Search Results

Search found 3874 results on 155 pages for 'nested transactions'.

Page 33/155 | < Previous Page | 29 30 31 32 33 34 35 36 37 38 39 40  | Next Page >

  • multithreading with database

    - by Darsin
    I am looking out for a strategy to utilize multithreading (probably asynchronous delegates) to do a synchronous operation. I am new to multithreading so i will outline my scenario first. This synchronous operation right now is done for one set of data (portfolio) based on the the parameters provided. The (psudeo-code) implementation is given below: public DataSet DoTests(int fundId, DateTime portfolioDate) { // Get test results for the portfolio // Call the database adapter method, which in turn is a stored procedure, // which in turns runs a series of "rule" stored procs and fills a local temp table and returns it back. DataSet resultsDataSet = GetTestResults(fundId, portfolioDate); try { // Do some local processing on the results DoSomeProcessing(resultsDataSet); // Save the results in Test, TestResults and TestAllocations tables in a transaction. // Sets a global transaction which is provided to all the adapter methods called below // It is defined in the Base class StartTransaction("TestTransaction"); // Save Test and get a testId int testId = UpdateTest(resultsDataSet); // Adapter method, uses the same transaction // Update testId in the other tables in the dataset UpdateTestId(resultsDataSet, testId); // Update TestResults UpdateTestResults(resultsDataSet); // Adapter method, uses the same transaction // Update TestAllocations UpdateTestAllocations(resultsDataSet); // Adapter method, uses the same transaction // It is defined in the base class CommitTransaction("TestTransaction"); } catch { RollbackTransaction("TestTransaction"); } return resultsDataSet; } Now the requirement is to do it for multiple set of data. One way would be to call the above DoTests() method in a loop and get the data. I would prefer doing it in parallel. But there are certain catches: StartTransaction() method creates a connection (and transaction) every time it is called. All the underlying database tables, procedures are the same for each call of DoTests(). (obviously). Thus my question are: Will using multithreading anyway improve performance? What are the chances of deadlock especially when new TestId's are being created and the Tests, TestResults and TestAllocations are being saved? How can these deadlocked be handled? Is there any other more efficient way of doing the above operation apart from looping over the DoTests() method repeatedly?

    Read the article

  • Oracle transaction read-consistency ?

    - by trojanwarrior3000
    I have problem understanding read consistency in db(oracle). Suppose I am manger of a bank . A customer has got lock (which I dont know) and is doing some updation. Now after he has got lock I am viewing account info of the same customer and try to do some thing on it.But because of read consistency I will see data as it existed before customer got the lock. So will not that affect inputs I am getting and the decisions that I am gonna make during that period?

    Read the article

  • How can the Three-Phase Commit Protocol (3PC) guarantee atomicity?

    - by AndiDog
    I'm currently exploring worst case scenarios of atomic commit protocols like 2PC and 3PC and am stuck at the point that I can't find out why 3PC can guarantee atomicity. That is, how does it guarantee that if cohort A commits, cohort B also commits? Here's the simplified 3PC from the Wikipedia article: Now let's assume the following case: Two cohorts participate in the transaction (A and B) Both do their work, then vote for commit Coordinator now sends precommit messages... A receives the precommit message, acknowledges, and then goes offline for a long time B doesn't receive the precommit message (whatever the reason might be) and is thus still in "uncertain" state The results: Coordinator aborts the transaction because not all precommit messages were sent and acknowledged successfully A, who is in precommit state, is still offline, thus times out and commits B aborts in any case: He either stays offline and times out (causes abort) or comes online and receives the abort command from the coordinator And there you have it: One cohort committed, another aborted. The transaction is screwed. So what am I missing here? In my understanding, if the automatic commit on timeout (in precommit state) was replaced by infinitely waiting for a coordinator command, that case should work fine.

    Read the article

  • MySQL: automatic rollback on transaction failure

    - by praksant
    Is there any way to set MySQL to rollback any transaction on first error/warning automatically? Now if everything goes well, it commits, but on failure it leaves transaction open and on another start of transaction it commits incomplete changes from failed transaction. (I'm executing queries from php, but i don't want to check in php for failure, as it would make more calls between mysql server and webserver.) Thank you

    Read the article

  • Django: How can I protect against concurrent modification of data base entries

    - by Ber
    If there a way to protect against concurrent modifications of the same data base entry by two or more users? It would be acceptable to show an error message to the user performing the second commit/save operation, but data should not be silently overwritten. I think locking the entry is not an option, as a user might use the "Back" button or simply close his browser, leaving the lock for ever.

