org.mariadb.jdbc.internal.protocol.AuroraProtocol Maven / Gradle / Ivy
/*
*
* MariaDB Client for Java
*
* Copyright (c) 2012-2014 Monty Program Ab.
* Copyright (c) 2015-2017 MariaDB Ab.
*
* This library is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 2.1 of the License, or (at your option)
* any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License along
* with this library; if not, write to Monty Program Ab [email protected].
*
* This particular MariaDB Client for Java file is work
* derived from a Drizzle-JDBC. Drizzle-JDBC file which is covered by subject to
* the following copyright and notice provisions:
*
* Copyright (c) 2009-2011, Marcus Eriksson
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
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* of conditions and the following disclaimer.
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* list of conditions and the following disclaimer in the documentation and/or
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package org.mariadb.jdbc.internal.protocol;
import org.mariadb.jdbc.HostAddress;
import org.mariadb.jdbc.UrlParser;
import org.mariadb.jdbc.internal.com.read.dao.Results;
import org.mariadb.jdbc.internal.failover.FailoverProxy;
import org.mariadb.jdbc.internal.failover.impl.AuroraListener;
import org.mariadb.jdbc.internal.failover.tools.SearchFilter;
import org.mariadb.jdbc.internal.util.pool.GlobalStateInfo;
import java.net.SocketException;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.*;
import java.util.concurrent.locks.ReentrantLock;
import static org.mariadb.jdbc.internal.util.SqlStates.CONNECTION_EXCEPTION;
public class AuroraProtocol extends MastersSlavesProtocol {
public AuroraProtocol(final UrlParser url, final GlobalStateInfo globalInfo, final ReentrantLock lock) {
super(url, globalInfo, lock);
}
/**
* Connect aurora probable master.
* Aurora master change in time. The only way to check that a server is a master is to asked him.
*
* @param listener aurora failover to call back if master is found
* @param globalInfo server global variables information
* @param probableMaster probable master host
*/
private static void searchProbableMaster(AuroraListener listener, final GlobalStateInfo globalInfo,
HostAddress probableMaster) {
AuroraProtocol protocol = getNewProtocol(listener.getProxy(), globalInfo, listener.getUrlParser());
try {
protocol.setHostAddress(probableMaster);
protocol.connect();
listener.removeFromBlacklist(protocol.getHostAddress());
if (listener.isMasterHostFailReconnect() && protocol.isMasterConnection()) {
protocol.setMustBeMasterConnection(true);
listener.foundActiveMaster(protocol);
} else if (listener.isSecondaryHostFailReconnect() && !protocol.isMasterConnection()) {
protocol.setMustBeMasterConnection(false);
listener.foundActiveSecondary(protocol);
} else {
protocol.close();
protocol = getNewProtocol(listener.getProxy(), globalInfo, listener.getUrlParser());
}
} catch (SQLException e) {
listener.addToBlacklist(protocol.getHostAddress());
}
}
/**
* loop until found the failed connection.
