com.zaxxer.hikari.pool.HikariPool Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of HikariCP Show documentation
Show all versions of HikariCP Show documentation
Ultimate JDBC Connection Pool
/*
* Copyright (C) 2013,2014 Brett Wooldridge
*
* 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.zaxxer.hikari.pool;
import com.codahale.metrics.MetricRegistry;
import com.codahale.metrics.health.HealthCheckRegistry;
import com.zaxxer.hikari.HikariConfig;
import com.zaxxer.hikari.HikariPoolMXBean;
import com.zaxxer.hikari.metrics.MetricsTrackerFactory;
import com.zaxxer.hikari.metrics.PoolStats;
import com.zaxxer.hikari.metrics.dropwizard.CodahaleHealthChecker;
import com.zaxxer.hikari.metrics.dropwizard.CodahaleMetricsTrackerFactory;
import com.zaxxer.hikari.metrics.micrometer.MicrometerMetricsTrackerFactory;
import com.zaxxer.hikari.util.ConcurrentBag;
import com.zaxxer.hikari.util.ConcurrentBag.IBagStateListener;
import com.zaxxer.hikari.util.SuspendResumeLock;
import io.micrometer.core.instrument.MeterRegistry;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.SQLTransientConnectionException;
import java.util.Optional;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
import static com.zaxxer.hikari.util.ClockSource.*;
import static com.zaxxer.hikari.util.ConcurrentBag.IConcurrentBagEntry.STATE_IN_USE;
import static com.zaxxer.hikari.util.ConcurrentBag.IConcurrentBagEntry.STATE_NOT_IN_USE;
import static com.zaxxer.hikari.util.UtilityElf.*;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.concurrent.TimeUnit.SECONDS;
/**
* This is the primary connection pool class that provides the basic
* pooling behavior for HikariCP.
*
* @author Brett Wooldridge
*/
public final class HikariPool extends PoolBase implements HikariPoolMXBean, IBagStateListener
{
private final Logger logger = LoggerFactory.getLogger(HikariPool.class);
public static final int POOL_NORMAL = 0;
public static final int POOL_SUSPENDED = 1;
public static final int POOL_SHUTDOWN = 2;
public volatile int poolState;
private final long aliveBypassWindowMs = Long.getLong("com.zaxxer.hikari.aliveBypassWindowMs", MILLISECONDS.toMillis(500));
private final long housekeepingPeriodMs = Long.getLong("com.zaxxer.hikari.housekeeping.periodMs", SECONDS.toMillis(30));
private final boolean isRequestBoundariesEnabled = Boolean.getBoolean("com.zaxxer.hikari.enableRequestBoundaries");
private static final String EVICTED_CONNECTION_MESSAGE = "(connection was evicted)";
private static final String DEAD_CONNECTION_MESSAGE = "(connection is dead)";
private final PoolEntryCreator poolEntryCreator = new PoolEntryCreator();
private final PoolEntryCreator postFillPoolEntryCreator = new PoolEntryCreator("After adding ");
private final ThreadPoolExecutor addConnectionExecutor;
private final ThreadPoolExecutor closeConnectionExecutor;
private final ConcurrentBag connectionBag;
private final ProxyLeakTaskFactory leakTaskFactory;
private final SuspendResumeLock suspendResumeLock;
private final ScheduledExecutorService houseKeepingExecutorService;
private ScheduledFuture houseKeeperTask;
/**
* Construct a HikariPool with the specified configuration.
