com.cisco.oss.foundation.cluster.masterslave.consul.ConsulMastershipElector Maven / Gradle / Ivy
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This project is a multi data center supported master slave cluster manager library
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package com.cisco.oss.foundation.cluster.masterslave.consul;
import com.cisco.oss.foundation.cluster.masterslave.MastershipElector;
import com.cisco.oss.foundation.cluster.utils.MasterSlaveConfigurationUtil;
import com.cisco.oss.foundation.configuration.CcpConstants;
import com.cisco.oss.foundation.configuration.ConfigurationFactory;
import com.cisco.oss.foundation.http.HttpClient;
import com.cisco.oss.foundation.http.HttpMethod;
import com.cisco.oss.foundation.http.HttpRequest;
import com.cisco.oss.foundation.http.HttpResponse;
import com.cisco.oss.foundation.http.apache.ApacheHttpClientFactory;
import com.google.common.io.BaseEncoding;
import com.jayway.jsonpath.Configuration;
import com.jayway.jsonpath.JsonPath;
import com.jayway.jsonpath.Option;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.concurrent.TimeUnit;
/**
* Consul implementation for logic for electing new masters.
* Created by Yair Ogen (yaogen) on 15/02/2016.
*/
public class ConsulMastershipElector implements MastershipElector {
public static final String ACTIVE_DATACENTER = "primaryDatacenter";
private static final Logger LOGGER = LoggerFactory.getLogger(ConsulMastershipElector.class);
protected HttpClient consulClient;
protected String activeVersionKey = "";
protected String sessionId = "";
protected String mastershipKey = "";
protected String jobName;
protected Thread sessionTTlThread;
// protected String checkId;
protected int ttlUpdateTime;
protected int ttlPeriod;
protected Configuration conf = Configuration.defaultConfiguration();
protected Configuration nullableConf = conf.addOptions(Option.DEFAULT_PATH_LEAF_TO_NULL);
@Override
public void init(String id, String jobName) {
this.mastershipKey = "master-slave/" + MasterSlaveConfigurationUtil.COMPONENT_NAME + "/" + jobName;
this.jobName = jobName;
this.activeVersionKey = getActiveVersionKey();
int numberOfInitAttempts = ConfigurationFactory.getConfiguration().getInt("consulClient.numberOfInitAttempts", 3);
boolean success = false;
ttlPeriod = MasterSlaveConfigurationUtil.getMasterSlaveLeaseTime(jobName);
if (ttlPeriod < 10) {
LOGGER.error("Lease time must be at least 10 seconds. For {} the value is: {}. Exiting the application", jobName, ttlPeriod);
System.exit(-1);
}
ttlUpdateTime = ttlPeriod / 3;
for (int attemptNumber = 1; attemptNumber <= numberOfInitAttempts && !success; attemptNumber++) {
try {
initConsul();
success = true;
} catch (Exception e) {
if (attemptNumber != numberOfInitAttempts) {
LOGGER.warn("problem initializing consul elector for: {}. Attempt: {}. Error is: {}", jobName, attemptNumber, e);
} else {
LOGGER.error("problem initializing consul elector for: {}. Attempt: {} Failed. EXITING the application. Error is: {}", jobName, attemptNumber, e);
System.exit(-1);
}
try {
TimeUnit.SECONDS.sleep(1);
} catch (InterruptedException e1) {
//ignore
}
}
}
}
private void initConsul() {
if (consulClient == null) {
consulClient = ApacheHttpClientFactory.createHttpClient("consulClient");
}
createSession();
}
private void closeSession() {
HttpRequest destroySession = HttpRequest.newBuilder()
.httpMethod(HttpMethod.PUT)
.uri("/v1/session/destroy/" + sessionId)
.build();
execute(destroySession, false, "destroy session");
}
private synchronized void createSession() {
String body = "{\n" +
" \"Name\": \"" + MasterSlaveConfigurationUtil.INSTANCE_ID + "\",\n" +
"\"TTL\": \"" + ttlPeriod + "s\"" +
"}";
HttpRequest createSession = HttpRequest.newBuilder()
.httpMethod(HttpMethod.PUT)
.uri("/v1/session/create")
.entity(body)
.build();
HttpResponse response = execute(createSession, true, "create session");
String jsonId = response.getResponseAsString();
this.sessionId = JsonPath.parse(jsonId).read("$.ID");
LOGGER.info("new Session Id is: {}", sessionId);
if (sessionTTlThread == null) {
startSessionHeartbeatThread();
}
try {
TimeUnit.SECONDS.sleep(2);
} catch (InterruptedException e) {
//ignore
}
}
private void startSessionHeartbeatThread() {
sessionTTlThread = new Thread(() -> {
while (true) {
try {
HttpRequest renewSession = HttpRequest.newBuilder()
.httpMethod(HttpMethod.PUT)
.uri("/v1/session/renew/" + sessionId)
.silentLogging()
.build();
HttpResponse response = consulClient.execute(renewSession);
if (!response.isSuccess()) {
String renewSessionResponse = response.getResponseAsString();
LOGGER.warn("failed to pass check. got response: {}, error response: {}", response.getStatus(), renewSessionResponse);
if(renewSessionResponse.contains("not found")){
createSession();
}
}
} catch (Exception e) {
LOGGER.warn("problem in heartbeat: {}", e.toString());
} finally {
try {
TimeUnit.SECONDS.sleep(ttlUpdateTime);
} catch (InterruptedException e) {
//ignore
}
}
}
}, jobName + "-SessionRenewThread");
sessionTTlThread.setDaemon(true);
sessionTTlThread.start();
