VALUE == recordingId)
            {
                throw new ConfigurationException("recordingId must be set");
            }

            if (Aeron.NULL_VALUE == liveStreamId)
            {
                throw new ConfigurationException("liveStreamId must be set");
            }

            if (Strings.isEmpty(liveChannel))
            {
                throw new ConfigurationException("liveChannel must be set");
            }

            if (Strings.isEmpty(replayChannel))
            {
                throw new ConfigurationException("replayChannel must be set");
            }

            if (Aeron.NULL_VALUE == replayStreamId)
            {
                throw new ConfigurationException("replayStreamId must be set");
            }

            if (null == aeronArchiveContext)

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