ru.yandex.clickhouse.BalancedClickhouseDataSource Maven / Gradle / Ivy
package ru.yandex.clickhouse;
import org.slf4j.LoggerFactory;
import ru.yandex.clickhouse.settings.ClickHouseProperties;
import javax.sql.DataSource;
import java.io.PrintWriter;
import java.net.URISyntaxException;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import java.util.*;
import java.util.concurrent.TimeUnit;
import java.util.logging.Logger;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import static ru.yandex.clickhouse.ClickhouseJdbcUrlParser.JDBC_CLICKHOUSE_PREFIX;
/**
* Database for clickhouse jdbc connections.
*
It has list of database urls.
* For every {@link #getConnection() getConnection} invocation, it returns connection to random host from the list.
* Furthermore, this class has method {@link #scheduleActualization(int, TimeUnit) scheduleActualization}
* which test hosts for availability. By default, this option is turned off.
*/
public class BalancedClickhouseDataSource implements DataSource {
private static final org.slf4j.Logger log = LoggerFactory.getLogger(BalancedClickhouseDataSource.class);
private static final Pattern URL_TEMPLATE = Pattern.compile(JDBC_CLICKHOUSE_PREFIX + "//([a-zA-Z0-9_:,.-]+)(/[a-zA-Z0-9_]+)?");
private PrintWriter printWriter;
private int loginTimeoutSeconds = 0;
private final Random random = new Random(System.currentTimeMillis());
private volatile List disabledUrls = new ArrayList();
private volatile List enabledUrls = new ArrayList();
private final ClickHouseProperties properties;
private final ClickHouseDriver driver = new ClickHouseDriver();
/**
* create Datasource for clickhouse JDBC connections
*
* @param url address for connection to the database
* must have the next format {@code jdbc:clickhouse://:,:/ }
* for example, {@code jdbc:clickhouse://localhost:8123,localhost:8123/database }
* @throws IllegalArgumentException if param have not correct format, or error happens when checking host availability
*/
public BalancedClickhouseDataSource(final String url) {
this(splitUrl(url), new ClickHouseProperties());
}
/**
* create Datasource for clickhouse JDBC connections
*
* @param url address for connection to the database
* @param properties database properties
* @see #BalancedClickhouseDataSource(String)
*/
public BalancedClickhouseDataSource(final String url, Properties properties) {
this(splitUrl(url), new ClickHouseProperties(properties));
}
/**
* create Datasource for clickhouse JDBC connections
*
* @param url address for connection to the database
* @param properties database properties
* @see #BalancedClickhouseDataSource(String)
*/
public BalancedClickhouseDataSource(final String url, ClickHouseProperties properties) {
this(splitUrl(url), properties);
}
private BalancedClickhouseDataSource(final List urls) {
this(urls, new ClickHouseProperties());
}
private BalancedClickhouseDataSource(final List urls, Properties info) {
this(urls, new ClickHouseProperties(info));
}
private BalancedClickhouseDataSource(final List urls, ClickHouseProperties properties) {
if (urls.isEmpty()) {
throw new IllegalArgumentException("Incorrect ClickHouse jdbc url list. It must be not empty");
}
try {
ClickHouseProperties localProperties = ClickhouseJdbcUrlParser.parse(urls.get(0), properties.asProperties());
localProperties.setHost(null);
localProperties.setPort(-1);
this.properties = localProperties;
} catch (URISyntaxException e) {
throw new IllegalArgumentException(e);
}
List enabledUrlList = new ArrayList(urls.size());
for (final String url : urls) {
try {
if (driver.acceptsURL(url)) {
enabledUrlList.add(url);
} else {
log.error("that url is has not correct format: {}", url);
}
} catch (SQLException e) {
throw new IllegalArgumentException("error while checking url: " + url, e);
}
}
if (enabledUrlList.isEmpty()) {
throw new IllegalArgumentException("there are no correct urls");
}
this.enabledUrls = enabledUrlList;
}
static List splitUrl(final String url) {
Matcher m = URL_TEMPLATE.matcher(url);
if (!m.matches()) {
throw new IllegalArgumentException("Incorrect url");
}
String database = m.group(2);
if (database == null) {
database = "";
}
String[] hosts = m.group(1).split(",");
final List result = new ArrayList(hosts.length);
for (final String host : hosts) {
result.add(JDBC_CLICKHOUSE_PREFIX + "//" + host + database);
}
return result;
}
private boolean ping(final String url) {
try {
driver.connect(url, properties).createStatement().execute("SELECT 1");
return true;
} catch (Exception e) {
return false;
}
}
/**
* Checks if clickhouse on url is alive, if it isn't, disable url, else enable.
