What causes "Unable to parse precision of value " in apache/cassandra?

Set precision to an exact uppercase TimeUnit constant, e.g. MICROSECONDS (the default).

apache/cassandra · error · RuntimeException

Unable to parse precision of value

Error message

Unable to parse precision of value

What it means

Thrown when the 'precision' property in commitlog_archiving.properties is not a valid java.util.concurrent.TimeUnit name. Cassandra parses it with TimeUnit.valueOf(), which only accepts HOURS, MINUTES, SECONDS, MILLISECONDS, MICROSECONDS (NANOSECONDS rejected separately). The IllegalArgumentException is chained.

Source

Thrown at src/java/org/apache/cassandra/db/commitlog/CommitLogArchiver.java:154

                if (!directory.exists())
                {
                    if (!directory.tryCreateDirectory())
                    {
                        throw new RuntimeException("Unable to create directory: " + dir);
                    }
                }
            }
        }

        String precisionPropertyValue = commitlogCommands.getProperty("precision", TimeUnit.MICROSECONDS.name());
        TimeUnit precision;
        try
        {
            precision = TimeUnit.valueOf(precisionPropertyValue);
        }
        catch (IllegalArgumentException ex)
        {
            throw new RuntimeException("Unable to parse precision of value " + precisionPropertyValue, ex);
        }
        if (precision == TimeUnit.NANOSECONDS)
            throw new RuntimeException("NANOSECONDS level precision is not supported.");

        String targetTime = commitlogCommands.getProperty("restore_point_in_time");
        long restorePointInTime = Long.MAX_VALUE;
        try
        {
            if (!Strings.isNullOrEmpty(targetTime))
            {
                // get restorePointInTime in microseconds level by default as cassandra use this level's timestamp
                restorePointInTime = getRestorationPointInTimeInMicroseconds(targetTime);
            }
        }
        catch (DateTimeParseException e)
        {
            throw new RuntimeException("Unable to parse restore target time", e);
        }

View on GitHub (pinned to 88fd0f6a0e)

Solutions

Set precision to an exact uppercase TimeUnit constant, e.g. MICROSECONDS (the default).
Remove the precision line entirely to accept the default (MICROSECONDS).
Use HOURS, MINUTES, SECONDS, MILLISECONDS, or MICROSECONDS only — NANOSECONDS is explicitly unsupported.

Example fix

# before
precision: microseconds
# after
precision: MICROSECONDS

Defensive patterns

Strategy: validation

Validate before calling

String p = props.getProperty("precision");
Set<String> allowed = Set.of("HOURS","MINUTES","SECONDS","MILLISECONDS","MICROSECONDS");
if (p != null && !allowed.contains(p.trim().toUpperCase()))
    throw new IllegalArgumentException("precision must be one of " + allowed);

Try / catch

try { archiver = CommitLogArchiver.construct(); }
catch (RuntimeException e) {
    if (e.getMessage().startsWith("Unable to parse precision"))
        log.error("precision must be an uppercase TimeUnit constant", e);
    throw e;
}

Prevention

Use only uppercase TimeUnit constant names in commitlog_archiving.properties
Add config linting to CI that validates precision values
Omit precision to accept the MICROSECONDS default

When it happens

Trigger: getArchiverFromProperties() reads property 'precision' with a value like 'microseconds', 'us', or 'Microseconds' and TimeUnit.valueOf() throws IllegalArgumentException.

Common situations: Lowercase or abbreviated time units in the properties file; copy-pasted values like 'micro' or 'µs'; confusion between the property name and accepted enum constants.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/39723fe2edbc195d. Report an issue: GitHub.