*
* @param config a HikariConfig instance
*/
public HikariPool(final HikariConfig config)
{
super(config);
this.connectionBag = new ConcurrentBag<>(this);
this.suspendResumeLock = config.isAllowPoolSuspension() ? new SuspendResumeLock() : SuspendResumeLock.FAUX_LOCK;
this.houseKeepingExecutorService = initializeHouseKeepingExecutorService();
checkFailFast();
if (config.getMetricsTrackerFactory() != null) {
setMetricsTrackerFactory(config.getMetricsTrackerFactory());
}
else {
setMetricRegistry(config.getMetricRegistry());
}
setHealthCheckRegistry(config.getHealthCheckRegistry());
handleMBeans(this, true);
ThreadFactory threadFactory = config.getThreadFactory();
final int maxPoolSize = config.getMaximumPoolSize();
LinkedBlockingQueue addConnectionQueue = new LinkedBlockingQueue<>(maxPoolSize);
this.addConnectionExecutor = createThreadPoolExecutor(addConnectionQueue, poolName + " connection adder", threadFactory, new CustomDiscardPolicy());
this.closeConnectionExecutor = createThreadPoolExecutor(maxPoolSize, poolName + " connection closer", threadFactory, new ThreadPoolExecutor.CallerRunsPolicy());
this.leakTaskFactory = new ProxyLeakTaskFactory(config.getLeakDetectionThreshold(), houseKeepingExecutorService);
this.houseKeeperTask = houseKeepingExecutorService.scheduleWithFixedDelay(new HouseKeeper(), 100L, housekeepingPeriodMs, MILLISECONDS);
if (Boolean.getBoolean("com.zaxxer.hikari.blockUntilFilled") && config.getInitializationFailTimeout() > 1) {
addConnectionExecutor.setMaximumPoolSize(Math.min(16, Runtime.getRuntime().availableProcessors()));
addConnectionExecutor.setCorePoolSize(Math.min(16, Runtime.getRuntime().availableProcessors()));
final long startTime = currentTime();
while (elapsedMillis(startTime) < config.getInitializationFailTimeout() && getTotalConnections() < config.getMinimumIdle()) {
quietlySleep(MILLISECONDS.toMillis(100));
}
addConnectionExecutor.setCorePoolSize(1);
addConnectionExecutor.setMaximumPoolSize(1);
}
}
/**
* Get a connection from the pool, or timeout after connectionTimeout milliseconds.
*
* @return a java.sql.Connection instance
* @throws SQLException thrown if a timeout occurs trying to obtain a connection
*/
public Connection getConnection() throws SQLException
{
return getConnection(connectionTimeout);
}
/**
* Get a connection from the pool, or timeout after the specified number of milliseconds.
*
* @param hardTimeout the maximum time to wait for a connection from the pool
* @return a java.sql.Connection instance
* @throws SQLException thrown if a timeout occurs trying to obtain a connection
*/
public Connection getConnection(final long hardTimeout) throws SQLException
{
suspendResumeLock.acquire();
final var startTime = currentTime();
try {
var timeout = hardTimeout;
do {
var poolEntry = connectionBag.borrow(timeout, MILLISECONDS);
if (poolEntry == null) {
break; // We timed out... break and throw exception
}
final var now = currentTime();
if (poolEntry.isMarkedEvicted() || (elapsedMillis(poolEntry.lastAccessed, now) > aliveBypassWindowMs && isConnectionDead(poolEntry.connection))) {
closeConnection(poolEntry, poolEntry.isMarkedEvicted() ? EVICTED_CONNECTION_MESSAGE : DEAD_CONNECTION_MESSAGE);
timeout = hardTimeout - elapsedMillis(startTime);
}
else {
metricsTracker.recordBorrowStats(poolEntry, startTime);
if (isRequestBoundariesEnabled) {
try {
poolEntry.connection.beginRequest();
} catch (SQLException e) {
logger.warn("beginRequest Failed for: {}, ({})", poolEntry.connection, e.getMessage());
}
}
return poolEntry.createProxyConnection(leakTaskFactory.schedule(poolEntry));
}
} while (timeout > 0L);
metricsTracker.recordBorrowTimeoutStats(startTime);
throw createTimeoutException(startTime);
}
catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw new SQLException(poolName + " - Interrupted during connection acquisition", e);
}
finally {
suspendResumeLock.release();
}
}
/**
* Shutdown the pool, closing all idle connections and aborting or closing
* active connections.
