クラス org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR

org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRRに対する継承グラフ

[凡例]org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRRのコラボレーション図

[凡例]すべてのメンバ一覧

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説明

RAIDb-1 Weighted Round Robin load balancer

The read requests coming from the request manager are sent to the backend nodes using a weighted round robin. Write requests are broadcasted to all backends.

作者:

Emmanuel Cecchet

Julie Marguerite

Nicolas Modrzyk

バージョン:

1.0

RAIDb1_WRR.java の 55 行で定義されています。

Public メソッド
	RAIDb1_WRR (VirtualDatabase vdb, WaitForCompletionPolicy waitForCompletionPolicy, long timestampResolution) throws SQLException
java.sql.ResultSet	execReadRequest (SelectRequest request) throws SQLException
ResultSet	execReadOnlyReadStoredProcedure (StoredProcedure proc) throws SQLException
void	setWeight (String name, int w) throws SQLException
String	getInformation ()
String	getRaidb1Xml ()
int	execWriteRequest (AbstractWriteRequest request) throws AllBackendsFailedException, SQLException
ResultSet	execWriteRequestWithKeys (AbstractWriteRequest request) throws AllBackendsFailedException, SQLException
ResultSet	execReadStoredProcedure (StoredProcedure proc) throws SQLException
int	execWriteStoredProcedure (StoredProcedure proc) throws SQLException
final void	begin (TransactionMarkerMetaData tm) throws SQLException
void	commit (TransactionMarkerMetaData tm) throws SQLException
void	rollback (TransactionMarkerMetaData tm) throws SQLException
void	enableBackend (DatabaseBackend db, boolean writeEnabled) throws SQLException
synchronized void	disableBackend (DatabaseBackend db) throws SQLException
String	getXmlImpl ()
int	getRAIDbLevel ()
void	setRAIDbLevel (int raidbLevel)
int	getParsingGranularity ()
void	setParsingGranularity (int parsingGranularity)
String	getXml ()
Protected メソッド
java.sql.ResultSet	executeRequestOnBackend (SelectRequest request, DatabaseBackend backend) throws SQLException, UnreachableBackendException
java.sql.ResultSet	executeStoredProcedureOnBackend (StoredProcedure proc, DatabaseBackend backend) throws SQLException, UnreachableBackendException
void	waitForAllWritesToComplete (long transactionId) throws SQLException
void	waitForAllWritesToComplete (DatabaseBackend backend, long transactionId) throws SQLException
void	waitForAllWritesToComplete (DatabaseBackend backend) throws SQLException
ResultSet	executeStatementOnBackend (SelectRequest request, DatabaseBackend backend, Connection c) throws SQLException, BadConnectionException
Protected 変数
ArrayList	backendBlockingThreads
ArrayList	backendNonBlockingThreads
ReadPrioritaryFIFOWriteLock	backendBlockingThreadsRWLock = new ReadPrioritaryFIFOWriteLock()
ReadPrioritaryFIFOWriteLock	backendNonBlockingThreadsRWLock = new ReadPrioritaryFIFOWriteLock()
WaitForCompletionPolicy	waitForCompletionPolicy
VirtualDatabase	vdb
int	raidbLevel
int	parsingGranularity
Static Protected 変数
Trace	logger
Private メソッド
ResultSet	executeWRR (AbstractRequest request, boolean isSelect, String errorMsgPrefix) throws SQLException
Private 変数
HashMap	weights = new HashMap()
int	index

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コンストラクタとデストラクタ

org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.RAIDb1_WRR (  VirtualDatabase  vdb, WaitForCompletionPolicy  waitForCompletionPolicy, long  timestampResolution )  throws SQLException

Creates a new RAIDb-1 Weighted Round Robin request load balancer. 引数: vdb  the virtual database this load balancer belongs to. waitForCompletionPolicy  How many backends must complete before returning the result? timestampResolution  timestamp resolution for NOW macros 例外: SQLException  if an error occurs RAIDb1_WRR.java の 80 行で定義されています。 { super(vdb, waitForCompletionPolicy, timestampResolution); index = -1; }

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メソッド

final void org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.begin (  TransactionMarkerMetaData  tm  )  throws SQLException [virtual, inherited]

Begins a new transaction. 引数: tm  the transaction marker metadata 例外: SQLException  if an error occurs org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancerに実装されています. RAIDb1.java の 910 行で定義されています。 { }

void org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.commit (  TransactionMarkerMetaData  tm  )  throws SQLException [virtual, inherited]

