Java：使用异步编程优化应用程序

Question

所需代码如下：-

/* Scheduler */
private long triggerDetection(String startDate, String endDate) {
for (UrlRequest request : urlRequests) {
                if (!validateRequests.isWhitelisted(request)) {
                    ContentDetectionClient.detectContent(request);
                }
            }
}

/* Client */
public void detectContent(UrlRequest urlRequest){
        Client client = new Client();
        URI uri = buildUrl(); /* It returns the URL of this dropwizard application's resource method provided below */

        ClientResponse response = client.resource(uri)
                .type(MediaType.APPLICATION_JSON_TYPE)
                .post(ClientResponse.class, urlRequest);

        Integer status = response.getStatus();
        if (status >= 200 && status < 300) {
            log.info("Completed request for url: {}", urlRequest.getUrl());

        }else{
            log.error("request failed for url: {}", urlRequest.getUrl());
        }
    }

    private URI buildUrl() {
        return UriBuilder
                .fromPath(uriConfiguration.getUrl())
                .build();
    }

/* Resource Method */
 @POST
    @Path("/pageDetection")
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    /**
     * Receives the url of the publisher, crawls the content of that url, applies a detector to check if the content is malicious.
     * @returns returns the probability of the page being malicious
     * @throws throws exception if the crawl call failed
     **/
    public DetectionScore detectContent(UrlRequest urlRequest) throws Exception {

        return contentAnalysisOrchestrator.detectContentPage(urlRequest);
    }

/* Orchestrator */
public DetectionScore detectContentPage(UrlRequest urlRequest) {
        try {

            Pair<Integer, HtmlPage> response =  crawler.rawLoad(urlRequest.getUrl());
            String content =   response.getValue().text();

            DetectionScore detectionScore = detector.getProbability(urlRequest.getUrl(), content);
            contentDetectionResultDao.insert(urlRequest.getAffiliateId(), urlRequest.getUrl(),detectionScore.getProbability()*1000,
                    detectionScore.getRecommendation(), urlRequest.getRequestsPerUrl(), -1, urlRequest.getCreatedAt() );

            return detectionScore;

        } catch (IOException e) {
            log.info("Error while analyzing the url : {}", e);
            throw new WebApplicationException(e, Response.Status.INTERNAL_SERVER_ERROR);
        }
    }

我在考虑以下方法：-

>

不是通过POST调用dropwizard资源方法，而是直接从计划程序调用Orchestrator.DetectContent(urlRequest)。

谢了。

编辑：我能想到两个瓶颈：

• 网页下载
• 将结果插入数据库（数据库位于另一个系统中）
• 似乎一次执行1个URL的处理

$ free -m
             total       used       free     shared    buffers     cached
Mem:          7843       4496       3346          0        193       2339
-/+ buffers/cache:       1964       5879 
Swap:         1952        489       1463 

top - 13:31:19 up 19 days, 15:39,  3 users,  load average: 0.00, 0.00, 0.00
Tasks: 215 total,   1 running, 214 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.5%us,  0.0%sy,  0.0%ni, 99.4%id,  0.1%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   8031412k total,  4605196k used,  3426216k free,   198040k buffers
Swap:  1999868k total,   501020k used,  1498848k free,  2395344k cached

Answer 1

首先检查你大部分时间都在哪里。

我想大部分时间都浪费在下载URL上了。

如果下载URL花费了90%以上的时间，那么可能无法改进应用程序，因为瓶颈不是java而是网络。

Downloading --> Parsing --> Saving 

注释后编辑

正如假设的那样，瓶颈不是cpu时间，所以对java代码进行干预并不重要。

如果您知道您每天下载多少千兆字节，就有可能看到它们是否接近您网络的最大带宽。

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