*
* @throws InterruptedException thrown if the thread is interrupted during shutdown
*/
public synchronized void shutdown() throws InterruptedException
{
try {
poolState = POOL_SHUTDOWN;
if (addConnectionExecutor == null) { // pool never started
return;
}
logPoolState("Before shutdown ");
if (houseKeeperTask != null) {
houseKeeperTask.cancel(false);
houseKeeperTask = null;
}
softEvictConnections();
addConnectionExecutor.shutdown();
if (!addConnectionExecutor.awaitTermination(getLoginTimeout(), SECONDS)) {
logger.warn("Timed-out waiting for add connection executor to shutdown");
}
destroyHouseKeepingExecutorService();
connectionBag.close();
final var assassinExecutor = createThreadPoolExecutor(config.getMaximumPoolSize(), poolName + " connection assassinator",
config.getThreadFactory(), new ThreadPoolExecutor.CallerRunsPolicy());
try {
final var start = currentTime();
do {
abortActiveConnections(assassinExecutor);
softEvictConnections();
} while (getTotalConnections() > 0 && elapsedMillis(start) < SECONDS.toMillis(10));
}
finally {
assassinExecutor.shutdown();
if (!assassinExecutor.awaitTermination(10L, SECONDS)) {
logger.warn("Timed-out waiting for connection assassin to shutdown");
}
}
shutdownNetworkTimeoutExecutor();
closeConnectionExecutor.shutdown();
if (!closeConnectionExecutor.awaitTermination(10L, SECONDS)) {
logger.warn("Timed-out waiting for close connection executor to shutdown");
}
}
finally {
logPoolState("After shutdown ");
handleMBeans(this, false);
metricsTracker.close();
}
}
/**
* Evict a Connection from the pool.
*
* @param connection the Connection to evict (actually a {@link ProxyConnection})
*/
public void evictConnection(Connection connection)
{
var proxyConnection = (ProxyConnection) connection;
proxyConnection.cancelLeakTask();
try {
softEvictConnection(proxyConnection.getPoolEntry(), "(connection evicted by user)", !connection.isClosed() /* owner */);
}
catch (SQLException e) {
// unreachable in HikariCP, but we're still forced to catch it
}
}
/**
* Set a metrics registry to be used when registering metrics collectors. The HikariDataSource prevents this
* method from being called more than once.
*
* @param metricRegistry the metrics registry instance to use
*/
@SuppressWarnings("PackageAccessibility")
public void setMetricRegistry(Object metricRegistry)
{
if (metricRegistry != null && safeIsAssignableFrom(metricRegistry, "com.codahale.metrics.MetricRegistry")) {
setMetricsTrackerFactory(new CodahaleMetricsTrackerFactory((MetricRegistry) metricRegistry));
}
else if (metricRegistry != null && safeIsAssignableFrom(metricRegistry, "io.micrometer.core.instrument.MeterRegistry")) {
setMetricsTrackerFactory(new MicrometerMetricsTrackerFactory((MeterRegistry) metricRegistry));
}
else {
setMetricsTrackerFactory(null);
}
}
/**
* Set the MetricsTrackerFactory to be used to create the IMetricsTracker instance used by the pool.
*
* @param metricsTrackerFactory an instance of a class that subclasses MetricsTrackerFactory
*/
public void setMetricsTrackerFactory(MetricsTrackerFactory metricsTrackerFactory)
{
if (metricsTrackerFactory != null) {
this.metricsTracker = new MetricsTrackerDelegate(metricsTrackerFactory.create(config.getPoolName(), getPoolStats()));
}
else {
this.metricsTracker = new NopMetricsTrackerDelegate();
}
}
/**
* Set the health check registry to be used when registering health checks. Currently only Codahale health
* checks are supported.
*
* @param healthCheckRegistry the health check registry instance to use
*/
public void setHealthCheckRegistry(Object healthCheckRegistry)
{
if (healthCheckRegistry != null) {
CodahaleHealthChecker.registerHealthChecks(this, config, (HealthCheckRegistry) healthCheckRegistry);
}
}
// ***********************************************************************
// IBagStateListener callback
// ***********************************************************************
/** {@inheritDoc} */
@Override
public void addBagItem(final int waiting)
{
if (waiting > addConnectionExecutor.getQueue().size())
addConnectionExecutor.submit(poolEntryCreator);
}
// ***********************************************************************
// HikariPoolMBean methods
// ***********************************************************************
/** {@inheritDoc} */
@Override
public int getActiveConnections()
{
return connectionBag.getCount(STATE_IN_USE);
}
/** {@inheritDoc} */
@Override
public int getIdleConnections()
{
return connectionBag.getCount(STATE_NOT_IN_USE);
}
/** {@inheritDoc} */
@Override
public int getTotalConnections()
{
return connectionBag.size();
}
/** {@inheritDoc} */
@Override
public int getThreadsAwaitingConnection()
{
return connectionBag.getWaitingThreadCount();
}
/** {@inheritDoc} */
@Override
public void softEvictConnections()
{
connectionBag.values().forEach(poolEntry -> softEvictConnection(poolEntry, "(connection evicted)", false /* not owner */));
}
/** {@inheritDoc} */
@Override
public synchronized void suspendPool()
{
if (suspendResumeLock == SuspendResumeLock.FAUX_LOCK) {
throw new IllegalStateException(poolName + " - is not suspendable");
}
else if (poolState != POOL_SUSPENDED) {
suspendResumeLock.suspend();
poolState = POOL_SUSPENDED;
}
}
/** {@inheritDoc} */
@Override
public synchronized void resumePool()
{
if (poolState == POOL_SUSPENDED) {
poolState = POOL_NORMAL;
fillPool(false);
suspendResumeLock.resume();
}
}
// ***********************************************************************
// Package methods
// ***********************************************************************
/**
* Log the current pool state at debug level.