sessionTTlThread.setUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {
@Override
public void uncaughtException(Thread t, Throwable e) {
LOGGER.error("Uncaught Exception for Job: {} in thread: {}. Exception is: {}", jobName, t.getName(), e);
}
});
}
@Override
public boolean isReady() {
HttpRequest ping = HttpRequest.newBuilder()
.httpMethod(HttpMethod.GET)
.uri("/v1/agent/self")
.silentLogging()
.build();
HttpResponse response = execute(ping, false, "ping agent");
return response.isSuccess();
}
public boolean isActiveKeyValue(String key, String currentValue) {
HttpRequest getActiveKey = HttpRequest.newBuilder()
.httpMethod(HttpMethod.GET)
.uri("/v1/kv/" + key)
.silentLogging()
.build();
boolean isActive = true;
String consulValue = "";
HttpResponse response = consulClient.execute(getActiveKey);
if (!response.isSuccess()) {
LOGGER.debug("failed to get value from KV store for key: {}. got response: {}, error response: {}", key, response.getStatus(), response.getResponseAsString());
} else {
String jsonKeyValue = response.getResponseAsString();
String valueInBase64 = JsonPath.parse(jsonKeyValue).read("$.[0].Value");
if (StringUtils.isNotEmpty(valueInBase64)) {
consulValue = new String(BaseEncoding.base64().decode(valueInBase64));
isActive = currentValue.equals(consulValue);
}
}
LOGGER.debug("isActive: {}, env value: {}, consul key: {}, consul value: {}", isActive, currentValue, key, consulValue);
return isActive;
}
@Override
public boolean isActiveVersion(String currentVersion) {
return isActiveKeyValue(activeVersionKey, currentVersion);
}
@Override
public boolean isActiveDataCenter(String currentDataCenter) {
return isActiveKeyValue(ACTIVE_DATACENTER, currentDataCenter);
}
@Override
public boolean isMaster() {
boolean lockAcquired = false;
HttpRequest getSession = HttpRequest.newBuilder()
.httpMethod(HttpMethod.GET)
.uri("/v1/kv/" + mastershipKey)
.silentLogging()
.build();
HttpResponse getSessionResponse = consulClient.execute(getSession);
if (getSessionResponse.isSuccess()) {
String sessionOwner = JsonPath.using(nullableConf).parse(getSessionResponse.getResponseAsString()).read("$.[0].Session");
if (StringUtils.isNoneBlank(sessionOwner)) {
LOGGER.trace("Lock is by session: {}", sessionOwner);
return sessionId.equals(sessionOwner);
}
}
HttpRequest acquireLock = HttpRequest.newBuilder()
.httpMethod(HttpMethod.PUT)
.uri("/v1/kv/" + mastershipKey)
.queryParams("acquire", sessionId)
.silentLogging()
.build();
HttpResponse response = consulClient.execute(acquireLock);
String responseAsString = response.getResponseAsString();
String lockResponseReason = "";
if (!response.isSuccess()) {
LOGGER.error("failed to acquire lock for key: {}. got response: {}, error response: {}", mastershipKey, response.getStatus(), responseAsString);
if (responseAsString.contains("invalid session") || responseAsString.contains("Invalid session")) {
closeSession();
createSession();
acquireLock = HttpRequest.newBuilder()
.httpMethod(HttpMethod.PUT)
.uri("/v1/kv/" + mastershipKey)
.queryParams("acquire", sessionId)
.silentLogging()
.build();
HttpResponse acquireLockRetryResponse = execute(acquireLock, false, "acquire lock");
if (acquireLockRetryResponse.isSuccess()) {
lockAcquired = Boolean.valueOf(acquireLockRetryResponse.getResponseAsString());
lockResponseReason = "Successful response from consul with response for acquire lock: " + lockAcquired;
}else{
lockResponseReason = acquireLockRetryResponse.getResponseAsString();
}
}
} else {
lockAcquired = Boolean.valueOf(responseAsString);
lockResponseReason = "Successful response from consul with response for acquire lock: " + lockAcquired;
}
LOGGER.debug("lock acquired: {}. reason: {}", lockAcquired, lockResponseReason);
return lockAcquired;
}
@Override
public void close() {
if (consulClient != null) {
releaseLock();
closeSession();
}
}
private void releaseLock() {
LOGGER.trace("going to release lock");
HttpRequest releaseLock = HttpRequest.newBuilder()
.httpMethod(HttpMethod.PUT)
.uri("/v1/kv/" + mastershipKey)
.queryParams("release", sessionId)
.build();
HttpResponse response = execute(releaseLock, false, "release lock");
LOGGER.trace("release lock response: " + response.getStatus());
}
private HttpResponse execute(HttpRequest request, boolean throwOnError, String opName) {
HttpResponse response = consulClient.execute(request);
String responseAsString = response.getResponseAsString();
if (!response.isSuccess()) {
LOGGER.error("failed to " + opName + ". got response: {}, error response: {}", response.getStatus(), responseAsString);
if (throwOnError) {
throw new ConsulException("failed to " + opName + ". status: " + response.getStatus());
}
}
return response;
}
protected String getActiveVersionKey() {
return MasterSlaveConfigurationUtil.COMPONENT_NAME + "-version";
}
@Override
public String getActiveVersion() {
return System.getenv(CcpConstants.ARTIFACT_VERSION);
}
@Override
public void cleanupMaster() {
try {
releaseLock();
} catch (Exception e) {
LOGGER.error("instance is turning into slave but can't release lock. error: {}", e);
}
}
}
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