    Read the article

  • Spring transaction management breaks hibernate cascade

    - by TimmyJ
    I'm having a problem where the addition of spring's transaction management to an application causes Hibernate to throw the following error: org.hibernate.HibernateException: A collection with cascade="all-delete-orphan" was no longer referenced by the owning entity instance: org.fstrf.masterpk.domain.ReportCriteriaBean.treatmentArms org.hibernate.engine.Collections.processDereferencedCollection(Collections.java:96) org.hibernate.engine.Collections.processUnreachableCollection(Collections.java:39) org.hibernate.event.def.AbstractFlushingEventListener.flushCollections(AbstractFlushingEventListener.java:218) org.hibernate.event.def.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:77) org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:26) org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1000) org.springframework.orm.hibernate3.SpringSessionSynchronization.beforeCommit(SpringSessionSynchronization.java:135) org.springframework.transaction.support.TransactionSynchronizationUtils.triggerBeforeCommit(TransactionSynchronizationUtils.java:72) org.springframework.transaction.support.AbstractPlatformTransactionManager.triggerBeforeCommit(AbstractPlatformTransactionManager.java:905) org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:715) org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:701) org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:321) org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:116) org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171) org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204) $Proxy92.saveNewReportCriteria(Unknown Source) org.fstrf.masterpk.domain.logic.MasterPkFacade.saveNewReportCriteria(MasterPkFacade.java:134) org.fstrf.masterpk.controllers.ReportCriteriaController.setupReportType(ReportCriteriaController.java:302) sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) java.lang.reflect.Method.invoke(Method.java:585) org.springframework.web.bind.annotation.support.HandlerMethodInvoker.doInvokeMethod(HandlerMethodInvoker.java:413) org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:134) org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:310) org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:297) org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:875) org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:809) org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:571) org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:511) javax.servlet.http.HttpServlet.service(HttpServlet.java:710) javax.servlet.http.HttpServlet.service(HttpServlet.java:803) org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96) I'm using Spring 2.5 and annotations to implement this management. Here is the class containing the saveNewReportCriteria method (which, as can be seen by the stack trace, is causing the error) @Transactional( propagation = Propagation.REQUIRED, isolation = Isolation.DEFAULT, readOnly = false) public class HibernateReportCriteriaDao implements ReportCriteriaDao{ private HibernateTemplate hibernateTemplate; public Integer saveNewReportCriteria(ReportCriteriaBean reportCriteria) { hibernateTemplate.save(reportCriteria); List<Integer> maxIdList = hibernateTemplate.find("SELECT max(id) from ReportCriteriaBean"); logger.info("ID of newly saved list is: " + maxIdList.get(0)); return maxIdList.get(0); } public void setHibernateTemplate(HibernateTemplate hibernateTemplate) { this.hibernateTemplate = hibernateTemplate; } } Then I added the following sections to my configuration files to tell spring that I am using annotation driven transaction management: <bean id="actgDataSource" class="org.springframework.jndi.JndiObjectFactoryBean"> <property name="jndiName" value="jdbc/actg" /> <property name="resourceRef" value="true" /> </bean> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="actgDataSource" /> </bean> <tx:annotation-driven/> I'm pretty sure that the de-referencing error is being caused due to the proxy class that Spring AOP creates and uses in order to handle transaction management, but I have no idea how I'd go about fixing it.

    Read the article

  • How to create entities in one Entity group ?

    - by Gopi
    I am building an app based on google app engine (Java) using JDO for persistence. Can someone give me an example or a point me to some code which shows persisting of multiple entities (of same type) using javax.jdo.PersistenceManager.makePersistentAll() within a transaction. Basically I need to understand how to put multiple entites in one Entity Group so that they can be saved using makePersistentAll() inside transaction.

    Read the article

  • OptimisticLockException in inner transaction ruins outer transaction

    - by Pace
    I have the following code (OLE = OptimisticLockException)... public void outer() { try { middle() } catch (OLE) { updateEntities(); outer(); } } @Transactional public void middle() { try { inner() } catch (OLE) { updateEntities(); middle(); } @Transactional public void inner() { //Do DB operation } inner() is called by other non-transactional methods which is why both middle() and inner() are transactional. As you can see, I deal with OLEs by updating the entities and retrying the operation. The problem I'm having is that when I designed things this way I was assuming that the only time one could get an OLE was when a transaction closed. This is apparently not the case as the call to inner() is throwing an OLE even when the stack is outer()->middle()->inner(). Now, middle() is properly handling the OLE and the retry succeeds but when it comes time to close the transaction it has been marked rollbackOnly by Spring. When the middle() method call finally returns the closing aspect throws an exception because it can't commit a transaction marked rollbackOnly. I'm uncertain what to do here. I can't clear the rollbackOnly state. I don't want to force create a transaction on every call to inner because that kills my performance. Am I missing something or can anyone see a way I can structure this differently? EDIT: To clarify what I'm asking, let me explain my main question. Is it possible to catch and handle OLE if you are inside of an @Transactional method? FYI: The transaction manager is a JpaTransactionManager and the JPA provider is Hibernate.

