Re: Removing definitions
On Mon, Mar 31, 2008 at 1:13 PM, Venkata Krishnan [EMAIL PROTECTED] wrote: Hi Ramkumar, Welcome to Tuscany! Yes, this is a good simple start. Please go ahead and create a JIRA for this. Also would like to see you discuss the alternatives you have in mind for this. Thanks - Venkat On Mon, Mar 31, 2008 at 3:58 PM, Ramkumar R [EMAIL PROTECTED] wrote: On 3/27/08, Greg Dritschler [EMAIL PROTECTED] wrote: I'm not sure I'm getting the multi-threading thing, could you say a bit more about it? -- Jean-Sebastien [EMAIL PROTECTED] Thread 1 and thread 2 call ContributionService.contribute. Each contribution contains a defintions.xml file so both threads try to add policy sets etc. Since SCADefinitions uses unsynchronized ArrayLists this is exposed to failure. SCADefinitionsUtil also has some code that isn't thread safe. Greg Hi, I am new to Tuscany Community and trying to catch up. Right now am going through the code to get a feel of it and this threading issue seems to something simple that I can fix to try a hand with Tuscany. Can I create a JIRA for the threading issue alone and attach a patch ? -- Thanks Regards, Ramkumar Ramalingam I want to comment again on the original subject that started this thread and which is recorded in the associated JIRA ( https://issues.apache.org/jira/browse/TUSCANY-2172), i.e. removing definitions when contributions are removed. Two approaches for managing contributions in a domain come to mind. 1. Keep a cache of contributions up to date w.r.t additions and deletions and create a stream of events to modify the live runtimes as the cache changes in terms of available composites, definitions etc. 2. Keep a cache of contributions up to date w.r.t additions and deletions and restart the live runtimes when anything in the cache changes. Calculating from scratch all the policies, reference/service relationships etc. While we did think about contribution removal operations in the old domain/node implementation they didn't really get bottomed out as it started to get complicated (approach 1) this was replaced with the workspace (approach 2) so we aren't really dealing with the case where things get removed. We simply treat the resulting domain as if it were a new domain and recalculate everything. Does this help at all? Regards Simon
Re: Removing definitions
On 3/27/08, Greg Dritschler [EMAIL PROTECTED] wrote: I'm not sure I'm getting the multi-threading thing, could you say a bit more about it? -- Jean-Sebastien [EMAIL PROTECTED] Thread 1 and thread 2 call ContributionService.contribute. Each contribution contains a defintions.xml file so both threads try to add policy sets etc. Since SCADefinitions uses unsynchronized ArrayLists this is exposed to failure. SCADefinitionsUtil also has some code that isn't thread safe. Greg Hi, I am new to Tuscany Community and trying to catch up. Right now am going through the code to get a feel of it and this threading issue seems to something simple that I can fix to try a hand with Tuscany. Can I create a JIRA for the threading issue alone and attach a patch ? -- Thanks Regards, Ramkumar Ramalingam
Re: Removing definitions
Hi Ramkumar, Welcome to Tuscany! Yes, this is a good simple start. Please go ahead and create a JIRA for this. Also would like to see you discuss the alternatives you have in mind for this. Thanks - Venkat On Mon, Mar 31, 2008 at 3:58 PM, Ramkumar R [EMAIL PROTECTED] wrote: On 3/27/08, Greg Dritschler [EMAIL PROTECTED] wrote: I'm not sure I'm getting the multi-threading thing, could you say a bit more about it? -- Jean-Sebastien [EMAIL PROTECTED] Thread 1 and thread 2 call ContributionService.contribute. Each contribution contains a defintions.xml file so both threads try to add policy sets etc. Since SCADefinitions uses unsynchronized ArrayLists this is exposed to failure. SCADefinitionsUtil also has some code that isn't thread safe. Greg Hi, I am new to Tuscany Community and trying to catch up. Right now am going through the code to get a feel of it and this threading issue seems to something simple that I can fix to try a hand with Tuscany. Can I create a JIRA for the threading issue alone and attach a patch ? -- Thanks Regards, Ramkumar Ramalingam
Removing definitions