Commits a transaction. 引数: tm  the transaction marker metadata 例外: SQLException  if an error occurs org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancerに実装されています. RAIDb1.java の 920 行で定義されています。 参照先 org.objectweb.cjdbc.controller.loadbalancer.BackendWorkerThread.addTask(), org.objectweb.cjdbc.controller.loadbalancer.BackendWorkerThread.getBackend(), org.objectweb.cjdbc.controller.loadbalancer.tasks.AbstractTask.getFailed(), org.objectweb.cjdbc.controller.loadbalancer.tasks.AbstractTask.getSuccess(), と org.objectweb.cjdbc.controller.backend.DatabaseBackend.isStartedTransaction(). { if (waitForCompletionPolicy.getPolicy() != WaitForCompletionPolicy.ALL) waitForAllWritesToComplete(tm.getTransactionId()); try { backendNonBlockingThreadsRWLock.acquireRead(); } catch (InterruptedException e) { String msg = Translate.get( "loadbalancer.backendlist.acquire.readlock.failed", e); logger.error(msg); throw new SQLException(msg); } int nbOfThreads = backendNonBlockingThreads.size(); ArrayList commitList = new ArrayList(); Long lTid = new Long(tm.getTransactionId()); // Build the list of backend that need to commit this transaction for (int i = 0; i < nbOfThreads; i++) { BackendWorkerThread thread = (BackendWorkerThread) backendNonBlockingThreads .get(i); if (thread.getBackend().isStartedTransaction(lTid)) commitList.add(thread); } nbOfThreads = commitList.size(); if (nbOfThreads == 0) { backendNonBlockingThreadsRWLock.releaseRead(); return; } // Create the task CommitTask task = new CommitTask(getNbToWait(nbOfThreads), nbOfThreads, tm .getTimeout(), tm.getLogin(), tm.getTransactionId()); synchronized (task) { // Post the task in each backendThread tasklist and wakeup the threads for (int i = 0; i < nbOfThreads; i++) { BackendWorkerThread thread = (BackendWorkerThread) commitList.get(i); synchronized (thread) { thread.addTask(task); thread.notify(); } } backendNonBlockingThreadsRWLock.releaseRead(); // Wait for completion (notified by the task) try { // Wait on task long timeout = tm.getTimeout(); if (timeout > 0) { long start = System.currentTimeMillis(); task.wait(timeout); long end = System.currentTimeMillis(); long remaining = timeout - (end - start); if (remaining <= 0) { String msg = Translate.get("loadbalancer.commit.timeout", new String[]{String.valueOf(tm.getTransactionId()), String.valueOf(task.getSuccess()), String.valueOf(task.getFailed())}); logger.warn(msg); throw new SQLException(msg); } } else task.wait(); } catch (InterruptedException e) { throw new SQLException(Translate.get("loadbalancer.commit.timeout", new String[]{String.valueOf(tm.getTransactionId()), String.valueOf(task.getSuccess()), String.valueOf(task.getFailed())})); } if (task.getSuccess() > 0) return; else { // All tasks failed ArrayList exceptions = task.getExceptions(); if (exceptions == null) throw new SQLException(Translate.get( "loadbalancer.commit.all.failed", tm.getTransactionId())); else { String errorMsg = Translate.get("loadbalancer.commit.failed.stack", tm.getTransactionId()) + "\n"; for (int i = 0; i < exceptions.size(); i++) errorMsg += ((SQLException) exceptions.get(i)).getMessage() + "\n"; logger.error(errorMsg); throw new SQLException(errorMsg); } } } }

synchronized void org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.disableBackend (  DatabaseBackend  db  )  throws SQLException [virtual, inherited]

Disables a backend that was previously enabled. Ask the corresponding connection manager to finalize the connections if needed. No sanity checks are performed by this function. 引数: db  the database backend to disable 例外: SQLException  if an error occurs org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancerに実装されています. org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1ecで再定義されています。 RAIDb1.java の 1326 行で定義されています。 参照先 org.objectweb.cjdbc.controller.loadbalancer.BackendWorkerThread.addPriorityTask(), org.objectweb.cjdbc.controller.backend.DatabaseBackend.equals(), と org.objectweb.cjdbc.controller.loadbalancer.BackendWorkerThread.getBackend(). { if (db.isWriteEnabled()) { // Starts with backendBlockingThreads try { backendBlockingThreadsRWLock.acquireWrite(); } catch (InterruptedException e) { String msg = Translate.get( "loadbalancer.backendlist.acquire.writelock.failed", e); logger.error(msg); throw new SQLException(msg); } int nbOfThreads = backendBlockingThreads.size(); // Find the right blocking thread for (int i = 0; i < nbOfThreads; i++) { BackendWorkerThread thread = (BackendWorkerThread) backendBlockingThreads .get(i); if (thread.getBackend().equals(db)) { logger.info(Translate .get("loadbalancer.backend.workerthread.blocking.remove", db .getName())); // Remove it from the backendBlockingThread list backendBlockingThreads.remove(thread); synchronized (thread) { // Kill the thread thread.addPriorityTask(new KillThreadTask(1, 1)); thread.notify(); } break; } } backendBlockingThreadsRWLock.releaseWrite(); // Continue with backendNonBlockingThreads try { backendNonBlockingThreadsRWLock.acquireWrite(); } catch (InterruptedException e) { String msg = Translate.get( "loadbalancer.backendlist.acquire.writelock.failed", e); logger.error(msg); throw new SQLException(msg); } // Find the right non-blocking thread nbOfThreads = backendNonBlockingThreads.size(); for (int i = 0; i < nbOfThreads; i++) { BackendWorkerThread thread = (BackendWorkerThread) backendNonBlockingThreads .get(i); if (thread.getBackend().equals(db)) { logger.info(Translate.get( "loadbalancer.backend.workerthread.non.blocking.remove", db .getName())); // Remove it from the backendNonBlockingThreads list backendNonBlockingThreads.remove(thread); synchronized (thread) { // Kill the thread thread.addPriorityTask(new KillThreadTask(1, 1)); thread.notify(); } break; } } backendNonBlockingThreadsRWLock.releaseWrite(); } db.disable(); if (db.isInitialized()) db.finalizeConnections(); }

void org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.enableBackend (  DatabaseBackend  db, boolean  writeEnabled )  throws SQLException [virtual, inherited]