*
* @param prefix an optional prefix to prepend the log message
*/
void logPoolState(String... prefix)
{
if (logger.isDebugEnabled()) {
logger.debug("{} - {}stats (total={}/{}, idle={}/{}, active={}, waiting={})",
poolName, (prefix.length > 0 ? prefix[0] : ""),
getTotalConnections(), config.getMaximumPoolSize(), getIdleConnections(), config.getMinimumIdle(), getActiveConnections(), getThreadsAwaitingConnection());
}
}
/**
* Recycle PoolEntry (add back to the pool)
*
* @param poolEntry the PoolEntry to recycle
*/
@Override
void recycle(final PoolEntry poolEntry)
{
metricsTracker.recordConnectionUsage(poolEntry);
if (poolEntry.isMarkedEvicted()) {
closeConnection(poolEntry, EVICTED_CONNECTION_MESSAGE);
} else {
if (isRequestBoundariesEnabled) {
try {
poolEntry.connection.endRequest();
} catch (SQLException e) {
logger.warn("endRequest Failed for: {},({})", poolEntry.connection, e.getMessage());
}
}
connectionBag.requite(poolEntry);
}
}
/**
* Permanently close the real (underlying) connection (eat any exception).
*
* @param poolEntry poolEntry having the connection to close
* @param closureReason reason to close
*/
void closeConnection(final PoolEntry poolEntry, final String closureReason)
{
if (connectionBag.remove(poolEntry)) {
final var connection = poolEntry.close();
closeConnectionExecutor.execute(() -> {
quietlyCloseConnection(connection, closureReason);
if (poolState == POOL_NORMAL) {
fillPool(false);
}
});
}
}
@SuppressWarnings("unused")
int[] getPoolStateCounts()
{
return connectionBag.getStateCounts();
}
// ***********************************************************************
// Private methods
// ***********************************************************************
/**
* Creating new poolEntry. If maxLifetime is configured, create a future End-of-life task with 2.5% variance from
* the maxLifetime time to ensure there is no massive die-off of Connections in the pool.
*/
private PoolEntry createPoolEntry()
{
try {
final var poolEntry = newPoolEntry();
final var maxLifetime = config.getMaxLifetime();
if (maxLifetime > 0) {
// variance up to 2.5% of the maxlifetime
final var variance = maxLifetime > 10_000 ? ThreadLocalRandom.current().nextLong( maxLifetime / 40 ) : 0;
final var lifetime = maxLifetime - variance;
poolEntry.setFutureEol(houseKeepingExecutorService.schedule(new MaxLifetimeTask(poolEntry), lifetime, MILLISECONDS));
}
final long keepaliveTime = config.getKeepaliveTime();
if (keepaliveTime > 0) {
// variance up to 10% of the heartbeat time
final var variance = ThreadLocalRandom.current().nextLong(keepaliveTime / 10);
final var heartbeatTime = keepaliveTime - variance;
poolEntry.setKeepalive(houseKeepingExecutorService.scheduleWithFixedDelay(new KeepaliveTask(poolEntry), heartbeatTime, heartbeatTime, MILLISECONDS));
}
return poolEntry;
}
catch (ConnectionSetupException e) {
if (poolState == POOL_NORMAL) { // we check POOL_NORMAL to avoid a flood of messages if shutdown() is running concurrently
logger.error("{} - Error thrown while acquiring connection from data source", poolName, e.getCause());
lastConnectionFailure.set(e);
}
}
catch (Exception e) {
if (poolState == POOL_NORMAL) { // we check POOL_NORMAL to avoid a flood of messages if shutdown() is running concurrently
logger.debug("{} - Cannot acquire connection from data source", poolName, e);
}
}
return null;
}
/**
* Fill pool up from current idle connections (as they are perceived at the point of execution) to minimumIdle connections.
