apache/flink · error · IllegalArgumentException

%s is an unknown value of RestartStrategyType.

Error message

%s is an unknown value of RestartStrategyType.

What it means

Thrown by RestartStrategyType.of(String) when the supplied value does not match any accepted display value of the four restart strategy types (disable/none/off, fixed-delay, failure-rate, exponential-delay). The enum lookup iterates all available aliases before rejecting.

Source

Thrown at flink-core/src/main/java/org/apache/flink/configuration/RestartStrategyOptions.java:91

        EXPONENTIAL_DELAY("exponential-delay", Sets.newHashSet("exponentialdelay"));

        private final String mainValue;
        private final Set<String> allAvailableValues;

        RestartStrategyType(String mainValue, Set<String> otherAvailableValues) {
            this.mainValue = mainValue;
            this.allAvailableValues = Sets.newHashSet(mainValue);
            allAvailableValues.addAll(otherAvailableValues);
        }

        /** Return the corresponding RestartStrategyType based on the displayed value. */
        public static RestartStrategyType of(String value) {
            for (RestartStrategyType restartStrategyType : RestartStrategyType.values()) {
                if (restartStrategyType.getAllAvailableValues().contains(value)) {
                    return restartStrategyType;
                }
            }
            throw new IllegalArgumentException(
                    String.format("%s is an unknown value of RestartStrategyType.", value));
        }

        public String getMainValue() {
            return mainValue;
        }

        public Set<String> getAllAvailableValues() {
            return allAvailableValues;
        }

        public TextElement[] getAllTextElement() {
            return allAvailableValues.stream().map(TextElement::code).toArray(TextElement[]::new);
        }
    }

    private static InlineElement[] concat(InlineElement[] first, InlineElement... second) {
        InlineElement[] result = new InlineElement[first.length + second.length];

View on GitHub (pinned to 2f3c205e92)

Solutions

1. Use one of the exact accepted values: disable, none, off, fixed-delay, failure-rate, exponential-delay.
2. Check for typos, extra spaces, or wrong casing (values are matched exactly, not case-insensitively).
3. Consult RestartStrategyOptions.RestartStrategyType.getAllAvailableValues() for the authoritative list.

Example fix

# before
restart-strategy.type: fixed delay

# after
restart-strategy.type: fixed-delay

Set<String> valid = Set.of("disable", "none", "off", "fixed-delay", "failure-rate", "exponential-delay");
if (!valid.contains(value)) {
    throw new IllegalArgumentException("Invalid restart strategy: " + value);
}

static boolean isValidRestartStrategy(String v) {
    return Set.of("disable", "none", "off", "fixed-delay", "fixeddelay",
        "failure-rate", "failurerate", "exponential-delay", "exponentialdelay").contains(v);
}

try {
    RestartStrategyType.of(value);
} catch (IllegalArgumentException e) {
    if (e.getMessage().contains("unknown value of RestartStrategyType")) { /* fix value */ }
}

When it happens

Trigger: Setting restart-strategy.type (or the deprecated restart-strategy key) to a misspelled or unsupported value in flink-conf.yaml or via -D. Values are matched exactly against the alias sets, so typos like 'fixed delay' (space) or 'fixeddelay-' fail.

Common situations: Using hyphens inconsistently (fixed-delay vs fixeddelay vs fixed delay). Copying a strategy name from old documentation. Using 'none' on a version that only accepts 'disable' (though aliases exist, exact match is required).

Related errors

• Value for config option %s must be one of %s (was %s)
• No cluster id was specified. Please specify a cluster to whi
• The configuration directory '{}', specified in the '{}' envi
• The configuration directory was not specified. Please specif
• No valid command-line found.

AI-assisted analysis of apache/flink@2f3c205e92 (2026-08-14). Data as JSON: /api/errors/8222d951af105b86. Report an issue: GitHub.