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Merged V3.3-BUG-FIX to HEAD

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23257: Merged V3.3 to V3.3-BUG-FIX
      23224: (RECORD ONLY) MERGE V3.3 BUG FIX to V3.3 
         23199 : imap message test
      23247: Merged HEAD to V3.3
         23246: Fix for ALF-5032: findAuthorities() getting slow when many groups are created.
            - moved to PARENT driven queries where possible in preference to PATH
      23255: Merged PATCHES/V3.2.0 to V3.3
         23252: ALF-5141, ALF-5302, ALF-5281: Improved transaction limiting mechanism
            - No ceiling. Just monitor transaction start times and reject new transactions when the oldest transaction is older than the threshold.


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@23258 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261
This commit is contained in:
Dave Ward
2010-10-25 14:30:27 +00:00
parent 2709b5fe47
commit bcf40763a3
2 changed files with 97 additions and 139 deletions
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119
source/java/org/alfresco/repo/transaction/RetryingTransactionHelper.java
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@@ -22,6 +22,8 @@ import java.lang.reflect.Method;
import java.sql.BatchUpdateException;
import java.sql.SQLException;
import java.util.Random;
import java.util.SortedMap;
import java.util.TreeMap;
import javax.transaction.RollbackException;
import javax.transaction.Status;
@@ -128,14 +130,11 @@ public class RetryingTransactionHelper
*/
private long maxExecutionMs;
/** Map of transaction start times to counts. Only maintained when maxExecutionMs is set. */
private SortedMap <Long, Integer> txnsInProgress = new TreeMap<Long, Integer>();
/** The number of concurrently exeucting transactions. Only maintained when maxExecutionMs is set. */
private int txnCount;
/**
* A 'ceiling' for the number of concurrent transactions that can execute. Dynamically maintained so that exeuction
* time is within maxExecutionMs. Transactions above this limit will be rejected with a {@link TooBusyException}.
*/
private Integer txnCeiling;
/**
* Whether the the transactions may only be reads
@@ -294,20 +293,52 @@ public class RetryingTransactionHelper
throw new AccessDeniedException(MSG_READ_ONLY);
}
// First validate the requiresNew setting
boolean startingNew = requiresNew;
if (!startingNew)
{
TxnReadState readState = AlfrescoTransactionSupport.getTransactionReadState();
switch (readState)
{
case TXN_READ_ONLY:
if (!readOnly)
{
// The current transaction is read-only, but a writable transaction is requested
throw new AlfrescoRuntimeException("Read-Write transaction started within read-only transaction");
}
// We are in a read-only transaction and this is what we require so continue with it.
break;
case TXN_READ_WRITE:
// We are in a read-write transaction. It cannot be downgraded so just continue with it.
break;
case TXN_NONE:
// There is no current transaction so we need a new one.
startingNew = true;
break;
default:
throw new RuntimeException("Unknown transaction state: " + readState);
}
}
// If we are time limiting, set ourselves a time limit and maintain the count of concurrent transactions
long startTime = 0, endTime = 0, txnStartTime = 0;
int txnCountWhenStarted = 0;
if (maxExecutionMs > 0)
if (startingNew && maxExecutionMs > 0)
{
startTime = System.currentTimeMillis();
synchronized (this)
{
// If this transaction would take us above our ceiling, reject it
if (txnCeiling != null && txnCount >= txnCeiling)
if (txnCount > 0)
{
throw new TooBusyException("Too busy: " + txnCount + " transactions");
// If this transaction would take us above our ceiling, reject it
long oldestDuration = startTime - txnsInProgress.firstKey();
if (oldestDuration > maxExecutionMs)
{
throw new TooBusyException("Too busy: " + txnCount + " transactions. Oldest " + oldestDuration + " milliseconds");
}
}
txnCountWhenStarted = ++txnCount;
Integer count = txnsInProgress.get(startTime);
txnsInProgress.put(startTime, count == null ? 1 : count + 1);
++txnCount;
}
endTime = startTime + maxExecutionMs;
}
@@ -319,45 +350,19 @@ public class RetryingTransactionHelper
RuntimeException lastException = null;
for (int count = 0; count == 0 || count < maxRetries; count++)
{
// Monitor duration of each retry so that we can project an end time
if (maxExecutionMs > 0)
{
txnStartTime = System.currentTimeMillis();
}
UserTransaction txn = null;
try
{
if (requiresNew)
if (startingNew)
{
txn = txnService.getNonPropagatingUserTransaction(readOnly);
}
else
{
TxnReadState readState = AlfrescoTransactionSupport.getTransactionReadState();
switch (readState)
{
case TXN_READ_ONLY:
if (!readOnly)
{
// The current transaction is read-only, but a writable transaction is requested
throw new AlfrescoRuntimeException("Read-Write transaction started within read-only transaction");
}
// We are in a read-only transaction and this is what we require so continue with it.
break;
case TXN_READ_WRITE:
// We are in a read-write transaction. It cannot be downgraded so just continue with it.
break;
case TXN_NONE:
// There is no current transaction so we need a new one.
txn = txnService.getUserTransaction(readOnly);
break;
default:
throw new RuntimeException("Unknown transaction state: " + readState);
// Monitor duration of each retry so that we can project an end time
if (maxExecutionMs > 0)
{
txnStartTime = System.currentTimeMillis();
}
}
if (txn != null)
{
txn = requiresNew ? txnService.getNonPropagatingUserTransaction(readOnly) : txnService
.getUserTransaction(readOnly);
txn.begin();
// Wrap it to protect it
UserTransactionProtectionAdvise advise = new UserTransactionProtectionAdvise();
@@ -475,8 +480,7 @@ public class RetryingTransactionHelper
long projectedEndTime = txnEndTime + (txnEndTime - txnStartTime);
if (projectedEndTime > endTime)
{
// Force the ceiling to be lowered and reject
endTime = 0;
// Reject the retry
throw new TooBusyException("Too busy to retry", e);
}
// Limit the wait duration to fit into the time we have left
@@ -522,23 +526,22 @@ public class RetryingTransactionHelper
}
finally
{
if (maxExecutionMs > 0)
if (startingNew && maxExecutionMs > 0)
{
synchronized (this)
{
txnCount--;
if(System.currentTimeMillis() > endTime)
Integer count = txnsInProgress.get(startTime);
if (count != null)
{
// Lower the ceiling
if (txnCeiling == null || txnCeiling > txnCountWhenStarted - 1)
if (count == 1)
{
txnCeiling = Math.max(1, txnCountWhenStarted - 1);
txnsInProgress.remove(startTime);
}
else
{
txnsInProgress.put(startTime, count-1);
}
}
else if (txnCeiling != null && txnCeiling < txnCountWhenStarted + 1)
{
// Raise the ceiling
txnCeiling = txnCountWhenStarted + 1;
}
}
}