*/
private synchronized void fillPool(final boolean isAfterAdd)
{
final var idle = getIdleConnections();
final var shouldAdd = getTotalConnections() < config.getMaximumPoolSize() && idle < config.getMinimumIdle();
if (shouldAdd) {
final var countToAdd = config.getMinimumIdle() - idle;
for (int i = 0; i < countToAdd; i++)
addConnectionExecutor.submit(isAfterAdd ? postFillPoolEntryCreator : poolEntryCreator);
}
else if (isAfterAdd) {
logger.debug("{} - Fill pool skipped, pool has sufficient level or currently being filled.", poolName);
}
}
/**
* Attempt to abort or close active connections.
*
* @param assassinExecutor the ExecutorService to pass to Connection.abort()
*/
private void abortActiveConnections(final ExecutorService assassinExecutor)
{
for (var poolEntry : connectionBag.values(STATE_IN_USE)) {
Connection connection = poolEntry.close();
try {
connection.abort(assassinExecutor);
}
catch (Throwable e) {
quietlyCloseConnection(connection, "(connection aborted during shutdown)");
}
finally {
connectionBag.remove(poolEntry);
}
}
}
/**
* If initializationFailFast is configured, check that we have DB connectivity.
*
* @throws PoolInitializationException if fails to create or validate connection
* @see HikariConfig#setInitializationFailTimeout(long)
*/
private void checkFailFast()
{
final var initializationTimeout = config.getInitializationFailTimeout();
if (initializationTimeout < 0) {
return;
}
final var startTime = currentTime();
do {
final var poolEntry = createPoolEntry();
if (poolEntry != null) {
if (config.getMinimumIdle() > 0) {
connectionBag.add(poolEntry);
logger.info("{} - Added connection {}", poolName, poolEntry.connection);
}
else {
quietlyCloseConnection(poolEntry.close(), "(initialization check complete and minimumIdle is zero)");
}
return;
}
if (getLastConnectionFailure() instanceof ConnectionSetupException) {
throwPoolInitializationException(getLastConnectionFailure().getCause());
}
quietlySleep(SECONDS.toMillis(1));
} while (elapsedMillis(startTime) < initializationTimeout);
if (initializationTimeout > 0) {
throwPoolInitializationException(getLastConnectionFailure());
}
}
/**
* Log the Throwable that caused pool initialization to fail, and then throw a PoolInitializationException with
* that cause attached.
*
* @param t the Throwable that caused the pool to fail to initialize (possibly null)
*/
private void throwPoolInitializationException(Throwable t)
{
destroyHouseKeepingExecutorService();
throw new PoolInitializationException(t);
}
/**
* "Soft" evict a Connection (/PoolEntry) from the pool. If this method is being called by the user directly
* through {@link com.zaxxer.hikari.HikariDataSource#evictConnection(Connection)} then {@code owner} is {@code true}.
*
* If the caller is the owner, or if the Connection is idle (i.e. can be "reserved" in the {@link ConcurrentBag}),
* then we can close the connection immediately. Otherwise, we leave it "marked" for eviction so that it is evicted
* the next time someone tries to acquire it from the pool.
*
* @param poolEntry the PoolEntry (/Connection) to "soft" evict from the pool
* @param reason the reason that the connection is being evicted
* @param owner true if the caller is the owner of the connection, false otherwise
* @return true if the connection was evicted (closed), false if it was merely marked for eviction
*/
private boolean softEvictConnection(final PoolEntry poolEntry, final String reason, final boolean owner)
{
poolEntry.markEvicted();
if (owner || connectionBag.reserve(poolEntry)) {
closeConnection(poolEntry, reason);
return true;
}
return false;
}
/**
* Create/initialize the Housekeeping service {@link ScheduledExecutorService}. If the user specified an Executor
* to be used in the {@link HikariConfig}, then we use that. If no Executor was specified (typical), then create
* an Executor and configure it.