Enables a Backend that was previously disabled. Ask the corresponding connection manager to initialize the connections if needed. No sanity checks are performed by this function. 引数: db  the database backend to enable writeEnabled  True if the backend must be enabled for writes 例外: SQLException  if an error occurs org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancerに実装されています. org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1ecで再定義されています。 RAIDb1.java の 1261 行で定義されています。 参照先 org.objectweb.cjdbc.controller.backend.DatabaseBackend.enableWrite(), と org.objectweb.cjdbc.controller.backend.DatabaseBackend.getName(). { if (writeEnabled) { // Create 2 worker threads BackendWorkerThread blockingThread = new BackendWorkerThread( (DatabaseBackend) db, this); BackendWorkerThread nonBlockingThread = new BackendWorkerThread( (DatabaseBackend) db, this); // Add first to the blocking thread list try { backendBlockingThreadsRWLock.acquireWrite(); } catch (InterruptedException e) { String msg = Translate.get( "loadbalancer.backendlist.acquire.writelock.failed", e); logger.error(msg); throw new SQLException(msg); } backendBlockingThreads.add(blockingThread); backendBlockingThreadsRWLock.releaseWrite(); blockingThread.start(); logger.info(Translate.get( "loadbalancer.backend.workerthread.blocking.add", db.getName())); // Then add to the non-blocking thread list try { backendNonBlockingThreadsRWLock.acquireWrite(); } catch (InterruptedException e) { String msg = Translate.get( "loadbalancer.backendlist.acquire.writelock.failed", e); logger.error(msg); throw new SQLException(msg); } backendNonBlockingThreads.add(nonBlockingThread); backendNonBlockingThreadsRWLock.releaseWrite(); nonBlockingThread.start(); logger.info(Translate.get( "loadbalancer.backend.workerthread.non.blocking.add", db.getName())); db.enableWrite(); } if (!db.isInitialized()) db.initializeConnections(); db.enableRead(); }

ResultSet org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.execReadOnlyReadStoredProcedure (  StoredProcedure  proc  )  throws SQLException [virtual]

Selects the backend using a least pending request first policy. The backend that has the shortest queue of currently executing queries is chosen to execute this stored procedure. 参照: org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.execReadOnlyReadStoredProcedure(org.objectweb.cjdbc.common.sql.StoredProcedure) org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancerに実装されています. RAIDb1_WRR.java の 112 行で定義されています。 参照先 org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.executeWRR(). { return executeWRR(proc, false, "Stored procedure "); }

java.sql.ResultSet org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.execReadRequest (  SelectRequest  request  )  throws SQLException [virtual]

Selects the backend using a weighted round-robin algorithm and executes the read request. 参照: org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.execReadRequest(SelectRequest request) org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1に実装されています. RAIDb1_WRR.java の 99 行で定義されています。 参照先 org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.executeWRR(). { return executeWRR(request, true, "Request "); }

ResultSet org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.execReadStoredProcedure (  StoredProcedure  proc  )  throws SQLException [virtual, inherited]

参照: org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.execReadStoredProcedure(org.objectweb.cjdbc.common.sql.StoredProcedure) org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancerに実装されています. RAIDb1.java の 734 行で定義されています。 参照先 org.objectweb.cjdbc.controller.loadbalancer.tasks.ReadStoredProcedureTask.getResult(). { ReadStoredProcedureTask task = (ReadStoredProcedureTask) callStoredProcedure( proc, true); return task.getResult(); }

java.sql.ResultSet org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.executeRequestOnBackend (  SelectRequest  request, DatabaseBackend  backend )  throws SQLException, UnreachableBackendException [protected, inherited]

