com.alibaba.nacos.config.server.service.LongPollingService Maven / Gradle / Ivy
/*
* Copyright 1999-2018 Alibaba Group Holding Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.alibaba.nacos.config.server.service;
import com.alibaba.nacos.api.remote.RpcScheduledExecutor;
import com.alibaba.nacos.common.notify.Event;
import com.alibaba.nacos.common.notify.NotifyCenter;
import com.alibaba.nacos.common.notify.listener.Subscriber;
import com.alibaba.nacos.common.utils.ExceptionUtil;
import com.alibaba.nacos.common.utils.StringUtils;
import com.alibaba.nacos.config.server.model.SampleResult;
import com.alibaba.nacos.config.server.model.event.LocalDataChangeEvent;
import com.alibaba.nacos.config.server.monitor.MetricsMonitor;
import com.alibaba.nacos.config.server.utils.ConfigExecutor;
import com.alibaba.nacos.config.server.utils.GroupKey;
import com.alibaba.nacos.config.server.utils.LogUtil;
import com.alibaba.nacos.config.server.utils.MD5Util;
import com.alibaba.nacos.config.server.utils.RequestUtil;
import com.alibaba.nacos.plugin.control.ControlManagerCenter;
import com.alibaba.nacos.plugin.control.connection.request.ConnectionCheckRequest;
import com.alibaba.nacos.plugin.control.connection.response.ConnectionCheckResponse;
import org.springframework.stereotype.Service;
import javax.servlet.AsyncContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import java.util.Random;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import static com.alibaba.nacos.config.server.utils.LogUtil.MEMORY_LOG;
import static com.alibaba.nacos.config.server.utils.LogUtil.PULL_LOG;
/**
* LongPollingService.
*
* @author Nacos
*/
@Service
public class LongPollingService {
private static final int SAMPLE_PERIOD = 100;
private static final int SAMPLE_TIMES = 3;
private static final String TRUE_STR = "true";
private Map retainIps = new ConcurrentHashMap<>();
public SampleResult getSubscribleInfo(String dataId, String group, String tenant) {
String groupKey = GroupKey.getKeyTenant(dataId, group, tenant);
SampleResult sampleResult = new SampleResult();
Map lisentersGroupkeyStatus = new HashMap<>(50);
for (ClientLongPolling clientLongPolling : allSubs) {
if (clientLongPolling.clientMd5Map.containsKey(groupKey)) {
lisentersGroupkeyStatus.put(clientLongPolling.ip, clientLongPolling.clientMd5Map.get(groupKey));
}
}
sampleResult.setLisentersGroupkeyStatus(lisentersGroupkeyStatus);
return sampleResult;
}
public SampleResult getSubscribleInfoByIp(String clientIp) {
SampleResult sampleResult = new SampleResult();
Map lisentersGroupkeyStatus = new HashMap<>(50);
for (ClientLongPolling clientLongPolling : allSubs) {
if (clientLongPolling.ip.equals(clientIp)) {
// One ip can have multiple listener.
if (!lisentersGroupkeyStatus.equals(clientLongPolling.clientMd5Map)) {
lisentersGroupkeyStatus.putAll(clientLongPolling.clientMd5Map);
}
}
}
sampleResult.setLisentersGroupkeyStatus(lisentersGroupkeyStatus);
return sampleResult;
}
/**
* Aggregate the sampling IP and monitoring configuration information in the sampling results. There is no problem
* for the merging strategy to cover the previous one with the latter.
*
* @param sampleResults sample Results.
* @return Results.
