RE: Isolation level
Thank you Armin!
I am using DB2 and I failed to use something like jdbc.TransactionLevel
nor could I find anything on the docs for DB2.
So I am going to implement it, as long as anyone on this list know a setting
for DB2?
Thanks, CL
-Original Message-
From: Armin Waibel [mailto:[EMAIL PROTECTED]
Sent: Mittwoch, 20. Februar 2008 14:47
To: OJB Users List
Subject: Re: Isolation level
Hi Christian,
Christian Lipp wrote:
Hi Armin,
thank you for quick answer and sorry for my long delay.
We are using an older OJB version (1.0.1.x), so I thought I cannot use
your recommendation and wanted to perform a backport now.
I got the actual OJB now and examined it, but also couldn't find an
attribute in the jdbc-connection-descriptor (I checked the
repository.dtd).
So I asume I have to implement the JDBC transaction level as attribute
for jdbc-connection-descriptor into OJB or do I miss something?
Some databases support transaction-isolation settings by append a property
in the database URL - e.g. maxDB:
dbalias=//localhost/ojb?isolation=TRANSACTION_READ_COMMITTED
Additionally you can specify connection/database properties as custom
attributes with prefix jdbc..
jdbc-connection-descriptor
attribute attribute-name=jdbc.xyz attribute-value=zxy /
/jdbc-connection-descriptor
OJB will set these properties (with jdbc.* prefix) when create the
connection:
Connection con = DriverManager.getConnection(url, properties);
Could someone point me in the right direction for this implementation? I
assume I have to read the attribute and apply it in the function
PlatformDefaultImpl.initializeJdbcConnection.
If your database doesn't support isolation setting shown above, you can
indeed extend a existing Platform class and override
#initializeJdbcConnection. Within this method you can easily get custom
attributes using:
jdbc-connection-descriptor
platform=org.apache.ojb.broker.platforms.PlatformMyOwnImpl
attribute attribute-name=isolation attribute-value=READ_COMMITED /
/jdbc-connection-descriptor
class PlatformMyOwnImpl extends PlatformMySQLImpl{
...
public void initializeJdbcConnection(Connection conn)
{
String isolation = jcd.getAttribute(isolation, null);
...
}
}
All shown solutions will work with latest OJB source
http://www.mail-archive.com/ojb-user%40db.apache.org/msg16078.html
I don't check the older versions.
regards,
Armin
Thanks in advance, CL
-Original Message-
From: Armin Waibel [mailto:[EMAIL PROTECTED]
Sent: Freitag, 25. Jänner 2008 03:03
To: OJB Users List
Subject: Re: Isolation level
Hi Christian,
Christian Lipp wrote:
I am still looking for an solution for my lock level settings and
therefore I am digging through the OJB source.
What I am not sure at the moment is if the setting of the
isolation-level is generally ignored in OJB?
descriptor-repository version=1.0 isolation-level=read-comitted
I couldn't find the place in the OJB code where the isolation level is
set to the DescriptorRepository and later to the connection.
In my optionion the isolation-level in the XML file is ignored.
Could someone point me in the right direction?
Out of the box the isolation-level setting is only used by the ODMG-api
which use pessimistic locking by default.
http://db.apache.org/ojb/docu/guides/lockmanager.html#Pessimistic-Locking
The PB-api doesn't use pessimistic locking, thus it will ignore these
settings.
The database transaction levels are completely independent from the
isolation-level setting in OJB. So you can use different database
transaction levels (e.g. as property in the dbalias attribute in the
jdbc-connection-descriptor)
regards,
Armin
Thanks in advance,
CL
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Re: Isolation level
Hi Christian,
Christian Lipp wrote:
Hi Armin,
thank you for quick answer and sorry for my long delay.
We are using an older OJB version (1.0.1.x), so I thought I cannot use your
recommendation and wanted to perform a backport now.
I got the actual OJB now and examined it, but also couldn't find an
attribute in the jdbc-connection-descriptor (I checked the repository.dtd).
So I asume I have to implement the JDBC transaction level as attribute for
jdbc-connection-descriptor into OJB or do I miss something?
Some databases support transaction-isolation settings by append a
property in the database URL - e.g. maxDB:
dbalias=//localhost/ojb?isolation=TRANSACTION_READ_COMMITTED
Additionally you can specify connection/database properties as custom
attributes with prefix jdbc..
jdbc-connection-descriptor
attribute attribute-name=jdbc.xyz attribute-value=zxy /
/jdbc-connection-descriptor
OJB will set these properties (with jdbc.* prefix) when create the
connection:
Connection con = DriverManager.getConnection(url, properties);
Could someone point me in the right direction for this implementation? I
assume I have to read the attribute and apply it in the function
PlatformDefaultImpl.initializeJdbcConnection.
