com.netflix.loadbalancer.PingUrl Maven / Gradle / Ivy
/*
*
* Copyright 2013 Netflix, Inc.
*
* 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.netflix.loadbalancer;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
/**
* Ping implementation if you want to do a "health check" kind of Ping. This
* will be a "real" ping. As in a real http/s call is made to this url e.g.
* http://ec2-75-101-231-85.compute-1.amazonaws.com:7101/cs/hostRunning
*
* Some services/clients choose PingDiscovery - which is quick but is not a real
* ping. i.e It just asks discovery (eureka) in-memory cache if the server is present
* in its Roster PingUrl on the other hand, makes an actual call. This is more
* expensive - but its the "standard" way most VIPs and other services perform
* HealthChecks.
*
* Choose your Ping based on your needs.
*
* @author stonse
*
*/
public class PingUrl implements IPing {
private static final Logger LOGGER = LoggerFactory.getLogger(PingUrl.class);
String pingAppendString = "";
boolean isSecure = false;
String expectedContent = null;
/*
*
* Send one ping only.
*
* Well, send what you need to determine whether or not the
* server is still alive. Should return within a "reasonable"
* time.
*/
public PingUrl() {
}
public PingUrl(boolean isSecure, String pingAppendString) {
this.isSecure = isSecure;
this.pingAppendString = (pingAppendString != null) ? pingAppendString : "";
}
public void setPingAppendString(String pingAppendString) {
this.pingAppendString = (pingAppendString != null) ? pingAppendString : "";
}
public String getPingAppendString() {
return pingAppendString;
}
public boolean isSecure() {
return isSecure;
}
/**
* Should the Secure protocol be used to Ping
* @param isSecure
*/
public void setSecure(boolean isSecure) {
this.isSecure = isSecure;
}
public String getExpectedContent() {
return expectedContent;
}
/**
* Is there a particular content you are hoping to see?
* If so -set this here.
* for e.g. the WCS server sets the content body to be 'true'
* Please be advised that this content should match the actual
* content exactly for this to work. Else yo may get false status.
* @param expectedContent
*/
public void setExpectedContent(String expectedContent) {
this.expectedContent = expectedContent;
}
public boolean isAlive(Server server) {
String urlStr = "";
if (isSecure){
urlStr = "https://";
}else{
urlStr = "http://";
}
urlStr += server.getId();
urlStr += getPingAppendString();
boolean isAlive = false;
HttpClient httpClient = new DefaultHttpClient();
HttpUriRequest getRequest = new HttpGet(urlStr);
String content=null;
try {
HttpResponse response = httpClient.execute(getRequest);
content = EntityUtils.toString(response.getEntity());
isAlive = (response.getStatusLine().getStatusCode() == 200);
if (getExpectedContent()!=null){
LOGGER.debug("content:" + content);
if (content == null){
isAlive = false;
}else{
if (content.equals(getExpectedContent())){
isAlive = true;
}else{
isAlive = false;
}
}
}
} catch (IOException e) {
e.printStackTrace();
}finally{
// Release the connection.
getRequest.abort();
}
return isAlive;
}
public static void main(String[] args){
PingUrl p = new PingUrl(false,"/cs/hostRunning");
p.setExpectedContent("true");
Server s = new Server("ec2-75-101-231-85.compute-1.amazonaws.com", 7101);
boolean isAlive = p.isAlive(s);
System.out.println("isAlive:" + isAlive);
}
}
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