org.mariadb.jdbc.internal.protocol.AuroraProtocol Maven / Gradle / Ivy
/*
MariaDB Client for Java
Copyright (c) 2012-2014 Monty Program 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:
Redistributions of source code must retain the above copyright notice, this list
of conditions and the following disclaimer.
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list of conditions and the following disclaimer in the documentation and/or
other materials provided with the distribution.
Neither the name of the driver nor the names of its contributors may not be
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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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.failover.FailoverProxy;
import org.mariadb.jdbc.internal.failover.impl.AuroraListener;
import org.mariadb.jdbc.internal.failover.tools.SearchFilter;
import org.mariadb.jdbc.internal.queryresults.SingleExecutionResult;
import org.mariadb.jdbc.internal.queryresults.resultset.MariaSelectResultSet;
import org.mariadb.jdbc.internal.util.dao.QueryException;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayDeque;
import java.util.List;
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 ReentrantLock lock) {
super(url, 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 probableMaster probable master host
*/
public static void searchProbableMaster(AuroraListener listener, HostAddress probableMaster) {
AuroraProtocol protocol = getNewProtocol(listener.getProxy(), 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(), listener.getUrlParser());
}
} catch (QueryException e) {
listener.addToBlacklist(protocol.getHostAddress());
}
}
/**
* loop until found the failed connection.
*
* @param listener current failover
* @param addresses list of HostAddress to loop
* @param searchFilter search parameter
* @throws QueryException if not found
*/
public static void loop(AuroraListener listener, final List addresses, SearchFilter searchFilter)
throws QueryException {
AuroraProtocol protocol;
ArrayDeque loopAddresses = new ArrayDeque<>((!addresses.isEmpty()) ? addresses : listener.getBlacklistKeys());
if (loopAddresses.isEmpty()) {
loopAddresses.addAll(listener.getUrlParser().getHostAddresses());
}
int maxConnectionTry = listener.getRetriesAllDown();
QueryException lastQueryException = null;
HostAddress probableMasterHost = null;
while (!loopAddresses.isEmpty() || (!searchFilter.isFailoverLoop() && maxConnectionTry > 0)) {
protocol = getNewProtocol(listener.getProxy(), 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()) {
if (foundSecondary(listener, protocol, searchFilter)) {
return;
}
}
if (listener.isSecondaryHostFailReconnect()
|| (listener.isMasterHostFailReconnect() && probableMasterHost == null)) {
probableMasterHost = listener.searchByStartName(protocol, listener.getUrlParser().getHostAddresses());
if (probableMasterHost != null) {
loopAddresses.remove(probableMasterHost);
AuroraProtocol.searchProbableMaster(listener, probableMasterHost);
if (listener.isMasterHostFailReconnect() && searchFilter.isFineIfFoundOnlySlave()) {
return;
}
}
}
} else {
protocol.close();
}
} catch (QueryException e) {
lastQueryException = e;
listener.addToBlacklist(protocol.getHostAddress());
}
if (!listener.isMasterHostFailReconnect() && !listener.isSecondaryHostFailReconnect()) {
return;
}
//loop is set so
if (loopAddresses.isEmpty() && !searchFilter.isFailoverLoop() && maxConnectionTry > 0) {
//use blacklist if all server has been connected and no result
loopAddresses = new ArrayDeque<>(listener.getBlacklistKeys());
}
// 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 QueryException(error, lastQueryException.getErrorCode(), lastQueryException.getSqlState(), lastQueryException);
}
throw new QueryException(error);
}
}
/**
* Initialize new protocol instance.
* @param proxy proxy
* @param urlParser connection string data's
* @return new AuroraProtocol
*/
public static AuroraProtocol getNewProtocol(FailoverProxy proxy, UrlParser urlParser) {
AuroraProtocol newProtocol = new AuroraProtocol(urlParser, proxy.lock);
newProtocol.setProxy(proxy);
return newProtocol;
}
@Override
public boolean isMasterConnection() {
return this.masterConnection;
}
/**
* 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 QueryException {
proxy.lock.lock();
try {
SingleExecutionResult executionResult = new SingleExecutionResult(null, 0, true, false);
executeQuery(this.isMasterConnection(), executionResult, "show global variables like 'innodb_read_only'", ResultSet.TYPE_FORWARD_ONLY);
MariaSelectResultSet queryResult = executionResult.getResultSet();
if (queryResult != null) {
queryResult.next();
this.masterConnection = "OFF".equals(queryResult.getString(2));
} else {
this.masterConnection = false;
}
this.readOnly = !this.masterConnection;
return this.masterConnection;
} catch (SQLException sqle) {
throw new QueryException("could not check the 'innodb_read_only' variable status on " + this.getHostAddress()
+ " : " + sqle.getMessage(), -1, CONNECTION_EXCEPTION.getSqlState(), sqle);
} finally {
proxy.lock.unlock();
}
}
}
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