Execute a read request on the selected backend. 引数: request  the request to execute backend  the backend that will execute the request 戻り値: the ResultSet 例外: SQLException  if an error occurs RAIDb1.java の 162 行で定義されています。 参照先 org.objectweb.cjdbc.common.log.Trace.error(). { // Handle macros request.setSQL(RequestManager.handleSQLMacros(request.getSQL(), timestampResolution, false)); // Ok, we have a backend, let's execute the request AbstractConnectionManager cm = backend.getConnectionManager(request .getLogin()); // Sanity check if (cm == null) { String msg = Translate.get("loadbalancer.connectionmanager.not.found", new String[]{request.getLogin(), backend.getName()}); logger.error(msg); throw new SQLException(msg); } // Execute the query if (request.isAutoCommit()) { if (waitForCompletionPolicy.getPolicy() != WaitForCompletionPolicy.ALL) // We could do something finer grain here by waiting // only for writes that depend on the tables we need // but is that really worth the overhead ? waitForAllWritesToComplete(backend); ResultSet rs = null; boolean badConnection; do { badConnection = false; // Use a connection just for this request Connection c = null; try { c = cm.getConnection(); } catch (UnreachableBackendException e1) { logger.error(Translate.get( "loadbalancer.backend.disabling.unreachable", backend.getName())); backend.disable(); throw new UnreachableBackendException(Translate.get( "loadbalancer.backend.unreacheable", backend.getName())); } // Sanity check if (c == null) throw new SQLException(Translate.get( "loadbalancer.backend.no.connection", backend.getName())); // Execute Query try { rs = executeStatementOnBackend(request, backend, c); cm.releaseConnection(c); } catch (SQLException e) { cm.releaseConnection(c); throw new SQLException(Translate.get( "loadbalancer.request.failed.on.backend", new String[]{ request.getSQLShortForm(vdb.getSQLShortFormLength()), backend.getName(), e.getMessage()})); } catch (BadConnectionException e) { // Get rid of the bad connection cm.deleteConnection(c); badConnection = true; } } while (badConnection); if (logger.isDebugEnabled()) logger.debug(Translate.get("loadbalancer.execute.on", new String[]{ String.valueOf(request.getId()), backend.getName()})); return rs; } else { // Inside a transaction Connection c; long tid = request.getTransactionId(); Long lTid = new Long(tid); // Wait for previous writes to complete if (waitForCompletionPolicy.getPolicy() != WaitForCompletionPolicy.ALL) waitForAllWritesToComplete(backend, request.getTransactionId()); if (!backend.isStartedTransaction(lTid)) { // transaction has not been started yet on this backend try { c = cm.getConnection(tid); } catch (UnreachableBackendException e1) { logger.error(Translate.get( "loadbalancer.backend.disabling.unreachable", backend.getName())); backend.disable(); throw new SQLException(Translate.get( "loadbalancer.backend.unreacheable", backend.getName())); } // Sanity check if (c == null) throw new SQLException(Translate.get( "loadbalancer.unable.get.connection", new String[]{ String.valueOf(tid), backend.getName()})); // begin transaction backend.startTransaction(lTid); c.setAutoCommit(false); } else { // Re-use the connection used by this transaction c = cm.retrieveConnection(tid); // Sanity check if (c == null) throw new SQLException(Translate.get( "loadbalancer.unable.retrieve.connection", new String[]{ String.valueOf(tid), backend.getName()})); } // Execute Query ResultSet rs = null; try { rs = executeStatementOnBackend(request, backend, c); } catch (SQLException e) { throw new SQLException(Translate.get( "loadbalancer.request.failed.on.backend", new String[]{ request.getSQLShortForm(vdb.getSQLShortFormLength()), backend.getName(), e.getMessage()})); } catch (BadConnectionException e) { // Connection failed, so did the transaction // Disable the backend. cm.deleteConnection(tid); String msg = Translate.get( "loadbalancer.backend.disabling.connection.failure", backend .getName()); logger.error(msg); backend.disable(); throw new SQLException(msg); } if (logger.isDebugEnabled()) logger.debug(Translate.get("loadbalancer.execute.transaction.on", new String[]{String.valueOf(tid), String.valueOf(request.getId()), backend.getName()})); return rs; } }

ResultSet org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.executeStatementOnBackend (  SelectRequest  request, DatabaseBackend  backend, Connection  c )  throws SQLException, BadConnectionException [protected, inherited]

Execute a statement on a backend. If the execution fails, the connection is checked for validity. If the connection was not valid, the query is automatically retried on a new connection. 引数: request  the request to execute backend  the backend on which the request is executed c  connection used to create the statement 戻り値: the ResultSet 例外: SQLException  if an error occurs AbstractLoadBalancer.java の 251 行で定義されています。 参照先 java.sql.Statement.executeQuery(), java.sql.Statement.setCursorName(), java.sql.Statement.setFetchSize(), java.sql.Statement.setMaxRows(), java.sql.Statement.setQueryTimeout(), org.objectweb.cjdbc.controller.backend.DriverCompliance.supportSetCursorName, org.objectweb.cjdbc.controller.backend.DriverCompliance.supportSetFetchSize, org.objectweb.cjdbc.controller.backend.DriverCompliance.supportSetMaxRows, と org.objectweb.cjdbc.controller.backend.DriverCompliance.supportSetQueryTimeout. 参照元 org.objectweb.cjdbc.controller.loadbalancer.singledb.SingleDB.execReadRequest(). { ResultSet rs = null; try { backend.addPendingReadRequest(request); String sql = request.getSQL(); // Rewrite the query if needed sql = backend.rewriteQuery(sql); // Execute the query Statement s = c.createStatement(); DriverCompliance driverCompliance = backend.getDriverCompliance(); if (driverCompliance.supportSetQueryTimeout()) s.setQueryTimeout(request.getTimeout()); if ((request.getCursorName() != null) && (driverCompliance.supportSetCursorName())) s.setCursorName(request.getCursorName()); if ((request.getFetchSize() != 0) && driverCompliance.supportSetFetchSize()) s.setFetchSize(request.getFetchSize()); if ((request.getMaxRows() > 0) && driverCompliance.supportSetMaxRows()) s.setMaxRows(request.getMaxRows()); rs = s.executeQuery(sql); } catch (SQLException e) { // Something bad happened if (backend.isValidConnection(c)) throw e; // Connection is valid, throw the exception else throw new BadConnectionException(); } finally { backend.removePendingRequest(request); } return rs; }

java.sql.ResultSet org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.executeStoredProcedureOnBackend (  StoredProcedure  proc, DatabaseBackend  backend )  throws SQLException, UnreachableBackendException [protected, inherited]