*/
public SampleResult mergeSampleResult(List sampleResults) {
SampleResult mergeResult = new SampleResult();
Map lisentersGroupkeyStatus = new HashMap<>(50);
for (SampleResult sampleResult : sampleResults) {
Map lisentersGroupkeyStatusTmp = sampleResult.getLisentersGroupkeyStatus();
for (Map.Entry entry : lisentersGroupkeyStatusTmp.entrySet()) {
lisentersGroupkeyStatus.put(entry.getKey(), entry.getValue());
}
}
mergeResult.setLisentersGroupkeyStatus(lisentersGroupkeyStatus);
return mergeResult;
}
public SampleResult getCollectSubscribleInfo(String dataId, String group, String tenant) {
List sampleResultLst = new ArrayList<>(50);
for (int i = 0; i < SAMPLE_TIMES; i++) {
SampleResult sampleTmp = getSubscribleInfo(dataId, group, tenant);
if (sampleTmp != null) {
sampleResultLst.add(sampleTmp);
}
if (i < SAMPLE_TIMES - 1) {
try {
Thread.sleep(SAMPLE_PERIOD);
} catch (InterruptedException e) {
LogUtil.CLIENT_LOG.error("sleep wrong", e);
}
}
}
return mergeSampleResult(sampleResultLst);
}
public SampleResult getCollectSubscribleInfoByIp(String ip) {
SampleResult sampleResult = new SampleResult();
sampleResult.setLisentersGroupkeyStatus(new HashMap(50));
for (int i = 0; i < SAMPLE_TIMES; i++) {
SampleResult sampleTmp = getSubscribleInfoByIp(ip);
if (sampleTmp != null) {
if (sampleTmp.getLisentersGroupkeyStatus() != null && !sampleResult.getLisentersGroupkeyStatus()
.equals(sampleTmp.getLisentersGroupkeyStatus())) {
sampleResult.getLisentersGroupkeyStatus().putAll(sampleTmp.getLisentersGroupkeyStatus());
}
}
if (i < SAMPLE_TIMES - 1) {
try {
Thread.sleep(SAMPLE_PERIOD);
} catch (InterruptedException e) {
LogUtil.CLIENT_LOG.error("sleep wrong", e);
}
}
}
return sampleResult;
}
/**
* Add LongPollingClient.
*
* @param req HttpServletRequest.
* @param rsp HttpServletResponse.
* @param clientMd5Map clientMd5Map.
* @param probeRequestSize probeRequestSize.
*/
public void addLongPollingClient(HttpServletRequest req, HttpServletResponse rsp, Map clientMd5Map,
int probeRequestSize) {
String noHangUpFlag = req.getHeader(LongPollingService.LONG_POLLING_NO_HANG_UP_HEADER);
long start = System.currentTimeMillis();
List changedGroups = MD5Util.compareMd5(req, rsp, clientMd5Map);
if (changedGroups.size() > 0) {
generateResponse(req, rsp, changedGroups);
LogUtil.CLIENT_LOG.info("{}|{}|{}|{}|{}|{}|{}", System.currentTimeMillis() - start, "instant",
RequestUtil.getRemoteIp(req), "polling", clientMd5Map.size(), probeRequestSize,
changedGroups.size());
return;
} else if (noHangUpFlag != null && noHangUpFlag.equalsIgnoreCase(TRUE_STR)) {
LogUtil.CLIENT_LOG.info("{}|{}|{}|{}|{}|{}|{}", System.currentTimeMillis() - start, "nohangup",
RequestUtil.getRemoteIp(req), "polling", clientMd5Map.size(), probeRequestSize,
changedGroups.size());
return;
}
// Must be called by http thread, or send response.
final AsyncContext asyncContext = req.startAsync();
// AsyncContext.setTimeout() is incorrect, Control by oneself
asyncContext.setTimeout(0L);
String ip = RequestUtil.getRemoteIp(req);
ConnectionCheckResponse connectionCheckResponse = checkLimit(req);
if (!connectionCheckResponse.isSuccess()) {
RpcScheduledExecutor.CONTROL_SCHEDULER.schedule(
() -> generate503Response(asyncContext, rsp, connectionCheckResponse.getMessage()),
1000L + new Random().nextInt(2000), TimeUnit.MILLISECONDS);
return;
}
String appName = req.getHeader(RequestUtil.CLIENT_APPNAME_HEADER);
String tag = req.getHeader("Vipserver-Tag");
int delayTime = SwitchService.getSwitchInteger(SwitchService.FIXED_DELAY_TIME, 500);
int minLongPoolingTimeout = SwitchService.getSwitchInteger("MIN_LONG_POOLING_TIMEOUT", 10000);
// Add delay time for LoadBalance, and one response is returned 500 ms in advance to avoid client timeout.