Hi. I have noticed that there doesn't seem to be a way to remove definitions (policy sets etc) from the domain. The specs don't explicitly say how this would happen, but surely this can't be a one-way process (you can add but can't delete). I can only guess that if definitions are added as part of a contribution, then those definitions should be removed when the contribution is removed? There are some interesting issues, like what if there are other contributions using elements of those definitions. As an aside, I've noticed that SCADefinitionsImpl doesn't synchronize the lists of policy sets, intents, etc. that it keeps, so it is exposed to bad things happening if multiple threads try to add definitions at the same time. SCADefinitionsUtil also does clear/addAll operations that need to be made thread-safe. Greg
Re: Removing definitions
Greg Dritschler wrote: Hi. I have noticed that there doesn't seem to be a way to remove definitions (policy sets etc) from the domain. The specs don't explicitly say how this would happen, but surely this can't be a one-way process (you can add but can't delete). I can only guess that if definitions are added as part of a contribution, then those definitions should be removed when the contribution is removed? There are some interesting issues, like what if there are other contributions using elements of those definitions. As an aside, I've noticed that SCADefinitionsImpl doesn't synchronize the lists of policy sets, intents, etc. that it keeps, so it is exposed to bad things happening if multiple threads try to add definitions at the same time. SCADefinitionsUtil also does clear/addAll operations that need to be made thread-safe. Greg Greg, Artifacts arrive in the domain through Contributions being added to the domain. Those same contributions can be removed from the domain - and this causes the artifacts in the contribution to be removed from the domain. This applies to definitions as much as it applies to composites or to Java class files. It might be wise to keep some forms of definition separate from contributions containing executable code, so that Policy Sets can be changed without the need to redeploy all the contributions in the domain, for example. That's how it looks from the SCA spec point of view. You make a good point about the SCADefinitionsImpl - sounds like some changes are needed there to handle multi threading. Yours, Mike. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Removing definitions
Mike Edwards wrote: Greg Dritschler wrote: Hi. I have noticed that there doesn't seem to be a way to remove definitions (policy sets etc) from the domain. The specs don't explicitly say how this would happen, but surely this can't be a one-way process (you can add but can't delete). I can only guess that if definitions are added as part of a contribution, then those definitions should be removed when the contribution is removed? There are some interesting issues, like what if there are other contributions using elements of those definitions. As an aside, I've noticed that SCADefinitionsImpl doesn't synchronize the lists of policy sets, intents, etc. that it keeps, so it is exposed to bad things happening if multiple threads try to add definitions at the same time. SCADefinitionsUtil also does clear/addAll operations that need to be made thread-safe. Greg Greg, Artifacts arrive in the domain through Contributions being added to the domain. Those same contributions can be removed from the domain - and this causes the artifacts in the contribution to be removed from the domain. This applies to definitions as much as it applies to composites or to Java class files. It might be wise to keep some forms of definition separate from contributions containing executable code, so that Policy Sets can be changed without the need to redeploy all the contributions in the domain, for example. Or make deployment of contributions really seamless... For example a contribution can be a directory that the domain points to, that directory can contain a definitions.xml file, and we shouldn't require a special deployment step to tell the code that reads that definitions.xml file that it has changed. The good news is that it's how it works in Tuscany at the moment :) The process for updating a policySet is as follows: 1. notepad c:/a-contribution/definitions.xml 2. make changes 3. save 4. restart the nodes 5. they'll get the new updated stuff That's how it looks from the SCA spec point of view. You make a good point about the SCADefinitionsImpl - sounds like some changes are needed there to handle multi threading. I'm not sure I'm getting the multi-threading thing, could you say a bit more about it? -- Jean-Sebastien - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