Execute a stored procedure on the selected backend. 引数: proc  the stored procedure to execute backend  the backend that will execute the request 戻り値: the ResultSet 例外: SQLException  if an error occurs RAIDb1.java の 576 行で定義されています。 { // Handle macros proc.setSQL(RequestManager.handleSQLMacros(proc.getSQL(), timestampResolution, false)); // Ok, we have a backend, let's execute the request AbstractConnectionManager cm = backend .getConnectionManager(proc.getLogin()); // Sanity check if (cm == null) { String msg = Translate.get("loadbalancer.connectionmanager.not.found", new String[]{proc.getLogin(), backend.getName()}); logger.error(msg); throw new SQLException(msg); } // Execute the query if (proc.isAutoCommit()) { if (waitForCompletionPolicy.getPolicy() != WaitForCompletionPolicy.ALL) // We could do something finer grain here by waiting // only for writes that depend on the tables we need // but is that really worth the overhead ? waitForAllWritesToComplete(backend); // Use a connection just for this request Connection c = null; try { c = cm.getConnection(); } catch (UnreachableBackendException e1) { logger.error(Translate.get( "loadbalancer.backend.disabling.unreachable", backend.getName())); backend.disable(); throw new UnreachableBackendException(Translate.get( "loadbalancer.backend.unreacheable", backend.getName())); } // Sanity check if (c == null) throw new UnreachableBackendException(Translate.get( "loadbalancer.backend.no.connection", backend.getName())); // Execute Query ResultSet rs = null; try { // We suppose here that the request does not modify the schema since // it is a read-only query. CallableStatement cs = c.prepareCall(proc.getSQL()); if (backend.getDriverCompliance().supportSetQueryTimeout()) cs.setQueryTimeout(proc.getTimeout()); if ((proc.getMaxRows() > 0) && backend.getDriverCompliance().supportSetMaxRows()) cs.setMaxRows(proc.getMaxRows()); rs = cs.executeQuery(); } catch (SQLException e) { throw new SQLException(Translate.get( "loadbalancer.storedprocedure.failed.on.backend", new String[]{ proc.getSQLShortForm(vdb.getSQLShortFormLength()), backend.getName(), e.getMessage()})); } finally { cm.releaseConnection(c); } if (logger.isDebugEnabled()) logger.debug(Translate.get("loadbalancer.storedprocedure.on", new String[]{String.valueOf(proc.getId()), backend.getName()})); return rs; } else { // Inside a transaction Connection c; long tid = proc.getTransactionId(); Long lTid = new Long(tid); // Wait for previous writes to complete if (waitForCompletionPolicy.getPolicy() != WaitForCompletionPolicy.ALL) waitForAllWritesToComplete(backend, proc.getTransactionId()); if (!backend.isStartedTransaction(lTid)) { // transaction has not been started yet on this backend try { c = cm.getConnection(tid); } catch (UnreachableBackendException e1) { logger.error(Translate.get( "loadbalancer.backend.disabling.unreachable", backend.getName())); backend.disable(); throw new SQLException(Translate.get( "loadbalancer.backend.unreacheable", backend.getName())); } // Sanity check if (c == null) throw new SQLException(Translate.get( "loadbalancer.unable.get.connection", new String[]{ String.valueOf(tid), backend.getName()})); // begin transaction backend.startTransaction(lTid); c.setAutoCommit(false); } else { // Re-use the connection used by this transaction c = cm.retrieveConnection(tid); // Sanity check if (c == null) throw new SQLException(Translate.get( "loadbalancer.unable.retrieve.connection", new String[]{ String.valueOf(tid), backend.getName()})); } // Execute Query ResultSet rs; try { // We suppose here that the request does not modify the schema since // it is a read-only query. CallableStatement cs = c.prepareCall(proc.getSQL()); if (backend.getDriverCompliance().supportSetQueryTimeout()) cs.setQueryTimeout(proc.getTimeout()); if ((proc.getMaxRows() > 0) && backend.getDriverCompliance().supportSetMaxRows()) cs.setMaxRows(proc.getMaxRows()); rs = cs.executeQuery(); } catch (SQLException e) { throw new SQLException(Translate.get( "loadbalancer.storedprocedure.failed.on.backend", new String[]{ proc.getSQLShortForm(vdb.getSQLShortFormLength()), backend.getName(), e.getMessage()})); } if (logger.isDebugEnabled()) logger.debug(Translate.get("loadbalancer.execute.transaction.on", new String[]{String.valueOf(tid), String.valueOf(proc.getId()), backend.getName()})); return rs; } }

ResultSet org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.executeWRR (  AbstractRequest  request, boolean  isSelect, String  errorMsgPrefix )  throws SQLException [private]

