Re: Oracle database calling the web app?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Bill, Bill Davidson wrote: Mark Thomas wrote: 1. JMS? I thought Tomcat didn't support JMS. Am I wrong about this? Tomcat doesn't /provide/ JMS. You can add any JSM-compatible library to Tomcat (really, your own application) that you want. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAklvTBYACgkQ9CaO5/Lv0PC14wCfXiKvbDG66RCLbFlmpizfRYo7 vxoAnRQFqwD3k8lfi15ZLkWMeAjaXtTx =V8nq -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: Oracle database calling the web app?
Placing a request in a queue such as JMS is One way to accomplish the objective In the meanwhile take a look at the doc on how to setup an Oracle job at http://www.psoug.org/reference/dbms_job.html And Burlesons site has some information on how to create and call a job http://www.dba-oracle.com/tips_oracle_dbms_job.htm Feel free to contact me offline for solutions as this most definitely Oracle specific and not necessarily related to TOMCAT Martin __ Disclaimer and confidentiality note Everything in this e-mail and any attachments relates to the official business of Sender. This transmission is of a confidential nature and Sender does not endorse distribution to any party other than intended recipient. Sender does not necessarily endorse content contained within this transmission. Date: Thu, 15 Jan 2009 09:49:53 -0500 From: ch...@christopherschultz.net To: users@tomcat.apache.org Subject: Re: Oracle database calling the web app? -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Bill, Bill Davidson wrote: Mark Thomas wrote: 1. JMS? I thought Tomcat didn't support JMS. Am I wrong about this? Tomcat doesn't /provide/ JMS. You can add any JSM-compatible library to Tomcat (really, your own application) that you want. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAklvTBYACgkQ9CaO5/Lv0PC14wCfXiKvbDG66RCLbFlmpizfRYo7 vxoAnRQFqwD3k8lfi15ZLkWMeAjaXtTx =V8nq -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org _ Windows Live™: Keep your life in sync. http://windowslive.com/explore?ocid=TXT_TAGLM_WL_t1_allup_explore_012009
Re: Oracle database calling the web app?
Bill Davidson wrote: Is it possible to set up a callback like situation so that a trigger in an Oracle 10g database can call a method in a currently running webapp that's running in Tomcat 6? Yes, there's UTL_HTTP PL/SQL package available in Oracle, which provides HTTP client functionality. AQ can also do the job, as others have already told. See f.ex. http://www.psoug.org/reference/utl_http.html for details. My situation is that I want to cache some infrequently changed database data in memory but when that data does change in the database, I want the web applications, running on multiple servers, to immediately pick up the change. As you say it's on multiple servers, remember that you'll also need to send the update event to multiple destinations. If it were just a single server, I think you could've arranged things so that also the update would arrive via the single server. However, have you actually measured how much load it would put to various pieces of your system to not cache this data, but just fetch it from the DB more or less each time it is needed? Right now, one idea I have for this is to have the database trigger create a file in a file system that's shared by the database server and the application servers and have the web apps check for the existence of this file to know whether to update the cache. It feels ugly and means hitting a networked file system a lot but it seems like it should work and it seems like it should not be as bad as hitting the database constantly for something that doesn't change very often. DB's are pretty adept at caching frequently used data (and queries and ...), so I'm not certain whether you're achieving anything by replacing one cache with another (esp. if handling the whole use case does anyway require accessing some data from the same database). -- ..Juha - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Oracle database calling the web app?
Juha Laiho wrote: However, have you actually measured how much load it would put to various pieces of your system to not cache this data, but just fetch it from the DB more or less each time it is needed? We currently have the ability to turn the caching on or off. We generally only turn it on when we anticipate a massive traffic storm coming to our site (caused by new highly in demand items going on sale). At the moment, once we turn the cache on, the cached data only gets updated by turning caching off and then back on -- which is something we don't like to do when we are getting thousands of hits per minute. While I'm not aware of exact measurements, the system can handle major traffic loads much better when we have the caching on. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Oracle database calling the web app?
Ken Bowen wrote: Whoops, hold that. This is ok for outbound. For inbound, it seems Jboss is needed: http://activemq.apache.org/jboss-integration.html I'm not sure I understand how that says JBoss is needed to do inbound communications. There is a page on configuring Tomcat: http://activemq.apache.org/tomcat.html I'm finding the ActiveMQ docs less than obvious. I'm not entirely clear on what it is I'm trying to do when setting this up. I'm confused about whether I need to run ActiveMQ as a stand alone process with a connector to Tomcat or whether I can run ActiveMQ inside Tomcat (is that what they mean by embeded?). The latter sounds better. I've had no luck finding an Introduction to setting up ActiveMQ with Tomcat for people who've never set up JMS before tutorial. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Oracle database calling the web app?