*
* @return either the user specified {@link ScheduledExecutorService}, or the one we created
*/
private ScheduledExecutorService initializeHouseKeepingExecutorService()
{
if (config.getScheduledExecutor() == null) {
final var threadFactory = Optional.ofNullable(config.getThreadFactory()).orElseGet(() -> new DefaultThreadFactory(poolName + " housekeeper"));
final var executor = new ScheduledThreadPoolExecutor(1, threadFactory, new ThreadPoolExecutor.DiscardPolicy());
executor.setExecuteExistingDelayedTasksAfterShutdownPolicy(false);
executor.setRemoveOnCancelPolicy(true);
return executor;
}
else {
return config.getScheduledExecutor();
}
}
/**
* Destroy (/shutdown) the Housekeeping service Executor, if it was the one that we created.
*/
private void destroyHouseKeepingExecutorService()
{
if (config.getScheduledExecutor() == null) {
houseKeepingExecutorService.shutdownNow();
}
}
/**
* Create a PoolStats instance that will be used by metrics tracking, with a pollable resolution of 1 second.
*
* @return a PoolStats instance
*/
private PoolStats getPoolStats()
{
return new PoolStats(SECONDS.toMillis(1)) {
@Override
protected void update() {
this.pendingThreads = HikariPool.this.getThreadsAwaitingConnection();
this.idleConnections = HikariPool.this.getIdleConnections();
this.totalConnections = HikariPool.this.getTotalConnections();
this.activeConnections = HikariPool.this.getActiveConnections();
this.maxConnections = config.getMaximumPoolSize();
this.minConnections = config.getMinimumIdle();
}
};
}
/**
* Create a timeout exception (specifically, {@link SQLTransientConnectionException}) to be thrown, because a
* timeout occurred when trying to acquire a Connection from the pool. If there was an underlying cause for the
* timeout, e.g. a SQLException thrown by the driver while trying to create a new Connection, then use the
* SQL State from that exception as our own and additionally set that exception as the "next" SQLException inside
* our exception.
*
* As a side effect, log the timeout failure at DEBUG, and record the timeout failure in the metrics tracker.
*
* @param startTime the start time (timestamp) of the acquisition attempt
* @return a SQLException to be thrown from {@link #getConnection()}
*/
private SQLException createTimeoutException(long startTime)
{
logPoolState("Timeout failure ");
metricsTracker.recordConnectionTimeout();
String sqlState = null;
int errorCode = 0;
final var originalException = getLastConnectionFailure();
if (originalException instanceof SQLException) {
sqlState = ((SQLException) originalException).getSQLState();
errorCode = ((SQLException) originalException).getErrorCode();
}
final var connectionException = new SQLTransientConnectionException(
poolName + " - Connection is not available, request timed out after " + elapsedMillis(startTime) + "ms " +
"(total=" + getTotalConnections() + ", active=" + getActiveConnections() + ", idle=" + getIdleConnections() + ", waiting=" + getThreadsAwaitingConnection() + ")",
sqlState, errorCode, originalException);
if (originalException instanceof SQLException) {
connectionException.setNextException((SQLException) originalException);
}
return connectionException;
}
// ***********************************************************************
// Non-anonymous Inner-classes
// ***********************************************************************
/**
* Creating and adding poolEntries (connections) to the pool.
*/
private final class PoolEntryCreator implements Callable
{
private final String loggingPrefix;
PoolEntryCreator()
{
this(null);
}
PoolEntryCreator(String loggingPrefix)
{
this.loggingPrefix = loggingPrefix;
}
@Override
public Boolean call()
{
var backoffMs = 10L;
var added = false;
try {
while (shouldContinueCreating()) {
final var poolEntry = createPoolEntry();
if (poolEntry != null) {
added = true;
connectionBag.add(poolEntry);
logger.debug("{} - Added connection {}", poolName, poolEntry.connection);
quietlySleep(30L);
break;
} else { // failed to get connection from db, sleep and retry
if (loggingPrefix != null && backoffMs % 50 == 0)
logger.debug("{} - Connection add failed, sleeping with backoff: {}ms", poolName, backoffMs);
quietlySleep(backoffMs);
backoffMs = Math.min(SECONDS.toMillis(5), backoffMs * 2);
}
}
}
finally {
if (added && loggingPrefix != null)
logPoolState(loggingPrefix);
else if (!added)
logPoolState("Connection not added, ");
}
// Pool is suspended, shutdown, or at max size
return Boolean.FALSE;
}
/**
* We only create connections if we need another idle connection or have threads still waiting
* for a new connection. Otherwise we bail out of the request to create.
