記錄一次springboot druid連接池配置信息錯誤，一直重試連接的問題

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轉載地址：https://blog.csdn.net/sadness_lxy/article/details/89136418

在昨天項目開發中，使用了Druid作為數據庫連接池，當數據源密碼錯誤時，報出了以下錯誤：

2019-04-09 10:09:36 [Druid-ConnectionPool-Create-2053591126] [ com.alibaba.druid.pool.DruidDataSource ] [ 53 ] [ ERROR ] create connection SQLException, url: jdbc:mysql://*.*.*.*:3306/*?characterEncoding=utf-8&useSSL=false, errorCode 1045, state 28000
java.sql.SQLException: Access denied for user 'malluser'@'*.*.*.*' (using password: YES)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:545) ~[mysql-connector-java-6.0.6.jar:6.0.6]
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:513) ~[mysql-connector-java-6.0.6.jar:6.0.6]
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:115) ~[mysql-connector-java-6.0.6.jar:6.0.6]
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:1606) ~[mysql-connector-java-6.0.6.jar:6.0.6]
at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:633) ~[mysql-connector-java-6.0.6.jar:6.0.6]
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:347) ~[mysql-connector-java-6.0.6.jar:6.0.6]
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:219) ~[mysql-connector-java-6.0.6.jar:6.0.6]
at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:149) ~[druid-1.1.6%20.jar:1.1.6]
at com.alibaba.druid.filter.stat.StatFilter.connection_connect(StatFilter.java:218) ~[druid-1.1.6%20.jar:1.1.6]
at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:143) ~[druid-1.1.6%20.jar:1.1.6]
at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1512) ~[druid-1.1.6%20.jar:1.1.6]
at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1575) ~[druid-1.1.6%20.jar:1.1.6]
at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:2450) [druid-1.1.6%20.jar:1.1.6]
對於錯誤相信大家一看都明白是怎么回事，但是問題是Druid會一直不停的對數據源進行重試連接，這樣的話我們的日志很快就爆了，為什么Druid會一直進行重試呢？首先讓我們看一下源碼：

public class CreateConnectionTask implements Runnable {

private int errorCount = 0;

@Override
public void run() {
runInternal();
}

private void runInternal() {
for (;;) {

// addLast
lock.lock();
try {
if (closed || closing) {
createTaskCount--;
return;
}

boolean emptyWait = true;

if (createError != null && poolingCount == 0) {
emptyWait = false;
}

if (emptyWait) {
// 必須存在線程等待，才創建連接
if (poolingCount >= notEmptyWaitThreadCount //
&& !(keepAlive && activeCount + poolingCount < minIdle)) {
createTaskCount--;
return;
}

// 防止創建超過maxActive數量的連接
if (activeCount + poolingCount >= maxActive) {
createTaskCount--;
return;
}
}
} finally {
lock.unlock();
}

PhysicalConnectionInfo physicalConnection = null;

try {
physicalConnection = createPhysicalConnection();
setFailContinuous(false);
} catch (OutOfMemoryError e) {
LOG.error("create connection OutOfMemoryError, out memory. ", e);

errorCount++;
if (errorCount > connectionErrorRetryAttempts && timeBetweenConnectErrorMillis > 0) {
// fail over retry attempts
setFailContinuous(true);
if (failFast) {
lock.lock();
try {
notEmpty.signalAll();
} finally {
lock.unlock();
}
}

if (breakAfterAcquireFailure) {
lock.lock();
try {
createTaskCount--;
} finally {
lock.unlock();
}
return;
}

this.errorCount = 0; // reset errorCount
if (closing || closed) {
createTaskCount--;
return;
}
createSchedulerFuture = createScheduler.schedule(this, timeBetweenConnectErrorMillis, TimeUnit.MILLISECONDS);
return;
}
} catch (SQLException e) {
LOG.error("create connection SQLException, url: " + jdbcUrl, e);

errorCount++;
if (errorCount > connectionErrorRetryAttempts && timeBetweenConnectErrorMillis > 0) {
// fail over retry attempts
setFailContinuous(true);
if (failFast) {
lock.lock();
try {
notEmpty.signalAll();
} finally {
lock.unlock();
}
}

if (breakAfterAcquireFailure) {
lock.lock();
try {
createTaskCount--;
} finally {
lock.unlock();
}
return;
}

this.errorCount = 0; // reset errorCount
if (closing || closed) {
createTaskCount--;
return;
}
createSchedulerFuture = createScheduler.schedule(this, timeBetweenConnectErrorMillis, TimeUnit.MILLISECONDS);
return;
}
} catch (RuntimeException e) {
LOG.error("create connection RuntimeException", e);
// unknow fatal exception
setFailContinuous(true);
continue;
} catch (Error e) {
lock.lock();
try {
createTaskCount--;
} finally {
lock.unlock();
}
LOG.error("create connection Error", e);
// unknow fatal exception
setFailContinuous(true);
break;
} catch (Throwable e) {
LOG.error("create connection unexecpted error.", e);
break;
}

if (physicalConnection == null) {
continue;
}

boolean result = put(physicalConnection);
if (!result) {
JdbcUtils.close(physicalConnection.getPhysicalConnection());
LOG.info("put physical connection to pool failed.");
}
break;
}
}
}

public class CreateConnectionThread extends Thread {

public CreateConnectionThread(String name){
super(name);
this.setDaemon(true);
}

public void run() {
initedLatch.countDown();

long lastDiscardCount = 0;
int errorCount = 0;
for (;;) {
// addLast
try {
lock.lockInterruptibly();
} catch (InterruptedException e2) {
break;
}

long discardCount = DruidDataSource.this.discardCount;
boolean discardChanged = discardCount - lastDiscardCount > 0;
lastDiscardCount = discardCount;

try {
boolean emptyWait = true;

if (createError != null
&& poolingCount == 0
&& !discardChanged) {
emptyWait = false;
}

if (emptyWait
&& asyncInit && createCount.get() < initialSize) {
emptyWait = false;
}

if (emptyWait) {
// 必須存在線程等待，才創建連接
if (poolingCount >= notEmptyWaitThreadCount //
&& !(keepAlive && activeCount + poolingCount < minIdle)) {
empty.await();
}

