RE: [JBoss-user] CMP entity bean "load balancig"
Hi, Roman, re the firebird jca-jdbc driver, Help would be appreciated. Do you want to work on the driver generally or mostly on the event notification? The driver is in cvs at firebird.sourceforge.net under client-java. I'm checking in my latest changes, which can build a rar that deploys in jboss, creates tables, but doesn't work thereafter. As far as I know, noone else has looked at this code, so one helpful thing would be a code review! Let me know what you would like to do! If we talk about the driver, we should probably move to the firebird-devel list. Thanks! david jencks On 2001.06.28 04:01:56 -0400 [EMAIL PROTECTED] wrote: > > I think this would be really cool too, however the events I am talking > > about are I think an interbase specific feature - I think > > Borland has a > > patent on them, although I don't know the details. Can other > > db's notify > > you when rows change? What other sources of events are you > > considering? > > > > I guess you could have instances of jboss broadcast commit/change > > notifications to all the other clustered jbosses? > > I think we can have some kind generic cache multicast, notifying about > events. I've implemented similar approach for Tomcat session update > multicasting, and prototype works pretty nice. > > At the begining we can just have an event that invalidate the cached > item, > if some multicast event comes. > > > Are you thinking jms? I was thinking of adding something to the jca > > firebird driver I am writing that would notify the cache more or less > > directly. > > Do you need any help in this? I thin I can invest some time into the > development... > > Best regards, > Roman > > ___ > JBoss-user mailing list > [EMAIL PROTECTED] > http://lists.sourceforge.net/lists/listinfo/jboss-user > ___ JBoss-user mailing list [EMAIL PROTECTED] http://lists.sourceforge.net/lists/listinfo/jboss-user
RE: [JBoss-user] CMP entity bean "load balancig"
> You _might_ also want to turn on the JAWS 'select for update' option I think this will not work for Interbase (that I'm using at present time), because, as far as I know, Interbase being optimistic from the roots does not have such option. Pessimistic locking is obtained by the explicit UPDATE command. ___ JBoss-user mailing list [EMAIL PROTECTED] http://lists.sourceforge.net/lists/listinfo/jboss-user
RE: [JBoss-user] CMP entity bean "load balancig"
> I think this would be really cool too, however the events I am talking > about are I think an interbase specific feature - I think > Borland has a > patent on them, although I don't know the details. Can other > db's notify > you when rows change? What other sources of events are you > considering? > > I guess you could have instances of jboss broadcast commit/change > notifications to all the other clustered jbosses? I think we can have some kind generic cache multicast, notifying about events. I've implemented similar approach for Tomcat session update multicasting, and prototype works pretty nice. At the begining we can just have an event that invalidate the cached item, if some multicast event comes. > Are you thinking jms? I was thinking of adding something to the jca > firebird driver I am writing that would notify the cache more or less > directly. Do you need any help in this? I thin I can invest some time into the development... Best regards, Roman ___ JBoss-user mailing list [EMAIL PROTECTED] http://lists.sourceforge.net/lists/listinfo/jboss-user
RE: [JBoss-user] CMP entity bean "load balancig"
On 2001.06.27 11:09:47 -0400 marc fleury wrote: > > |It seems to me that it should be possible to have an interbase/firebird > |specific option E using interbase events to notify the container of db > > that would be really cool, in fact we could have a generic option E > listening to events on a given topic and then adaptors to the event > generation. > > That would really be cool, because then we could code "soft ball" > distributed caches easily with publishing on a topic > I think this would be really cool too, however the events I am talking about are I think an interbase specific feature - I think Borland has a patent on them, although I don't know the details. Can other db's notify you when rows change? What other sources of events are you considering? I guess you could have instances of jboss broadcast commit/change notifications to all the other clustered jbosses? Are you thinking jms? I was thinking of adding something to the jca firebird driver I am writing that would notify the cache more or less directly. david jencks ___ JBoss-user mailing list [EMAIL PROTECTED] http://lists.sourceforge.net/lists/listinfo/jboss-user
