private HttpResponse triggerReindexing(ApplicationId applicationId, HttpRequest request) {
        double speed = Double.parseDouble(Objects.requireNonNullElse(request.getProperty("speed"), "1"));
        String cause = Objects.requireNonNullElse(request.getProperty("cause"), "reindexing for an unknown reason");
        Instant now = applicationRepository.clock().instant();

        return modifyReindexing(applicationId, request,
                                (original, cluster, type) -> original.withReady(cluster, type, now, speed, cause),
                                new StringJoiner(", ", "Reindexing document types ", " of application " + applicationId)
                                        .setEmptyValue("Not reindexing any document types of application " + applicationId));
    }
Operations on applications (delete, wait for config convergence, restart, application content etc.)

@author hmusum
configserver/src/main/java/com/yahoo/vespa/config/server/http/v2/ApplicationHandler.java