String requestLongPollingTimeOut = req.getHeader(LongPollingService.LONG_POLLING_HEADER);
long timeout = Math.max(minLongPoolingTimeout, Long.parseLong(requestLongPollingTimeOut) - delayTime);
ConfigExecutor.executeLongPolling(
new ClientLongPolling(asyncContext, clientMd5Map, ip, probeRequestSize, timeout, appName, tag));
}
private ConnectionCheckResponse checkLimit(HttpServletRequest httpServletRequest) {
String ip = RequestUtil.getRemoteIp(httpServletRequest);
String appName = httpServletRequest.getHeader(RequestUtil.CLIENT_APPNAME_HEADER);
ConnectionCheckRequest connectionCheckRequest = new ConnectionCheckRequest(ip, appName, "LongPolling");
ConnectionCheckResponse checkResponse = ControlManagerCenter.getInstance().getConnectionControlManager()
.check(connectionCheckRequest);
return checkResponse;
}
public static boolean isSupportLongPolling(HttpServletRequest req) {
return null != req.getHeader(LONG_POLLING_HEADER);
}
@SuppressWarnings("PMD.ThreadPoolCreationRule")
public LongPollingService() {
allSubs = new ConcurrentLinkedQueue<>();
ConfigExecutor.scheduleLongPolling(new StatTask(), 0L, 10L, TimeUnit.SECONDS);
// Register LocalDataChangeEvent to NotifyCenter.
NotifyCenter.registerToPublisher(LocalDataChangeEvent.class, NotifyCenter.ringBufferSize);
// Register A Subscriber to subscribe LocalDataChangeEvent.
NotifyCenter.registerSubscriber(new Subscriber() {
@Override
public void onEvent(Event event) {
if (event instanceof LocalDataChangeEvent) {
LocalDataChangeEvent evt = (LocalDataChangeEvent) event;
ConfigExecutor.executeLongPolling(new DataChangeTask(evt.groupKey, evt.isBeta, evt.betaIps));
}
}
@Override
public Class subscribeType() {
return LocalDataChangeEvent.class;
}
});
}
public static final String LONG_POLLING_HEADER = "Long-Pulling-Timeout";
public static final String LONG_POLLING_NO_HANG_UP_HEADER = "Long-Pulling-Timeout-No-Hangup";
/**
* ClientLongPolling subscibers.
*/
final Queue allSubs;
class DataChangeTask implements Runnable {
@Override
public void run() {
try {
for (Iterator iter = allSubs.iterator(); iter.hasNext(); ) {
ClientLongPolling clientSub = iter.next();
if (clientSub.clientMd5Map.containsKey(groupKey)) {
// If published tag is not in the tag list, then it skipped.
if (StringUtils.isNotBlank(tag) && !tag.equals(clientSub.tag)) {
continue;
}
getRetainIps().put(clientSub.ip, System.currentTimeMillis());
iter.remove(); // Delete subscribers' relationships.
LogUtil.CLIENT_LOG.info("{}|{}|{}|{}|{}|{}|{}", (System.currentTimeMillis() - changeTime),
"in-advance",
RequestUtil.getRemoteIp((HttpServletRequest) clientSub.asyncContext.getRequest()),
"polling", clientSub.clientMd5Map.size(), clientSub.probeRequestSize, groupKey);
clientSub.sendResponse(Collections.singletonList(groupKey));
}
}
} catch (Throwable t) {
LogUtil.DEFAULT_LOG.error("data change error: {}", ExceptionUtil.getStackTrace(t));
}
}
DataChangeTask(String groupKey, boolean isBeta, List betaIps) {
this(groupKey, isBeta, betaIps, null);
}
DataChangeTask(String groupKey, boolean isBeta, List betaIps, String tag) {
this.groupKey = groupKey;
this.isBeta = isBeta;
this.betaIps = betaIps;
this.tag = tag;
}
final String groupKey;
final long changeTime = System.currentTimeMillis();
final boolean isBeta;
final List betaIps;
final String tag;
}
class StatTask implements Runnable {
@Override
public void run() {
MEMORY_LOG.info("[long-pulling] client count " + allSubs.size());
MetricsMonitor.getLongPollingMonitor().set(allSubs.size());
}
}
public class ClientLongPolling implements Runnable {
@Override
public void run() {
asyncTimeoutFuture = ConfigExecutor.scheduleLongPolling(() -> {
try {
getRetainIps().put(ClientLongPolling.this.ip, System.currentTimeMillis());
// Delete subscriber's relations.