*
* @return true if we should create a connection, false if the need has disappeared
*/
private synchronized boolean shouldContinueCreating() {
return poolState == POOL_NORMAL && getTotalConnections() < config.getMaximumPoolSize() &&
(getIdleConnections() < config.getMinimumIdle() || connectionBag.getWaitingThreadCount() > getIdleConnections());
}
}
/**
* The housekeeping task to retire and maintain minimum idle connections.
*/
private final class HouseKeeper implements Runnable
{
private volatile long previous = plusMillis(currentTime(), -housekeepingPeriodMs);
@SuppressWarnings("AtomicFieldUpdaterNotStaticFinal")
private final AtomicReferenceFieldUpdater catalogUpdater = AtomicReferenceFieldUpdater.newUpdater(PoolBase.class, String.class, "catalog");
@Override
public void run()
{
try {
// refresh values in case they changed via MBean
connectionTimeout = config.getConnectionTimeout();
validationTimeout = config.getValidationTimeout();
leakTaskFactory.updateLeakDetectionThreshold(config.getLeakDetectionThreshold());
if (config.getCatalog() != null && !config.getCatalog().equals(catalog)) {
catalogUpdater.set(HikariPool.this, config.getCatalog());
}
final var idleTimeout = config.getIdleTimeout();
final var now = currentTime();
// Detect retrograde time, allowing +128ms as per NTP spec.
if (plusMillis(now, 128) < plusMillis(previous, housekeepingPeriodMs)) {
logger.warn("{} - Retrograde clock change detected (housekeeper delta={}), soft-evicting connections from pool.",
poolName, elapsedDisplayString(previous, now));
previous = now;
softEvictConnections();
return;
}
else if (now > plusMillis(previous, (3 * housekeepingPeriodMs) / 2)) {
// No point evicting for forward clock motion, this merely accelerates connection retirement anyway
logger.warn("{} - Thread starvation or clock leap detected (housekeeper delta={}).", poolName, elapsedDisplayString(previous, now));
}
previous = now;
if (idleTimeout > 0L && config.getMinimumIdle() < config.getMaximumPoolSize()) {
logPoolState("Before cleanup ");
final var notInUse = connectionBag.values(STATE_NOT_IN_USE);
var maxToRemove = notInUse.size() - config.getMinimumIdle();
for (PoolEntry entry : notInUse) {
if (maxToRemove > 0 && elapsedMillis(entry.lastAccessed, now) > idleTimeout && connectionBag.reserve(entry)) {
closeConnection(entry, "(connection has passed idleTimeout)");
maxToRemove--;
}
}
logPoolState("After cleanup ");
}
else
logPoolState("Pool ");
fillPool(true); // Try to maintain minimum connections
}
catch (Exception e) {
logger.error("Unexpected exception in housekeeping task", e);
}
}
}
private final class MaxLifetimeTask implements Runnable
{
private final PoolEntry poolEntry;
MaxLifetimeTask(final PoolEntry poolEntry)
{
this.poolEntry = poolEntry;
}
public void run()
{
if (softEvictConnection(poolEntry, "(connection has passed maxLifetime)", false /* not owner */)) {
addBagItem(connectionBag.getWaitingThreadCount());
}
}
}
private final class KeepaliveTask implements Runnable
{
private final PoolEntry poolEntry;
KeepaliveTask(final PoolEntry poolEntry)
{
this.poolEntry = poolEntry;
}
public void run()
{
if (connectionBag.reserve(poolEntry)) {
if (isConnectionDead(poolEntry.connection)) {
softEvictConnection(poolEntry, DEAD_CONNECTION_MESSAGE, true);
addBagItem(connectionBag.getWaitingThreadCount());
}
else {
connectionBag.unreserve(poolEntry);
logger.debug("{} - keepalive: connection {} is alive", poolName, poolEntry.connection);
}
}
}
}
public static class PoolInitializationException extends RuntimeException
{
private static final long serialVersionUID = 929872118275916520L;
/**
* Construct an exception, possibly wrapping the provided Throwable as the cause.
* @param t the Throwable to wrap
*/
public PoolInitializationException(Throwable t)
{
super("Failed to initialize pool: " + t.getMessage(), t);
}
}
}