If your database doesn't support isolation setting shown above, you can
indeed extend a existing Platform class and override
#initializeJdbcConnection. Within this method you can easily get custom
attributes using:
jdbc-connection-descriptor
platform=org.apache.ojb.broker.platforms.PlatformMyOwnImpl
attribute attribute-name=isolation attribute-value=READ_COMMITED /
/jdbc-connection-descriptor
class PlatformMyOwnImpl extends PlatformMySQLImpl{
...
public void initializeJdbcConnection(Connection conn)
{
String isolation = jcd.getAttribute(isolation, null);
...
}
}
All shown solutions will work with latest OJB source
http://www.mail-archive.com/ojb-user%40db.apache.org/msg16078.html
I don't check the older versions.
regards,
Armin
Thanks in advance, CL
-Original Message-
From: Armin Waibel [mailto:[EMAIL PROTECTED]
Sent: Freitag, 25. Jänner 2008 03:03
To: OJB Users List
Subject: Re: Isolation level
Hi Christian,
Christian Lipp wrote:
I am still looking for an solution for my lock level settings and
therefore I am digging through the OJB source.
What I am not sure at the moment is if the setting of the
isolation-level is generally ignored in OJB?
descriptor-repository version=1.0 isolation-level=read-comitted
I couldn't find the place in the OJB code where the isolation level is
set to the DescriptorRepository and later to the connection.
In my optionion the isolation-level in the XML file is ignored.
Could someone point me in the right direction?
Out of the box the isolation-level setting is only used by the ODMG-api
which use pessimistic locking by default.
http://db.apache.org/ojb/docu/guides/lockmanager.html#Pessimistic-Locking
The PB-api doesn't use pessimistic locking, thus it will ignore these
settings.
The database transaction levels are completely independent from the
isolation-level setting in OJB. So you can use different database
transaction levels (e.g. as property in the dbalias attribute in the
jdbc-connection-descriptor)
regards,
Armin
Thanks in advance,
CL
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RE: Isolation level
Hi Armin, thank you for quick answer and sorry for my long delay. We are using an older OJB version (1.0.1.x), so I thought I cannot use your recommendation and wanted to perform a backport now. I got the actual OJB now and examined it, but also couldn't find an attribute in the jdbc-connection-descriptor (I checked the repository.dtd). So I asume I have to implement the JDBC transaction level as attribute for jdbc-connection-descriptor into OJB or do I miss something? Could someone point me in the right direction for this implementation? I assume I have to read the attribute and apply it in the function PlatformDefaultImpl.initializeJdbcConnection. Thanks in advance, CL -Original Message- From: Armin Waibel [mailto:[EMAIL PROTECTED] Sent: Freitag, 25. Jänner 2008 03:03 To: OJB Users List Subject: Re: Isolation level Hi Christian, Christian Lipp wrote: I am still looking for an solution for my lock level settings and therefore I am digging through the OJB source. What I am not sure at the moment is if the setting of the isolation-level is generally ignored in OJB? descriptor-repository version=1.0 isolation-level=read-comitted I couldn't find the place in the OJB code where the isolation level is set to the DescriptorRepository and later to the connection. In my optionion the isolation-level in the XML file is ignored. Could someone point me in the right direction? Out of the box the isolation-level setting is only used by the ODMG-api which use pessimistic locking by default. http://db.apache.org/ojb/docu/guides/lockmanager.html#Pessimistic-Locking The PB-api doesn't use pessimistic locking, thus it will ignore these settings. The database transaction levels are completely independent from the isolation-level setting in OJB. So you can use different database transaction levels (e.g. as property in the dbalias attribute in the jdbc-connection-descriptor) regards, Armin Thanks in advance, CL - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Isolation level
Hi Christian, Christian Lipp wrote: I am still looking for an solution for my lock level settings and therefore I am digging through the OJB source. What I am not sure at the moment is if the setting of the isolation-level is generally ignored in OJB? descriptor-repository version=1.0 isolation-level=read-comitted I couldn't find the place in the OJB code where the isolation level is set to the DescriptorRepository and later to the connection. In my optionion the isolation-level in the XML file is ignored. Could someone point me in the right direction? Out of the box the isolation-level setting is only used by the ODMG-api which use pessimistic locking by default. http://db.apache.org/ojb/docu/guides/lockmanager.html#Pessimistic-Locking The PB-api doesn't use pessimistic locking, thus it will ignore these settings. The database transaction levels are completely independent from the isolation-level setting in OJB. So you can use different database transaction levels (e.g. as property in the dbalias attribute in the jdbc-connection-descriptor) regards, Armin Thanks in advance, CL - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Isolation level for Persistence broker queries