*
* @param listener current failover
* @param globalInfo server global variables information
* @param addresses list of HostAddress to loop
* @param initialSearchFilter search parameter
* @throws SQLException if not found
*/
public static void loop(AuroraListener listener, final GlobalStateInfo globalInfo, final List addresses,
SearchFilter initialSearchFilter) throws SQLException {
SearchFilter searchFilter = initialSearchFilter;
AuroraProtocol protocol;
Deque loopAddresses = new ArrayDeque<>(addresses);
if (loopAddresses.isEmpty()) resetHostList(listener, loopAddresses);
int maxConnectionTry = listener.getRetriesAllDown();
SQLException lastQueryException = null;
HostAddress probableMasterHost = null;
boolean firstLoop = true;
while (!loopAddresses.isEmpty() || (!searchFilter.isFailoverLoop() && maxConnectionTry > 0)) {
protocol = getNewProtocol(listener.getProxy(), globalInfo, listener.getUrlParser());
if (listener.isExplicitClosed() || (!listener.isSecondaryHostFailReconnect() && !listener.isMasterHostFailReconnect())) {
return;
}
maxConnectionTry--;
try {
HostAddress host = loopAddresses.pollFirst();
if (host == null) {
for (HostAddress hostAddress : listener.getUrlParser().getHostAddresses()) {
if (!hostAddress.equals(listener.getClusterHostAddress())) {
loopAddresses.add(hostAddress);
}
}
// Use cluster last as backup
if (listener.getClusterHostAddress() != null && listener.getUrlParser().getHostAddresses().size() < 2) {
loopAddresses.add(listener.getClusterHostAddress());
}
host = loopAddresses.pollFirst();
}
protocol.setHostAddress(host);
protocol.connect();
if (listener.isExplicitClosed()) {
protocol.close();
return;
}
listener.removeFromBlacklist(protocol.getHostAddress());
if (listener.isMasterHostFailReconnect() && protocol.isMasterConnection()) {
// Look for secondary when only known endpoint is the cluster endpoint
if (searchFilter.isFineIfFoundOnlyMaster() && listener.getUrlParser().getHostAddresses().size() <= 1
&& protocol.getHostAddress().equals(listener.getClusterHostAddress())) {
listener.retrieveAllEndpointsAndSet(protocol);
if (listener.getUrlParser().getHostAddresses().size() > 1) {
//add newly discovered end-point to loop
loopAddresses.addAll(listener.getUrlParser().getHostAddresses());
//since there is more than one end point, reactivate connection to a read-only host
searchFilter = new SearchFilter(false);
}
}
if (foundMaster(listener, protocol, searchFilter)) {
return;
}
} else if (!protocol.isMasterConnection()) {
if (listener.isSecondaryHostFailReconnect()) {
//in case cluster DNS is currently pointing to a slave host
if (listener.getUrlParser().getHostAddresses().size() <= 1
&& protocol.getHostAddress().equals(listener.getClusterHostAddress())) {
listener.retrieveAllEndpointsAndSet(protocol);
if (listener.getUrlParser().getHostAddresses().size() > 1) {
//add newly discovered end-point to loop
loopAddresses.addAll(listener.getUrlParser().getHostAddresses());
//since there is more than one end point, reactivate connection to a read-only host
searchFilter = new SearchFilter(false);
}
} else {
if (foundSecondary(listener, protocol, searchFilter)) {
return;
}
}
} else {
try {
if (listener.isSecondaryHostFailReconnect()
|| (listener.isMasterHostFailReconnect() && probableMasterHost == null)) {
probableMasterHost = listener.searchByStartName(protocol, listener.getUrlParser().getHostAddresses());
if (probableMasterHost != null) {
loopAddresses.remove(probableMasterHost);
AuroraProtocol.searchProbableMaster(listener, globalInfo, probableMasterHost);
if (listener.isMasterHostFailReconnect() && searchFilter.isFineIfFoundOnlySlave()) {
return;
}
}
}
} finally {
protocol.close();
}
}
} else {
protocol.close();
}
} catch (SQLException e) {
lastQueryException = e;
listener.addToBlacklist(protocol.getHostAddress());
}
if (!listener.isMasterHostFailReconnect() && !listener.isSecondaryHostFailReconnect()) {
return;
}
//in case master not found but slave is , and allowing master down
if (loopAddresses.isEmpty()
&& (listener.isMasterHostFailReconnect()
&& listener.urlParser.getOptions().allowMasterDownConnection
&& !listener.isSecondaryHostFailReconnect())) {
return;
}
// if server has try to connect to all host, and there is remaining master or slave that fail
// add all servers back to continue looping until maxConnectionTry is reached
if (loopAddresses.isEmpty() && !searchFilter.isFailoverLoop() && maxConnectionTry > 0) {
resetHostList(listener, loopAddresses);
if (firstLoop) {
firstLoop = false;
} else {
try {
//wait 250ms before looping through all connection another time
Thread.sleep(250);
} catch (InterruptedException interrupted) {
//interrupted, continue
}
}
}
// Try to connect to the cluster if no other connection is good
if (maxConnectionTry == 0 && !loopAddresses.contains(listener.getClusterHostAddress()) && listener.getClusterHostAddress() != null) {
loopAddresses.add(listener.getClusterHostAddress());
}
}
if (listener.isMasterHostFailReconnect() || listener.isSecondaryHostFailReconnect()) {
String error = "No active connection found for replica";
if (listener.isMasterHostFailReconnect()) {
error = "No active connection found for master";
}
if (lastQueryException != null) {
throw new SQLException(error, lastQueryException.getSQLState(), lastQueryException.getErrorCode(), lastQueryException);
}
throw new SQLException(error);
}
}
/**
* Reinitialize loopAddresses with all hosts : all servers in randomize order with cluster address.