// 防止創建超過maxActive數量的連接
if (activeCount + poolingCount >= maxActive) {
empty.await();
continue;
}
}

} catch (InterruptedException e) {
lastCreateError = e;
lastErrorTimeMillis = System.currentTimeMillis();

if (!closing) {
LOG.error("create connection Thread Interrupted, url: " + jdbcUrl, e);
}
break;
} finally {
lock.unlock();
}

PhysicalConnectionInfo connection = null;

try {
connection = createPhysicalConnection();
setFailContinuous(false);
} catch (SQLException e) {
LOG.error("create connection SQLException, url: " + jdbcUrl + ", errorCode " + e.getErrorCode()
+ ", state " + e.getSQLState(), e);

errorCount++;
if (errorCount > connectionErrorRetryAttempts && timeBetweenConnectErrorMillis > 0) {
// fail over retry attempts
setFailContinuous(true);
if (failFast) {
lock.lock();
try {
notEmpty.signalAll();
} finally {
lock.unlock();
}
}

if (breakAfterAcquireFailure) {
break;
}

try {
Thread.sleep(timeBetweenConnectErrorMillis);
} catch (InterruptedException interruptEx) {
break;
}
}
} catch (RuntimeException e) {
LOG.error("create connection RuntimeException", e);
setFailContinuous(true);
continue;
} catch (Error e) {
LOG.error("create connection Error", e);
setFailContinuous(true);
break;
}

if (connection == null) {
continue;
}

boolean result = put(connection);
if (!result) {
JdbcUtils.close(connection.getPhysicalConnection());
LOG.info("put physical connection to pool failed.");
}

errorCount = 0; // reset errorCount
}
}
}

 

從源碼中我們可以看到，線程中使用了無參for循環再一直嘗試進行數據源連接，代碼中【errorCount > connectionErrorRetryAttempts && timeBetweenConnectErrorMillis > 0】當滿足該判斷條件時就會進行重試連接，接下來我們看一下源碼中這兩個屬性值設置的是什么呢？（源碼過長，只展示我們需要的代碼，其他屬性信息可自行扒源碼~）

private static final long serialVersionUID = 1L;
public final static int DEFAULT_INITIAL_SIZE = 0;
public final static int DEFAULT_MAX_ACTIVE_SIZE = 8;
public final static int DEFAULT_MAX_IDLE = 8;
public final static int DEFAULT_MIN_IDLE = 0;
public final static int DEFAULT_MAX_WAIT = -1;
public final static String DEFAULT_VALIDATION_QUERY = null; //
public final static boolean DEFAULT_TEST_ON_BORROW = false;
public final static boolean DEFAULT_TEST_ON_RETURN = false;
public final static boolean DEFAULT_WHILE_IDLE = true;
public static final long DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS = 60 * 1000L;
public static final long DEFAULT_TIME_BETWEEN_CONNECT_ERROR_MILLIS = 500;
public static final int DEFAULT_NUM_TESTS_PER_EVICTION_RUN = 3;
/*****************************華麗的分割線中間省略代碼若干行*********************************/
protected volatile long timeBetweenEvictionRunsMillis = DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS;
protected int connectionErrorRetryAttempts = 1;
protected boolean breakAfterAcquireFailure = false;

 

從中這段代碼中我們可以看到connectionErrorRetryAttempts值為1，timeBetweenConnectErrorMillis值為60000，而breakAfterAcquireFailure值為false，因此當我們數據源連接失敗后，就會不斷的進行重試連接，因此我對於對於該如何解決這樣的問題我們就有了答案:

    1.若不想讓重試，我們可以設置breakAfterAcquireFailure(true);connectionErrorRetryAttempts(0);

    2.若想要設置多久重試，我們只需要設置timeBetweenConnectErrorMillis(time）；

action：經過親測，直接在配置文件中配置屬性並不能讀取到（Druid設計時就這樣，大神的思維暫時還不能參悟~），我們可直接將值寫入程序當中，如下：

private static void Init() {
try {
Properties properties = loadPropertiesFile("db.properties");
druidDataSource = (DruidDataSource) DruidDataSourceFactory.createDataSource(properties); // DruidDataSrouce工廠模式
// TODO 調試配置，用完刪除
druidDataSource.setRemoveAbandoned(true);
druidDataSource.setRemoveAbandonedTimeout(600);
druidDataSource.setLogAbandoned(true);
//    druidDataSource.setBreakAfterAcquireFailure(true);
druidDataSource.setTimeBetweenConnectErrorMillis(60000);
//    druidDataSource.setConnectionErrorRetryAttempts(0);

} catch (Exception e) {
logger.error(DbPoolConnection.class, e);
}
}

當然若是想要方便以后修改，我們可以在properties文件中設置該值，讀取出來配置文件的值再賦值給druidDataSource。

到這里，本文就結束了，如有不當之處，歡迎指正！