Hello, With the PersistenceBroker api you can't specify the isolation level. You can use optimistic transaction to enhance the consistency of your data but you should be very cautious if you use it with a cache because it can introduce some strange behaviour on data highly exposed to concurrency update ! -Message d'origine- De: Vesely, Max [IT] A: OJB Users List Date: 31/12/2004 01:12 Objet: RE: Isolation level for Persistence broker queries Thanks. I'll wait for the next week then. Max. -Original Message- From: Thomas Dudziak [mailto:[EMAIL PROTECTED] Sent: Thursday, December 30, 2004 7:04 PM To: OJB Users List Subject:Re: Isolation level for Persistence broker queries Vesely, Max [IT] wrote: Is there a particular reason I don't get my questions answered? Just to know it will save me some time in the future. Well, I would say it is because currently there are holidays, so you can only reasonably expect answers next week the earliest, I'd say. And the people that every once in a while check their mail (like myself) are likely not able to answer your question. I for one don't know much about the isolation level stuff so I can't help you there. Tom - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] *** We scanned this email for malicious content *** *** IMPORTANT: Do not open attachments from unrecognized senders *** *** MailSystem ASTON *** - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Isolation level for Persistence broker queries
Thank you. What I was trying to do, actually, was to change default isolation level to lesser level of read-uncommitted for some of my selects. I replaced OJB SQL generator to append database engine (DB2) specific clause (WITH UR) in my SQL command to achieve that. Max. -Original Message- From: CLARAMONTE Jean-Baptiste [mailto:[EMAIL PROTECTED] Sent: Monday, January 03, 2005 4:38 AM To: Vesely, Max [IT]; 'OJB Users List ' Subject:RE: Isolation level for Persistence broker queries Hello, With the PersistenceBroker api you can't specify the isolation level. You can use optimistic transaction to enhance the consistency of your data but you should be very cautious if you use it with a cache because it can introduce some strange behaviour on data highly exposed to concurrency update ! -Message d'origine- De: Vesely, Max [IT] A: OJB Users List Date: 31/12/2004 01:12 Objet: RE: Isolation level for Persistence broker queries Thanks. I'll wait for the next week then. Max. -Original Message- From: Thomas Dudziak [mailto:[EMAIL PROTECTED] Sent: Thursday, December 30, 2004 7:04 PM To: OJB Users List Subject:Re: Isolation level for Persistence broker queries Vesely, Max [IT] wrote: Is there a particular reason I don't get my questions answered? Just to know it will save me some time in the future. Well, I would say it is because currently there are holidays, so you can only reasonably expect answers next week the earliest, I'd say. And the people that every once in a while check their mail (like myself) are likely not able to answer your question. I for one don't know much about the isolation level stuff so I can't help you there. Tom - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] *** We scanned this email for malicious content *** *** IMPORTANT: Do not open attachments from unrecognized senders *** *** MailSystem ASTON *** - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Isolation level for Persistence broker queries
Is there a particular reason I don't get my questions answered? Just to know it will save me some time in the future. Thanks. -Original Message- From: Vesely, Max [IT] Sent: Wednesday, December 29, 2004 5:48 PM To: ojb-user@db.apache.org Subject:Isolation level for Persistence broker queries Hello, Is there any way to specify isolation level for OJB query executed using Persistence Broker API? I can see that there's isolation-level attribute available for class-descriptor but documentation says it's only used in ODMG implementation. Any help would be greatly appreciated. Max. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Isolation level for Persistence broker queries
Vesely, Max [IT] wrote: Is there a particular reason I don't get my questions answered? Just to know it will save me some time in the future. Well, I would say it is because currently there are holidays, so you can only reasonably expect answers next week the earliest, I'd say. And the people that every once in a while check their mail (like myself) are likely not able to answer your question. I for one don't know much about the isolation level stuff so I can't help you there. Tom - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Isolation level for Persistence broker queries