    Read the article

  • Cannot save model due to bad transaction? Django

    - by Kenneth Love
    Trying to save a model in Django admin and I keep getting the error: Transaction managed block ended with pending COMMIT/ROLLBACK I tried restarting both the Django (1.2) and PostgreSQL (8.4) processes but nothing changed. I added "autocommit": True to my database settings but that didn't change anything either. Everything that Google has turned up has either not been answered or the answer involved not having records in the users table, which I definitely have. The model does not have a custom save method and there are no pre/post save signals tied to it. Any ideas or anything else I can provide to make answering this easier?

    Read the article

  • Why are these two sql statements deadlocking? (Deadlock graph + details included).

    - by Pure.Krome
    Hi folks, I've got the following deadlock graph that describes two sql statements that are deadlocking each other. I'm just not sure how to analyse this and then fix up my sql code to prevent this from happening. Main deadlock graph Click here for a bigger image. Left side, details Click here for a bigger image. Right side, details Click here for a bigger image. What is the code doing? I'm reading in a number of files (eg. lets say 3, for this example). Each file contains different data BUT the same type of data. I then insert data into LogEntries table and then (if required) I insert or delete something from the ConnectedClients table. Here's my sql code. using (TransactionScope transactionScope = new TransactionScope()) { _logEntryRepository.InsertOrUpdate(logEntry); // Now, if this log entry was a NewConnection or an LostConnection, then we need to make sure we update the ConnectedClients. if (logEntry.EventType == EventType.NewConnection) { _connectedClientRepository.Insert(new ConnectedClient { LogEntryId = logEntry.LogEntryId }); } // A (PB) BanKick does _NOT_ register a lost connection .. so we need to make sure we handle those scenario's as a LostConnection. if (logEntry.EventType == EventType.LostConnection || logEntry.EventType == EventType.BanKick) { _connectedClientRepository.Delete(logEntry.ClientName, logEntry.ClientIpAndPort); } _unitOfWork.Commit(); transactionScope.Complete(); } Now each file has it's own UnitOfWork instance (which means it has it's own database connection, transaction and repository context). So i'm assuming this means there's 3 different connections to the db all happening at the same time. Finally, this is using Entity Framework as the repository, but please don't let that stop you from having a think about this problem. Using a profiling tool, the Isolation Level is Serializable. I've also tried ReadCommited and ReadUncommited, but they both error :- ReadCommited: same as above. Deadlock. ReadUncommited: different error. EF exception that says it expected some result back, but got nothing. I'm guessing this is the LogEntryId Identity (scope_identity) value that is expected but not retrieve because of the dirty read. Please help! PS. It's Sql Server 2008, btw.

    Read the article

  • Data access strategy for a site like SO - sorted SQL queries and simultaneous updates that affect th

    - by Kaleb Brasee
    I'm working on a Grails web app that would be similar in access patterns to StackOverflow or MyLifeIsAverage - users can vote on entries, and their votes are used to sort a list of entries based on the number of votes. Votes can be placed while the sorted select queries are being performed. Since the selects would lock a large portion of the table, it seems that normal transaction locking would cause updates to take forever (given enough traffic). Has anyone worked on an app with a data access pattern such as this, and if so, did you find a way to allow these updates and selects to happen more or less concurrently? Does anyone know how sites like SO approach this? My thought was to make the sorted selects dirty reads, since it is acceptable if they're not completely up to date all of the time. This is my only idea for possibly improving performance of these selects and updates, but I thought someone might know a better way.

    Read the article

  • Why do updates inside of a SQL transaction still need disk IO?

    - by usr
    In SQL Profiler you can see that very simple updates to a table by primary key take about 10-30ms each. On about every 10th update the write column shows 1, on all other updates it shows 0. This must mean that about every 10th update statement still requires disk IO. I wonder why that is. Would it not be more efficient queue up all IO until the transaction commits?

