JAVA程序连接es(Elasticsearch)会出现长时间不请求，突然请求会连接超时的问题

 可以使用这个方法试试 设置长时间保持策略

伪代码

/**
     * 配置长连接保持策略
     *
     * @return
     */
    public ConnectionKeepAliveStrategy connectionKeepAliveStrategy() {
        return (response, context) -> {
            // Honor 'keep-alive' header
            HeaderElementIterator it = new BasicHeaderElementIterator(
                    response.headerIterator(HTTP.CONN_KEEP_ALIVE));
            while (it.hasNext()) {
                HeaderElement he = it.nextElement();
                log.info("HeaderElement:{}", JSON.toJSONString(he));
                String param = he.getName();
                String value = he.getValue();
                if (value != null && "timeout".equalsIgnoreCase(param)) {
                    try {
                        return Long.parseLong(value) * 1000;
                    } catch (NumberFormatException ignore) {
                        log.error("解析长连接过期时间异常", ignore);
                    }
                }
            }
            HttpHost target = (HttpHost) context.getAttribute(
                    HttpClientContext.HTTP_TARGET_HOST);
            //如果请求目标地址,单独配置了长连接保持时间,使用该配置
            Optional<Map.Entry<String, Integer>> any = Optional.ofNullable(httpClientPoolConfig.getKeepAliveTargetHost()).orElseGet(HashMap::new)
                    .entrySet().stream().filter(
                            e -> e.getKey().equalsIgnoreCase(target.getHostName())).findAny();
            //否则使用默认长连接保持时间
            return any.map(en -> en.getValue() * 1000L).orElse(httpClientPoolConfig.getKeepAliveTime() * 1000L);
        };
    }

调用  根据自己实际的连接方式来 这里只是设置了其中一个参数

RestClientBuilder builder = RestClient.builder(httpHosts).setRequestConfigCallback(requestConfigBuilder -> {
            requestConfigBuilder.setConnectTimeout(5000);
            requestConfigBuilder.setSocketTimeout(40000);
            requestConfigBuilder.setConnectionRequestTimeout(1000);
            return requestConfigBuilder;
        });
        if (null != username && null != password) {
            final CredentialsProvider provider = new BasicCredentialsProvider();
            provider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(username, password));
            builder.setHttpClientConfigCallback(httpClientBuilder -> {
                httpClientBuilder.disableAuthCaching();
                httpClientBuilder.setDefaultCredentialsProvider(provider);
                httpClientBuilder.setKeepAliveStrategy(connectionKeepAliveStrategy());
                return httpClientBuilder;
            });
        }