Timeout between request retries Apache HttpClient

Question

Could somebody share how to configure modern HttpClient 4.5.3 to retry failed requests and wait for some time before each retry?

So far it looks like I got it correctly that .setRetryHandler(new DefaultHttpRequestRetryHandler(X, false)) will allow to retry requests X times.

But I cannot understand how to configure backoff: .setConnectionBackoffStrategy() / .setBackoffManager() according to JavaDocs regulate something else, not timeout between retries.

Answer 1

BackoffManager / ConnectionBackoffStrategy combo can be used to dynamically increase or decrease max connection per route limits based on rate of I/O errors and 503 responses. They have no influence on request execution and cannot be used to control request re-execution

This is the best one can do with HC 4.x APIs

CloseableHttpClient client = HttpClientBuilder.create()
        .setRetryHandler(new HttpRequestRetryHandler() {
            @Override
            public boolean retryRequest(IOException exception, int executionCount, HttpContext context) {
                return executionCount <= maxRetries &&
                        exception instanceof SocketException;
            }
        })
        .setServiceUnavailableRetryStrategy(new ServiceUnavailableRetryStrategy() {
            @Override
            public boolean retryRequest(HttpResponse response, int executionCount, HttpContext context) {
                return executionCount <= maxRetries &&
                        response.getStatusLine().getStatusCode() == HttpStatus.SC_SERVICE_UNAVAILABLE;
            }

            @Override
            public long getRetryInterval() {
                return 100;
            }
        })
        .build();

Please note there is presently no elegant way of enforcing a delay between request execution attempts in case of an I/O error or dynamically adjusting the retry interval based on request route.