Common code to execute a SelectRequest or a StoredProcedure on a backend chosen using a weighted round-robin algorithm. 引数: request  a SelectRequest or StoredProcedure isSelect  true if it is a SelectRequest, false if it is a StoredProcedure errorMsgPrefix  the error message prefix, usually "Request " or "Stored procedure " ... failed because ... 戻り値: a ResultSet 例外: SQLException  if an error occurs RAIDb1_WRR.java の 131 行で定義されています。 参照先 org.objectweb.cjdbc.controller.virtualdatabase.VirtualDatabase.acquireReadLockBackendLists(), org.objectweb.cjdbc.common.log.Trace.error(), org.objectweb.cjdbc.controller.virtualdatabase.VirtualDatabase.getBackends(), org.objectweb.cjdbc.controller.virtualdatabase.VirtualDatabase.getSQLShortFormLength(), org.objectweb.cjdbc.controller.backend.DatabaseBackend.isReadEnabled, と org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.weights. 参照元 org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.execReadOnlyReadStoredProcedure(), と org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.execReadRequest(). { // Choose a backend try { vdb.acquireReadLockBackendLists(); } catch (InterruptedException e) { String msg = Translate.get( "loadbalancer.backendlist.acquire.readlock.failed", e); logger.error(msg); throw new SQLException(msg); } DatabaseBackend backend = null; // Note that vdb lock is released in the finally clause of this try/catch // block try { ArrayList backends = vdb.getBackends(); int size = backends.size(); if (size == 0) throw new SQLException(Translate.get( "loadbalancer.execute.no.backend.available", request.getId())); // Choose the backend (WRR algorithm starts here) int w = 0; // cumulative weight for (int i = 0; i < size; i++) { DatabaseBackend b = (DatabaseBackend) backends.get(index); if (b.isReadEnabled()) { if (backend == null) backend = b; // Fallback if no backend found // Add the weight of this backend Integer weight = (Integer) weights.get(b.getName()); if (weight == null) logger.error("No weight defined for backend " + b.getName()); else w += weight.intValue(); // Ok we reached the needed weight, take this backend if (index <= w) { backend = b; index++; // Next time take the next break; } } } if (backend == null) throw new SQLException(Translate.get( "loadbalancer.execute.no.backend.enabled", request.getId())); // We are over the total weight and we are using the // first available node. Let's reset the index to 1 // since we used this first node (0++). if (index > w) index = 1; } catch (RuntimeException e) { String msg = Translate.get("loadbalancer.execute.find.backend.failed", new String[]{request.getSQLShortForm(vdb.getSQLShortFormLength()), e.getMessage()}); logger.error(msg, e); throw new SQLException(msg); } finally { vdb.releaseReadLockBackendLists(); } ResultSet rs = null; // Execute the request on the chosen backend try { if (isSelect) rs = executeRequestOnBackend((SelectRequest) request, backend); else rs = executeStoredProcedureOnBackend((StoredProcedure) request, backend); } catch (UnreachableBackendException urbe) { // Try to execute query on different backend return executeWRR(request, isSelect, errorMsgPrefix); } catch (SQLException se) { String msg = Translate.get("loadbalancer.something.failed", new String[]{ errorMsgPrefix, String.valueOf(request.getId()), se.getMessage()}); if (logger.isInfoEnabled()) logger.info(msg); throw new SQLException(msg); } catch (RuntimeException e) { String msg = Translate.get("loadbalancer.something.failed.on", new String[]{errorMsgPrefix, request.getSQLShortForm(vdb.getSQLShortFormLength()), backend.getName(), e.getMessage()}); logger.error(msg, e); throw new SQLException(msg); } return rs; }

int org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.execWriteRequest (  AbstractWriteRequest  request  )  throws AllBackendsFailedException, SQLException [virtual, inherited]

Performs a write request. This request is broadcasted to all nodes. 引数: request  an AbstractWriteRequest 戻り値: number of rows affected by the request 例外: AllBackendsFailedException  if all backends failed to execute the request SQLException  if an error occurs org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancerに実装されています. RAIDb1.java の 329 行で定義されています。 { if (!request.isParsed() && (request.isCreate() || request.isDrop())) request.parse(null, ParsingGranularities.TABLE, true); return ((WriteRequestTask) execWriteRequest(request, false)).getResult(); }

ResultSet org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.execWriteRequestWithKeys (  AbstractWriteRequest  request  )  throws AllBackendsFailedException, SQLException [virtual, inherited]

Perform a write request and return the auto generated keys. 引数: request  the request to execute 戻り値: auto generated keys. 例外: AllBackendsFailedException  if all backends failed to execute the request SQLException  if an error occurs org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancerに実装されています. RAIDb1.java の 346 行で定義されています。 { if (!request.isParsed() && (request.isCreate() || request.isDrop())) request.parse(null, ParsingGranularities.TABLE, true); return ((WriteRequestWithKeysTask) execWriteRequest(request, false)) .getResult(); }

int org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.execWriteStoredProcedure (  StoredProcedure  proc  )  throws SQLException [virtual, inherited]

参照: org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.execWriteStoredProcedure(org.objectweb.cjdbc.common.sql.StoredProcedure) org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancerに実装されています. RAIDb1.java の 745 行で定義されています。 参照先 org.objectweb.cjdbc.controller.loadbalancer.tasks.WriteStoredProcedureTask.getResult(). { WriteStoredProcedureTask task = (WriteStoredProcedureTask) callStoredProcedure( proc, false); return task.getResult(); }

String org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.getInformation (   )  [virtual]

Gets information about the request load balancer. 戻り値: String containing information org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancerに実装されています. RAIDb1_WRR.java の 271 行で定義されています。 { // We don't lock since we don't need a top accurate value int size = vdb.getBackends().size(); if (size == 0) return "RAIDb-1 with Weighted Round Robin Request load balancer: !!!Warning!!! No backend nodes found\n"; else return "RAIDb-1 Weighted Round-Robin Request load balancer (" + size + " backends)\n"; }

int org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.getParsingGranularity (   )  [inherited]

Get the needed query parsing granularity. 戻り値: needed query parsing granularity AbstractLoadBalancer.java の 151 行で定義されています。 参照元 org.objectweb.cjdbc.controller.requestmanager.RequestManager.setLoadBalancer(). { return parsingGranularity; }

String org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.getRaidb1Xml (   )  [virtual]

参照: org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.getRaidb1Xml org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1に実装されています. RAIDb1_WRR.java の 286 行で定義されています。 { return WeightedBalancer.getRaidbXml(weights, DatabasesXmlTags.ELT_RAIDb_1_WeightedRoundRobin); }

int org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.getRAIDbLevel (   )  [inherited]

Returns the RAIDbLevel. 戻り値: int the RAIDb level AbstractLoadBalancer.java の 131 行で定義されています。 参照先 org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.raidbLevel. 参照元 org.objectweb.cjdbc.controller.requestmanager.RequestManager.assignAndCheckSchedulerLoadBalancerValidity(). { return raidbLevel; }

String org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.getXml (   )  [inherited]

