apache/kafka · error · IllegalArgumentException

The method: memberResult is not applicable in 'removeAll'…

Error message

The method: memberResult is not applicable in 'removeAll' mode

What it means

Thrown by RemoveMembersFromConsumerGroupResult.memberResult(MemberToRemove) when removeAll() is true, i.e. the result was created from a 'remove all members' request. In removeAll mode there are no per-member futures because no specific members were supplied, so per-member lookup is meaningless. Use all() to wait for the bulk operation instead.

Solutions

1. Branch on the request mode: if removeAll, call result.all(); otherwise call memberResult(member).
2. Track whether you used the no-arg options and route the result handling accordingly.
3. Read result.all() which works in both modes for a top-level success future.

Example fix

// before
KafkaFuture<Void> f = result.memberResult(member);

// after
KafkaFuture<Void> f = removeAllMode
    ? result.all()
    : result.memberResult(member);

KafkaFuture<Void> f = removeAllMode
    ? result.all()
    : result.memberResult(member);

static boolean isRemoveAll(RemoveMembersFromConsumerGroupOptions o) {
    // removeAll mode is created by the no-arg constructor; track it at call site
    return removeAllMode;
}

KafkaFuture<Void> f;
try {
    f = result.memberResult(member);
} catch (IllegalArgumentException e) {
    if (e.getMessage().contains("removeAll")) {
        f = result.all();
    } else throw e;
}

When it happens

Trigger: Calling `result.memberResult(someMember)` on a RemoveMembersFromConsumerGroupResult returned by an admin.removeMembersFromConsumerGroup call made with the no-arg RemoveMembersFromConsumerGroupOptions (removeAll mode).

Common situations: Code reused across both targeted-removal and removeAll flows; UI that always calls memberResult regardless of how the request was issued; copy-paste from a targeted-removal example into a removeAll context.

Related errors

• Member was not included in the original request
• Invalid empty members has been provided
• Cannot create a new partition reassignment without any…
• Empty string is not allowed.
• Expected 0 <= minVersion <= maxVersion but received…

AI-assisted analysis of apache/kafka@996fb4585a (2026-08-11). Data as JSON: /api/errors/bcd6817707db52bc. Report an issue: GitHub.

Appendix: source

Thrown at clients/src/main/java/org/apache/kafka/clients/admin/RemoveMembersFromConsumerGroupResult.java:85

                } else {
                    for (MemberToRemove memberToRemove : memberInfos) {
                        if (maybeCompleteExceptionally(memberErrors, memberToRemove.toMemberIdentity(), result)) {
                            return;
                        }
                    }
                }
                result.complete(null);
            }
        });
        return result;
    }

    /**
     * Returns the selected member future.
     */
    public KafkaFuture<Void> memberResult(MemberToRemove member) {
        if (removeAll()) {
            throw new IllegalArgumentException("The method: memberResult is not applicable in 'removeAll' mode");
        }
        if (!memberInfos.contains(member)) {
            throw new IllegalArgumentException("Member " + member + " was not included in the original request");
        }

        final KafkaFutureImpl<Void> result = new KafkaFutureImpl<>();
        this.future.whenComplete((memberErrors, throwable) -> {
            if (throwable != null) {
                result.completeExceptionally(throwable);
            } else if (!maybeCompleteExceptionally(memberErrors, member.toMemberIdentity(), result)) {
                result.complete(null);
            }
        });
        return result;
    }

    private boolean maybeCompleteExceptionally(Map<MemberIdentity, Errors> memberErrors,
                                               MemberIdentity member,

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