Thanks. I'll wait for the next week then. Max. -Original Message- From: Thomas Dudziak [mailto:[EMAIL PROTECTED] Sent: Thursday, December 30, 2004 7:04 PM To: OJB Users List Subject:Re: Isolation level for Persistence broker queries Vesely, Max [IT] wrote: Is there a particular reason I don't get my questions answered? Just to know it will save me some time in the future. Well, I would say it is because currently there are holidays, so you can only reasonably expect answers next week the earliest, I'd say. And the people that every once in a while check their mail (like myself) are likely not able to answer your question. I for one don't know much about the isolation level stuff so I can't help you there. Tom - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: isolation-level: null
Hinnerk, I think this is a problem with the XML parser rather than the web container. I have had similar problems with different versions of Tomcat. I think it's down to the parser not being able to interpret spaces in the file path of the repository.dtd, repository_database.xml, repository_internal.xml, repository_user.xml files etc. I resolved the problem by changing to DOCTYPE tag to: !DOCTYPE descriptor-repository PUBLIC -//Apache Software Foundation//DTD OJB Repository//EN repository.dtd and copying and pasting the contents of the entity files into the repository.xml file, i.e. the repository.xml file contains repository_database.xml, repository_internal.xml, repository_user.xml etc. I notice that OJB 1.0.rc4 has a slightly different DOCTYPE tag to rc3, it is similar to above so repository.dtd problem might have been resolved but I think you'll still have problems with the entity files. Hope this helps, Joss Hello, I'm using OJB for a struts- project, and tried to migrate it to another server; e.g. from a PC running resin as jsp- server to another PC running the same version of resin, struts etc. I tried my best to copy the necessary java- archives, but I'm getting the following exception. Tried everything to debug it, changed the repository.xml to track the error, but unfortunatly this didn't help; do you have a hint for me? That would be great! I will attach my repository.xml and the error- log with debugging- information in a zip- file. Thank you, Hinnerk and here follows the error: java.lang.ExceptionInInitializerError at org.apache.ojb.broker.core.PersistenceBrokerFactoryDefaultImpl.buildDefaultKey(PersistenceBrokerFactoryDefaultImpl.java:150) at org.apache.ojb.broker.core.PersistenceBrokerFactoryDefaultImpl.init(PersistenceBrokerFactoryDefaultImpl.java:121) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:274) at java.lang.Class.newInstance0(Class.java:306) at java.lang.Class.newInstance(Class.java:259) at org.apache.ojb.broker.core.PersistenceBrokerFactoryFactory.init(PersistenceBrokerFactoryFactory.java:95) at org.apache.ojb.broker.core.PersistenceBrokerFactoryFactory.clinit(PersistenceBrokerFactoryFactory.java:71) at org.apache.ojb.broker.PersistenceBrokerFactory.createPersistenceBroker(PersistenceBrokerFactory.java:129) at org.rolli.user.UserManager.init(UserManager.java:51) at javax.servlet.GenericServlet.init(GenericServlet.java:258 (...) at com.caucho.server.http.HttpServer.main(HttpServer.java:103) Caused by: org.apache.ojb.broker.metadata.MetadataException: Could not read repository class descriptor data, using repository: repository.xml: Exception when reading metadata information, please check your repository.xml file at org.apache.ojb.broker.metadata.MetadataManager.init(MetadataManager.java:133) at org.apache.ojb.broker.metadata.MetadataManager.init(MetadataManager.java:119) at org.apache.ojb.broker.metadata.MetadataManager.clinit(MetadataManager.java:109) ... 24 more Caused by: org.apache.ojb.broker.metadata.MetadataException: Exception when reading metadata information, please check your repository.xml file at org.apache.ojb.broker.metadata.RepositoryXmlHandler.startElement(RepositoryXmlHandler.java:764) at com.caucho.xml.XmlParser.addElement(XmlParser.java:2249) at com.caucho.xml.XmlParser.parseElement(XmlParser.java:615) at com.caucho.xml.XmlParser.parseNode(XmlParser.java:364) at com.caucho.xml.XmlParser.parseInt(XmlParser.java:246) at com.caucho.xml.AbstractParser.parse(AbstractParser.java:614) at org.apache.ojb.broker.metadata.RepositoryPersistor.readMetadataFromXML(RepositoryPersistor.java:343) at org.apache.ojb.broker.metadata.RepositoryPersistor.buildRepository(RepositoryPersistor.java:300) at org.apache.ojb.broker.metadata.RepositoryPersistor.readDescriptorRepository(RepositoryPersistor.java:215) at org.apache.ojb.broker.metadata.MetadataManager.init(MetadataManager.java:129) ... 26 more Caused by: java.lang.NullPointerException at org.apache.ojb.broker.metadata.RepositoryXmlHandler.getIsoLevel(RepositoryXmlHandler.java:946) at org.apache.ojb.broker.metadata.RepositoryXmlHandler.startElement(RepositoryXmlHandler.java:216) ... 35 more --- - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] talk21 your FREE portable and