参照: org.objectweb.cjdbc.common.xml.XmlComponent.getXml() AbstractLoadBalancer.java の 385 行で定義されています。 参照先 org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.getXmlImpl(). { StringBuffer info = new StringBuffer(); info.append("<" + DatabasesXmlTags.ELT_LoadBalancer + ">"); info.append(getXmlImpl()); info.append("</" + DatabasesXmlTags.ELT_LoadBalancer + ">"); return info.toString(); }

String org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.getXmlImpl (   )  [virtual, inherited]

参照: org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.getXmlImpl org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancerに実装されています. org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1ecで再定義されています。 RAIDb1.java の 1422 行で定義されています。 { StringBuffer info = new StringBuffer(); info.append("<" + DatabasesXmlTags.ELT_RAIDb_1 + " " + DatabasesXmlTags.ATT_timestampResolution + "=\"" + timestampResolution + "\" >"); if (waitForCompletionPolicy != null) info.append(waitForCompletionPolicy.getXml()); info.append(getRaidb1Xml()); info.append("</" + DatabasesXmlTags.ELT_RAIDb_1 + ">"); return info.toString(); }

void org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.rollback (  TransactionMarkerMetaData  tm  )  throws SQLException [virtual, inherited]

Rollbacks a transaction. 引数: tm  the transaction marker metadata 例外: SQLException  if an error occurs org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancerに実装されています. RAIDb1.java の 1036 行で定義されています。 参照先 org.objectweb.cjdbc.controller.loadbalancer.BackendWorkerThread.addTask(), org.objectweb.cjdbc.controller.loadbalancer.BackendWorkerThread.getBackend(), org.objectweb.cjdbc.controller.loadbalancer.tasks.AbstractTask.getFailed(), org.objectweb.cjdbc.controller.loadbalancer.tasks.AbstractTask.getSuccess(), と org.objectweb.cjdbc.controller.backend.DatabaseBackend.isStartedTransaction(). { if (waitForCompletionPolicy.getPolicy() != WaitForCompletionPolicy.ALL) waitForAllWritesToComplete(tm.getTransactionId()); try { backendNonBlockingThreadsRWLock.acquireRead(); } catch (InterruptedException e) { String msg = Translate.get( "loadbalancer.backendlist.acquire.readlock.failed", e); logger.error(msg); throw new SQLException(msg); } int nbOfThreads = backendNonBlockingThreads.size(); ArrayList rollbackList = new ArrayList(); Long lTid = new Long(tm.getTransactionId()); // Build the list of backend that need to rollback this transaction for (int i = 0; i < nbOfThreads; i++) { BackendWorkerThread thread = (BackendWorkerThread) backendNonBlockingThreads .get(i); if (thread.getBackend().isStartedTransaction(lTid)) rollbackList.add(thread); } nbOfThreads = rollbackList.size(); if (nbOfThreads == 0) { backendNonBlockingThreadsRWLock.releaseRead(); return; } // Create the task RollbackTask task = new RollbackTask(getNbToWait(nbOfThreads), nbOfThreads, tm.getTimeout(), tm.getLogin(), tm.getTransactionId()); synchronized (task) { // Post the task in each backendThread tasklist and wakeup the threads for (int i = 0; i < nbOfThreads; i++) { BackendWorkerThread thread = (BackendWorkerThread) rollbackList.get(i); synchronized (thread) { thread.addTask(task); thread.notify(); } } backendNonBlockingThreadsRWLock.releaseRead(); // Wait for completion (notified by the task) try { // Wait on task long timeout = tm.getTimeout(); if (timeout > 0) { long start = System.currentTimeMillis(); task.wait(timeout); long end = System.currentTimeMillis(); long remaining = timeout - (end - start); if (remaining <= 0) { String msg = Translate.get("loadbalancer.rollback.timeout", new String[]{String.valueOf(tm.getTransactionId()), String.valueOf(task.getSuccess()), String.valueOf(task.getFailed())}); logger.warn(msg); throw new SQLException(msg); } } else task.wait(); } catch (InterruptedException e) { throw new SQLException(Translate.get("loadbalancer.rollback.timeout", new String[]{String.valueOf(tm.getTransactionId()), String.valueOf(task.getSuccess()), String.valueOf(task.getFailed())})); } if (task.getSuccess() > 0) return; else { // All tasks failed ArrayList exceptions = task.getExceptions(); if (exceptions == null) throw new SQLException(Translate.get( "loadbalancer.rollback.all.failed", tm.getTransactionId())); else { String errorMsg = Translate.get("loadbalancer.rollback.failed.stack", tm.getTransactionId()) + "\n"; for (int i = 0; i < exceptions.size(); i++) errorMsg += ((SQLException) exceptions.get(i)).getMessage() + "\n"; logger.error(errorMsg); throw new SQLException(errorMsg); } } } }

void org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.setParsingGranularity (  int  parsingGranularity  )  [inherited]

Set the needed query parsing granularity. 引数: parsingGranularity  the granularity to set AbstractLoadBalancer.java の 161 行で定義されています。 { this.parsingGranularity = parsingGranularity; }

void org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.setRAIDbLevel (  int  raidbLevel  )  [inherited]

Sets the RAIDbLevel. 引数: raidbLevel  The RAIDb level to set AbstractLoadBalancer.java の 141 行で定義されています。 { this.raidbLevel = raidbLevel; }

void org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.setWeight (  String  name, int  w )  throws SQLException