Support for what you want to do is actually a feature in Oracle 11g. For Oracle 10g, you want to look at the publish/subscribe support which is part of advanced queueing. The documentation is available online at http://otn.oracle.com. Ed On Tue, Jan 6, 2009 at 5:22 PM, Bill Davidson bill...@gmail.com wrote: Is it possible to set up a callback like situation so that a trigger in an Oracle 10g database can call a method in a currently running webapp that's running in Tomcat 6? My situation is that I want to cache some infrequently changed database data in memory but when that data does change in the database, I want the web applications, running on multiple servers, to immediately pick up the change. Right now, one idea I have for this is to have the database trigger create a file in a file system that's shared by the database server and the application servers and have the web apps check for the existence of this file to know whether to update the cache. It feels ugly and means hitting a networked file system a lot but it seems like it should work and it seems like it should not be as bad as hitting the database constantly for something that doesn't change very often. I'd rather have the database send a message somehow to the web app that it needs to update its cache of the data. Any suggestions? - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Oracle database calling the web app?
Bill Davidson wrote: Is it possible to set up a callback like situation so that a trigger in an Oracle 10g database can call a method in a currently running webapp that's running in Tomcat 6? My situation is that I want to cache some infrequently changed database data in memory but when that data does change in the database, I want the web applications, running on multiple servers, to immediately pick up the change. Right now, one idea I have for this is to have the database trigger create a file in a file system that's shared by the database server and the application servers and have the web apps check for the existence of this file to know whether to update the cache. It feels ugly and means hitting a networked file system a lot but it seems like it should work and it seems like it should not be as bad as hitting the database constantly for something that doesn't change very often. I'd rather have the database send a message somehow to the web app that it needs to update its cache of the data. Any suggestions? 1. JMS? 2. Call an reload servlet from the database? 3. Drop the immediate update requirement and poll a data changed flag in the db every x seconds? Personally, I'd go with 3. For a simple flag this could be every few seconds with very little load on the db or Tomcat and would take all of a few minutes to code. Mark - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Oracle database calling the web app?
you can also have your trigger call a java package where you can simply call a web service (SOAP or RESTful). Regards, Youssef On Wed, Jan 7, 2009 at 12:26 AM, Edward Dowgiallo eddowgia...@gmail.comwrote: Support for what you want to do is actually a feature in Oracle 11g. For Oracle 10g, you want to look at the publish/subscribe support which is part of advanced queueing. The documentation is available online at http://otn.oracle.com. Ed On Tue, Jan 6, 2009 at 5:22 PM, Bill Davidson bill...@gmail.com wrote: Is it possible to set up a callback like situation so that a trigger in an Oracle 10g database can call a method in a currently running webapp that's running in Tomcat 6? My situation is that I want to cache some infrequently changed database data in memory but when that data does change in the database, I want the web applications, running on multiple servers, to immediately pick up the change. Right now, one idea I have for this is to have the database trigger create a file in a file system that's shared by the database server and the application servers and have the web apps check for the existence of this file to know whether to update the cache. It feels ugly and means hitting a networked file system a lot but it seems like it should work and it seems like it should not be as bad as hitting the database constantly for something that doesn't change very often. I'd rather have the database send a message somehow to the web app that it needs to update its cache of the data. Any suggestions? - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Oracle database calling the web app?
It is not necessary to poll an Oracle database. Advanced queueing in combination with triggers provide an event driven framework. Ed On Tue, Jan 6, 2009 at 5:28 PM, Mark Thomas ma...@apache.org wrote: Bill Davidson wrote: Is it possible to set up a callback like situation so that a trigger in an Oracle 10g database can call a method in a currently running webapp that's running in Tomcat 6? My situation is that I want to cache some infrequently changed database data in memory but when that data does change in the database, I want the web applications, running on multiple servers, to immediately pick up the change. Right now, one idea I have for this is to have the database trigger create a file in a file system that's shared by the database server and the application servers and have the web apps check for the existence of this file to know whether to update the cache. It feels ugly and means hitting a networked file system a lot but it seems like it should work and it seems like it should not be as bad as hitting the database constantly for something that doesn't change very often. I'd rather have the database send a message somehow to the web app that it needs to update its cache of the data. Any suggestions? 1. JMS? 2. Call an reload servlet from the database? 3. Drop the immediate update requirement and poll a data changed flag in the db every x seconds? Personally, I'd go with 3. For a simple flag this could be every few seconds with very little load on the db or Tomcat and would take all of a few minutes to code. Mark - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Oracle database calling the web app?
