一则推送api使用不当导致的服务端内存溢出问题分析

Caused by: java.lang.OutOfMemoryError: GC overhead limit exceeded

Following changes in Client JVM fixed this issue(Can you let me know Is this required at java Client end, if yes then it would be nice if you mention this in ES documents for TransportClient):

-Dio.netty.noUnsafe=true
-Dio.netty.noKeySetOptimization=true
-Dio.netty.recycler.maxCapacityPerThread=0
-Dio.netty.allocator.type=unpooled

public static final Setting<Integer> WORKER_COUNT =
        new Setting<>("transport.netty.worker_count",
            (s) -> Integer.toString(EsExecutors.numberOfProcessors(s) * 2),
            (s) -> Setting.parseInt(s, 1, "transport.netty.worker_count"), Property.NodeScope);

  public static int numberOfProcessors(final Settings settings) {
         return PROCESSORS_SETTING.get(settings);
  }

  public static final Setting<Integer> PROCESSORS_SETTING =
          Setting.intSetting("processors", Runtime.getRuntime().availableProcessors(), 1, Property.NodeScope);

/**
     * 极光推送方法(采用java SDK)
     * @param alias
     * @param alert
     * @return PushResult
     */
    public static  PushResult push(String alias, String alert){
        ClientConfig clientConfig = ClientConfig.getInstance();
        JPushClient jpushClient = new JPushClient(masterSecret, appKey, null, clientConfig);
        PushPayload payload = buildPushObject_android_ios_alias_alert(alias,alert);
        try {
            return jpushClient.sendPush(payload);
        } catch (APIConnectionException e) {
            log.error("Connection error. Should retry later. ", e);
            return null;
        } catch (APIRequestException e) {
            log.error("Error response from JPush server. Should review and fix it. ", e);
            log.info("HTTP Status: " + e.getStatus());
            log.info("Error Code: " + e.getErrorCode());
            log.info("Error Message: " + e.getErrorMessage());
            log.info("Msg ID: " + e.getMsgId());
            return null;
        }
    }

     /**
         * Create a JPush Client by custom Client configuration.
         *
         * @param masterSecret API access secret of the appKey.
         * @param appKey The KEY of one application on JPush.
         * @param proxy The proxy, if there is no proxy, should be null.
         * @param conf The client configuration. Can use ClientConfig.getInstance() as default.
         */
        public JPushClient(String masterSecret, String appKey, HttpProxy proxy, ClientConfig conf) {
            _pushClient = new PushClient(masterSecret, appKey, proxy, conf);
            _reportClient = new ReportClient(masterSecret, appKey, proxy, conf);
            _deviceClient = new DeviceClient(masterSecret, appKey, proxy, conf);
            _scheduleClient = new ScheduleClient(masterSecret, appKey, proxy, conf);
        }

_sslCtx = SslContextBuilder.forClient().trustManager(InsecureTrustManagerFactory.INSTANCE).build();
            _workerGroup = new NioEventLoopGroup();
            b = new Bootstrap(); // (1)
            b.group(_workerGroup); // (2)

private static final int DEFAULT_EVENT_LOOP_THREADS;

    static {
        DEFAULT_EVENT_LOOP_THREADS = Math.max(1, SystemPropertyUtil.getInt(
                "io.netty.eventLoopThreads", NettyRuntime.availableProcessors() * 2));

        if (logger.isDebugEnabled()) {
            logger.debug("-Dio.netty.eventLoopThreads: {}", DEFAULT_EVENT_LOOP_THREADS);
        }
    }

如果使用 NettyHttpClient(v3.2.15 版本新增），需要在响应返回后手动调用一下 NettyHttpClient 中的 close 方法，否则进程不会退出。代码示例：


try {
    PushResult result = jpushClient.sendPush(payload);
    LOG.info("Got result - " + result);
    Thread.sleep(5000);
    // 请求结束后，调用 NettyHttpClient 中的 close 方法，否则进程不会退出。
    jpushClient.close();
} catch(InterruptedException e) {
    e.printStackTrace();
}

3.2.17 版本后，在 PushClient 中添加了 setHttpClient(IHttpClient client) 方法，用户可以自由切换 ApacheHttpClient，NettyHttpClient 或是 NativeHttpClient。

public void close() {
        if (null != _channel) {
            _channel.closeFuture().syncUninterruptibly();
            _workerGroup.shutdownGracefully();
            _channel = null;
            _workerGroup = null;
        }
        System.out.println("Finished request(s)");
    }