* If there is an active connection, connected host are remove from list.
*
* @param listener current listener
* @param loopAddresses the list to reinitialize
*/
private static void resetHostList(AuroraListener listener, Deque loopAddresses) {
//if all servers have been connected without result
//add back all servers
List servers = new ArrayList<>();
servers.addAll(listener.getUrlParser().getHostAddresses());
Collections.shuffle(servers);
//if cluster host is set, add it to the end of the list
if (listener.getClusterHostAddress() != null && listener.getUrlParser().getHostAddresses().size() < 2) {
servers.add(listener.getClusterHostAddress());
}
//remove current connected hosts to avoid reconnect them
servers.removeAll(listener.connectedHosts());
loopAddresses.clear();
loopAddresses.addAll(servers);
}
/**
* Initialize new protocol instance.
*
* @param proxy proxy
* @param globalInfo server global variables information
* @param urlParser connection string data's
* @return new AuroraProtocol
*/
public static AuroraProtocol getNewProtocol(FailoverProxy proxy, final GlobalStateInfo globalInfo, UrlParser urlParser) {
AuroraProtocol newProtocol = new AuroraProtocol(urlParser, globalInfo, proxy.lock);
newProtocol.setProxy(proxy);
return newProtocol;
}
@Override
public boolean isMasterConnection() {
return this.masterConnection;
}
@Override
public void readPipelineCheckMaster() throws SQLException {
Results results = new Results();
getResult(results);
results.commandEnd();
ResultSet resultSet = results.getResultSet();
if (!resultSet.next()) throw new SQLException("Error checking Aurora's master status : No information");
this.masterConnection = "OFF".equals(resultSet.getString(2));
reader.setServerThreadId(this.serverThreadId, this.masterConnection);
writer.setServerThreadId(this.serverThreadId, this.masterConnection);
//Aurora replicas have read-only flag forced
this.readOnly = !this.masterConnection;
}
@Override
public boolean isValid(int timeout) throws SQLException {
int initialTimeout = -1;
try {
initialTimeout = socket.getSoTimeout();
this.socket.setSoTimeout(timeout);
if (isMasterConnection()) return checkIfMaster();
return ping();
} catch (SocketException socketException) {
throw new SQLException("Could not valid connection : " + socketException.getMessage(),
CONNECTION_EXCEPTION.getSqlState(),
socketException);
} finally {
//set back initial socket timeout
try {
if (initialTimeout != -1) socket.setSoTimeout(initialTimeout);
} catch (SocketException socketException) {
//eat
}
}
}
/**
* Aurora best way to check if a node is a master : is not in read-only mode.
*
* @return indicate if master has been found
*/
@Override
public boolean checkIfMaster() throws SQLException {
proxy.lock.lock();
try {
Results results = new Results();
executeQuery(this.isMasterConnection(), results, "show global variables like 'innodb_read_only'");
results.commandEnd();
ResultSet queryResult = results.getResultSet();
if (queryResult != null) {
queryResult.next();
this.masterConnection = "OFF".equals(queryResult.getString(2));
reader.setServerThreadId(this.serverThreadId, this.masterConnection);
writer.setServerThreadId(this.serverThreadId, this.masterConnection);
} else {
this.masterConnection = false;
}
this.readOnly = !this.masterConnection;
return this.masterConnection;
} catch (SQLException sqle) {
throw new SQLException("could not check the 'innodb_read_only' variable status on " + this.getHostAddress()
+ " : " + sqle.getMessage(), CONNECTION_EXCEPTION.getSqlState(), sqle);
} finally {
proxy.lock.unlock();
}
}
}
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