This is also highly inefficient. You are taking on all the additional overhead of a web service call for no reason. Ed On Tue, Jan 6, 2009 at 5:31 PM, Youssef Mohammed youssef.moham...@gmail.com wrote: you can also have your trigger call a java package where you can simply call a web service (SOAP or RESTful). Regards, Youssef On Wed, Jan 7, 2009 at 12:26 AM, Edward Dowgiallo eddowgia...@gmail.com wrote: Support for what you want to do is actually a feature in Oracle 11g. For Oracle 10g, you want to look at the publish/subscribe support which is part of advanced queueing. The documentation is available online at http://otn.oracle.com. Ed On Tue, Jan 6, 2009 at 5:22 PM, Bill Davidson bill...@gmail.com wrote: Is it possible to set up a callback like situation so that a trigger in an Oracle 10g database can call a method in a currently running webapp that's running in Tomcat 6? My situation is that I want to cache some infrequently changed database data in memory but when that data does change in the database, I want the web applications, running on multiple servers, to immediately pick up the change. Right now, one idea I have for this is to have the database trigger create a file in a file system that's shared by the database server and the application servers and have the web apps check for the existence of this file to know whether to update the cache. It feels ugly and means hitting a networked file system a lot but it seems like it should work and it seems like it should not be as bad as hitting the database constantly for something that doesn't change very often. I'd rather have the database send a message somehow to the web app that it needs to update its cache of the data. Any suggestions? - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Oracle database calling the web app?
an asynchronous solution is definitely a better solution but either ways, you have to call some web services at the end to notify the web app , no ? Regards, Youssef On Wed, Jan 7, 2009 at 12:35 AM, Edward Dowgiallo eddowgia...@gmail.comwrote: This is also highly inefficient. You are taking on all the additional overhead of a web service call for no reason. Ed On Tue, Jan 6, 2009 at 5:31 PM, Youssef Mohammed youssef.moham...@gmail.com wrote: you can also have your trigger call a java package where you can simply call a web service (SOAP or RESTful). Regards, Youssef On Wed, Jan 7, 2009 at 12:26 AM, Edward Dowgiallo eddowgia...@gmail.com wrote: Support for what you want to do is actually a feature in Oracle 11g. For Oracle 10g, you want to look at the publish/subscribe support which is part of advanced queueing. The documentation is available online at http://otn.oracle.com. Ed On Tue, Jan 6, 2009 at 5:22 PM, Bill Davidson bill...@gmail.com wrote: Is it possible to set up a callback like situation so that a trigger in an Oracle 10g database can call a method in a currently running webapp that's running in Tomcat 6? My situation is that I want to cache some infrequently changed database data in memory but when that data does change in the database, I want the web applications, running on multiple servers, to immediately pick up the change. Right now, one idea I have for this is to have the database trigger create a file in a file system that's shared by the database server and the application servers and have the web apps check for the existence of this file to know whether to update the cache. It feels ugly and means hitting a networked file system a lot but it seems like it should work and it seems like it should not be as bad as hitting the database constantly for something that doesn't change very often. I'd rather have the database send a message somehow to the web app that it needs to update its cache of the data. Any suggestions? - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Oracle database calling the web app?
Mark Thomas wrote: 1. JMS? I thought Tomcat didn't support JMS. Am I wrong about this? 2. Call an reload servlet from the database? Sounds slightly painful but at least it's event driven. 3. Drop the immediate update requirement and poll a data changed flag in the db every x seconds? Still not event driven like I'd like but it might be acceptable. Thanks. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Oracle database calling the web app?
Edward Dowgiallo wrote: Support for what you want to do is actually a feature in Oracle 11g. For Oracle 10g, you want to look at the publish/subscribe support which is part of advanced queueing. The documentation is available online at http://otn.oracle.com. Is this the book I should be reading? Oracle Streams Advanced Queuing User's Guide and Reference - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Oracle database calling the web app?
Bill Davidson wrote: Oracle Streams Advanced Queuing User's Guide and Reference Looking through that, it looks like it uses JMS to send a message back to Java. Being on Tomcat, that's a problem. Some searching shows I may be able to use OpenJMS or ActiveMQ to get JMS in Tomcat. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Oracle database calling the web app?
It's possible to integrate Tomcat and ActiveMQ (a JMS superset): http://activemq.apache.org/tomcat.html On Jan 6, 2009, at 6:08 PM, Bill Davidson wrote: Bill Davidson wrote: Oracle Streams Advanced Queuing User's Guide and Reference Looking through that, it looks like it uses JMS to send a message back to Java. Being on Tomcat, that's a problem. Some searching shows I may be able to use OpenJMS or ActiveMQ to get JMS in Tomcat. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Oracle database calling the web app?
Whoops, hold that. This is ok for outbound. For inbound, it seems Jboss is needed: http://activemq.apache.org/jboss-integration.html On Jan 6, 2009, at 6:51 PM, Ken Bowen wrote: It's possible to integrate Tomcat and ActiveMQ (a JMS superset): http://activemq.apache.org/tomcat.html On Jan 6, 2009, at 6:08 PM, Bill Davidson wrote: Bill Davidson wrote: Oracle Streams Advanced Queuing User's Guide and Reference Looking through that, it looks like it uses JMS to send a message back to Java. Being on Tomcat, that's a problem. Some searching shows I may be able to use OpenJMS or ActiveMQ to get JMS in Tomcat. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
