private Throwable wrapRollException(final Path sourceFile,
                                        final Path destFile,
                                        final Throwable e) {
        final String msg = String.format("Failed to roll file '%s' to '%s' - %s",
                getFullPath(sourceFile),
                getFullPath(destFile),
                e.getMessage());

        return new IOException(msg, e);
    }
Optional file permissions to apply to finished files
stroom-pipeline/src/main/java/stroom/pipeline/destination/RollingFileDestination.java