Re: [JBoss-user] CMP entity bean "load balancig"
David Jencks wrote: > Hi, > you need to use commit option B or C, or maybe the jboss specific D. > You _might_ also want to turn on the JAWS 'select for update' option ___ JBoss-user mailing list [EMAIL PROTECTED] http://lists.sourceforge.net/lists/listinfo/jboss-user
RE: [JBoss-user] CMP entity bean "load balancig"
|It seems to me that it should be possible to have an interbase/firebird |specific option E using interbase events to notify the container of db that would be really cool, in fact we could have a generic option E listening to events on a given topic and then adaptors to the event generation. That would really be cool, because then we could code "soft ball" distributed caches easily with publishing on a topic marcf |changes... but this will have to wait a bit. | |david jencks | |On 2001.06.27 10:38:59 -0400 [EMAIL PROTECTED] wrote: |> Hi! |> |> I'm thinking about putting two JBoss instancess to access one single |> database to achive some kind of load balancing on the JBoss side (HTTP |> requests will go to a hardware load balancer, that in trun will forward |> them |> to two different Tomcats, each of them connected to its own JBoss). |> |> The question is: |> |> Does JBoss persistence manager (namely JAWS) checks if the record in |> database was changed by a third party, even if no transaction conflict |> occur? |> |> Such situation is possible when JBoss 1 commits and leaves the entity |> bean |> activated, then JBoss 2 updates that very entity bean and commits, and |> then |> JBoss 1 tries to read data from that entity bean. Can JBoss 1 detect |> changes |> in the database and will it reload the bean state? |> |> Regards, |> Roman Rokytskyy |> |> ___ |> JBoss-user mailing list |> [EMAIL PROTECTED] |> http://lists.sourceforge.net/lists/listinfo/jboss-user |> | | |___ |JBoss-user mailing list |[EMAIL PROTECTED] |http://lists.sourceforge.net/lists/listinfo/jboss-user ___ JBoss-user mailing list [EMAIL PROTECTED] http://lists.sourceforge.net/lists/listinfo/jboss-user
Re: [JBoss-user] CMP entity bean "load balancig"
Hi, you need to use commit option B or C, or maybe the jboss specific D. It seems to me that it should be possible to have an interbase/firebird specific option E using interbase events to notify the container of db changes... but this will have to wait a bit. david jencks On 2001.06.27 10:38:59 -0400 [EMAIL PROTECTED] wrote: > Hi! > > I'm thinking about putting two JBoss instancess to access one single > database to achive some kind of load balancing on the JBoss side (HTTP > requests will go to a hardware load balancer, that in trun will forward > them > to two different Tomcats, each of them connected to its own JBoss). > > The question is: > > Does JBoss persistence manager (namely JAWS) checks if the record in > database was changed by a third party, even if no transaction conflict > occur? > > Such situation is possible when JBoss 1 commits and leaves the entity > bean > activated, then JBoss 2 updates that very entity bean and commits, and > then > JBoss 1 tries to read data from that entity bean. Can JBoss 1 detect > changes > in the database and will it reload the bean state? > > Regards, > Roman Rokytskyy > > ___ > JBoss-user mailing list > [EMAIL PROTECTED] > http://lists.sourceforge.net/lists/listinfo/jboss-user > ___ JBoss-user mailing list [EMAIL PROTECTED] http://lists.sourceforge.net/lists/listinfo/jboss-user
[JBoss-user] CMP entity bean "load balancig"
Hi! I'm thinking about putting two JBoss instancess to access one single database to achive some kind of load balancing on the JBoss side (HTTP requests will go to a hardware load balancer, that in trun will forward them to two different Tomcats, each of them connected to its own JBoss). The question is: Does JBoss persistence manager (namely JAWS) checks if the record in database was changed by a third party, even if no transaction conflict occur? Such situation is possible when JBoss 1 commits and leaves the entity bean activated, then JBoss 2 updates that very entity bean and commits, and then JBoss 1 tries to read data from that entity bean. Can JBoss 1 detect changes in the database and will it reload the bean state? Regards, Roman Rokytskyy ___ JBoss-user mailing list [EMAIL PROTECTED] http://lists.sourceforge.net/lists/listinfo/jboss-user