    Read the article

  • Exit and rollback everything in script on error

    - by Jan W.
    Hey guys ! I'm in a bit of a pickle here. I have a TSQL script that does a lot of database structure adjustments but it's not really safe to just let it go through when something fails. to make things clear: using MS SQL 2005 it's NOT a stored procedure, just a script file (.sql) what I have is something in the following order BEGIN TRANSACTION ALTER Stuff GO CREATE New Stuff GO DROP Old Stuff GO IF @@ERROR != 0 BEGIN PRINT 'Errors Found ... Rolling back' ROLLBACK TRANSACTION RETURN END ELSE PRINT 'No Errors ... Committing changes' COMMIT TRANSACTION just to illustrate what I'm working with ... can't go into specifics now, the problem ... When I introduce an error (to test if things get rolled back), I get a statement that the ROLLBACK TRANSACTION could not find a corresponding BEGIN TRANSACTION. This leads me to believe that something when REALLY wrong and the transaction was already killed. what I also noticed is that the script didn't fully quit on error and thus DID try to execute every statement after the error occured. (I noticed this when new tables showed up when I wasn't expecting them because it should have rollbacked) any help in this department is welcome if more speficics are needed, ask! greetz

    Read the article

  • Forcing a method to be non-transactional in JPA (Eclipselink)

    - by rhinds
    Hi, I am developing an application using Eclipselink and as part of the app I need to be able to manipulate some of the objects which involves changing data without it being persisted to the database (i merging/changing objects for some batch generation processes). I am reluctant to change the data in the Entity objects, as there is a risk that even though i have not marked the methods as @Transactional, this method could in the future be inadvertantly called from within a transactional method and these changes could be persisted. So my question is, is there anyway to get around this? Such as force a method to always be non-transactional regardless; terminate any transactionality as soon as the method is started; etc. I know there is a .detach() method that can detach the objects from the Entity Manager, however, there are many objects and this seems like a potentially error prone fail-safe on my code.

    Read the article

  • Which isolation level should I use for the following insert-if-not-present transaction?

    - by Steve Guidi
    I've written a linq-to-sql program that essentially performs an ETL task, and I've noticed many places where parallelization will improve its performance. However, I'm concerned about preventing uniquness constraint violations when two threads perform the following task (psuedo code). Record CreateRecord(string recordText) { using (MyDataContext database = GetDatabase()) { Record existingRecord = database.MyTable.FirstOrDefault(record.KeyPredicate()); if(existingRecord == null) { existingRecord = CreateRecord(recordText); database.MyTable.InsertOnSubmit(existingRecord); } database.SubmitChanges(); return existingRecord; } } In general, this code executes a SELECT statement to test for record existance, followed by an INSERT statement if the record doesn't exist. It is encapsulated by an implicit transaction. When two threads run this code for the same instance of recordText, I want to prevent them from simultaneously determining that the record doesn't exist, thereby both attempting to create the same record. An isolation level and explicit transaction will work well, except I'm not certain which isolation level I should use -- Serializable should work, but seems too strict. Is there a better choice?

    Read the article

  • Translate HTML files to another language

    - by Saif Bechan
    I have a website with Dutch text which I want to translate to English. Is there a fast way of doing this with keeping the HTML tags(<strong>,<span>) in tact. I know I can just copy the parsed TEXT into a translator but this will remove the formatting. I also know that at the end I have to go trough the text manually to fix some minor spelling and grammar.

    Read the article

  • Is there any difference in which order I createCriteria and beginTransaction using Hibernate?

    - by user2519543
    Just wondering is there any difference when I beginTransaction [org.hibernate] before or after creating Criteria/Query etc.? example 1: ... Transaction tx= session.beginTransaction(); Criteria c = session.createCriteria(class); result = c.uniqueResult(); tx.commit(); ... example 2: ... Criteria c = session.createCriteria(class); Transaction tx= session.beginTransaction(); result = c.uniqueResult(); tx.commit(); ... Thanks.

    Read the article

  • Is it necessary to write ROLLBACK if queries fail?

    - by Donator
    I write mysql_query("SET AUTOCOMMIT=0"); mysql_query("START TRANSACTION"); before I write all queries. Then check if all of them are true and then write: mysql_query("COMMIT"); But if one of query fails, I just pass COMMIT query. So do I really need ROLLBACK function if one of the queries fail? Because without ROLLBACK it also works. Thanks.

    Read the article

  • JTA Transaction: What happens if an exception happens but rollback is not called on the transaction?

    - by kellyfj
    We have some third party code wherein they do the following 1) Create a User Transaction e.g. txn = (UserTransaction)ctx.lookup( "UserTransaction" ); txn.begin( ); 2) Do some work persisting to the database (via JPA) to a MySQL database 3) txn.commit() They have Exception blocks but NONE of them call txn.rollback. Good coding practice says they NEED to call rollback if an exception occurs but my question is If the txn is not commited, and an exception occurs what is the negative effect of them NOT calling rollback?

    Read the article

  • Row insertion order entity framework

    - by Wouter
    I'm using a transaction to insert multiple rows in multiple tables. For these rows I would like to add these rows in order. Upon calling SaveChanges all the rows are inserted out of order. When not using a transaction and saving changes after each insertion does keep order, but I really need a transaction for all entries.

    Read the article

< Previous Page | 29 30 31 32 33 34 35 36 37 38 39 40  | Next Page >