* This method is not {@code thread-safe}, but it is invoked from single thread and all are ok.
*/
void actualize() {
int countOfUrls = enabledUrls.size() + disabledUrls.size();
List urls = new ArrayList(countOfUrls);
urls.addAll(enabledUrls);
urls.addAll(disabledUrls);
List enabledUrlList = new ArrayList(countOfUrls);
List disabledUrlList = new ArrayList(countOfUrls);
for (String url : urls) {
log.debug("Pinging disabled url: {}", url);
if (ping(url)) {
log.debug("Url is alive now: {}", url);
enabledUrlList.add(url);
} else {
log.debug("Url is dead now: {}", url);
disabledUrlList.add(url);
}
}
this.enabledUrls = enabledUrlList;
this.disabledUrls = disabledUrlList;
}
private String getAnyUrl() throws SQLException{
List localEnabledUrls = enabledUrls;
if (localEnabledUrls.isEmpty()) {
throw new SQLException("Unable to get connection: there are no enabled urls");
}
int index = random.nextInt(localEnabledUrls.size());
return localEnabledUrls.get(index);
}
/**
* {@inheritDoc}
*/
@Override
public ClickHouseConnection getConnection() throws SQLException {
return driver.connect(getAnyUrl(), properties);
}
/**
* {@inheritDoc}
*/
@Override
public ClickHouseConnection getConnection(String username, String password) throws SQLException {
return driver.connect(getAnyUrl(), properties.withCredentials(username, password));
}
/**
* {@inheritDoc}
*/
@Override
public T unwrap(Class iface) throws SQLException {
if (iface.isAssignableFrom(getClass())) {
return iface.cast(this);
}
throw new SQLException("Cannot unwrap to " + iface.getName());
}
/**
* {@inheritDoc}
*/
@Override
public boolean isWrapperFor(Class iface) throws SQLException {
return iface.isAssignableFrom(getClass());
}
/**
* {@inheritDoc}
*/
@Override
public PrintWriter getLogWriter() throws SQLException {
return printWriter;
}
/**
* {@inheritDoc}
*/
@Override
public void setLogWriter(PrintWriter printWriter) throws SQLException {
this.printWriter = printWriter;
}
/**
* {@inheritDoc}
*/
@Override
public void setLoginTimeout(int seconds) throws SQLException {
// throw new SQLFeatureNotSupportedException();
loginTimeoutSeconds = seconds;
}
/**
* {@inheritDoc}
*/
@Override
public int getLoginTimeout() throws SQLException {
return loginTimeoutSeconds;
}
/**
* {@inheritDoc}
*/
public Logger getParentLogger() throws SQLFeatureNotSupportedException {
throw new SQLFeatureNotSupportedException();
}
/**
* set time period of removing connections
*
* @param rate value for time unit
* @param timeUnit time unit for checking
* @return this datasource with changed settings
* @see ClickHouseDriver#scheduleConnectionsCleaning
*/
public BalancedClickhouseDataSource withConnectionsCleaning(int rate, TimeUnit timeUnit) {
driver.scheduleConnectionsCleaning(rate, timeUnit);
return this;
}
/**
* set time period for checking availability connections
*
* @param rate value for time unit
* @param timeUnit time unit for checking
* @return this datasource with changed settings
*/
public BalancedClickhouseDataSource scheduleActualization(int rate, TimeUnit timeUnit) {
ClickHouseDriver.ScheduledConnectionCleaner.INSTANCE.scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
try {
actualize();
} catch (Exception e) {
log.error("Unable to actualize urls", e);
}
}
}, 0, rate, timeUnit);
return this;
}
}