参照: org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.setWeight(String, int) org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancerを再定義しています。 RAIDb1_WRR.java の 253 行で定義されています。 { if (logger.isDebugEnabled()) logger.debug(Translate.get("loadbalancer.weight.set", new String[]{ String.valueOf(w), name})); weights.put(name, new Integer(w)); }

void org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.waitForAllWritesToComplete (  DatabaseBackend  backend  )  throws SQLException [protected, inherited]

Waits for all writes in the blocking thread queue of the given backend to complete. 参照: executeRequestOnBackend RAIDb1.java の 1217 行で定義されています。 参照先 org.objectweb.cjdbc.controller.loadbalancer.BackendWorkerThread.getBackend(), と org.objectweb.cjdbc.controller.loadbalancer.BackendWorkerThread.waitForAllTasksToComplete(). { try { backendBlockingThreadsRWLock.acquireRead(); } catch (InterruptedException e) { String msg = Translate.get( "loadbalancer.backendlist.acquire.readlock.failed", e); logger.error(msg); throw new SQLException(msg); } int nbOfThreads = backendBlockingThreads.size(); for (int i = 0; i < nbOfThreads; i++) { BackendWorkerThread thread = (BackendWorkerThread) backendBlockingThreads .get(i); if (thread.getBackend() == backend) thread.waitForAllTasksToComplete(); } backendBlockingThreadsRWLock.releaseRead(); }

void org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.waitForAllWritesToComplete (  DatabaseBackend  backend, long  transactionId )  throws SQLException [protected, inherited]

Waits for all writes of the given transaction in the blocking thread queue of the given backend to complete before being able to complete the transaction. 参照: executeRequestOnBackend RAIDb1.java の 1183 行で定義されています。 参照先 org.objectweb.cjdbc.controller.loadbalancer.BackendWorkerThread.getBackend(), と org.objectweb.cjdbc.controller.loadbalancer.BackendWorkerThread.waitForAllTasksToComplete(). { try { backendBlockingThreadsRWLock.acquireRead(); } catch (InterruptedException e) { String msg = Translate.get( "loadbalancer.backendlist.acquire.readlock.failed", e); logger.error(msg); throw new SQLException(msg); } int nbOfThreads = backendBlockingThreads.size(); for (int i = 0; i < nbOfThreads; i++) { BackendWorkerThread thread = (BackendWorkerThread) backendBlockingThreads .get(i); if (thread.getBackend() == backend) thread.waitForAllTasksToComplete(transactionId); } backendBlockingThreadsRWLock.releaseRead(); }

void org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.waitForAllWritesToComplete (  long  transactionId  )  throws SQLException [protected, inherited]

Waits for all writes of the given transaction in the blocking thread queue to complete before being able to complete the transaction. RAIDb1.java の 1149 行で定義されています。 参照先 org.objectweb.cjdbc.controller.loadbalancer.BackendWorkerThread.waitForAllTasksToComplete(). { try { backendBlockingThreadsRWLock.acquireRead(); } catch (InterruptedException e) { String msg = Translate.get( "loadbalancer.backendlist.acquire.readlock.failed", e); logger.error(msg); throw new SQLException(msg); } int nbOfThreads = backendBlockingThreads.size(); for (int i = 0; i < nbOfThreads; i++) { BackendWorkerThread thread = (BackendWorkerThread) backendBlockingThreads .get(i); thread.waitForAllTasksToComplete(transactionId); } backendBlockingThreadsRWLock.releaseRead(); }

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変数

ArrayList org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.backendBlockingThreads [protected, inherited]

RAIDb1.java の 79 行で定義されています。 参照元 org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.RAIDb1().

ReadPrioritaryFIFOWriteLock org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.backendBlockingThreadsRWLock = new ReadPrioritaryFIFOWriteLock() [protected, inherited]

RAIDb1.java の 81 行で定義されています。

ArrayList org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.backendNonBlockingThreads [protected, inherited]

RAIDb1.java の 80 行で定義されています。 参照元 org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.RAIDb1().

ReadPrioritaryFIFOWriteLock org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.backendNonBlockingThreadsRWLock = new ReadPrioritaryFIFOWriteLock() [protected, inherited]

RAIDb1.java の 82 行で定義されています。

int org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.index [private]

RAIDb1_WRR.java の 63 行で定義されています。

Trace org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.logger [static, protected, inherited]

初期値: Trace .getLogger("org.objectweb.cjdbc.controller.loadbalancer.RAIDb1") org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancerを再定義しています。 org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1ecで再定義されています。 RAIDb1.java の 87 行で定義されています。

int org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.parsingGranularity [protected, inherited]

AbstractLoadBalancer.java の 74 行で定義されています。

int org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.raidbLevel [protected, inherited]

AbstractLoadBalancer.java の 73 行で定義されています。 参照元 org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.AbstractLoadBalancer(), と org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.getRAIDbLevel().

VirtualDatabase org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.vdb [protected, inherited]

AbstractLoadBalancer.java の 72 行で定義されています。 参照元 org.objectweb.cjdbc.controller.loadbalancer.AbstractLoadBalancer.AbstractLoadBalancer().

WaitForCompletionPolicy org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.waitForCompletionPolicy [protected, inherited]

RAIDb1.java の 84 行で定義されています。 参照元 org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.getNbToWait(), と org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1.RAIDb1().

HashMap org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.weights = new HashMap() [private]

RAIDb1_WRR.java の 62 行で定義されています。 参照元 org.objectweb.cjdbc.controller.loadbalancer.raidb1.RAIDb1_WRR.executeWRR().

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このクラスの説明は次のファイルから生成されました:

• RAIDb1_WRR.java

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