boolean removeFlag = allSubs.remove(ClientLongPolling.this);
if (removeFlag) {
LogUtil.CLIENT_LOG.info("{}|{}|{}|{}|{}|{}", (System.currentTimeMillis() - createTime),
"timeout", RequestUtil.getRemoteIp((HttpServletRequest) asyncContext.getRequest()),
"polling", clientMd5Map.size(), probeRequestSize);
sendResponse(null);
} else {
LogUtil.DEFAULT_LOG.warn("client subsciber's relations delete fail.");
}
} catch (Throwable t) {
LogUtil.DEFAULT_LOG.error("long polling error:" + t.getMessage(), t.getCause());
}
}, timeoutTime, TimeUnit.MILLISECONDS);
allSubs.add(this);
}
void sendResponse(List changedGroups) {
// Cancel time out task.
if (null != asyncTimeoutFuture) {
asyncTimeoutFuture.cancel(false);
}
generateResponse(changedGroups);
}
void generateResponse(List changedGroups) {
if (null == changedGroups) {
// Tell web container to send http response.
asyncContext.complete();
return;
}
HttpServletResponse response = (HttpServletResponse) asyncContext.getResponse();
try {
final String respString = MD5Util.compareMd5ResultString(changedGroups);
// Disable cache.
response.setHeader("Pragma", "no-cache");
response.setDateHeader("Expires", 0);
response.setHeader("Cache-Control", "no-cache,no-store");
response.setStatus(HttpServletResponse.SC_OK);
response.getWriter().println(respString);
asyncContext.complete();
} catch (Exception ex) {
PULL_LOG.error(ex.toString(), ex);
asyncContext.complete();
}
}
ClientLongPolling(AsyncContext ac, Map clientMd5Map, String ip, int probeRequestSize,
long timeoutTime, String appName, String tag) {
this.asyncContext = ac;
this.clientMd5Map = clientMd5Map;
this.probeRequestSize = probeRequestSize;
this.createTime = System.currentTimeMillis();
this.ip = ip;
this.timeoutTime = timeoutTime;
this.appName = appName;
this.tag = tag;
}
final AsyncContext asyncContext;
final Map clientMd5Map;
final long createTime;
final String ip;
final String appName;
final String tag;
final int probeRequestSize;
final long timeoutTime;
Future asyncTimeoutFuture;
@Override
public String toString() {
return "ClientLongPolling{" + "clientMd5Map=" + clientMd5Map + ", createTime=" + createTime + ", ip='" + ip
+ '\'' + ", appName='" + appName + '\'' + ", tag='" + tag + '\'' + ", probeRequestSize="
+ probeRequestSize + ", timeoutTime=" + timeoutTime + '}';
}
}
void generateResponse(HttpServletRequest request, HttpServletResponse response, List changedGroups) {
if (null == changedGroups) {
return;
}
try {
final String respString = MD5Util.compareMd5ResultString(changedGroups);
// Disable cache.
response.setHeader("Pragma", "no-cache");
response.setDateHeader("Expires", 0);
response.setHeader("Cache-Control", "no-cache,no-store");
response.setStatus(HttpServletResponse.SC_OK);
response.getWriter().println(respString);
} catch (Exception ex) {
PULL_LOG.error(ex.toString(), ex);
}
}
void generate503Response(AsyncContext asyncContext, HttpServletResponse response, String message) {
try {
// Disable cache.
response.setHeader("Pragma", "no-cache");
response.setDateHeader("Expires", 0);
response.setHeader("Cache-Control", "no-cache,no-store");
response.setStatus(HttpServletResponse.SC_SERVICE_UNAVAILABLE);
response.getWriter().println(message);
asyncContext.complete();
} catch (Exception ex) {
PULL_LOG.error(ex.toString(), ex);
}
}
public Map getRetainIps() {
return retainIps;
}
public int getSubscriberCount() {
return allSubs.size();
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy